Note: Descriptions are shown in the official language in which they were submitted.
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METHOD AND APPARATUS FOR FORMING APERTURES IN BLOOD
VESSELS
RELATED APPLICATIONS
The present application is related to and is a continuation in part of
PCT/11,01/01019 filed on 4 November 2001 (04.11.01), PCT/IL,O1/00903 filed on
25
September 2001 (25.09.01), USSN 09/936,806 filed on 17 September 2001
(17.09.01),
USSN 09/936,805 filed on 17 September 2001 (17.09.01), PCT/ILO1/00600 filed on
28
June 2001 (28.06.01), PCT/IL,O1/00267 filed on 20 March 2001 (20.3.01),
PCT/ILO1/00266 filed on 20 March 2001 (20.03.01), PCT/IL01100074 filed on 25
January
2001 (25.01.01), PCT/ILO1/00069 filed on 24 January 2001 (24.01.01), USSN
09/701,531
filed on 28 November 2000 (28.11.00), PCT/IL,00/00609 filed on 28 September
2000
(28.09.00), and claims the benefit under 119 (e) of USSN 60/254,689 filed on
11
December 2000 (11.12.00). The disclosures of all of these documents are
incorporated
herein by reference.
FIELD OF THE INVENTION
The present invention relates to devices and methods for manipulating blood
conduits, for example for forming openings in blood vessels and grafts.
BACKGROUND OF THE INVENTION
Holes are formed in blood vessels for various reasons, principal among which
are
(a) for insertion of a tube (and later removing the tube sealing the hole);
and (b) forming
an anastomosis connection between a graft and the blood vessel.
PCT publication WO 00/74579, the disclosure of which is incorporated herein by
reference, describes a hole former in which an outer tube is advanced and
optionally
rotated to cut into a blood vessel from the outside, while the cut part of the
blood vessel is
prevented from motion by a barb coupled to the hole former.
US patent 5,129,913, the disclosure of which is incorporated herein by
reference,
describes a retracting shearing-cut punch, in which a non-rotating and blunt
cutting head is
inserted into a slit in a blood vessel and retracted while a base tube having
a cutting lip is
rotated. This effects a shearing cutting of a portion of the blood vessel as
the cutting head
is retracted towards and into the base tube.
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SUMMARY OF THE INVENTION
An object of some embodiments of the invention relates to methods for forming
holes in blood vessels, using cutting action or other types of action. Other
embodiments
possibly provide alternative or additional benefits.
Forming a hole in a blood vessel optionally involves three functions: 1)
penetrating
or transfixing the wall of the blood vessel, 2) holding the wall of the blood
vessel, and 3)
cutting out a hole in the wall. Holding the wall optionally prevents the cut
out plug of
tissue from falling into the blood vessel, and/or optionally provides a
reference plane to
cut against. In some hole formers, two or more of these three (or four)
functions are
performed by the same element, and one of the functions cannot be performed
without
also performing one of the other functions. For example, if a penetration
shaft used to
penetrate the wall has barbs near its tip, it necessarily holds the wall once
it has penetrated.
Even though the barbs can be pushed through the wall into the blood vessel
without
engaging the wall immediately, the penetration shaft cannot be pulled back out
of the
blood vessel, once it has started to penetrate the wall, without having the
barbs engage the
wall. Tn this sense, initiating the penetration function makes the holding
function
inevitable.
An aspect of some embodiments of the invention concerns a hole former in which
penetrating the blood vessel wall, at least, is independent of holding the
wall and/or a
tissue plug. (Cutting the wall may or may not be independent of the other two
functions.)
For example, a penetration shaft with a sharp tip first penetrates the blood
vessel wall, and
then a holding shaft with rigid or flexible barbs on its sides enters the
blood vessel through
the opening made by the penetration shaft, and holds onto the wall by means of
the barbs.
The barbs may engages the wall from the surface or they may be embedded inside
the
vessel wall, for example never penetrating to the blood vessel interior.
Optionally, the
holding shaft is hollow and surrounds the penetration shaft, or the
penetration shaft is
hollow and surrounds the holding shaft, optionally with slots in the
penetration shaft for
the barbs to emerge, or the two shafts are side by side.
Alternatively, instead of separate holding and penetration shafts, there are
flexible
barbs, or other elements for holding the wall, such as an expandable disk, on
the sides of
the penetration shaft, but they are pressed against the side of the
penetration shaft, for
example by a hollow outer shaft that surrounds the penetration shaft. When the
flexible
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barbs (or other holding elements) are released, for example by withdrawing the
outer shaft,
then the barbs come out, and hold the wall of the blood vessel.
In one embodiment of the invention, the tissue holding function is activated
by
retracting a releaser that is on the side of the penetration shaft or tissue
holder. The
releaser may, for example compress barbs on the penetration shaft.
Alternatively, the barbs
are rigid and the releaser hides the barbs, for example, the releaser being
resilient or being
slotted, or the barb being in a depression in the penetration shaft (or tissue
holder).
A potential advantage of having the wall holding function independent of the
wall
penetration function is that the wall penetration can be reversed, without
serious damage
to the blood vessel, before the wall is held, if the surgeon finds something
wrong with the
penetration.
In some embodiments'of the invention, the cutting ftmction cannot be performed
independently of the penetration function. For example, there is a cutting
surface,
connected to the penetration shaft in such a way that the cutting surface and
penetration
shaft move together axially, and the cutting surface cuts out a hole in the
blood vessel wall
once the penetration shaft has penetrated a given distance into the blood
vessel. In other
embodiments of the invention, the cutting function cannot be performed
independently of
the holding function. For example, the cutting surface is connected to the
holding shaft. In
still other embodiments of the invention, cutting is independent of both
penetration and
holding.
An aspect of some embodiments of the invention concerns a hole former
comprising a penetrating element which penetrates a blood vessel wall, and a
protecting
element which covers the penetrating element, or otherwise prevents the
penetrating
element from doing any damage, after the penetrating element has penetrated
the wall. In
an exemplary embodiment of the present invention it is the protective element
which
moves or is activated to protect the penetrating element. For example, a
penetration shaft
with a sharpened tip pierces a blood vessel wall and enters the blood vessel.
A hollow
protective shaft, surrounding the penetration shaft, then enters the blood
vessel through the
opening made by the penetration shaft, guided by the penetration shaft, until
it covers the
tip of the penetration shaft, preventing the sharp tip from damaging the blood
vessel wall
on the other side. Optionally, the protective shaft also is a holding shaft as
described
above, and has any of the characteristics described for the holding shaft.
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In some embodiments of the invention, the penetration tip has a fixed axial
location relative to a cutting edge used to cut the blood vessel wall. The
location may be,
for example, permanently fixed or fixed once the penetration tip is once
advanced, for
example using a ratchet mechanism.
An aspect of some embodiments of the invention concerns a hole former which
does not penetrate the blood vessel wall in the center of the hole that is
later cut, but
penetrates the blood vessel asymmetrically, on one side of the hole. A
potential advantage
of this arrangement is that a wall holding element, also asymmetric, can have
an open slot
on one side which holds onto the wall, after entering the blood vessel through
the opening
made by the penetrating element. Optionally, the wall holding element holds
onto the wall
even after the hole is cut, and even after a tissue plug is removed. With a
symmetric hole
former, by contrast, the wall holding element generally only holds onto the
tissue plug,
and the hole former is removed when the hole is cut and the tissue plug is
removed.
An aspect of some embodiments of the invention concerns a hole former with an
asymmetric blood vessel wall holder, comprising a hollow tube or other member
with a
slot in one side which receives and holds the blood vessel wall. Optionally
the slot
includes barbs or other tissue holding elements, for example in a same plane
as the tube.
Optionally, instead of the wall holder having a complete slot, the sides of
the slot are
formed by two different parts of the hole former, for example the wall holder
and a base.
The two parts optionally move relative to each other to adjust the width of
the slot, for
example to match the thickness of the blood vessel wall, or to adjust the
force by which
the wall holder holds onto the wall.
An aspect of some embodiments of the invention concerns a hole former with a
caliper element which is used to measure the thickness of the blood vessel
wall.
Optionally, the two sides of the caliper, whose relative position is adjusted
while
performing the measurement, comprise an adjustable wall-holding element, for
example a
wall-holding element with an adjustable slot, or barbs whose distance from a
base is
adjustable. Alternatively or additionally, one side of the caliper is advanced
until it
touches the inside of the far wall of the blood vessel, while the other side
of the caliper
touches the outside or the inside of the near wall of the blood vessel, and
the thickness of
the wall is inferred by subtracting the caliper measurement from a measurement
of the
outer diameter of the blood vessel. Optionally, instead of or in addition to
measuring the
thickness of the wall, the force required to change the distance between the
two sides of
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the caliper is used to measure the compressibility of the wall. Knowing the
thickness
and/or compressibility of the wall may be useful, for example, in order to
verify that they
are within a range recommended for the medical procedure being performed.
An aspect of some embodiments of the invention concerns a hole former which
makes a hole whose boundary is part of an opening made initially by a
penetrating
element. Optionally, the initial opening is a straight slit, or a slit with
less curvature than
the rest of the boundary of the hole, and optionally the hole is D-shaped. For
example, a
penetration head with a sharp tip, located asymmetrically on one side of the
hole former,
initially makes a straight slit through which to enter the blood vessel. This
slit then
becomes the straight part of the boundary of a D-shaped hole, when a cutting
surface,
optionally rotating back and forth as it cuts, makes an arc-shaped cut to
complete the hole.
A D-shaped hole, particularly in the aorta, may be less subject to tearing at
the edges than
a circular hole. Alternatively, the initial opening is arc-shaped with the
same curvature as
the rest of the hole, or with greater curvature, and the hole is circular, or
lens-shaped, or
another shape.
An aspect of some embodiments of the invention concerns a hole former with a
penetration head catch, which couples to a penetration head, when the
penetration head
has finished penetrating the blood vessel wall. The penetration head catch
optionally is
attached to a base of the hole former, and keeps the penetration head locked
to the base
once it has finished penetrating the blood vessel wall. This may prevent the
penetration
head, which may have a sharp tip, from damaging the blood vessel wall, for
example on
the opposite side of the blood vessel. Alternatively or additionally, the
penetration head
catch covers the sharp tip of the penetration head, and may prevent it from
damaging the
blood vessel wall even without locking the penetration head to the base.
Optionally, the
penetration head catch is spring loaded and automatically couples to the
penetration head
when the penetration starts to retract. Alternatively, the penetration head
catch is made to
couple to the penetration head by the surgeon, for example by a control on the
handle of
the hole former. Optionally, there is a control on the handle which allows the
surgeon to
release the penetration head catch after it couples to the penetration head,
for example if
the penetration head catch was set by mistake.
An aspect of some embodiments of the invention concerns a hole former with a
helical penetration shaft and a cutting surface. The penetration shaft turns
as it penetrates
the blood vessel wall, creating a helical channel in the wall. The penetration
shaft can be
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withdrawn from the wall if desired, at any time, without serious damage to the
blood
vessel, by turning it in the other direction as it is retracted. If the
penetration shaft is
retracted without turning it, it will hold onto the wall, and optionally it is
used to remove a
plug of tissue cut out by the cutting surface after the penetration shaft has
penetrated the
wall. Optionally, there are two helical penetration shafts with opposite
helicity, which
penetrate the wall at the same time, to avoid exerting any torque on the blood
vessel.
Having two penetration shafts with opposite helicity possibly also prevents a
cut plug of
tissue from falling off the penetration shafts by twisting, as the penetration
shafts are
retracted without twisting. Optionally, the two helical penetration shafts are
located side
by side. Alternatively, they are coaxial to each other, or nearly coaxial, but
with diameters
that are at least slightly different so that they do not interfere with each
other. Optionally,
if the two helical penetration shafts are side by side, they have the same
helicity, which
may also prevent a cut plug of tissue from falling off the penetration shafts
by twisting.
The diameter of each helix is optionally about as large as possible, while
still small
enough so that two helixes can fit within the diameter of the cut plug,
without interfering
with each other. For example, each helix has a diameter of one third or one
quarter of the
plug diameter. The wire making up each helix optionally has a diameter at
least a few
times less than the helix diameter, so that the helix can be formed from a
straight piece of
wire without danger of it cracking, but large enough so that, when the helix
is imbedded in
the blood vessel wall, it can provide a counter force to the cutting surface,
without pulling
the helix out of the blood vessel wall, or stretching it past its yield
strain. Optionally, the
wire is also thick enough so that the helixes will not deform significantly
when they
penetrate the blood vessel wall. For example, the wire diameter is 20% of the
helix
diameter, or 10% or 5% of the helix diameter.
In accordance with another aspect of some exemplary embodiments of the
invention, a hole former includes a penetration tip which optionally retracts
after the tip is
inserted through a blood vessel wall, a penetration head that passes through
the wall and a
base that does not pass through the wall. A cutting lip is provided on the
base, to cut the
vessel wall. Optionally, the cutting action is assisted by rotation of the
base, for example
complete andlor oscillatory rotations. Optionally, once some or all of the
cutting is
completed, the penetration head is retracted relative to the blood vessel,
thus removing a
plug that is cut out of the vessel. Optionally, the penetration head includes
a thickened
portion to prevent the plug from slipping off the head. Optionally, the
retraction of the
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penetration head is relative to the base, for example the penetration head
being spring
loaded. Alternatively or additionally, the retraction is by retraction of the
hole former as a
whole, possibly advancing an over tube over the base to engage the opening
formed in the
vessel and prevent leakage.
It should be noted that in some embodiments of the invention, the hole former
does
not provide any contra. Rather, if any contra is necessary, it is provided by
the target
vessel itself. The penetration head is provided in these embodiments for
preventing the
cutting lip from slipping sideways andlor for preventing a cut out plug from
falling into
the blood vessel.
Optionally, the penetration head has a hollow lumen, which is optionally inner-
threaded, barbed or otherwise treated to engage tissue. In an exemplary
embodiment of the
invention, the lumen is attached to a medicine reservoir inside or outside of
the hole
former. Alternatively or additionally, the penetration head is threaded on its
outside, for
example, to assist penetration.
In an alternative embodiment of the invention, cutting lips are provided on
the
penetration head alternatively or additionally to on the base. Alternatively
or additionally
to a cutting action, a shearing action is provided by the base and the head
sliding by each
other. Alternatively or additionally, anvil cutting action is provided by
locating tissue
between an anvil and a cutting edge. In some, but not all, embodiments, there
is relative
rotation between the head and the base. In an exemplary embodiment of the
invention, the
head is retracted towards the base to effect the cutting of a blood vessel
from inside of the
blood vessel.
Another aspect of some embodiments of the invention relates to protecting an
inner leaflet valve of a mufti-tool anastomotic delivery system. In an
exemplary
embodiment of the invention, a same delivery system scaffold is used to
deliver a hole
former and to deliver an anastomotic connector (or for delivering a different
tool). While
replacing the two tools a valve is provided in the scaffold to prevent blood
leakage from
the vessel through the scaffold. In an exemplary embodiment of the invention,
the hole
former is inserted through the valve while covered while the hole former with
a cover
(e.g., a silicone tube), to prevent contact between sharp parts of the hole
former and the
valve. Optionally the cover is designed to be torn off, for example, being
perforated and/or
includes a rip cord.
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An aspect of some embodiments of the invention relates to a hole former
comprising a tube having a sharp cutting lip and a lumen in which there is
provided means
for engaging tissue, for example one way engaging, for example using barbs
and/or an
inner threading. As the tube is advanced (and/or rotated) against a blood
vessel or other
tissue, the tissue is cut by the lip and forced into the lumen, where it is
engaged.
Optionally, the tube comprises an outer threading, for example, to assist
advancing into
the tissue. Optionally, a central guide, for example a needle, is provided, to
stabilize the
location of the tube relative to the target tissue. Optionally, the central
guide is threaded.
The guide may be retractable relative to the tube or not. In different
exemplary
embodiments, the guide is advanced ahead of the lip, is approximately level
with a plane
defined by the lip or is retracted from the plane.
An aspect of some embodiments of the invention relates to a retracting hole
former, in which the penetration head includes a cutting lip and the head
rotates as it is
retracted towards a base. Optionally, the base rotates. In an exemplary
embodiment of the
invention, the cutting lip fits inside the base. Alternatively, the cutting
lip fits against the
base.
An aspect of some embodiments of the invention relates to a hole former
including
a receptacle in a distal end of a penetration head for receiving a tissue plug
being removed
from a vessel wall during the formation of a hole in the vessel wall.
Optionally, the
receptacle is formed by a cutting lip formed on said penetration head.
Alternatively or
additionally, a cutting lip is formed on a base portion of said hole former.
The cutting lip
(one or both, if two) can be of various designs, for example, smooth, serrated
and/or
oblique. In an exemplary embodiment of the invention, the receptacle is deep
enough to
contain tissue plugs from one, two or more hole forming activities, even if
the plug falls
apart.
In an exemplary embodiment of the invention, the receptacle includes a plug
extraction means. In one example, a spring element, for example a lump of soft
silicon or
a metal spring, is provided in the receptacle, so that when the hole forming
is completed
and the hole former removed from the vessel, the plug is ej ected from the
hole, at least
partly, by the spring element. Alternatively or additionally, an axially
retractable catch is
provided in the receptacle, which is retracted, for example, manually or by a
spring out of
said receptacle and/or remains° in place when said penetration head is
moved away from
said base.
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An aspect of some embodiments of the invention relates to a hole former that
combines anvil cutting and at least one of knife and shearing cutting for
forming a hole in
a blood vessel. In an exemplary embodiment of the invention, the anvil cutting
is used to
cut through an adventitsia of a blood vessel and the other cutting method is
used for
cutting through an intima of a blood vessel. The different cutting methods may
be
provided using a same cutting lip or using more than one cutting surface. In
one example,
an inclined part of the penetration head contacts the base to provide an anvil
cutting
action, while a cutting lip formed on the penetration head slides past the
base to provide
knife and/or shearing cutting action. In another example, the cutting lip
provides knife
cutting action until it contacts an inclined portion of the base and provides
anvil cutting
action.
An aspect of some embodiments of the invention relates to a rotating anvil-
cutting
hole former. Optionally, at least one of the anvil and the cutting head is
spring-loaded so
that when the anvil and head meet, one of them can retract, thus preventing
and/or
reducing damage to the cutting part. In an exemplary embodiment of the
invention, the
penetration head serves as a cutting part and the base is an anvil and is
spring loaded.
Optionally, the penetration head is retracted and rotated using a thread.
Optionally the
head can be rotated an infinite number of times once it reaches the base.
Optionally, when
the head reaches the base, it slips a thread, allowing the base to spring
forward.
An aspect of some embodiments of the invention relates to anvil punching
against
a resilient material, which may be, for example, on the base or on the
penetration head.
Optionally, the cutting part of the hole former rotates relative to the anvil
part. Optionally,
when the penetration head is forcefully retracted, it pushes aside the
resilient material and
retracts into a predefined axial aperture in the anvil.
An aspect of some embodiments of the invention relates to designing hole
former
parameters. In an exemplary embodiment of the invention, D designates an outer
diameter
of a cutting lip, while d designates a minimum diameter of the hole former
between the
penetration head and the base. In an exemplary embodiment of the invention,
the hole
remover is designed to achieved a desired hole diameter. Generally, as D is
closer to d, the
amount of tissue removed by the hole forming operation tend to be smaller, as
there is less
room for the tissue plug to be contained in during the hole forming operation.
While if D
is substantially larger than d, a larger hole can be formed, having a diameter
approaching
and possibly passing D.
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An aspect of some embodiments of the invention relates to various designs for
a
penetration tip and/or a penetration head. In an exemplary embodiment of the
invention,
the penetration head, which optionally serves as an anvil or as a plug holder
for holding
the vessel wall, is expandable, for example, as a spiral, as a deformable
silicon element or
as a plurality of radially extending (and, optionally, interconnected) arms.
Alternatively,
the penetration head may serve as a cutter, for example, in the spiral
embodiment.
Optionally, retraction of the penetration tip causes expansion of the
penetration head.
Alternatively or additionally, an anvil is provided opposite only some of a
circumference of a cutting lip.
In an alternative exemplary embodiment of the invention, the penetration tip
and
head comprise a threaded tube and the hole forming is performed by retracting
the thread
relative a base.
In an alternative exemplary embodiment of the invention, a penetration head
includes a disk that is inserted on its side and/or in a distorted
configuration into the vessel
wall after the penetration tip enters the vessel. The disk is then used for
the hole forming
operation, for example, as an anvil.
In the examples of the threaded head and disk head, the cutting action may be,
for
example, knife, shearing and/or anvil, optionally utilizing a cutting lip on
the penetration
head.
In an exemplary embodiment of the invention, the penetration tip has the form
of a
,.
one, two or more sided knife. Alternatively, the penetration tip has the form
of a screw.
Alternatively or additionally, the penetration head is deeply scalloped on
one, two, three or
more sides. Alternatively, the penetration head has a cross-section of a cross
or a polygon,
rather than having a circular cross-section as in some other embodiments.
In an alternative embodiment of the invention, one, two or more cutting spikes
are
formed as a cutting lip of the penetration head. The spikes have a wide base
and a narrow
tip and a cutting surface along their outer edge. In one'~example, two spikes
are provided,
with bases that together bridge the entire circumference of the penetration
head.
An aspect of some embodiments of the invention relates to a needle-like hole
former. In an exemplary embodiment of the invention, the base has the shape of
a needle
with an aperture, optionally oblique, at its tip. The needle itself may have,
for example, a
symmetric or an asymmetric conical tip. The edges of the aperture are
optionally
sharpened. A tissue penetration tip is provided through the aperture and
includes a trans
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axial extension that has the general profile of the aperture. In use, the
penetration tip is
inserted into a blood vessel so that the trans-axial extension also passes
through the blood
vessel wall. The penetration tip is then retracted, pulling the blood vessel
towards the
base, so that the sharpened lips of the base and/or an optionally sharpened
surface of the
trans-axial extension cut the vessel wall.
An aspect of some embodiments of the invention relates to marking of punch
motion. In an exemplary embodiment of the invention, the hole former includes
a visual
indication of the relative motion of the penetration head and the base and/or
of the base
relative to the rest of the hole former. In one example, a slot is formed in
the base or an
extension of the base, through which a marking on an extension of the
penetration head is
visible. Optionally, the hole former is provided via a delivery system. In an
exemplary
embodiment of the invention, the delivery system includes a window for viewing
relative
motion of the hole former and/or of other delivered tool, such as an
anastomotic connector
delivery tool, which optionally includes a similar progress indication.
Optionally, reaching
a desired point of progress is alternatively or additionally marked by a loud
mechanical
click.
An aspect of some embodiments of the invention relates to a side cutter for a
blood
vessel. In an exemplary embodiment of the invention, the side cutter includes
an L shaped
element having a sharpened tip. The tip is poked into a blood vessel and one
arm of the L
inserted into the blood vessel following the tip. The L element is optionally
rotated so that
its arm is parallel to the vessel axis. The L element is then retracted
relative to a base,
providing cutting action by an optional sharpened inner lip on the L and/or
shearing action
against the base. The base is optionally sharpened. The base may be provided
on one sides
of the L element or it may sandwich the L element. Optionally, the cutting arm
of the L is
parallel to the base, alternatively, the arm may be inclined towards the base
or away from
the base.
There is thus provided in accordance with an exemplary embodiment of the
invention, hole forming apparatus for forming a hole in a blood vessel,
comprising:
a penetration shaft, having a tip adapted to be inserted through a wall of a
blood
vessel;
a tissue holder, configured to hold a portion of said wall, said holder being
activated to perform said holding separately from an insertion of said
penetration shaft
through said wall; and
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a cutting surface adapted to cut through the wall. Optionally, said tissue
holder
comprises a rigid barb. Alternatively or additionally, said tissue holder
comprises a
flexible barb. Alternatively or additionally, said tissue holder comprises a
disk.
In an exemplary embodiment of the invention, the tissue holder comprises a
hollow tube surrounding the penetration shaft. Optionally, said hollow tube is
configured
to be advanced along said penetration shaft such that said tip is wholly
contained by said
hollow tube. Optionally, said hollow tube is long enough to contain said tip
at least until
said wall is cut through by said cutting surface.
In an exemplary embodiment of the invention, the penetration shaft at least
partially encloses said tissue holder. Optionally, said tissue holder
comprises at least one
flexible tissue holding element and wherein the penetration shaft comprises at
least one
slot wide enough to receive said flexible element therethrough and wherein
said tissue
holder and said penetration shaft are configured for selectively positioning
said
penetration shaft relative to said tissue holder such that said tissue holding
element and
said slot align. Optionally, said tissue holder and said penetration shaft are
configured
such that said tissue holding element is axially displaced from said slot.
Alternatively or
additionally, said tissue holder and said penetration shaft are configured
such that said
tissue holding element is angularly displaced from said slot.
In an exemplary embodiment of the invention, said tissue holder lies alongside
said
penetration shaft.
In an exemplary embodiment of the invention, said tissue holder is mounted on
said penetration shaft and comprising a holder releaser configured to
selectively release
said holder to hold tissue. Optionally, said holder releaser comprises a
hollow shaft which
at least partially encloses said penetration shaft. Alternatively, the holder
releaser lies
alongside said penetration shaft.
In an exemplary embodiment of the invention, said holder releaser covers said
tissue holder during said insertion of said penetration shaft into said wall.
Optionally, said
holder releaser resiliently compresses said tissue holder during said
insertion of said
penetration shaft into said wall.
In an exemplary embodiment of the invention, said tissue holder is configured
to
be advanced along said penetration shaft after said insertion. Alternatively
or additionally,
said tissue holder is configured to be axially moved relative to said
penetration shaft,
thereby activating said tissue holder.
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In an exemplary embodiment of the invention, said tissue holder is configured
to
be rotated relative to said penetration shaft, thereby activating said tissue
holder.
In an exemplary embodiment of the invention, said tissue holder is configured
to
retract relative to said cutting surface during said hole forming. Optionally,
said tissue
holder is spring loaded to retract. Alternatively or additionally, said
retraction is
mechanically coupled to a rotation of said cutting surface.
In an exemplary embodiment of the invention, said penetration shaft has a
fixed
axial position relative to said cutting surface at least after said insertion.
In an exemplary embodiment of the invention, said penetration shaft is axially
retractable relative to said cutting surface.
In an exemplary embodiment of the invention, said cutting surface is
configured to
cut by rotation. Optionally, said cutting surface is not rotationally fixed to
said tissue
holder.
In an exemplary embodiment of the invention, said cutting surface is
configured to
cut by from an opposite side of said wall from said penetration tip.
In an exemplary embodiment of the invention, said cutting surface is
configured to
cut by from a same side of said wall from said penetration tip.
In an exemplary embodiment of the invention, said penetration tip is
configured to
enter said wall from an outside of said vessel.
In an exemplary embodiment of the invention, said tissue holder engages a wall
of
said vessel.
In an exemplary embodiment of the invention, said tissue holder contacts a
wall of
said vessel at a stop location and thereby prevents relative motion of said
wall in a
direction of said stop location.
There is also provided in accordance with an exemplary embodiment of the
invention, hole forming apparatus for forming an opening in a blood vessel,
comprising:
a penetration shaft, having a tip adapted to be inserted through a wall of a
blood
vessel;
a cutting surface adapted to cut through the wall and having a fixed axial
position
relative to said penetration shaft tip; and
a tip protector, axially movable to protect the tip of the penetration shaft
from
damaging the blood vessel after the penetration shaft is inserted through the
wall of the
blood vessel. Optionally, said tip protector comprises at least one tissue
holding element
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configured to hold at least a portion of said wall after said insertion.
Optionally, said tip
protector has a length, distal of said tissue holder, greater than an axial
distance between
said tip and said cutting surface.
In an exemplary embodiment of the invention, the tip protector comprises a
hollow
tube which surrounds the penetration shaft.
There is also provide din accordance with an exemplary embodiment of the
invention, hole forming apparatus for forming a hole in a blood vessel,
comprising:
a slit-forming penetration head having a tip on a distal end thereof and
configured
to be inserted into, and form a slit, in a blood vessel wall; and
a cutting surface not-contiguous with said tip, configured to cut said wall
such that
said cut and said slit link to provide a boundary cut of said wall, defining
said hole.
Optionally, said cutting surface is formed on a proximal side of said head.
Alternatively or
additionally, said tip is asymmetrically located on said head relative to an
axis of said
apparatus.
In an exemplary embodiment of the invention, the penetration head is solid.
Alternatively, the penetration head is hollow. Optionally, the apparatus
includes at
least one head tissue holder positioned inside said head and configured to
prevent a cut out
portion of the wall of the blood vessel from passing through said head in a
direction of
said tip. Optionally, said tissue holder is fixed to said head. Alternatively
or additionally,
said tissue holder comprises a hook.
In an exemplary embodiment of the invention, said penetration head has an
arcuate
profile when viewed along its axis.
In an exemplary embodiment of the invention, the apparatus includes a
sharpened
tip at a proximal end of the penetration head. Optionally, said sharpened tip
is on a same
plane as said penetration tip and an axis of said penetration head.
In an exemplary embodiment of the invention, the apparatus includes an anchor
comprising a member defining a trans-axial slot, said slot having a width
sufficient to
receive a thickness of said wall. Optionally, said member comprises a tube
defining a
lumen having a diameter sufficient to enclose said penetration head.
Alternatively, said
member only partly surrounds said penetration head.
In an exemplary embodiment of the invention, the apparatus includes an anchor
tissue holder attached to said anchor, which anchor tissue holder prevents a
cut out portion
of the wall of the blood vessel from passing into the blood vessel.
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In an exemplary embodiment of the invention, said member has a distal end.
Optionally, said distal end comprises an anchor cutting surface.
Alternatively, said distal
end comprises said cutting surface.
In an exemplary embodiment of the invention, said distal end and a proximal
end
of said penetration head cooperate to provide a scissors cutting action.
Alternatively, said
distal end and a proximal end of said penetration head cooperate to provide an
anvil
cutting action.
There is also provided in accordance with an exemplary embodiment of the
invention, hole forming apparatus for forming a hole in a blood vessel,
comprising:
a penetration head adapted to penetrate a blood vessel wall;
a slotted anchor, defining a traps-axial slot having a width sufficient to
receive a
thickness of said wall; and
a cutting surface configured to cut said wall while said wall is held by said
slotted
anchor. Optionally, said anchor comprises a traps-axially-slotted tube.
Alternatively or
additionally, the penetration head comprises a distal portion of the anchor.
Alternatively or
additionally, the apparatus includes a tissue holder which prevents a cut out
portion of the
wall of the blood vessel from passing into the blood vessel.
In an exemplary embodiment of the invention, said cutting surface is formed on
a
proximal side of said penetration head.
There is also provided in accordance with an exemplary embodiment of the
invention, hole forming apparatus for forming a hole in a blood vessel,
comprising:
a penetration head having a tip adapted to penetrate a blood vessel wall and
defining an axial lumen; and
a tip protector configured to pass through said lumen and protect said tip
from
damaging the blood vessel after said penetration. Optionally, said tip
protector comprises a
folded tab defining a receptacle configured to receive said tip therein.
Optionally, said tab
is resiliently distorted during passage through said lumen.
In an exemplary embodiment of the invention, said tip protector has a fixed
axial
location relative to said apparatus such that retraction of said penetration
head causes said
tip protector to pass through said lumen and protect said tip. Alternatively
or additionally,
said tip protector comprises a control for manually positioning said tip
protector to
selectively protect said tip.
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There is also provided in accordance with an exemplary embodiment of the
invention, hole forming apparatus for forming a hole in a blood vessel,
comprising:
a tissue holder configured to be inserted through a blood vessel wall;
a base configured to be positioning on an opposite side of said wall; and
a display coupled to said tissue holder and said base and configured to show
an
indication based on a relative distance between said tissue holder and said
base.
Optionally, said tissue holder includes at least one tissue retraction
prevention element
which prevents retraction of said tissue holder back through said wall.
Alternatively or
additionally, said display is mechanically coupled to said holder and said
base.
Alternatively or additionally, said base contacts said wall with a blood
vessel wall cutting
surface. Alternatively or additionally, the apparatus includes a spring which
retracts said
holder relative to said base. Alternatively or additionally, said display
converts said
distance into a measure of compressibility of said wall. Alternatively or
additionally, said
display converts said distance into a measure of a thickness of said wall.
There is also provided in accordance with an exemplary embodiment of the
invention, hole forming apparatus for forming a hole in a blood vessel,
comprising:
a penetration head mounted on a shaft and adapted to penetrate a blood vessel
wall; and
a tissue receptacle configured to receive said wall after said penetration,
wherein said shaft is not co-axial with said tissue receptacle. Optionally,
said shaft
is outside of said tissue receptacle.
There is also provided in accordance with an exemplary embodiment of the
invention, hole forming apparatus for forming a hole in a blood vessel,
comprising:
a plurality of helical coils adapted to penetrate and engage a blood vessel
wall; and
a base defining a cutting surface for cutting said wall and configured to be
axially
moved relative to said helical coils. Optionally, said coils include at least
two coils having
opposite helicity. Alternatively or additionally, said coils include at least
two coaxial coils.
Alternatively or additionally, said coils include at least two non-coaxial
coils.
There is also provided in accordance with an exemplary embodiment of the
invention, a method of forming a hole in the wall of a vessel, comprising:
providing a hole former comprising a shaft having a penetrating tip formed at
a
distal end of the shaft, an outer shaft disposed about the shaft and
configured to be
slideable with respect to the shaft, the outer shaft having at least one
projecting element,
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and a base disposed about the outer shaft having a cutting lip, the base
configured to be
slideable relative to the outer shaft;
penetrating a vessel wall with the penetrating tip to form an opening;
passing the outer shaft and the at least one projecting element through the
opening;
and
cutting the vessel wall with the cutting lip of the base to form a hole in the
wall of
the vessel. Optionally, the method comprises retracting the outer shaft such
that the at
least one projecting element contacts the inner surface of the vessel wall
prior to said
cutting. Alternatively or additionally, the shaft and the base axe fixed
relative to one
another. Alternatively, the shaft is moveable independently of the base.
Optionally, the
penetrating tip is retracted into the outer shaft one the outer shaft has
passed through the
opening.
In an exemplary embodiment of the invention, the outer shaft shields the inner
surface of the vessel wall from the penetrating tip during the cutting step.
In an exemplary embodiment of the invention, the base is rotated to cut the
hole in
the vessel wall.
BRIEF DESCRIPTION OF THE FIGURES
Non-limiting embodiments of the invention will be described with reference to
the
following description of exemplary embodiments, in conjunction with the
figures. The
figures are generally not shown to scale and any measurements are only meant
to be
exemplary and not necessarily limiting. In the figures, identical structures,
elements or
parts which appear in more than one figure are preferably labeled with a same
or similar
number in all the figures in which they appear, in which:
Fig. 1A illustrates a hole former having an outer cutting lip, in accordance
with an
exemplary embodiment of the invention;
Fig. 1B illustrates a hole former having an inner cutting lip, in accordance
with an
exemplary embodiment of the invention;
Figs. 2A-2E are cut-through views of an exemplary hole former, in accordance
with an exemplary embodiment of the invention;
Fig. 3 illustrates various dimensions of a penetration head that may be
relevant in
accordance with an exemplary embodiment of the invention;
Figs. 4A and 4B illustrate plug removal mechanisms in accordance with an
exemplary embodiment of the invention;
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Fig. 5 illustrates a base retraction mechanism, in accordance with an
exemplary
embodiment of the invention;
Fig. 6 illustrates an alternative hole former, in accordance with an exemplary
embodiment of the invention;
Figs. 7A-7I illustrate various penetration tip and penetration head designs,
in
accordance with exemplary embodiments of the invention;
Figs. 8A and 8B illustrate an expanding penetration head, in accordance with
an
exemplary embodiment of the invention;
Figs. 9A and 9B illustrate an alternative expanding penetration head, in
accordance
with an exemplary embodiment of the invention;
Figs. 10A and lOB illustrate another alternative expanding penetration head,
in
accordance with an exemplary embodiment of the invention;
Figs. 11A and 11B illustrate a geometry changing anvil, in accordance with an
exemplary embodiment of the invention;
Fig. 12 illustrates a resilient anvil hole former, in accordance with an
exemplary
embodiment of the invention;
Fig. 13 illustrates a thread-type penetration head, in accordance with an
exemplary
embodiment of the invention;
Figs. 14A and 14B illustrate a needle-type hole former, in accordance with an
exemplary embodiment of the invention;
Figs. 15A and 15B illustrate two variants of an incision maker, in accordance
with
an exemplary embodiment of the invention;
Fig. 16A and 16B illustrate a hole former in accordance with an alternative
embodiment of the invention;
Figs. 17A-17E illustrate the use of the hole former of Fig. 16, in accordance
with
an exemplary embodiment of the invention;
Fig. 18 illustrates a tip of a hole former in accordance with an alternative
embodiment of the invention;
Fig. 19A is a perspective cut-away side view, and Fig. 19B is a cross-
sectional side
view, of a hole former, according to another exemplary embodiment of the
invention;
Figs. 19C, 19D, 19E, 19F, and 19G are cross-sectional side views showing
different stages in the process of a hole former making a hole in a blood
vessel, using the
device of Figs. 19A and 19B;
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Fig. 20A is a see-through side view of a hole former according to another
exemplary embodiment of the invention;
Figs. 20B, 20C, 20D, and 20E are a series of four side views of the device of
Fig.
20A, showing how the penetration tip moves with respect to the rest of the
hole former;
Fig. 20F is an axial view of the cuts made in a blood vessel by the device of
Fig.
20A;
Fig. 20G is a perspective view of the device of Fig. 20A;
Figs. 20H and 20I are side cross-sectional views of the device of Fig. 20A and
a
blood vessel wall, showing two steps in the process of cutting a hole in the
wall;
Figs. 2IA and 21B are side cross-sectional views of a hole former according to
an
exemplary embodiment of the invention; and
Figs. 22A-22E show a hole former with two helical penetration shafts, in
accordance with an exemplary embodiment of the invention.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
Side to end anastomosis connections typically require an opening to be made in
the
"side" vessel, which is typically a taxget vessel. If an incision is made in
the side vessel,
expanding the incision to an elliptical or circular opening, as typically
required in an
anastomosis connection, may cause tearing and/or distortion of the target
vessel. An
alternative method is to punch or cut out a hole in the vessel (e.g., using
the methods
described in the background). However, the inventors have found that such
punching may
create a hole with one or more tears on its circumference. For example,
punching a 2.5
mm diameter hole in an aorta, typically causes a tear, which, once the
anastomosis is
completed, may expand and cause a leak. In some cases, the size of the hole in
the aorta
has been shown to affect the probability of causing a tear, however, a minimal
hole size
may be required in order to prevent distortion of the aorta when performing an
anastomosis of a larger diameter.
A blood vessel is formed of several layers. The outermost layer is a tough
fibrous
layer called the adventitsia. The innermost layer is called the intima. The
inventors have
found that if the cutting proceeds from the outside in, the adventitsia may
catch on the
cutting element and distort the intima before it is cut. In addition, the
inventors have
determined that different cutting methods may be useful for the different
layers of the
blood vessel.
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Once a portion (a plug) is cut out of the vessel wall, it is typically
desirable to
prevent the plug from falling into the blood flow. In addition, the plug may
fall apart
during or after the hole formation.
One or more of the above problems is solved by some of the embodiments of the
invention.
Fig. 1A illustrates a hole former 100 in accordance with an exemplary
embodiment
of the invention, comprising a base tube 102 and a penetration head 104 for
insertion
through a wall of a blood vessel 106. As shown, vessel 106 comprises an intima
layer 108
and an adventitsia layer 110. As shown for example in Fig. 2, the tip of
penetration head
104 may comprises a retractable penetration tip.
In an exemplary embodiment of the invention, penetration head 104 comprises a
cutting lip 114 that cuts into vessel 106 when retracted towards the vessel.
Optionally,
cutting lip 114 is formed as the rim of a cup 116 having a wall 112. Cup 116
desirably
serves to contain a tissue plug that is cut out of vessel 106 by cutting lip
114.
In the embodiment of Fig. 1A, base tube 102 defines an anvil surface 118 that
contacts cutting lip 114 when penetration head 104 is retracted sufficiently.
In an
exemplary embodiment of the invention, as it is retracted, lip 114 performs a
knife cutting
action until it nears anvil 118, where it performs an anvil cutting action,
which may be
suitable for cutting through adventitsia 110.
Fig. 1B shows an alternative hole former 130, in which the knife cutting
action and
the anvil action are performed by different surfaces. Wall 112 has an outer
diameter
smaller than an inner diameter of base tube 102, so that cup 116 can be
retracted into a
bore 138 of tube 102. If the clearance between lip 114 and bore 138 is small
enough, a
shearing cutting action can be performed between penetration head 104 and base
tube 102.
Optionally, lip 114 is sharp enough for performing a knife cutting action.
In an exemplary embodiment of the invention, anvil cutting is provided between
a
cutting lip 142 of base tube 102 and an anvil portion 140, optionally
inclined, of
penetration head 134.
Optionally, one or both of penetration head 104 and base tube 102 rotate, in
same
or in opposite directions. Alternatively to complete rotations, oscillatory
rotation is
provided.
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When retracting penetration head towards base tube 102, one or both of head
104
and tube 102 may be moved. Optionally, for example as described below, the
motion is
intermittent, allowing an impulse anvil cutting action to be achieved.
Coupling between advancing and rotation is optional. In one example, coupling
is
achieved by a threading that links advancing to rotation. Alternatively to
rotation during
retraction, rotation is performed after retraction (e.g., when the edges begin
to pinch the
vessel wall). Optionally, rotation and retraction are controlled separately,
for example
using one control for rotation and one for retraction.
Figs. 2A-2E are cut-through views of an exemplary hole former 200, in
accordance
with an exemplary embodiment of the invention and similar to the embodiment of
Fig. 1B.
Fig. 2A shows an optional retracting penetration tip 202 that is retracted by
retracting a shaft 208 to which it is attached after penetration, so that the
sharp tip does not
damage the far wall of the blood vessel. Optionally, the retraction of the tip
unlocks a
retraction mechanism that manually or automatically (e.g., using a spring or a
motor)
retracts the penetration head towards the base section. Also shown is a shaft
206 used for
retracting penetration head 104. Former 200 is shown mounted in a delivery
system 210,
optionally a split delivery system.
Fig. 2B shows a handle section of former 200, which comprises, for example, a
rotating handle 212. A slot 210 is used to guide the retraction of penetration
tip 202 once
the tip penetrates a blood vessel. A threading 214 is used, for example, to
control the
retraction and rotation of penetration head 104 during use of hole former 200.
Fig. 2C shows a central section of former 200, including an optional clip 220
for
locking former 200 into delivery system 210.
Fig. 2D shows a section of former 200 in which base tube 102 is coupled to the
rest of former 200. As will be shown below, an optional volume 222 is used to
contain a
resilient element (e.g., silicon or a spring) that couples base tube 102 to
former 200.
Fig. 2E shows exemplary measurements for system 200 for use in a human aorta.
It should be noted that, in an exemplary embodiment of the invention, once the
plug is removed from the vessel wall, base tube 102 is advanced into the
formed hole, for
example, to prevent blood leakage.
Fig. 3 illustrates various dimensions of a penetration head 304 that may be
relevant
in accordance with an exemplary embodiment of the invention. A diameter d is
the outer
diameter of a shaft 308, used to retract head 304. A diameter D is the outer
diameter
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defined by a cutting lip 314. A depth W is a depth of a tissue receptacle area
316 that
contains the plug. The inventors have determined that the size of tissue plug
removed
from the target vessel is dependent on the geometry of the tissue receptacle.
Thus, if W is
too small, the tissue plug will be restricted in size. Similarly, if D is near
d, there is less
room for the tissue plug. Optionally, the use of a cutting lip 314 rather than
a blunt end
ensures that less tissue will slip past, since lip 314 cuts into the tissue
and holds it in place.
Optionally, the receptacle geometry is designed to affect a certain plug
geometry. For
example, if the receptacle fills up before cutting is completed, the plug
diameter will
decrease. The direction of decrease along the thickness of the plug may depend
on the
direction of cutting and/or receptacle orientation. For example, if the tissue
receptacle
and/or cutting lips are formed on tube 102, the decrease will be towards the
blood vessel.
In addition, knife cuts may be used to ensure that earlier cut tissue will
have a known
diameter, while a shearing cut can be used to ensure that later cut tissue
will have a
geometry based on available receptacle volume. An hourglass profile may be
achieved by
cutting from both sides of the vessel towards the middle, while using a
limited volume
tissue receptacle defined between the two cutting sides.
Various rotation/axial ratios may be used, for example, 1/1 - one rotation per
mm
advance. In one example, at least 10 or at least 30 rotations are provided
during a hole
forming. In another example, only one, or fewer rotations are provided.
If W is large enough, the tissue plug removed from the body will lodge in
receptacle 316 and additional use of the hole forming system will be
difficult. In
particular, a smooth cutting action may indicate a large value for W, so that
the tissue plug
is substantially inaccessible form outside. In an exemplary embodiment of the
invention,
mechanisms to assist in removing the plug are provided.
Fig. 4A shows a penetration head 400 in which a tissue extractor 420 is
provided
for pulling a tissue plug out of a tissue receptacle 416. In an exemplary
embodiment of the
invention, extractor 420 includes one or more radial extensions (or a lip) 422
that lie
inside receptacle 416. When penetration head 104 is advanced, the tissue plug
catches on
extensions 422 and is extracted from receptacle 416. An optional resilient
element 424, for
example a spring a soft rubber is provided to allow tissue retractor 420 to be
pushed
towards base 102. In an alternative embodiment, retractor 420 is free-moving.
Fig. 4B shows an alternative mechanism 440, in which a resilient element 442,
such as a spring or a silicon plug is provided in tissue receptacle 416. The
resilient element
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is compressed by the plug during the hole forming operation and rebounds when
the
operation is complete, to urge out the plug.
In some embodiments of the invention, for example as shown in Fig. 1A, a
cutting
lip contacts a non-moving element, and may be damaged thereby. Fig. 5
illustrates a base
retraction mechanism 500, in accordance with an exemplary embodiment of the
invention,
which allows base 102 to resiliently retract. Thus, for example, when
contacted by cutting
lips, base 102 is pushed back by the lips instead of the lips being ground
down. One
potential advantage of such resilient contact is that it allows a looser
manufacturing
tolerance when designing a thread for coupling axial and rotational motion of
penetration
head 104.
In an exemplary embodiment of the invention, mechanism 500 comprises a
resilient element 502 (or base 102 may be made resilient) such as a lump of
soft silicon
rubber or a spring, that allows some axial motion of base 102.
An additional potential advantage of such resilience is that it allows
penetration
head 104 to continue rotating after it contacts base 102. An additional
potential advantage
is that if penetration head jumps a thread after it contacts base 102, this
causes an impulse
motion of head 104 relative to base 102, which may assist in cutting the
adventitsia.
Fig. 6 illustrates an alternative hole former 600, in accordance with an
exemplary
embodiment of the invention. In this embodiment, former 600 comprises a
penetration
head 604 with an optional retracting penetration tip (not shown). Slicing
action is
optionally provided between the upper edge of penetration head 604 and the
inner
diameter of a base 602. Alternatively or additionally, knife cutting action is
provided by an
inner lip 60~ of penetration head and/or a forward lip 610 of base 602. One or
both of
head 604 and base 602 rotate. Optionally, head 604 is retracted using a
threaded drive
actuated in handle 606. Alternatively, head 604 (and similarly heads on other
embodiments described herein) may be retracted using a spring loaded
mechanism.
Also useful, as illustrated for example, in Fig. 6, are various marking
systems for
indicating the progress of hole forming. One exemplary system comprises an
aperture (or
transparent portion) 620 defined in handle 606 and a second aperture 622
formed in base
602. One or more visual markings 624 on a shaft 614 that is coupled to
penetration head
604 may be visible through the apertures/transparent sections to indicate a
relative location
of penetration head 604 and base 602.
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Another exemplary indication system comprises a transparent dome 612 through
which is visible the extension of a bar 610 (which extends as penetration head
604 is
retracted), is visible.
Another exemplary system is an electrical system in which references 624
indicate
contacts (rather than markings) on shaft 614 short together leads 632 to allow
a battery
(not shown) to power light 630, a LED for example. This allows the indication
to be better
located than using mechanical means. Alternatively or additionally, a
mechanical (or
electrical) sound, such as a click is sounded when the retraction of head 604
is completed.
Possibly, different sounds are generated during retraction and after head 604
contacts base
602. Alternatively or additionally, a resistor and slide arrangement is used
to indicate
progress on a meter other suitable scale display.
Figs. 7A-7I illustrate various penetration tip and penetration head designs,
in
accordance with exemplary embodiments of the invention. The penetration tips
are
optionally retractable in each of the diagrams shown.
Fig. 7A shows a penetration head 700 including a head body 704 that is deeply
scalloped on one, two, three or more sides and a penetration tip 702, that is
conical.
Fig. 7B shows a penetration head 710 including a head body 714 that is
asymmetric and sharpened along one edge 716 thereof and having a matching
knife
shaped penetration tip 712.
Fig. 7C shows a penetration head 720 including a conical head body 724 and a
penetration tip 722, that is scalloped.
Fig. 7D shows a penetration head 730 including a conical head body 734 and a
penetration tip 732, that is a one sided knife.
Fig. 7E shows a penetration head 740 in which scalloping on a head body 744
matches scalloping on a penetration tip 742.
Fig. 7F shows a penetration head 750 in which a head body 754 is a truncated
cone
having a longer and sharper penetration tip 752, for example, having a length
that is 2 or
three times its diameter.
Fig. 7G shows a penetration head 760 in which a head body 764 is bulbous and
blunt, with a regular penetration tip 762.
Fig. 7H shows a penetration head 770 in which a head body 774 is associated
with
a threaded penetration tip 772 that is optionally rotated as it is advanced.
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Fig. 7I shows a penetration head 780 in which a head body 784 and its
associated
penetration tip 782 are formed in the shape of a knife having the cross-
section of a cross.
Other variations are contemplated as well, for example, one or both of the
cutting
lips on the penetration head and base 102 may be oblique relative to the axis
or relative to
the radius of the system (e.g., have a non-constant radius). Such oblique
elements may be
provided, for example, for embodiments with inner lip cutting or with outer
lip cutting.
The different parts may have different degrees of obliqueness.
Optionally, for any embodiment of the invention with an asymmetric penetration
head or tip, such as those shown in Figs. 7A-7E, and 7I, there are markings
further back
on the hole former so that the surgeon can easily see how the penetration head
or tip is
oriented. Often there is an optimal angle of orientation for an asymmetric
penetration head
or tip with respect to the axis of the blood vessel, to minimize tearing for
example.
Figs. 8A and 8B illustrate an expanding penetration head 800, in accordance
with
an exemplary embodiment of the invention. Head 800 comprises a penetration tip
802
mounted on a shaft 810. A plurality of arms 804 extend radially at an angle
from shaft
810. Optionally, the arms are contained in slots 808 defined in shaft 810. In
an exemplary
embodiment of the invention, the arms spring out when shaft 810 exits a
confining outer
base tube 812 and after it passes through the confinement of a wall of vessel
106. In an
exemplary embodiment of the invention, arms 804 end in rounded tips 806. Fig.
8B shows
a top view of Fig. 8A. Optionally, arms 804 are slivers formed out of the body
of shaft
810.
In use, shaft 802 is retracted relative to base portion 812. Cutting action
may be
achieved by a cutting edge 814 of tube 812. Alternatively or additionally,
tips 806 serve as
a partial anvil for urging tissue against cutting edge 814. Optionally, shaft
802 and/or base
812 are rotated.
Figs. 9A and 9B illustrate an alternative expanding penetration head 904, in
accordance with an exemplary embodiment of the invention. A hole former system
900
comprises a base tube 902 having a cutting edge 912 and an expanding head that
has a
small diameter when inserted through a vessel 106 (Fig. 9A) and a larger
diameter during
hole forming (Fig. 9B). In an exemplary embodiment of the invention, head 904
comprises
a resilient andlor expandable element 908, for example comprising silicon or
other fluid or
semi-fluid material, that is deformed and caused to expand out so that
extensions 916 (or a
disc) are formed. In an exemplary embodiment of the invention, A penetration
tip 906 of
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head 904 (and optionally an associated base 914) or the whole of head 904 are
retracted
relative to a base portion 910 of head 904, this causes the silicon element
908 to be axially
compressed and radially extend. Alternatively, element 908 may be expanded or
it may be
deformed by the advancement of a rod into the element from the direction of
tube 902.
In an exemplary embodiment of the invention, extensions 916 serve to urge the
wall of vessel 106 towards base 902. Alternatively or additionally, extensions
916 serve as
an anvil for cutting edge 912. Optionally, silicon element 908 has one or more
hard
patches on its surface. In an exemplary embodiment of the invention, such hard
patches
can be used for the anvil cutting action, however, they are not required.
Alternatively or
additionally, extensions 916 fit inside base tube 902 and provide for shearing
cutting
action. Alternatively or additionally, the expansion of element 908 causes one
or more
sharp spikes or cutting edges (not shown) to extend in the direction of base
102.
Optionally, extensions 916 are inclined at the point of contact with cutting
edge 912,
providing for an angular anvil cutting action. Optionally, the resilience of
element 908 is
such that when cutting edge 912 meets/nears extensions 916, the extensions
give, allowing
a sliding of edge 912 relative to extensions 916.
It should be noted that even a soft anvil or scissors part can provide some
benefits
over a free cutting action. In addition, the resiliency of the silicon can be
manipulated
(during manufacture) to provide a maximum hardness that still allows the
silicon to be
deformed.
Figs. 10A and lOB illustrate a hole former 1000 that includes an expanding
penetration head 1004, in accordance with an exemplary embodiment of the
invention.
In an exemplary embodiment of the invention, head 1004 comprises a thin sheet
1008 that is tightly wound around its axis, as shown in a cross-section 1006.
Fig. lOB
shows former 1000 after deployment, when head 1004 is released to achieve a
conical
shape. A cross-section is shown as reference 1012. A shaft 1010 is optionally
welded to
the side or to the tip of head 1004. Alternatively, sheet 1008 is manufactured
out of shaft
1010.
Once head 1004 expands, head 1004 may be retracted towards a base tube 1002 to
provide for cutting action, for example, knife, shearing and/or anvil cutting
action, as
described herein, depending, inter alia, on the relative geometry of head 1004
and base
1002.
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Figs. 11A and 11B illustrate a hole former 1100 including a geometry changing
anvil 1104, in accordance with an exemplary embodiment of the invention. Hole
former
1100 includes a penetration tip 1114 mounted on a shaft 1110 and a base tube
1102. A
cut-assisting disk 1104, optionally having am aperture 1106 is mounted on
shaft 1110. In
an exemplary embodiment of the invention, an over tube 1112 (or other similar
restraining
element) maintains disk 1104 in a distorted configuration, for example, the
disk being held
between an extension 1108 of tube 1112 and shaft 1110. Optionally, a second
extension
1116, holds another portion of disk 1104 against penetration tip 1114.
In Fig. 11B, penetration tip 1114 and disk 1104 are inserted through a blood
vessel
wall and tube 1112 is retracted, thus freeing disk ll04 to achieve an
orientation
perpendicular to shaft 1110. Disk 1104 can now be used as an anvil or as a
shearing base,
depending, inter alia, on the relative geometries of disk 1104 and base 1102.
Optionally,
disk 1104 includes one or more spikes or a cutting edge 1118, so that it can
be used for
cutting. Optionally, aperture 1106 of disk 1110 has a geometry that mates the
cross-section
of shaft 1110, preventing rotation.
In an exemplary embodiment of the invention, disk ll04 is aligned with a
direction of a cut formed by penetration tip 1114. Alternatively or
additionally, disk 1104
has a sharp edge that assist in forming a cut.
Optionally, disk 1104 is made oblique by the distortion, so that its trans-
axial
dimension is small. Alternatively or additionally, disk ll04 is always
oblique.
Alternatively or additionally, disk 1104 is maintained in a distorted
configuration by
tension, between one part that is held by the penetration tip 1114 and another
part that is
held back by over tube 1112.
Alternatively or additionally, disk 1104 is plastically distorted, for
example, by the
advance of over tube 1112 flattening disk 1104. Alternatively or additionally,
disk 1104 is
bi-stable between the configurations of Figs. 1 1A and 11B.
In this and in other embodiments, various shape changing mechanisms may be
used, for example, the above mentioned shape changing mechanism and elastic,
super-
elastic and shape-memory based distortion.
Fig. 12 illustrates a resilient anvil hole former 1200, in accordance with an
exemplary embodiment of the invention. Former 1200 comprises a penetration
head 1204,
for example as described above, which includes a wall 1206 having a cutting
edge 1208. A
base 1202 is also provided, however, unlike some of the embodiments described
above,
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base 1202 has a front end 1210 that is resilient. In one embodiment, cutting
edge 1208 can
penetrate into front end 1210. In another embodiment, cutting edge 1208
compresses end
1210 and then optionally slides into an hollow axis 1214 defined by the
distorted base
1202. Optionally, the degree of resilience is selected to assist in cutting
adventitsia tissue.
Fig. 13 illustrates a hole former 1300 including a thread-type penetration
head
1304, in accordance with an exemplary embodiment of the invention. Head 1304
comprises a shaft 1310 on which a threading 1308 is provided. Optionally, a
retractable
penetration tip 1306 is provided. In use, shaft 1310 is inserted through a
blood vessel wall
and then rotated to advance the shaft using the threading. Once some or all
the threading is
through the wall, penetration head 1304 is retracted towards a base 1302, to
cut the wall
tissue. In one example a cutting edge 1312 is provided on thread 1308.
Alternatively or
additionally, a shearing cutting action is performed between a thread turn and
base 1302.
Figs. 14A and 14B are perpendicular side views of a needle-type hole former
1400,
in accordance with an exemplary embodiment of the invention. A hollow pointed
needle
1402 is formed with an oblique aperture 1408 optionally having a sharpened
cutting lip
1410. In use, a penetration tip 1404 is extended through a wall of a blood
vessel and then
retracted towards the needle. In an exemplary embodiment of the invention, tip
1404
includes an extension 1406, for example an elastically extending extension
that extends
once the penetration tip passes out of the needle and through the tissue.
Optionally,
extension 1406 serves as a knife. Alternatively or additionally, the tip of
extension 1406 is
inserted into the target blood vessel first and then turned, for example as in
the
embodiment of Fig. 15.
Figs. 15A and 15B illustrate two variants of an incision maker, in accordance
with
an exemplary embodiment of the invention. Fig. 15A shows an incision maker
1500. Two
moving parts are provided, a base face 1510 coupled to a first handle 1514 and
an 'L"
shaped spike 1504 coupled to a second handle 1512. Other handle designs may be
used.
The two parts are optionally coupled using a spring 1516. In use, a tip 1506
of an arm
1509 of spike 1504 is inserted into a blood vessel, for example a coronary
artery. Incision
maker 1500 is then turned so that arm 1509 is inside the vessel and parallel
to the vessel
axis (assuming that is the desired cut direction, as an oblique cut or a trans-
axial cut may
be desired). Arm 1509 is then retracted towards face 1510 and the vessel wall
is cut using
a shearing cut. Optionally an inner face 1508 of arm 1509 is sharp and
functions as a
knife.
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Fig. 15B shows an alternative embodiment of an incision maker in accordance
with the invention, in which two base faces 1560 are provided, one on either
side of a
spike 1554 (only one face is visible). A spike tip 1556 of an arm 1559 and an
optionally
cutting edge 1558 of arm 1159 may function as before.
Optionally, face 1560 and arm 1559 while optionally in substantially parallel
are
not parallel to each other, for example, spreading out (as shown) or pointing
in.
Fig. 16A and 16B illustrate a hole former system 1600 in accordance with an
alternative embodiment of the invention. Fig. 16A shows former 1600 in a
scaffold
delivery system 1616 and Fig. 16B shows an enlargement of a tip 1618 of former
1600.
Referring first to Fig. 16B, former tip 1618 comprises a sharp penetration
head 1604
adapted to be inserted into a blood vessel, so that a shaft portion 1609 of
penetration head
1604 transfixes the blood vessel wall. Optionally, head 1604 includes a
roughened surface,
barbs, threads, a tissue receptacle (e.g., 116 of Fig. 1) or a widening 1608
(such as the
cone shape shown), to prevent tissue from falling off head shaft 1609, as
described in
more detail below. In an exemplary embodiment of the invention, angled
extensions are
formed out of a straight shaft by cutting into the shaft at an angle at
several locations (e.g.,
2 or 3) and pulling or curling the cut sections out in a radial direction, for
example as
shown in Fig. 18 below.
Cutting of the target vessel is achieved by a cutting surface 1610 formed on a
base
section 1602, for example a tube. As noted above, the cutting surface may be
smooth,
jagged, serrated and/or wave-like, possibly different finishes on different
parts of the
surface. Optionally, cutting surface 1610 defines an oblique surface relative
to shaft 1609
or is not all in one plane. Base 1602 is optionally connected to a shaft 1614
of former
1600, using an inclined section 1612, which may be used for assisting in
advancing a
sleeve 1615 of scaffold 1616 into a formed aperture in a blood vessel.
Optionally, penetration head 1604 is locked to base section 1602, during
cutting, to
prevent its axial motion and optionally also its rotational motion.
In an exemplary embodiment of the invention, after a hole is cut using surface
1610, penetration head 1604 is retracted pulling a plug of tissue that is cut
out into a
lumen in base 1602. Optionally, the retraction is manual. Alternatively, the
retraction is
spring loaded. Alternatively, other power sources may be used for retraction,
for example,
pneumatic power, such as available at gas pressure outlets in many hospital
rooms. In
another example, an electrical motor or solenoid is used to retract
penetration head 1604.
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The retraction may be wholly axial or it may include a rotational component.
In some
embodiments of the invention, penetration head 1604 has rotational freedom
relative to
base 1602, while in other embodiments it is rotationally fixed. Base 1602 may
or may not
rotate relative to scaffold 1616.
In an exemplary embodiment of the invention, a peg 1620 is provided in a
channel
1621 which has two resting spots, the position of peg 1620 as shown in Fig.
16A (1624),
where head 1604 is extended and a position 1622 at which head 1604 is
retracted.
Optionally, a safety release switch 1626 is provided to lock head 1604 and
prevent axial
motion of head 1604 relative to base 1602 and/or to lock the hole former 1600
in delivery
scaffold 1616.
The use of a general scaffold 1616 with which different tools can be delivered
is
not crucial for carrying out the invention. However, some types of such
scaffolds include
an inner leaflet valve through which the tools are advanced. In some cases,
surface 1610
andlor head 1604 may damage the valve when. the hold former is advanced
through the
scaffold. In an exemplary embodiment of the invention, a protective covering
1630 is
provided. In an exemplary embodiment of the invention, covering 1630 comprises
a tube,
for example, a silicone tube or a shrink-fitted tube that isolates the valve
from the sharp
edges of former 1600 (or other tool), for example, surface 1610 and the tip of
head 1604.
After insertion, covering 1630 is torn off or pulled off (e.g., if it has one
sealed end.
Optionally, covering 1630 includes a perforation 1632, a rip cord and/or a
pull tab, to
assist in removal after it is inserted in scaffold 1616.
Figs. 17A-17E illustrate the use of hole former 1600, in accordance with an
exemplary embodiment of the invention.
In Fig. 17A, penetration head 1604 is advanced towards a blood vessel, for
example an aorta 1700.
In Fig. 17B, penetration head 1604 is advanced to penetrate vessel 1700, so
that
shaft 1609 transfixes vessel 1700 and penetration head 1604 does not engage
vessel 1700
in any way. In some embodiments, however, penetration head 1604 includes barbs
for
engaging vessel 1700 or remains inside the wall of the vessel. Such engagement
may
cause the vascular tissue to be stretched before being cut, possibly providing
apertures that
are smaller or larger than the diameter of base 1602 and/or have a conical
profile. The size
and shape may depend on whether penetration head 1604 is retracted prior to
cutting
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starting and/or being completed. Optionally, penetration head 1604 includes a
retracting
sharp tip (e.g., Fig. 4A).
In Fig. 17C, cutting is performed, for example, by rotating and/or advancing
base
1602 relative to vessel 1700, so that cutting surface 1610 cuts into vessel
1700. Depending
on the implementation of former 1600, the entire delivery system may be
moved/rotated or
only base 1610 and/or other sub-components of system 1600 are rotated and/or
moved.
In Fig. 17D, cutting is complete, so base 1610 is engaged by vessel 1700,
while a
plug 1702 of tissue remains on shaft 1609. Possibly, some or all of plug 1702
is contained
inside base 1602. Optionally, a tissue receptacle (not shown) is provided on
penetration
head 1604.
Penetration head 1604 is retracted, pulling along with it plug 1702, into a
lumen
formed in base 1602. Penetration head 1604 optionally has significant
clearance relative to
the inner diameter of the lumen. Alternatively, a small clearance is provided,
so that base
1602 and penetration head 1604 can exhibit a shearing action between them
(e.g., to cut
any loose strands). Optionally, penetration head 1604 is retracted prior to
the cutting being
completed, but in a the embodiment pictured, it is not so retracted.
Alternatively,
penetration head 1604 is retracted while base 1602 is advanced, for example to
ensure that
it does not damage the far side of the blood vessel. Optionally, however,
penetration head
1604 is retracted in a manner that ensures that penetration head 1604 does not
apply
tension or undue tension on vessel 1700, and affect the aperture cutting
shape. In one
example the penetration head is retracted such that the distance between
penetration head
1604 and base 1602 is greater than the thickness of plug 1702, or at least an
uncut
thickness thereof.
It should be noted that if vessel 1700 is filled with blood under pressure,
there is
little danger of penetration head 1604 damaging the far side of vessel 1700,
especially if
the length of shaft 1609 and penetration head 1604 is considerably less than
the diameter
of vessel 1700. Alternatively, a retracting penetration tip is provided.
Desirably surface
1610 is advanced under light pressure, possibly under its own weight, to
prevent distortion
of vessel 1700. Alternatively, vessel 1700 may be kept in shape by pressure
(e.g., with
forgers or a tool) on its sides that are perpendicular to the penetration.
In Fig. 17E, the entire hole former is advanced, so that sleeve 1615 enters
the wall
of vessel 1700 and the hole forming mechanism can be removed. An anastomosis
delivery
system may now be provided through scaffold 1616 and its valve.
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In an exemplary embodiment of the invention, shaft 1609 has a length greater
than
the thickness of the wall of vessel 1700, for example, being 150%, 200% or
300% its
thickness. In an aorta, this translates, for example, into a length of 4-6 mm.
Alternatively,
the shaft may be shorter than a vessel diameter. Optionally, different length
shafts are
provided for different patients and/or vessel sizes. Alternatively, a screw or
other
mechanism is used to adjust the length of shaft 1606, for example, by
controlling the
resting location of peg 1620. The diameter of penetration head 1604 may be
selected to be
the diameter that prevent sliding off of plug 1702, while allowing clearance
relative to
base 1602. The relation between the diameter of shaft 1609 and cutting surface
1610 is
optionally as defined in Fig. 3.
Fig. 18 illustrates a tip of a hole former 1800 in accordance with an
alternative
embodiment of the invention. Former 1800 comprises a shaft 1814 coupled by a
cone
1812 to a base section 1802 having a cutting lip 1810 and an inner lumen
having a surface
1828. A penetration head 1804 comprises a needle like shaft 1809 having formed
out of its
body one or more barbs 1820, cut out of depressions 1822. Other methods of
forming and
attaching such barbs may be used as well. Optionally, shaft 1809 has a needle
like tip 1824
with an optional inner lumen having an inner surface 1826.
In an exemplary embodiment of the invention, barbs 1820 are elastic, so that
when
inserting head 1804 into vessel 1700, barbs 1820 bend back into depressions
1822 and
present a smaller resistance to insertion. After insertion, the spring out
again.
Optionally, surface 1826 and/or surface 1828 have inner threads, barbs or
other
treatment, to better engage tissue plugs. Alternatively, the inner diameter of
the lumens
vary, for example, non-monotonicly, or monotonicly increasing (away form the
blood
vessel).
A hollow tip such as provided in Fig. 18 may have other uses as well, for
example,
for eluting medication (e.g., against clotting, for healing the cut tissue
and/or to assist in
cutting), for example, continuously or when a suitable control (e.g., attached
to a
reservoir) is used. Alternatively or additionally, such a lumen is used for
providing
vacuum to better couple former 1800 and vessel 1700. Alternatively or
additionally,
vacuum is provided between penetration head 1804 (if any) and base 1802, e.g.,
through
the lumen in base 1802. Alternatively, eluting of medication may be provided
in other
ways, for example, by penetration head 1804 being spongy or from base 1802,
for
example, from its lumen or its walls.
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In an alternative embodiment of the invention, no penetration head is
provided,
with tissue plug 1702 optionally prevented from falling off by inner threading
of surface
1828 of base 1802. Optionally, however, an axial stabilizer like penetration
head 1804 and
shaft 1809 are provided. In one example, a wire is provided. Alternatively, a
spiral cork-
s screw like shaft 1809 is provided. This inner stabilizer may or may not have
a fixed axial
position relative to base 1802. If not fixed, the range of motion may
nevertheless be fixed
and/or the number of stable positions be limited. In an exemplary embodiment
of the
invention, the stabilizer is fixed so that it protrudes by a large amount
(e.g., 1-5 mm for an
aorta), slightly (e.g., 1 mm), is even with or is retracted relative to a
plane defined by
surface 1810. Optionally, the stabilizer is not strong enough (or does not
engage vessel
1700 well enough) to be used to urge vessel 1700 against base 1802.
Figs. 19A and 19B show a hole former 1900 according to another exemplary
embodiment of the invention, and Figs. 19C-19G illustrate how this hole former
works, in
five steps. In this embodiment of the invention, there are separately
manipulated tissue
penetrating and tissue holding elements, and the blood vessel wall can be
penetrated
without holding it, making it possible, for example, for the surgeon to
withdraw the
penetration element with little damage to the blood vessel, before holding the
tissue.
A penetration tip 1904, at the end of an inner penetration shaft 1908,
penetrates the
blood vessel wall 1700 in Fig. 19D, and a base 1902 is then brought against
the outside of
the blood vessel. Alternatively, base 1902 is brought against the outside of
the blood
vessel even before penetration tip 1904 starts to penetrate the wall, or only
later, in the
stage shown in Fig. 19F, when the surgeon is ready to cut a hole in the wall.
An outer
penetration shaft 1986, fitting closely around inner shaft 1908, then (in Fig.
19E) passes
through the small opening made in the wall by the penetration tip, guided by
inner shaft
1908. Until outer shaft 1986 enters the blood vessel, the process is
completely reversible
with little damage to the blood vessel. For example, if the surgeon decides
that a better
location should be chosen, then he can withdraw shaft 1908 without pulling the
blood
vessel, and only minimally damaging the wall. Even if penetration tip 1904 has
already
reached the inside of the blood vessel, the hole it makes will be much smaller
than if the
hole former were torn out with the tissue held, and such a small hole is often
self sealing.
After inner shaft 1908 has penetrated the wall completely in a satisfactory
way,
outer shaft 1986 passes through the wall also. Optionally, outer shaft 1986
rotates as it
advances through the wall, and optionally it has a sharp lip at its end, so
that it actually
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cuts the wall as it advances, enlarging the opening made by inner shaft 1908.
Alternatively, outer shaft 1986 enlarges the opening by punching.
Alternatively outer shaft
1986 is blunt at its end, and it only pushes the wall tissue out of the way,
or dilates the
tissue, as it passes through the opening made by inner shaft 1908.
Optionally, penetration tip 1904 and penetration shaft 1908 are retracted into
outer
shaft 1986 once outer shaft 1986 is through the wall, to reduce the risk of
the penetration
tip inadvertently damaging the other side of the blood vessel. Optionally,
outer shaft 1986
has a small balloon or another deployable blunt element at its end, or
deployed through its
lumen, to keep the end of outer shaft 1986 from inadvertently damaging the
opposite wall
of the blood vessel. Alternatively or additionally, inner shaft 1908 has such
a deployable
blunt element near its end, or inside it. Optionally, penetration tip 1904 is
retractable into
shaft 1908, so that tip 1904 can be retracted any time after the end of shaft
1908 is through
the wall.
Alternatively, penetration tip 1904 and/or shaft 1908 has a fixed location and
cannot be axially retracted. Outer shaft 1986 is optionally made long enough
so that even
when retracted as far as expected (e.g., an tissue holding element as
described below is
brought to or into base 1902) during a cutting procedure, tip 1904 remains
covered.
In an exemplary embodiment of the invention, outer shaft 1986 has one or more
tissue holding elements 1920 on its side, for example projecting elements such
as barbs,
and once barbs 1920 have passed through the wall (and shaft 1986 has been
drawn back
somewhat), the barbs prevent shaft 1986 from pulling back through the wall, as
shown in
Fig. 19F. Optionally, barbs 1920 are flexible and are pressed against the side
of shaft 1986
by the tissue, until they get through the wall. Alternatively, barbs 1920 are
rigid. When
inserted, the barbs may push the sides of the opening away as they pass
through the
opening, or dilate the tissue, or cut through the sides of the opening as they
pass through it.
Optionally, instead of barbs, a disk or another kind of projecting element is
used, similar
to the disk shown in Fig. 11.
Alternatively, instead of having the barbs attached to outer shaft 1986, the
barbs
are flexible and are attached to shaft 1908, and they are covered by shaft
1986, which
presses them against the sides of shaft 1908, until the barbs on shaft 1908
(with shaft 1986
covering them) are through the wall. Then, shaft 1986 is withdrawn enough to
uncover the
barbs, which project outward, and prevent shaft 1908 from pulling back through
the wall.
Alternatively, shaft 1986 is withdrawn when the barbs are still in the middle
of the wall,
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and the sides of the opening hold the barbs against shaft 1908 until the shaft
1908 carries
the barbs through the wall. Optionally, instead of uncovering the barbs by
withdrawing
shaft 1986 axially, shaft 1986 has slots in it, and the barbs are uncovered by
rotating shaft
1986 azimuthally until the slots are aligned with the barbs. Alternatively,
the barbs are
uncovered when shaft 1986 moves axially so that the barbs are aligned with the
slots, or
shaft 1986 moves both axially and azimuthally to align the barbs with the
slots.
Optionally, there are three shafts, a penetration shaft 1908 without barbs, a
shaft 1986 with
flexible barbs on it, and an outer shaft which keeps the flexible barbs
pressed against shaft
1986 until the outer shaft is withdrawn.
Alternatively, shaft 1908, with penetration tip 1904 at its end, is hollow,
and shaft
1986, with barbs 1920 attached to it, is inside shaft 1908. In this embodiment
of the
invention, shaft 1908 has slots in it, which barbs 1920 fit through.
Optionally, the barbs
are flexible, and are pressed against the sides of shaft 1986 by the inside of
shaft 1908.
When shaft 1908, including the slots, has passed through the vessel wall,
shaft 1986
moves along the inside of shaft 1908 until barbs 1920 reach the slots, and
barbs 1920 then
project through the slots, locking shaft 1986 to shaft 1908, and preventing
either shaft
from withdrawing easily from the vessel wall. Optionally, the barbs are first
positioned at
a different azimuthal position than the slots, and once the barbs have reached
the axial
position of the slots, shaft 1986 is rotated until the barbs go through the
slots.
Alternatively, instead of short slots in shaft 1908, there are long slits
extending along shaft
1908. After shaft 1908, including the ends of the slits, has passed through
the vessel wall,
the barbs, which may be flexible or rigid, project through the slits as shaft
1986 advances
through shaft 1908, until the barbs reach the inside of the blood vessel. (If
the barbs are
rigid, then optionally the barbs push the sides of the opening out of the way
as they pass
through the wall, or they dilate the tissue, or they cut their way through the
wall, similar to
the situation described previously where shaft 1986 is outside shaft 1908.)
Alternatively, neither shaft 1986 nor shaft 1908 is inside the other, but the
two
shafts are side by side. For example, each has the cross-section of half a
circle.
It should be understood that, where shaft 1986 is described herein as moving
or
rotating relative to shaft 1908, optionally shaft 1986 moves or rotates while
shaft 1908
stays still, or shaft 1908 moves or rotates while shaft 1986 stays still, or
both shaft 1986
and shaft 1908 move or rotate but at different rates. Similar options exist in
any other case
where one part of the hole former moves relative to another part.
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Optionally, once barbs 1920 have passed through the wall, shaft 1986 (or
whatever
shaft barbs 1920 are attached to) is pulled back until the barbs touch the
wall inside the
blood vessel. Optionally, this touching is detected by the surgeon because
shaft 1986
resists being pulled back further. By putting base 1902 against the outside of
the blood
vessel wall at the same time as barbs 1920 are touching the inside of the
wall, and
measuring the relative position of shaft 1986 and base 1902, the surgeon
optionally
determines the thickness of the wall. If the wall is too compressible, then
barbs 1920 may
compress the wall significantly before the surgeon feels the resistance of
shaft 1986 to
being pulled back, and this will affect the accuracy of the thickness
measurement.
Alternatively, the degree of compression may be measured by comprising the
measured
thickness at two different controlled retraction forces, for example using one
or more
springs. The display may be, for example electronic, for example using a
linear encoder.
Alternatively, the display is mechanical, for example as described below.
Alternatively or additionally, shaft 1986 is advanced until it touches the fax
wall of
the blood vessel, and the relative position of shaft 1986 and base 1902 is
used to
determine the inner diameter of the blood vessel plus the thickness of the
wall. The
thickness of the wall may then be inferred by subtracting this distance from
the externally
measured outer diameter of the blood vessel. Optionally, shaft 1986 is not
advanced to the
far wall of the blood vessel unless shaft 1908, or at least penetration tip
1904, is covered
by shaft 1986, so that the far wall will not be damaged. If penetration tip
1904 is retracted
into shaft 1908, then shaft 1908 is optionally used, instead of shaft 1986, to
measure the
distance to the far wall.
Optionally, whether shaft 1986 is touching the far wall or the inside of the
near
wall, the relative position of shaft 1986 and base 1902 is measured by
markings on a knob
or another mechanism on the handle of the hole former, which controls the
motion of shaft
1986 relative to base 1902. Additionally or alternatively, a window in the
handle allows
the surgeon to see an extension of shaft 1986 inside the handle, with markings
on shaft
1986 or on the handle to show their relative position. Other mechanisms to
measure the
relative position of shaft 1986 and base 1902 will be apparent to persons
skilled in the art.
Optionally, in addition to or instead of measuring the thickness of the wall,
shaft
1986 is used to measure the compressibility of the wall, by measuring the
resistance of
shaft 1986 to being pulled back further, while base 1902 remains stationary
against the
outside of the blood vessel. Knowing the thickness and compressibility of the
wall may be
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useful in deciding the best way to cut the wall, or in deciding whether the
hole should be
cut in this blood vessel at all.
Once shaft 1986 and barbs 1920 have passed through the wall, a cutting lip
1910
on base 1902 starts to cut through the wall to form a hole. Optionally, base
1902 rotates as
cutting lip 1910 cuts through the wall, shown in Fig. 19G. Optionally, the
rotation is in
one direction. Alternatively, the rotation is back and forth. Optionally,
barbs 1920 are
brought up to the inner surface of the wall and remain there during the
cutting, in order to
provide a surface for base 1902 to push against, so base 1902 will not push
the whole
blood vessel or stretch it during the cutting. Barbs 1920 also prevent the
plug from falling
into the blood vessel, and allow shaft 1986 to pull the plug out of the wall
when shaft
1986 is retracted. Alternatively, instead of cutting lip 1910 cutting a hole
through the wall
from the outside, the barbs cut or punch a hole through the wall from the
inside, or the
barbs and cutting lip each cut part way through the wall and meet in the
middle of the
wall. Optionally, shaft 1986 andlor shaft 1908 do not rotate with base 1902.
Optionally, shaft 1908 is rigidly attached to base 1902, so that shaft 1908
moves
together with base 1902 as cutting lip 1910 cuts through the vessel wall, as
shown in Fig.
19G. Alternatively, shaft 1908 is attached to base 1902 in such a way that
shaft 1908
cannot move axially with respect to base 1902, but shaft 1908 is still free to
rotate
azimuthally with respect to base 1902. In either case, shaft 1986 is
optionally made long
enough so that, even when cutting lip 1910 has completely cut through the wall
and shaft
1986 has retracted enough so that barbs 1920 are in contact with the wall,
penetration tip
1904, which is sharp and can accidentally damage the vessel wall on the other
side, is still
inside shaft 1986. Designing shaft 1986 to be long enough to do this may
depend on
estimating a thickness of the blood vessel wall. Alternatively, shaft 1908 is
moveable
independently of base 1902, and cutting lip 1910 can cut through the wall
without shaft
1908 also moving. A potential advantage of this arrangement is that
penetration tip 1904
can be kept inside shaft 1986 as base 1902 moves through the wall and while
barbs 1920
are against the inside of the wall, even if base 1902 moves further than
intended, for
example if the wall is thicker than expected. Optionally, one or more controls
on the
handle of the hole former can lock shaft 1908 to base 1902, or lock shaft 1908
to shaft
1986. Optionally, a device in the handle can cause penetration tip 1904 to
retract into shaft
1986 automatically once shaft 1986 has gone through the wall. Optionally, the
device can
be activated or turned off at the discretion of the surgeon.
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Once the vessel wall is cut all the way through, outer shaft 1986, with or
without
inner shaft 1908, is brought back, taking a plug of cut tissue with it.
Optionally, outer shaft
1986 is spring loaded, and automatically goes back as soon as the tissue plug
is separated
completely from the wall. Base 1902 optionally is left in place temporarily,
to keep the
blood vessel from leaking.
Fig. 20A shows a hole former 2000 according to another exemplary embodiment
of the invention. Fig. 20A is a cut-away side view. A perspective view of the
same hole
former is shown in Fig. 20G. In this embodiment of the invention, there is a
penetration
head 2004 that is non-axisymmetric. There is a sharp penetration tip 2005 at
the end of
penetration head 2004. In many cases, a penetration tip of the shape shown in
Fig. 20G
will make a relatively straight slit in the wall, and the slit will not tend
to get longer in an
uncontrollable way after it is made. Also, in some cases, the slit will not
have a tendency
to tear, and these desirable properties will not be sensitive to its
orientation relative to the
axis of the blood vessel. Optionally, a different shape is used for the
penetration tip, and
the properties of a slit made by a differently shaped tip may depend on the
orientation of
the slit, and on the properties of the blood vessel wall. Differently shaped
penetration tips
may be desirable for different types of blood vessels. Other possible shapes
include a tip
with a sharp edge that is V-shaped rather than elliptical, a conical tip, and
a stiletto-shaped
tip.
The whole penetration head enters the blood vessel through the opening made by
the penetration tip, and a cutting edge (for cutting the wall from the inside)
and/or a wall
holder also enter the blood vessel, either as part of the penetration head or
together with it.
In the embodiment of the invention shown in Fig. 20A, once the penetration
head has
entered the wall of the blood vessel through this slit-like opening, it is
brought back, and a
cutting lip 2010 on the back of the penetration head makes an arc-shaped cut
in the vessel
wall from the inside, next to the slit. Alternatively, instead of cutting lip
2010, there is a
blade proj ecting from the back of penetration head 2004, to make a scissors
cut. This arc-
shaped cut together with the slit makes a D-shaped hole in the wall.
Optionally, penetration head 2004 is hollow, and there is a hook 2006, or more
than one hook, attached to its inner surface which keeps the plug of tissue
from slipping
off the penetration head into the blood vessel when the penetration head is
withdrawn
from the blood vessel. Alternatively, the hook is not attached to penetration
head 2004, but
is attached to the end of its own shaft, which enters the blood vessel through
the opening
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WO 02/074188 PCT/IL02/00215
made by penetration tip 2005, at the same time as penetration head 2004 enters
the blood
vessel, or afterwards.
Making penetration head 2004 hollow also allows cutting lip 2010 to cut
through
the vessel wall without compressing the tissue. If instead of the cutting lip,
there is a blade
extending far enough from the back of penetration head 2004, then penetration
head 2004
can be solid without compressing the tissue when the blade cuts through the
wall. An
inner penetration shaft 2008 is attached to the back of penetration head 2004
on one side,
the same side that penetration tip 2005 is on, and cutting lip 2010 is also on
the back of
penetration head 2004, but not at the place where penetration head 2004 is
attached to
inner shaft 2008. An outer penetration shaft 2086 is shown directly behind
inner shaft
2008 (to the right of inner shaft 2008 in Fig. 20A). Optionally, outer shaft
2086 is to the
side of inner shaft 2008 instead of behind it (in front or back of inner shaft
2008 in Fig.
20A). An anchor 2088 is optionally attached to the end of outer shaft 2086.
All of these
parts are mounted in a base 2002. Optionally, anchor 2088 and shaft 2086 move
relative to
base 2002. Alternatively, anchor 2088 and shaft 2086 are attached rigidly to
base 2002.
Optionally, if anchor 2088 and shaft 2086 move relative to base 2002, the
relative
position of base 2002 and shaft 2086 is used to measure the thickness of the
blood vessel
wall, as described above for base 1902 and shaft 1986 in Fig. 19.
Alternatively or
additionally, the compressibility of the wall is also measured, as described
above for Fig.
19. Optionally, base 2002 and anchor 2088 hold onto the blood vessel wall
after the plug
of tissue has been removed, and there is a valve inside base 2002, not shown
in the
drawings, which keeps blood from leaking out of the blood vessel until another
blood
vessel can be attached to the hole.
Figs. 20B-20E illustrates in four steps how hole former 2000 forms a hole in a
blood vessel. Fig. 20H shows a side cross-sectional view of the step shown in
Fig. 20B,
and Fig. 20I shows a side cross-sectional view of the step shown in Fig. 20E.
In Fig. 20B,
anchor 2088 is set at a position so that the distance between its lower
surface 2090 and the
top of base 2002 is somewhat more than the expected thickness of the blood
vessel wall.
Penetration head 2004, extending out beyond anchor 2088, then penetrates the
wall of the
blood vessel, starting with sharp tip 2005. The tip makes a slit 2092 (shown
in Fig. 20F) in
the blood vessel, and the slit opens enough for the entire penetration head
2004, and
anchor 2088, to enter the blood vessel. The length of the slit and whether it
is subject to
tearing may depend on the angle at which the tip is oriented with respect to
the axis of the
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CA 02442056 2003-09-18
WO 02/074188 PCT/IL02/00215
blood vessel, although the shape of penetration tip shown in Fig. 20G is
designed to work
well independent of its orientation. Optionally, hole former 2000 has markings
on it, for
example further back on the base, to assist the surgeon in orienting
penetration head 2004
so that the slit is oriented in a desired direction. Optionally, similar
markings are used to
help orient asymmetric penetration heads or asymmetric penetration tips in
other
embodiments of the invention, such as those shown in Figs. 7A-7E, and 7I.
Once penetration head 2004 and anchor 2088 are inside the blood vessel, the
slit
partially closes, since it is held open only by shafts 2008 and 2086. Base
2002 optionally
is brought up against the outside of the blood vessel, and anchor 2088
optionally is
brought back until it is touching the inner surface of the blood vessel. If
hole former 2000
is always used for blood vessels with walls of the same thickness, then anchor
2088
optionally is attached at a fixed distance from base 2002.
In Fig. 20C, penetration head 2004 is brought back toward base 2002, and
cutting
lip 2010, which optionally is shaped like an arc of a circle (missing the part
of the circle
1 S where penetration head 2004 is attached to shaft 2008) makes a C-shaped
cut 2094 (shown
in Fig. 20F) in the vessel wall from the inside, with both ends of the C
reaching the slit
that was made by penetration tip 2005 going into the vessel. Thus, cutting lip
2010 cuts
out a hole in the vessel wall. Fig. 20F shows the cut-out hole viewed axially,
including slit
2092 and C-shaped cut 2094. Alternatively, cutting lip 2010 could be a
different shape.
But if cutting lip 2010 is shaped like an arc of a circle, then it can be
rotated back and
forth as it cuts, while keeping the cut narrow and undistorted. Optionally,
the center part
2090 of cutting lip 2010, seen in profile in Fig. 20C, projects out from the
rest of cutting
lip 2010. Optionally, center part 2090 has a sharp point; alternatively is it
is rounded.
Center part 2090 allows cutting lip 2010 to make a clean initial cut into the
wall, with
minimal or no tearing. The cut is then extended by the rest of cutting lip
2010 into a C-
shaped cut which reaches the slit. By starting the cut in the middle, away
from the slit,
cutting lip 2010 does not pull on and distort the slit as it is cutting, or at
least does not
distort the slit in a lopsided way.
Optionally, hook 2006 engages the back of the plug of tissue that is removed
to
30' make the hole, and keeps it from going into the blood vessel when
penetration head 2004
is withdrawn from the blood vessel in Figs. 20D and 20E. Optionally, there is
a sharp
spike at the end of hook 2006 which penetrates into the plug of tissue, to
prevent it from
slipping off the one side. Anchor 2088, pressed against the inside of the
blood vessel
CA 02442056 2003-09-18
WO 02/074188 PCT/IL02/00215
slightly beyond the boundary of the hole, keeps base 2002 pressed against the
outside of
the blood vessel, so that blood does not leak out. Optionally, penetration
head 2004 and
the plug of tissue are withdrawn while base 2002 and anchor 2088 remain in
place, until
the surgeon is ready to attach another blood vessel to the hole.
Alternatively, penetration
head 2004 and the plug of tissue remain in place together with base 2002 and
anchor 2088,
and the plug of tissue further reduces leakage of blood, until the surgeon is
ready to attach
another blood vessel.
Alternatively, there is no hook 2006, and other means are used to keep the
plug of
tissue from falling into the blood vessel. For example, flexible barbs are
located on the
. inside of anchor 2088. These barbs are pushed downward against the inside
surface of
anchor 2088 by penetration head 2004, until penetration head 2004 is pulled
out of the
blood vessel, leaving the plug of tissue in place but separated from the blood
vessel wall,
and largely plugging the hole and keeping blood from leaking out. When anchor
2088 is
withdrawn from the blood vessel, then the barbs engage the plug and pull it
out also.
Alternatively, the cutting is provided by base 2002 or by an additional outer
cutting
tube. Alternatively or additionally, scissors type cutting or anvil type
cutting is provided,
for example, between lip 2010 and base 2088.
In Figs. 20A-20E and 20G, anchor 2088 is concentric with penetration head 2004
and surrounds it. Alternatively, anchor 2088 does not go all the way around
penetration
head 2004, but only goes part way around it, for example, head 2004 traveling
in a groove
formed in anchor 2088 or along side it.
In an exemplary embodiment of the invention, head 2004 defines a cutting
surface
on its proximal side that corresponds to the sections of anchor 2088 that are
not trans-
axially slotted. This may be provided, for example, by head 2004 traveling in
a groove in
anchor 2088 and wings extending from head 2004, out of the groove and covering
the un-
slotted parts, so that head 2004 partly encloses anchor 2088 and anchor 2088
partly
encloses head 2004.
It should be noted that while some of the above embodiments have been
described
with head 2004 mounted on a shaft that is outside anchor 2088, in some
embodiments,
head 2004 is mounted on a shaft that is at least partly surrounded by anchor
2088, albeit
not in a coaxial configuration with relation to anchor 2088. Alternatively or
additionally,
head 2004 is symmetrically designed and arranged relative to anchor 2088.
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Figs. 21A and 21B show a hole former according to another exemplary
embodiment of the invention. The hole cutter shown in Figs. 21A and 21B is
similar to
that shown in Figs. 20A-20I, but it also includes a penetration head catch
2102.
Optionally, penetration head catch 2102 is fixed to base 2002, as shown in
Figs. 21A and
21B. Alternatively, penetration head catch 2102 is fixed to shaft 2086, if
shaft 2086 exists,
or penetration head catch 2102 is an independent part of the hole former. When
penetration head 2004 is some distance away from base 2002, as it is when
penetration
head 2004 has finished penetrating the blood vessel wall, penetration head
catch 2102 is
located inside the hollow penetration head, as shown in Fig. 21A. A spring
2104 keeps
penetration head catch 2102 pressed against the inside surface of penetration
head 2004.
As penetration head 2004 is retracted, as shown in Fig. 21B, catch 2102
extends past the
tip of penetration head 2004, and spring 2104 pushes catch 2102 over the tip.
If catch
2102 is fixed to base 2002, this locks penetration head 2004 to base 2002, and
penetration
head 2004 is prevented from accidentally moving away from base 2002, where it
may
damage the blood vessel wall on the other side of the blood vessel, for
example. Similarly,
penetration head 2004 is constrained from moving if catch 2102 is fixed to
another part of
the hole former, for example a shaft similar to shaft 2086 in Fig. 20. Whether
or not
penetration head 2004 is constrained from moving by catch 2012, catch 2102
optionally
covers a sharp tip on penetration head 2004, and may prevent it from damaging
the blood
vessel wall. Optionally, catch 2102 is not fixed to base 2002 or to any other
part of the
hole former, and does not automatically slip over penetration head 2004 when
penetration
head 2004 is retracted, but catch 2102 is manipulated to slip over penetration
head 2004
by the surgeon, at any desired time. Optionally, there is a control in the
handle of the hole
former enabling the surgeon to manipulate catch 2102. Additionally or
alternatively, there
is a control in the handle of the hole former which allows the surgeon to
release catch
2102, for example if it was set by mistake.
Figs. 22A-22E show a hole former with two helical penetration shafts 2208 and
2209, attached to a base 2202 with a cutting surface 2210. The five drawings
show the
procedure by which the hole former makes a hole in a blood vessel wall 1700.
In Fig. 22A,
helical shafts 2208 and 2209, with opposite helicities, are located just
outside wall 1700.
In Fig. 22B, the two shafts rotate in opposite directions as they penetrate
the wall, creating
two helical channels matching the helicities of the shafts. In Fig. 22C, the
shafts have
penetrated the wall, and cutting edge 2210 starts to cut a circular hole in
the wall,
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WO 02/074188 PCT/IL02/00215
optionally rotating as it cuts. Alternatively cutting edge 2210 does not
rotate, but cuts the
wall with a punching motion. In Fig. 22D, shafts 2208 and 2209 retract with
respect to
cutting edge 2210 and base 2202, without rotating, as cutting edge 2202 cuts
through the
wall, providing cutting edge 2210 with something to push against as it cuts.
In Fig. 22E,
the cutting edge 2210 has completely cut through the wall, leaving a cut out
plug of tissue
2212. Optionally, shafts 2208 and 2209 then retract fixrther into base 2202
without
rotating, pulling out tissue plug 2212. Alternatively, shafts 2208 and 2209
rotate in the
same direction as they did while penetrating the wall, while not retracting
with respect to
base 2202, which also causes plug 2212 to be pulled into base 2202, or shafts
2208 and
2209 rotate and retract at the same time.
Optionally, instead of two shafts 2208 and 2209 with opposite helicities,
there is
only one shaft. A potential advantage of having two shafts with opposite
helicities is that
the torques exerted by the two shafts may cancel out, so that they do not
exert any net
torque on the blood vessel. If there are two shafts, they may be side by side,
as shown in
Figs. 22A-22E, or they may be overlapping, or even coaxial. If the two shafts
are coaxial,
they can avoid intersecting each other by having at least slightly different
diameters.
Another potential advantage of having two shafts of opposite helicities, as
opposed to a
single helical shaft with its axis coinciding with the axis of circular tissue
plug 2212, is
that tissue plug 2212 cannot slip off the shafts by twisting, as the shafts
rotate and/or
retract. This advantage could also apply to two shafts with the same helicity,
if they are not
coaxial, or even to a single helical shaft that is not coaxial with the
circular tissue plug. In
order for the tissue plug to slip off the shaft or shafts in those cases, the
tissue plug would
have to be stretched, compressed, and/or sheared, rather than simply twisting
rigidly as in
the case of a single centered helical shaft.
The hole former shown in Figs. 22A-22E has the potential advantage that the
penetration of the wall can be reversed at any time simply by rotating the
shafts in the
opposite direction that they were rotated in while penetrating the wall, while
retracting
them. If this is done, the shafts will only leave small openings in the wall,
which may
close up by themselves with minimal loss of blood. This can be done even after
cutting
surface 2210 has started to cut through the wall. The penetration shafts could
be used to
measure the thickness and/or compressibility of the blood vessel wall, for
example, using
a method similar to that described above for Figs. 19 and 20. If the wall does
not have a
thickness and/or compressibility within the expected range, and the surgeon
decides that
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the blood vessel is therefore not suitable for the procedure being performed,
then the
penetration shafts can be removed with little damage, and another blood vessel
can be
chosen.
The above description has focused on devices that are applied from outside a
blood
vessel. However, they can also be applied from inside of blood vessels.
In an exemplary embodiment of the invention, the design is optionally changed
to
accommodate one or more of the following factors:
(a) which layer of the blood vessel is to be cut more precisely;
(b) what type of cutting action to apply to each blood vessel layer;
(c) disposal of the tissue plug (if any) to outside the blood vessel or to
inside the
delivery system; and
(d) desired cut profile.
In one example of an inside-out punch, the tissue receptacle is located on the
base
and has a cutting lip that extends forward. In another example, the tissue
receptacle is on
the penetration head but the base advances forwards towards the receptacle.
In addition, the aperture forming systems may be provided in several sizes,
for
example, two, three or more sizes.
It should be noted that the elements described as tubes are not generally
required to
be tubes. In one example, the apertured base tube can be replaced by a slotted
solid rod, in
which the slot carries a shaft for retraction of the penetration head. The
shaft need not
attach to the center of the penetration head.
It should also be noted that hole formers can be used to create incomplete
removal
of plugs, for example, to create rectangular or triangular flaps.
In an exemplary embodiment of the invention, the above devices are used in
combination with anastomosis-related tools as described in PCT applications
and
publications WO 99/62415, WO 00/56226, WO 00/56228, WO 01/41623, WO 01/41624,
PCT/ILO1/00267, PCT/IL,O1/00069, PCT/11,01/00074, and PCT/IhO1/00266, the
disclosures of which are incorporated herein by reference. However, they may
also be used
as stand alone devices or as part of surgical kits for other uses and/or
anastomosis
connectors.
It will be appreciated that the above described methods and devices of
vascular
manipulation may be varied in many ways, including, changing the order of
steps, the
exact materials used for the devices, which vessel is a "side" side, which
vessel (or graft)
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is an "end" side of an end-to-side anastomosis and whether the device is used
from inside
or from outside a blood vessel. Further, in the mechanical embodiments, the
location of
various elements may be switched, without exceeding the spirit of the
disclosure, for
example, switching the moving elements for non-moving elements where relative
motion
is required. In addition, a multiplicity of various features, both of methods
and of devices
have been described. It should be appreciated that different features may be
combined in
different ways. In particular, not all the features shown above in a
particular embodiment
are necessary in every similar exemplary embodiment of the invention. Further,
combinations of the above features, from different described embodiments are
also
considered to be within the scope of some exemplary embodiments of the
invention. In
addition, some of the features of the invention described herein may be
adapted for use
with prior art devices, in accordance with other exemplary embodiments of the
invention.
The particular geometric forms used to illustrate the invention should not be
considered as
necessarily limiting the invention in its broadest aspect to only those forms,
for example,
where a circular lumen is shown, in other embodiments an oval lumen may be
used.
Also within the scope of the invention are surgical kits which include sets of
medical devices suitable for making a single or a small number of anastomosis
connections and/or apertures. Measurements are provided to serve only as
exemplary
measurements for particular cases, the exact measurements applied will vary
depending on
the application. When used in the following claims, the terms "comprises",
"comprising",
"includes", "including" or the like means "including but not limited to".
It will be appreciated by a person skilled in the art that the present
invention is not
limited by what has thus far been described. Rather, the scope of the present
invention is
limited only by the following claims.
