Note: Descriptions are shown in the official language in which they were submitted.
218~469
WO95/19139 1
KNOT TYING METhOD AND APPARATUS
FIELD OF THE INVENTION
The present invention relates to the broad
field of knot tying, and particularly knot tying in the
context of medicine such as the tying of sutures. More
specifically, the invention has special applicably to the
tying of sutures and other knots in the field of
laparoscopic surgery.
BACKGROUN~ OF TH~ INVENTION
Knot tying and suturing as a method to
approximate tissue is a critical element of surgery.
Skill in knot tying is so basic to surgery that medical
students learn knot tying early in their studies, and
they routinely practice tying various kinds of knots with
one hand or both hands.
In laparoscopic procedures, the tying of
sutures and other knots is especially difficult and it is
not uncommon for the tying of a ~ingle knot to require an
hour or more. In laparoscopy, there is no tactile sense
to the surgeon because of the surgeon ' s lack of direct
contact with the tissue, since the surgeon ' s sense of
f eel is reduced by the imposition of the laparoscopic
instruments. Further, the surgeon is unable to view
directly the site of the surgery, but instead must rely
upon a two-dimensional video screen which both magnifies
the site and eliminates the opportunity for any depth
perception.
Another difficulty is presented by the fact
that laparoscopic surgery nPcr~g~Arily is conducted in a
confined space, and the instruments are preferably
positioned in this c~lnf; nr~rl space in a particular
orientation in relation to one another and in relation to
the patient. For example, it is desirable that within
this conf ined space, the instruments not be too close
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together or too far apart, that they be visible through
the laparoscope, and that they enter the field of view of
the laparoscope tangentially rather than coaxially so
that they do not obstruct the view too much. It is also
desirable that the instruments advance out of their
sheaths toward the video screen and away f rom the
laparoscope in order to avoid the surgeon having to
operate under "mirror vision". Finally, procedures
employing a single operating port encourage the surgeon
to use the dominant hand to manipulate the instrument in
the port while using the other hand merely to stabilize
the laparoscopic sheath. E~owever, knot tying typically
requires both hands, and so an assistant or a device is
then necessary to stabilize the sheath while both the
surgeon ' s hands tie the knot .
Suturing and other knot tying are applicable to
many different laparoscopic procedures. In laparoscopic
cholecystectomy, the cystic duct or artery can be ligated
using manual suturing or knot tying techniques rather
than an automatic clip. In a laparoscopic ~rr~ndectomy,
the surgeon can u6e slip knots rather than using a
disposable linear stapler. Although laparoscopic
staplers have been developed, laparoscopic sutures and
other knots will still be needed for many purposes such
as closing defects in a staple line, placing purse-string
sutures for end-to-end stapling, closing mesenteric
defects, and ligating large blood vessels.
I;nots used in laparoscopy may be tied either
intracorporeally or extracorporeally. Internal knotting
requires a high level of expertise by the surgeon, and
normally requires at least two operating cannulae and
associated graspers. For a square knot, a loop is made ~:
in a first end of the material using the first grasper;
the second grasper is inserted through the loop and used
to grasp the second end; the second end is pulled through
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the loop to produce ~ flat knot; another loop is made in
the f irst end of the material using the f irst grasper;
the second grasper is inserted through that loop and used
to grasp the second end; and the second end is pulled
through that loop to produce an orros; ng f lat knot . The
resulting square knot can then be tightened with the two
graspers. The first throw may be a simple overhead knot
or may be a surgeon ' s knot . Additional throws may be
applied over the second throw to provide additional
security. It is important that sequential throws are in
opposite directions to avoid producing a "granny" knot.
Many other types of knots are possible
depending on the characteristics of the material used,
the dexterity of the surgeon, and the circumstances at
the suture site. Ma}ly knots in laparoscopy are slip
knots of some kind to allow the knot to be cinched
against the sutured material. These include the Roeder
knot, a clinch knot c~nd so-called "hangman's" knots.
Extracorpo]-eally tied knots are obviously much
easier to tie than illtracorporeally tied knots, but
extracorporeally tied knots can be very difficult to
place effectively. l~ number of devices have been
developed to assist in placing an extracorporeally tied
knot including the "Clarke" ligator, the "Weston" ligator
(see "A New Cinch Kn~t", Obstetrics & Gynecology, Vol.
78, No. 1, July 1991" 144-47) and other devices. See,
e.g. "An Improved Needleholder for Endoscopic Knot
Tying", Fertility an~ Sterility, Vol. 58, No. 3, Sept.
1992, 640-42; "Roeder Knot for Tight Corners in
Conventional 1~h~- in;~l Surgery", J.R. Coll. Surg. Vol.
36, Dec. 1991, 412; "A Simple Method for Ligating with
Straight and Curved l~eedles in Operative Lapa usc~ ~y ",
obstetrics and Gynecology, Vol. 79, No. 1, Jn. 1992, 143-
47. Most of the devices for placing an extracorporeally
tied knot fall into 1:he category of "knot pushers"; A
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knot is formed extracorporeally and is pushed through the
cannula by sliding it down the material using a device
that engages the knot. The Clarke ligator mentioned
above was one of the first knot pushers. It simply
consists of a grasping end and an end opposite the
grasping end with an open ring. It engages the knot by
passing the material through the opening in the ring.
There are also a number of patented knot
pushers, including those described in U. S . Patent Nos .
5,234,445 by Walker, 5,234,444 by Christondias, 5,217,471
by Burkhart, 5,192,287 by Fournier, 5,163,946 by Li,
5,129,912 by Noda, 5,133,723 by Li, 5,084,058 by Li,
3,871,379 by Clarke, and 2,012,776 by Roeder. There are
also a number of patents directed more toward endoscopic
knotters, including U.S. Patent Nos. 5,234,443 by Phan,
5,211,650 by Noda, 4,961,741 by Hayhurst, 4,923,461 by
Caspari, 4,890,614 by Caspari, 4,641,652 by Hatterer, and
4,602,635 by Mulhollan. It is believed that an important
limitation to these devices is that they do not include a
rl i ~rosAhle knot carrier in the manner of the present
invention .
SUMMARY OF THE INVENTIQN
The present invention is a system for placing a
pretied extracorporeal knot, with particular but not
exclusive application to laparoscopy. The knot may be a
slip knot or some other knot, especially a knot that can
be formed by passing the free end through a knot body
which incudes a loop or set of loops.
A device is disclosed which includes a knot
pusher assembly that comprises a pusher tube with an
inner concentric tube. The pusher tube and inner
concentric tube each include a slot, the two slots being
aligned with one another to function as scissors. The
material is cut by sliding it into the two aligned slots
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and rotating the inner tube in relation to the pusher
tube to unalign the slots to divide the material.
A plunger assembly is slidably received by the
inner tube of the kno~ pusher assembly. The plunger
assembly includes a needle clamp at the distal end which
is normally closed bu~ can be opened or "sprung" by
actuating a clamp actuator at the proximal end. Also at
the distal end of the plunger assembly is a carrier
holder which holds a knot carrier. The carrier holder is
preferably a cylindri~cal portion of the plunger assembly
behind the needle clamp, and the knot carrier is
preferably a tubular element that slides and fits snugly
onto the carrier holder. The carrier itself includes a
sheath which fits over and is concentric with the spool.
The outside diameter of the spool is less than the inside
diameter of the sheath, so that an annular space is
def ined between the two . The annular space receives the
tied knot or substantially tied knot.
The outer surf ace of the distal end of the
spool iS flared radially outward, and the inner surface
of the distal end of the sheath is chamfered to receive
the f lare of the spool . The f lared distal end of the
spool is also slotted in the longitudinal direction.
When the carrier is positioned onto the carrier holder,
the carrier holder expands the f lared distal end of the
spool radially outward toward the sheath to firmly hold
in place the tied knot in the annular space between the
spool and the sheath. However, when the carrier is
displaced by sliding it partway of f the carrier holder so
that the carrier holder no longer is inside the flared
distal end of the spool, then the f lared distal end of
the spool relaxes and moves radially inward. This
relieves the binding force on the tied knot in the
annular space between the spool and the sheath, thereby
allowing the knot to come out of the carrier. A tubular
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carrier relea&er extends the length of the plunger
assembly to accomplish this displacement of the carrier
upon actuation by an activator on the plunger assembly
proximal end.
The device is operated by inserting the knot
pusher assembly into a cannula to a desired site, loading
the knot carrier with its pre-tied knot onto the carrier
holder of the plunger assembly, and inserting the plunger
assembly into the knot pusher assembly. Once the desired
suture is made using a needle, or some other knot need is
satisfied, the free end of material is grasped with the
needle clamp. The knot is then released from the carrier
by actuating the carrier relea6er actuator to displace
the carrier distally so that the distal end of the
carrier spool is no longer urged radially outward by the
needle clamp. The plunger a6sembly is then withdrawn
from the knot pusher assembly while the knot pusher
assembly receives the material in the aligned slots of
the pusher tube and inner concentric tube, thereby
tightening the knot. The free end of material can be
divided by rotating the inner concentric tube in relation
to the pusher tube to unalign the slots. The plunger
assembly, with the carrier displaced but still on the
carrier holder, is then withdrawn from the plunger knot
pusher assembly. If desired, another knot or suture can
then be made by removing the spent knot carrier f rom the
carrier holder and reloading a new knot carrier onto the
carrier holder, and then repeating the procedure.
Although the system is described prinri~lly in
the preferred embodiment of laparoscopy applications, it
can be appreciated that the system is also suitable for
many other intracorporeal and extracorporeal
applications .
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BRIEF DESC~IPTION OE` THE DRAWINGS
- FIG. 1 shows a perspective view of an apparatus
in accordance with t he present invention .
FIG. 2 shows a side sectional view of the knot
pusher assembly of the invention.
FIG. 3 shows a detailed-side sectional view of
the distal end of the knot pusher assembly.
FIG. 4 shows a bottom view of the distal end of
the knot pusher ass~mbly.
FIG. 5 shows an end view of the distal end of
the knot pusher assembly prepared for the cutting of
suture material.
FIG. 6 shows an end view of the distal end of
the knot pusher assembly cutting suture material.
FIG. 7 shows a side sectional view of the
proximal end of the plunger assembly of the present
invention .
FIG. 8 shows a side sectional view of the
distal end of the p~ unger assembly .
FIG. 9 shows a side sectional view of the
distal end of the p~,unger assembly with the clamp jaws in
their relaxed open E~osition.
FIG. 10 s~lows a side sectional view of the knot
carrier of the invention.
FIG. 11 s~lows a side sectional view of the
distal end of the invention showing the knot carrier in
the carrying position.
FIG. 12 shows a side sectional view of the
distal end of the invention showing the knot carrier in
the releasing position.
FIGS. 12A--12F show schematically the process of
tying, positioning and trimming a knot in accordance with
the process of the present invention.
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DETAI~ED l)ESCRIPTION OF THE INVENTION
An overall view of a pref erred embodiment of
the invention is shown in FIG. l, including the knot
pusher assembly 20 and the plunger assembly 80. As shown
in FIG. l and also in more detail in the side sectional
views of FIG. 2, the knot pusher assembly 20 includes a
pusher tube 22 and an inner concentric tube 50. At the
proximal end of the knot pusher assembly 20, the pusher
tube i5 attached to a cylindrical handle 24 and the inner
concentric tube 50 is attached to a rotator 52 having a
longitudinal, radially extending wing 54. The proximal
end of the inner concentric tube 50 extends beyond the
proximal end of the pusher tube 22 to allow the
connection between the inner concentric tube 50 and the
rotator 52. The rotator 52 includes a sleeve 56 which
extends f rom the region where the rotator 52 i6 connected
to the inner concentric tube 50, distally over the
proximal end of the pusher tube handle 24. An annular
space is provided between the rotator sleeve 50 and the
inner connector tube 50, which receives a coil spring 60,
one end of which is attached to the inner concentric tube
50 or rotator 52, and the other end of which is attached
to the pusher tube 22 or pusher tube handle 24. The
rotator 52 is capped at the proximal end by a cap 62.
The pusher tube 22 and inner concentric tube 50
are rotatable with respect to one another. This rotation
is accomplished by rotating the rotator 52 in relation to
the handle 24. The rotation biases and is therefore
resisted by the coil spring 60.
The distal end of the knot pusher assembly 20
includes the distal ends of the pusher tube 22 and inner
connector tube 50, which are better shown in the detail
view of FIG. 3-6. FIG. 3 and FIG. 4 are detailed views
showing the distal end of the pusher tu~e 22 and inner
concentric tube 50. As can be seen, the distal end of
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the inner concentric tube 50 is slightly recessed from
the distal end of the pusher tube 22. Moreover, the ends
are specially shaped. The end of the pusher tube 20 has
a bevel 30 on one side and has a indentation 32 on the
opposite side. At thl~ proximal extreme of the
indentation 32 is a pllsher tube slot 34 extending
longitudinally toward the proximal end of the knot pusher
assembly 20. The end of the inner concentric tube 50
includes a bevelled side 66 and a flat portion 68.
Intermediate in the flat portion 68 is an inner
concentric tube slot '70 which extends longitudinally
toward the proximal e1ld of the knot pusher assembly 20.
The inner concentric tube slot 70 aligns with
the pusher tube slot 34 when the inner concentric tube 50
is in its unrotated position in relation to the pusher
tube 22, or in other l,7ords, when the spring 60 in the
proximal end of the k]not pusher assembly 20 ( see FIG . 2 )
is unbiased. As showm in the end view of FIG. 6, when
the inner concentric ~ube 50 ls rotated in relation to
the pusher tube 22 to bias the spring 60, the inner
concentric tube slot 70 becomes unaligned with the pusher
tube slot 34. In the aligned position of FIG. 5, the
aligned slots 34 and 70 can receive a length of material
72. By rotating the inner concentric tube S0 in relation
to the pusher tube 22, they become unaligned to thereby
cut the material 72 as shown in FIG. 6.
The plunger assembly 80 is shown in detail in
FIGs. 7-8. The plung,er assembly 80 includes a plunger
shaft 82 which is a elongated tubular element. The
proximal end of the plunger shaft 82 is attached to a
plunger handle 84. Inside and concentric with the
tubular plunger shaft 82 is a carrier releaser 86 which
is also a tubular elelment. The distal end of the carrier
releaser 86 coincides with the distal end of the plunger
shaft 82. The proximal end of the carrier releaser 86
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extends past the proximal end of the plunger shaft 82 and
into the interior cavity of plunger handle 84 where it
engages the r--hAniFm of a carrier release button 88.
The r~~hzlni sm is any suitable arrangement which drives
the carrier releaser 86 distally upon actuation of the
carrier release button 88. In the ~ nt shown, the
proximal end of the carrier releaser 86 is attached to a
ramp 90 which engages a sloped surface on the carrier
release button 88. Thus by pushing the carrier release
button 88 into the plunger handle 84, the æloped surface
of the carrier release button 88 engages the ramp 90 at
the proximal end of the carrier releaser 86 to drive the
carrier releaser distally relative to the plunger shaft
82 and plunger handle 84. This distal displacement has
the effect of protruding the distal end of the carrier
releaser 86 past the distal end of the plunger shaft 82.
The carrier releaser 86 may be biased toward the proximal
end by a suitable spring (not shown) so that it returns
proximally each time the carrier release button 88 is
released.
Inside and concentric with the carrier release
is a carrier holder 140 which is fixed in relation to the
plunger shaft 82. Inside and concentric with the carrier
holder 140 is a clamp holder 96 which extends from the
distal end to the proximal end where it is attached to a
clamp actuator 98. The clamp actuator 98 is a
cylindrical element received by the plunger assembly
handle 84. The clamp actuator 98 has a central cavity to
contain the inner potion of the carrier release button 88
and the ramp 90 at the proximal end of the carrier
releaser 86. The distal end of the clamp actuator 98
abuts against the end of a coil spring 102 contained
within the plunger assembly handle 84 so that the clamp
actuator 98 and attached clamp holder 96 are biased
proximally.
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The distal end of the clamp holder 96 i5
attached to a spring clamp 110, better shown in FIGs. 8-
9, in which the carrier is omitted for clarity. FIG. 8
shows the æpring clamp 110 in the closed position,
wherein the clamp holder 96 is positioned distally by the
relaxed clamp actuator 98 so that the clamp holder 96 is
retracted partially into the plunger assembly 80. The
proximal retraction of the clamp holder 96 urges the
sloped backs 116 of the clamp jaws 118 against the distal
end of the carrier holder 86. The distal end of the
carrier holder 140 thereby exert an axial force on the
backs 116 of the clam,p jaws 118, to urge the clamp jaws
118 shut. In FIG. 9, the clamp actuator 98 ~see FIG. 7)
has been depressed, to displace the clamp holder 96 and
attached clamp jaws 118 distally. This causes the backs
116 of the clamp jaws 118 to protrude past the distal end
of the carrier holde~ 140, thereby allowing the clamp
jaws 118 to assume their normally open position.
The carrier 120 is shown in detail in FIG. 10.
The carrier 120 includes a spool 122 and a sheath 124
over the spool 122. ~he spool is a tubular element being
f lared at the distal end 125 with a plurality of
longitudinally extending slots 126. The slots 126 allow
for space for the flared distal end to deform radially
lnward to reduce the effective diameter and circumference
of the distal end 125. At the proximal end of the spool
122 is a set of threads 130 on the radially outer
surface. Between the distal end 125 and proximal end is
a radially extending ring 132. A length of material and
a knot, together 142, is rolled onto the spool 122 in the
region between the e~treme digital end 125 and the ring
132 .
The sheath 124 is also a tubular element,
concentric with the ~pool 122. ~t the distal end of the
sheath, the radially inner surface is chamfered in the
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region overlying the flared distal end 125 of the spool.
At the proximal end, the radially inner surface includes
a set of threads 136 that mate with the threads 130 in
the radially outer surface of the spool 122. The spool
122 and the sheath 124 are held together by the
f~n~ nt of these respective threads 130 and 136.
A detail of the carrier 120 positioned on the
plunger assembly 80 is shown in FIG. 11. As can be seen,
the carrier 120 slides over the distal end of the carrier
holder 140. The extreme distal end of the carrier holder
140 is dimensioned such that it exerts a radially outward
force on the flared distal end 125 of the spool 122 of
the carrier holder 120. This radially outward force
deforms the flared distal end 125 of the spool 122
radially outward to bind the material and knot 142 that
is rolled onto the spool 122, between the spool 122 and
the sheath 124.
FIG. 12 shows the carrier 120 being released
from the carrier holder 140. As explained above, the
carrier 120 can be pushed partly of f the carrier holder
84 by actuating the carrier release button 88 (see FIG.
7 ) to protrude the carrier releaser 86 distal end past
the plunger shaft 82 distal end. This causes the flared
distal end 125 of the carrier 120 to extend past the
distal end of the carrier holder 140, thereby allowing
the f lared distal end 125 of the carrier 120 to relax and
contract radially. This relieves the binding force
between the spool 122 and the sheath 124 so that the
material 142 can come out of the carrier 120.
The operation of the device is shown in FIGs.
12A-12F. As shown in FIG. 12A, the knot pusher assembly
20 is inserted into a cannula 21 prior to the plunger
assembly 80 being inserted into the knot pusher. This
ensures the safety and security of the needle and suture
during their insertion. The carrier 120 is then placed
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over the clamp 110 and onto the carrier 140. A needle
150 is previously attached to the suture material 142.
The carrier 120 is then secured in the clamp 110, and the
plunger assembly 80 ~is inserted into the knot pusher
assembly 20.
As shown in FIG. 12B, the needle 150 is taken
from the clamp 110 by another instrument 160 (such as a
needle holder or cla]np) passing through another cannula.
The needle 150 is pa~sed through or around a feature,
such as through tiss~ue or around a vessel 170, and handed
back to the clamp 110. As shown by FIG. 12C, the knot
and material 142 is released from the carrier 120 by
actuating the carrier release 86 to protrude the carrier
120 past the distal end of the carrier holder 140 so that
the flared distal en~ 125 of the carrier spool 122
relaxes radially inward to relieve the binding on the
knot and material 142 (see FIG. 12). This releasing of
the knot and material provides the necessary slack in the
material to accomplish the suturing or tying. The
releasing of the kno~ allows the knot to lightly cinch
down on the lead end of the material which is now grasped
by the clamp 110.
As shown i]ll FIG. 12D, pulling on the plunger
assembly within the ]~not pusher assembly 20 while pushing
on the knot pusher assembly 20 retracts and tensions the
leads of the material 140 which allows the knot pusher
assembly 20 to engage the leads. Specifically, the leads
pass into the aligned pusher tube slot 34 and inner
concentric tube slot 70 (see FIG. 4). Continued pulling
- 30 on the plunger asseml~ly 80 while pushing on the knot
pusher assembly 20 tightens and drives the knot 142 into
position against the vessel 170 to tightly tie the vessel
170 .
The leads of material 140 may then be cut,
either immediately adjacent to the knot or away from the
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knot to leave longer loose ends as desired. ~he cutting
is accomplished by positioning the knot pusher assembly
20 at the cutting 6ite, still with the material in the
aligned pusher tube slot 34 and inner concentric tube
S slot 70 (see FIG. 4 again). The inner concentric tube 50
is then rotated in relation to the pusher tube 22 ~ see
FIG . 6 ) by rotating the rotator 52 while grasping the
handle 24 ~see FIG. 2) to unalign the pusher tube slot 34
and the inner concentric tube slot 70. This leaves a
tied knot on a vessel 170 as shown in FIG. 12E`.
The plunger assembly 80 is then withdrawn from
the knot pusher assembly 20, and the carrier 120 and
material leads including the needle are discarded. The
instrument is then ready to be reloaded with a new
lS carrier 120 and needle for tying the next knot or suture.
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