Note: Descriptions are shown in the official language in which they were submitted.
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BODY PASSAGE CLEANSING DEVICE
Field of the Invention
The present invention relates to a device for cleaning the
lumen of the colon or other body cavity via the working
channel of an endoscope. More specifically, said device is
constructed such that it permits. both optimal irrigation of
the body passage and large-volume aspiration of the irrigation
fluid and debris.
Background of the Invention
During endoscopic procedures the physician inserts a flexible
endoscope manually and navigates the device by visualizing the
internal path using the integrated camera. In Colonoscopy,
despite the use of various pre-colonoscopy cleansing regimes,
in many cases the operator's field of view is severely
restricted by fecal debris and other particulate matter that
is left behind in the colonic lumen or other body passage.
Various attempts have been made to provide procedures and
means for washing the colonic lumen prior to performing a
colonoscopic investigation. The diagnostic accuracy and the
therapeutic safety of colonoscopy (as well as of other
diagnostic/therapeutic procedures such as virtual colonoscopy,
sigmoidoscopy, barium enemas and pill camera) depend, to a
large extent, on the quality of the colonic cleansing or
preparation. The ideal preparation for colonoscopy would be
one that is acceptable to the patient, cleans the bowel and
reliably empties the colon of all fecal material in a rapid
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fashion without causing damage to the colonic tissues. An
ideal preparation would also minimize or eliminate any patient
discomfort. Common preparations for cleansing include diet in
combination with a cathartic agent, polyethylene glycol
preparations, gut lavage and phosphate preparations (oral
sodium phosphate and tablet form of sodium phosphate). The use
of each of these techniques, however, has significant
limitations.
Various attempts have been made to provide procedures and
means for washing the colonic lumen during the endoscopic
procedure by means of flushing water through the working
channel onto the gastro-intestinal (GI) tract walls to spray
the mucosa and cleanse it of areas of bleeding, fecal remains
etc., and aspirating the liquids and remains through the
working channel. In certain endoscopes there exists a separate
small channel (e.g. 0.8mm diameter) for irrigation, in
addition to the aspiration channel. It has been found that
flushing liquids through the working channel and/or the
abovementioned smaller channel is not effective. Thus, when
the working channel is used for this purpose, the fluids do
not have sufficient force momentum to wash the debris and is
only effective for cleansing minor areas of bleeding and for
very soft feces. In the case of the small channel, it is
possible to achieve higher liquid momentum that could, in
principle, be used to cleanse fecal material, but such a
procedure is not effective since it has only one point focus
and would require the endoscope head to be moved in order to
cleanse a larger area.
In prior art methods, aspiration has been achieved using
vacuum pressure through the endoscope working channel. While
this is relatively effective when aspirating liquid remains
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and/or extremely soft solid fecal material, it is less so when
dealing with thicker and harder fecal material. It has
previously been suggested that endoscopes with a larger
channel (up to 6 mm) may be used, but this solution is limited
since the main limitation of the aspiration, in addition to
the limited aspiration channels, is the vacuum pressure force
that is limited to 1 atm.
In principle, it should be possible to use the endoscope
working channel both for insertion of endoscopic accessories
such as: biopsy forceps, polypectomy snares, injection needle,
spray catheters etc and for insufflation and suction of air
that assist the insertion of the endoscope. It is further used
for passage of cleansing fluid to the region of the colon
immediately distal to the distal end of the endoscope and for
the aspiration and removal of said fluid together with fecal
debris. However, when using the working channel of the
endoscope the irrigation has no momentum since only minimal
resistive pressure exists and the irrigation fluid introduced
has very low efficacy. One way to overcome this problem would
be to use a catheter that is introduced to the working channel
with a build in nozzle on the distal end of the catheter to
enable efficient cleansing. However, a major drawback of such
an approach is the fact that the presence of an irrigation
catheter in the working channel would restrict the available
volume that may be used for aspiration. Furthermore, the
restriction in working channel volume would also prevent said
volume being used for the passage of endoscopic tools or for
insufflation and/or aspiration of air and aspiration of
debris.
It is therefore a primary aim of the present invention to
provide a device that permits effective and higher-pressure
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irrigation of a body cavity via an endoscopic working channel
while still allowing for the use of the same working channel
for other purposes, most particularly the aspiration of fluid
and debris from said body cavity.
A further aim of the present invention is to provide a device
that will permit irrigation and cleansing of the working
channel of an endoscopic instrument without the removal of
said instrument from the body, such that blockages of said
channel by fecal material and debris may be prevented or
removed.
A further aim of the present invention is to provide a device
that. will permit irrigation, cleansing and aspiration for
additional applications such as: upper and lower GI bleeding,
bronchoscopy, cystoscopy, gastrostomy trauma surgery where no
preparation was available and endo-surgery preparation. It is
a primary objective to irrigate and aspirate blood and clots
as well as feces and remains in an effective way without
blockage of the aspiration channel by clots and/or feces.
A further aim of the invention is to permit the upgrading of
all endoscopic devices by integrating them together with a
nozzle assembly, thereby not requiring the replacement of
tools (for example biopsy forceps, snares, injection needles,
and so on) during the procedure.
Further aims and objectives will be discussed as the
description proceeds.
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Summary of the Invention
The present inventors have unexpectedly found that it is
possible to utilize a single working channel of an endoscope
(or internal lumen of another elongate medical instrument such
as a catheter or cannula) for both passing irrigation fluid
distally and aspirating fluid and solid debris proximally,
wherein both of these processes may be performed in a highly
effective manner as part of a procedure for cleansing internal
body passages and cavities.
The present invention is primarily directed to a body passage
cleansing device suitable for passage through an endoscopic
channel, comprising a distal plug having a proximal end and a
distal end, wherein said plug comprises channels, apertures
and/or nozzles which are capable of allowing the passage of a
fluid therethrough from said proximal end to said distal end,
wherein said plug is connected to the distal end of a
wire;
wherein at least an outer portion of said distal plug is
capable of being elastically deformed such that the external
diameter thereof may be reduced in response to inwardly-
directed radial compression forces exerted thereon;
and wherein said channels, apertures and/or nozzles are
in a closed conformation when said distal plug is subject to
said compression forces, and in an open conformation when said
plug is not subject to said compression forces.
It should be noted that for the purpose of the present
disclosure the term "distal spray head unit" and the like are
sometimes used interchangeably with the term "distal plug".
It should further be noted that the term `distal' refers to
the direction away from the operator and towards the center of
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the patient's body. Consequently, the term `proximal' is taken
to refer to the opposite direction.
In one preferred embodiment of the invention, the external
diameter of the distal plug when not subjected to inwardly-
directed radial compression forces is slightly larger than the
internal diameter of an endoscope working channel. In many
cases, the internal diameter of the working channel in a
colonoscope is 3.8 mm, and generally in the range of 2 - 4mm.
In one particularly preferred embodiment of the device, the
outer, elastically deformable portion of the distal plug is an
O-ring.
In a particularly preferred embodiment of the aforementioned
device, said device further comprises a partial length tube
surrounding the wire in a coaxial manner,
wherein said tube extends from the proximal end of said
wire;
and wherein the length of said tube is less than the
length of said wire, such that a portion of the distal region
of said wire is left unenclosed by said tube.
In another particularly preferred embodiment, the device
further comprises a proximal control handle,
wherein the proximal end of the tube is connected to said
handle;
wherein the proximal end of the wire is movably connected
to said handle;
wherein said handle comprises means for changing the
distance between said handle and the distal end of said wire;
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wherein said handle comprises one or more passages for
connecting a fluid-supply channel to one of two or more fluid
outlet channels;
and wherein said handle comprises means for switching
between the fluid outlet channels to which said fluid-supply
channel is connected.
Preferably, the proximal handle disclosed immediately
hereinabove comprises one fluid outlet channel in fluid
communication with the lumen of the partial length tube, and a
second fluid outlet channel in fluid communication with the
space surrounding the external surface of said tube. When
inserted into the working channel of an endoscope, this latter
space will be bounded externally by the walls of said channel.
Preferably, the means for changing the distance between the
handle and the distal end of the wire comprises a slider
mounted on said handle.
In another aspect, the present invention provides a body
passage cleansing device suitable for passage through an
endoscopic channel, comprising a distal head spray unit fitted
with channels, apertures and/or nozzles formed therewithin,
wherein said distal head spray unit is connected to the
distal end of a collapsible catheter and to the distal end of
an associated stiffening wire;
wherein said collapsible catheter is capable of adopting
an expanded conformation when a fluid stream is passed through
it and of adopting a collapsed conformation in the absence of
the passage of a fluid stream therethrough.
In one preferred embodiment of this aspect of the invention,
the collapsible catheter is a single lumen catheter. In
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another preferred embodiment, said catheter is a bilumen or
multilumen catheter.
In a further aspect, the present invention also provides a
system for cleansing body passages comprising:
a) a device according to any one of the embodiments disclosed
hereinabove and described in detail hereinbelow;
b) an aspiration pump;
c) an irrigation pump;
d) relays, transformers and computer equipment for controlling
the functioning of said device and pumps.
The present invention further provides a method for cleansing
a body passage comprising:
a) inserting an elongate medical device into said body passage
such that the distal end thereof becomes located close to, and
on the proximal side of, the area of said passage to be
cleansed;
b) passing a distal plug fitted with channels, apertures
and/or nozzles formed therewithin through an internal channel
of said elongate medical device such that said plug becomes
located beyond the distal exit of said internal channel and in
contact with the distal face of said medical device;
c) introducing irrigation fluid into said internal channel at
a pressure that is sufficient to cause said fluid to form a
spray or jet upon passing through the channels, apertures
and/or nozzles formed in said distal plug;
d) allowing said spray or jet to cleanse the region of the
body passage that is situated immediately distal to the end of
said channel;
e) causing said distal plug to move distally such that there
is no contact between said plug and the distal face of said
elongate medical instrument within the body passage;
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f) applying a negative pressure to the proximal end of the
internal channel of the elongate medical instrument, in order
to cause aspiration of fluid and solid particulate matter
through said internal channel;
g) if necessary, bringing said distal plug back to the
location defined in step (b) and repeating steps (c) to (f).
In a particularly preferred embodiment of this method, the
elongate medical instrument is an endoscope and the internal
channel is a working channel contained therein. In one
especially preferred embodiment, the endoscope is a
colonoscope and the body passage to be cleansed is a portion
of the large intestine.
In one preferred embodiment of this method, the aforementioned
distal plug is attached to a guidewire.
In a particularly preferred embodiment of this method, the
guidewire is surrounded (in a coaxial fashion) by a partial
length tube that extends distally from the proximal end of
said guidewire, wherein the length of said tube is less than
the length of said wire, such that a portion of the distal
region of said wire is left unenclosed by said tube. In a
particularly preferred embodiment of this version of the
method, said method further comprises the steps of:
i) withdrawing the distal plug into the distal end of the
internal channel such that said plug is radially compressed,
thereby causing its external diameter to be reduced, thereby
sealing the distal end of said internal channel;
ii) introducing irrigation fluid into the lumen of the partial
length tube such that when said fluid leaves the distal end of
said tube, the positive fluid pressure provided thereby
assists in preventing or removing blockages in the distal
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portion of the internal channel of the elongate medical
device.
The present invention further provides a method for cleansing
a body passage comprising:
a) inserting an elongate medical device into said body passage
such that the distal end thereof becomes located close to, and
on the proximal side of, the area of said passage to be
cleansed;
b) passing a device comprising a distal head spray unit fitted
with channels, apertures and/or nozzles formed therewithin
through an internal channel of said elongate medical device,
wherein said distal head spray unit is connected to the distal
end of a collapsible catheter and to the distal end of an
associated stiffening wire, such that said distal spray head
unit becomes located beyond the distal exit of said internal
channel;
c) introducing irrigation fluid into the lumen of said
collapsible catheter at a pressure that is sufficient to cause
said fluid to form a spray or jet upon passing through the
channels, apertures and/or nozzles formed in said distal spray
head unit;
d) allowing said spray or jet to cleanse the region of the
body passage in which said distal spray head unit is located;
e) closing the supply of irrigation fluid to the lumen of said
collapsible catheter, and optionally applying a negative
pressure to the proximal opening of said lumen, such that the
walls of said catheter collapse thereby decreasing the volume
of the internal channel occupied by said catheter;
f) applying a negative pressure to the proximal end of the
internal channel of the elongate medical instrument, in order
to cause aspiration of fluid and solid particulate matter
through said internal channel;
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g) if necessary, repeating steps (c) to (f).
Other advantages and features of the invention will become
apparent as the description proceeds'
Brief Description of the Drawings
The present invention is illustrated by way of example in the
accompanying drawings, in which similar references
consistently indicate similar elements and in which:
- Fig. 1 schematically illustrates one preferred embodiment
of a single lumen collapsible catheter of the invention;
- Fig. 2 schematically illustrates an embodiment of the
single lumen collapsible catheter shown in Fig. 1, having
a control wire and flexible tie wrap rings;
- Fig. 3 schematically illustrates the catheter shown in
Fig. 2 when introduced via a working channel of an
endoscope;
- Figs. 4A and 4B respectfully illustrate an irrigation
tube and a colonoscope of the prior art;
- Figs. 5A and 5B schematically illustrate cross-sectional
views of an embodiment of the collapsible tube of the
invention having an externally attached stiffening wire,
where in Fig. 5A the tube is in an expanded state and in
Fig. 5B it is in a collapsed state;
- Fig. 6A and 6B schematically illustrate cross-sectional
views of an embodiment of the collapsible tube of the
invention having an internally attached stiffening wire,
where in Fig. 6A the tube is in a collapsed state and in
Fig. 6B it is in an expanded state;
- Figs. 7A and 7B schematically illustrate cross-sectional
views of a multi-lumen catheter having a collapsible
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internal wall, where in Fig. 7A the internal wall in a
collapsed state and in Fig. 7B it is in an expanded
state;
- Fig. 8 schematically illustrates a perspective view of a
bilumen embodiment with a partly-collapsed state internal
wall;
- Fig. 9 schematically illustrates a perspective view of a
bilumen embodiment with a partly-collapsed state internal
wall, wherein said wall is perforated by a series of
apertures;
- Figs. 10A and 10B schematically illustrate an irrigation
catheter of the invention in which a balloon is employed
for controlling irrigation modes, where in Fig. 10A the
balloon is in a deflated state and in Fig. l0B it is in
an inflated state;
- Figs. 11A to 11C schematically illustrate a distal spray
head embodiment of the invention employing slideable
overtube for controlling the jet spray in a proximal-most
position state in Fig. 11A, in a partially cover state in
Fig. 11B, and in a distal-most position in Fig. 11C;
- Figs. 12A to 12C schematically illustrate a distal spray
head embodiment employing a rotatable overtube for
controlling the jet spray in a misaligned state in Fig.
12A, in a partially overlapping state in Fig. 12B, and in
a precise alignment state in Fig. 12C;
- Fig. 13 schematically illustrates a distal spray head
embodiment of the invention utilizing dismantle springs;
- Figs. 14A to 14D schematically illustrate a distal spray
head embodiment configured to direct the flow of
irrigation fluid in a convergent direction, wherein Fig.
14A shows a perspective view of the distal spray head,
and Figs. 14B to 14D show sectional views illustrating
the flow passing thereinside;
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- Fig. 15 shows a sectional view of a distal spray head
embodiment of the invention configured to direct the flow
of irrigation fluid in a convergent direction by means of
a pre-set internal nozzle angle;
- Figs. 16A to 16D schematically illustrate a distal spray
head embodiment of the invention configured to provide a
divergent flow, wherein Fig. 16A shows a perspective view
of the distal spray head, and Figs. 16B to 16D show
sectional views illustrating the flow passing
thereinside;
- Fig. 17 schematically illustrate a distal spray head
embodiment of the invention configured to provide a
divergent flow by means of a pre-set internal nozzle
angle;
- Fig. 18 shows a perspective view of one preferred
embodiment of a distal spray head of the invention;
- Figs. 19A and 19B schematically illustrate an embodiment
of the cleansing catheter of the invention comprising a
filter, wherein Fig. 19A shows the filter assembled on
the distal part of catheter tube and Fig. 19B shows the
catheter and filter when introduced via a colonoscope;
- Figs. 20A and 20B show perspective views of one preferred
embodiment of the distal head unit of the invention in a
"closed" conformation, wherein Fig. 20A shows a
perspective front view and Fig. 20B shows a perspective
back view;
- Figs. 21A and 21B show perspective views of the distal
head unit shown in Figs. 20A and 20B in a conical/frusto-
conical conformation, wherein Fig. 21B shows, a
perspective front view and Fig. 21A shows a perspective
back view;
- Figs. 22A and 22B shows perspective views of the distal
head unit shown in Figs. 20A and 20B in a second frusto-
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conical conformation, wherein Fig. 22A shows a
perspective front view and Fig. 22B shows a perspective
back view;
- Figs. 23A and 23B respectively show perspective and front
views of the spray head unit shown in Figs. 20 to 22 in
the irrigation mode when placed over the exit opening of
the working channel;
- Figs. 24A to 24F show side and sectional views of one
preferred embodiment of the spray head unit constructed
from a flexible plug placed over an inner rigid element,
wherein Fig. 24A shows a side view of the spray head
unit, Fig. 24B shows a sectional view of the spray head
unit, Fig, 24C shows a sectional view of the spray head
unit when advanced inside the working channel, Figs. 24D
and 24E respectively show sectional and top views of the
spray head unit in the irrigation mode wherein it is
placed over the exit opening of the working channel, and
Fig. 24F shows a sectional view of the spray head unit
when it is retracted back into, and sealably lock the
passage through, the working channel;
- Figs. 25A to 25C illustrate an exemplary mechanism which
may be used with the device of the invention for removal
of solid debris;
- Fig. 26 schematically illustrates a possible aspiration
method with the device of the invention;
- Figs. 27A to 27D schematically illustrate a preferred
embodiment of the invention wherein the spray head unit
is provided in the form of a small balloon, wherein Fig.
27A shows a front view of the balloon in a deflated
state, Fig. 27B shows the balloon in an inflated state,
Fig. 27C shows the balloon in an inflated state inside
the working channel, and Fig. 27D shows the balloon in a
deflated state inside the working channel;
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- Figs. 28A to 28E schematically illustrate an embodiment
of the spray head unit provided in the form of a flexible
mushroom-shaped valve, wherein Fig. 28A shows flexible
mushroom-shaped valve in a reduced state, Fig. 28B shows
flexible mushroom-shaped valve in an expanded state,
Figs. 28C and 28D show possible nozzle implementations in
the flexible mushroom-shaped valve, and Fig. 28E show the
flexible mushroom-shaped valve when expanded by a flow of
irrigation fluid;
- Figs. 29A to 29E schematically illustrate distal spray
head units of the invention comprising biopsy forceps;
- Figs. 30A and 30B schematically illustrate a possible
embodiment wherein deflectors are mounted on the
wire/tube of the catheter device, wherein Fig. 30A
further illustrates an embodiment wherein a hollow wire
or tube is used which further include washing apertures;
- Fig. 31 schematically illustrate a cleansing device of
the invention when introduced via a working channel of an
endoscope/colonoscope;
- Figs. 32A to 32C depicts perspective views of three
different states of a particularly preferred embodiment
of the cleansing device in the working channel of the
endoscope/colonoscope, where in Fig. 32A the rear portion
of the distal spray unit is positioned in the distal end
opening of the working channel, in Fig. 32B the distal
spray unit is positioned entirely outside of the working
channel, and in Fig. 32C a significant portion of the
distal spray unit is sealably positioned inside working
channel;
Figs. 33A to 33C show further views of the spray head
unit shown in Figs. 24 in the irrigation and aspiration
modes, wherein Figs. 33A and 33B respectively show front
and perspective views of the spray head unit in the
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irrigation mode, wherein it is placed over exit opening
of the working channel, and Fig. 33C shows a perspective
view showing the state of spray head unit in the
aspiration mode, wherein it is advanced further distally
away from the exit opening of working channel;
Figs. 34A to 34E shows a preferred embodiment of the
invention wherein the catheter device comprises nozzle
and sealing balloons, wherein Fig. 34A shows the catheter
device inside working channel when both balloons are in a
deflated state, Figs. 34B and 34C show the catheter
device inside working channel in the irrigation mode
wherein nozzle balloon is in an inflated state and
sealing balloon is in a deflated state, Fig. 34D shows
the catheter device inside working channel in an
aspiration mode wherein both balloons are in a deflated
state, and Fig. 34E shows the catheter device inside
working channel in a clearing mode wherein the nozzle
balloon is in a deflated state and the sealing balloon is
in an inflated state;
Fig. 35 is a block diagram exemplifying one possible type
of aspiration system of the invention;
Figs. 36A to 36D schematically illustrate changing
operation modes of the device of the invention by means
of a proximal control handle, wherein Fig. 36A illustrate
setting the device into the irrigation mode by means of
handle component, Fig. 36B illustrate setting the device
into the aspiration mode by means of handle component,
Fig. 36C illustrate setting the device into the clearing
mode by means of handle component, and Fig. 36D
schematically illustrates a proximal control handle
further comprising a trigger for seting the device into
the clearing operation mode;
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- Figs. 37A to 37C schematically illustrates an embodiment
of the distal spray head of the invention which enables
to control the angle of the sprayed jets, wherein Fig.
37A demonstrates adjusting the distal spray head to
provide a wide-angle forward spray, Fig. 37B demonstrates
adjusting the distal spray head to provide a narrow-angle
forward spray, Fig. 37C demonstrates adjusting the distal
spray head to provide a lateral spray;
- Figs. 38A to 38C schematically illustrate an embodiment
of the catheter device of the invention wherein sealing
of the distal end of the endoscope working channel is
accomplished by means of a balloon mechanism, wherein
Fig. 38A shows the device with the balloon in a deflated
state, and Figs. 38B and 38C show the device with the
balloon in an inflated state;
- Fig. 39 is a block diagram illustrating a possible
implementation of a console for operation of the
cleansing device of the invention; and
- Figs. 40A and 40B schematically illustrate a preferred
embodiment of a proximal control handle, wherein Fig. 40A
shows the state of proximal control handle in the
irrigation mode of operation and Fig. 40B show the state
of proximal control handle in the working channel
clearing mode of operation.
It should be noted that the embodiments exemplified in the
Figs. are not intended to be to scale and are in diagrammatic
form to facilitate ease of understanding and description.
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Detailed Description of Preferred Embodiments
The present invention provides two general solutions to the
abovementioned technical problem that is encountered when
using the endoscope working channel for both irrigation of a
body passage (such as the colon) and for large-volume
aspiration of the irrigation fluid (together with displaced
solid and semi-solid debris). In the first of these two
approaches, the device of the present invention incorporates a
collapsible catheter which provides both a large volume
irrigation lumen (when in its non-collapsed state) and a large
volume aspiration lumen (i.e. the working channel volume) when
said catheter is in its collapsed state.
In the second approach, the device comprises a novel distal
plug/spray head mounted on the distal end of a guidewire. In
one highly preferred embodiment of this approach, as will be
described hereinafter, the device of the present invention
further comprises a partial length non-collapsible catheter or
sheath extending from the proximal end of the guidewire and
ending a few centimeters short of the distal end of said
guidewire. This partial length tube, in most cases, is non-
collapsible, but in some embodiments may be provided in the
form of a collapsible catheter. As will be explained further,
this unique structure combines optimum irrigation and
aspiration of the body cavity being treated or cleansed with
the ability to prevent and free blockages of the endoscopic
working channel which would otherwise occur during the
cleansing process.
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COLLAPSIBLE CATHETER APPROACH:
Two main embodiments of the collapsible catheter device will
now be described: a single lumen catheter and a multi-lumen
catheter.
First main embodiment: single lumen collapsible catheter
The first embodiment comprises a device that is introduced
through the working channel of an endoscope to cleanse the
colon. As shown in Fig. 1, the cleansing (or irrigation)
catheter 1 comprises a collapsible sheath lc and a metal (e.g.
stainless steel or aluminum) stiffening wire lb. The distal
end of the sheath is in fluid connection with a jet spray head
la that is fitted with nozzles id which are capable of
directing the irrigation fluid spray, as will be described in
more detail hereinbelow. The purpose of the distal end of the
stiffening wire lb, which is connected to the spray head la,
is to permit insertion and advancement of catheter 1, even
when the sheath is in its flaccid, collapsed state. In order
to assist the operator in guiding the device of the invention,
the stiffening wire lb may contain one or more radiopaque
materials at various points along its length (not shown).
These radiopaque markers may be used to locate the device by
means of real, time visualization using X-ray imaging. The use
of such markers is particularly important in upper GI
endoscopic procedures, for example when introducing endoscopic
tooling trough the papilla.
The proximal end of the catheter is connected to a source of
irrigation fluid (e.g. saline) and suitable pumping apparatus
shown in Fig.39. When said irrigation fluid is pumped through
catheter 10, the collapsible sheath adopts its fully expanded
conformation, thereby allowing maximum transfer of the
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irrigation fluid to the jet spray head la. When the irrigation
fluid ceases to flow through the catheter (e.g. as a result of
both turning off the irrigation fluid pump and connecting the
proximal end of the sheath to a negative pressure source), the
collapsible sheath loses its source of structural rigidity
(the column of irrigation fluid) and returns to its flaccid,
collapsed state, thereby increasing the volume of the working
channel that is external to the irrigation catheter. This is
highly advantageous, for at least the following three reasons:
a) maximum space for aspiration of irrigation fluid and
fecal debris through the working channel is provided;
b) additional space for the introduction and passage of
endoscopic surgical tools (without the need to remove
the irrigation catheter) is created; and
c) insufflation of the body cavity (e.g. colon) may be
performed in the presence of the collapsed catheter.
In the absence of the collapsible sheath of the present
invention, it would be necessary to entirely remove the
irrigation catheter from the working channel prior to applying
suction thereto or inserting endoscopic tools therein. Thus,
the collapsible catheter of the present invention has the
distinct advantage of obviating the tedious and labor-
intensive need for removing and re-inserting said catheter
several times during the cleansing procedure.
As shown in Fig. 2, this embodiment of the device of the
invention may also further comprise a control wire le for
directing the distal jet spray head la during irrigation and
aspiration, when said head is caused to leave the distal exit
of the working channel. The distal end of control wire le is
connected to the jet spray head la, while the proximal end
remains outside of the patient's body (optionally terminating
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in a control handle, as is commonly used in endoscopic
procedures).
While the stiffening wire lb may be unconnected to the
collapsible sheath 1c, in one preferred embodiment of the
invention, said wire and said sheath may be mutually connected
by means of plurality of flexible tie wrap rings If, as shown
in Fig. 2 or be inserted inside the collapsible tube.
With reference to Fig. 3, as explained hereinabove, irrigation
catheter 1 is inserted into the proximal end of a working
channel 3c of an endoscope 3e and advanced distally until the
distal end of said catheter leaves the working channel and
enters the colonic lumen.
Fig. 4A is a cross-sectional view of a simple irrigation tube
4b of the prior art, having a lumen 4c which diameter is
approximately 1-3mm, passing through a 3.8mm diameter working
channel 4d of a conventional colonoscope 4a shown is Fig. 4B.
It will be seen that this non-collapsible catheter occupies a
significant fraction of the available cross-sectional area
(and hence volume) of the working channel 4b.
Figs. 5A and 5B are cross-sectional views of an embodiment of
the present invention showing collapsible tube 5d in its
expanded form in Fig. 5A, and in Fig. 5B, in its collapsed
state (5d'), connected to a relatively small diameter (e.g.,
-0.25-0.6mm) rigid metal wire 5e passing through a working
channel 5b. Fig. 5A depicts catheter 5 in its expanded state,
i.e. when irrigation fluid is pumped through the sheath, in
order to cleanse the body cavity (e.g. colon). When negative
pressure is applied to the proximal end of the sheath, it
collapse and shrinks (5d'), as shown in Fig. 5B. For optimal
collapsing a one way valve may be used.
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In order to pump irrigation fluid into the sheath, the device
may be connected to a positive pressure liquid pump
(centrifugal, peristaltic or other) or to a manual injector.
To cause collapse of the sheath, it can be connected to a
manual injector or through a negative pressure vacuum pump.
An additional advantage of the present invention is that it
permits the use of larger diameter irrigation catheters,
thereby reducing the tubing resistance, thus enabling the use
of an irrigation pump that generates a lower pressure, while
maintaining the same water jet force.
Figs 6A and 6B illustrate an alternative configuration,
wherein the metal stiffening wire 6e (e.g., having a diameter
of about 0.25mm-0.6mm) is located inside the collapsible
sheath 6d (shown in Fig. 6A in a collapsed state - 6d'), which
in turn passes' through working channel 6b. When irrigation
fluid is pumped through the sheath under positive pressure,
said fluid is directed to the body cavity that is being
cleansed (e.g.' the colon). Conversely, when a negative
pressure source is connected to the proximal end of the
device, the sheath collapses (6d' in Fig. 6A), thereby
creating a larger free volume within the working channel 6b.
In order to create optimal sheath collapse, a one way valve
may be used.
The collapsible irrigation catheter 6 may be constructed from
a non-compliant material such as nylon, Pebax (or a blend
thereof), polyurethane and polyethylene terephthalate (PET)
In such a case, the empty (i.e. evacuated) sheath has a random
flat shape (6d'), which becomes circular (6d in Fig. 6B) in
cross section when expanded with irrigation fluid. In another
embodiment, the collapsible irrigation catheter may be made
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from a compliant material such as silicone or a thermoplastic
elastomer (TPE), wherein said catheter is able to expands in
the same manner as a compliant balloon
Second main embodiment: multi-lumen collapsible catheter
The second embodiment similarly comprises a device suitable
for passage through the working channel of an endoscope.
However, in contradistinction to the first embodiment,
described hereinabove, the device of this embodiment comprises
a multi-lumen catheter tube, in which at least one wall of at
least one of the lumens is collapsible. The multi-lumen tube
is in fluid connection, via at least one of its lumens to a
jet spray head located at the distal end of said tube. In one
preferred embodiment, the multi-lumen tube is a bilumen tube,
wherein one lumen is suitable for passing the irrigation
liquid forward (i.e. in a distal direction) to the
aforementioned jet spray head, while the second lumen may be
used as a "virtual working channel", which may be used for a
number of purposes, including aspiration and removal of fecal
debris and the passage of endoscopic tools (such as: forceps,
baskets, polypectomy devices, and so on).
Figs. 7A and 7B depict an exemplary preferred embodiment of a
bilumen catheter tube 7 of the present invention. These figs.
provide cross-sectional views of bilumen catheter 7 situated
within the lumen of the working channel of a colonoscope 7d,
wherein an internal wall 7s separates a larger "virtual
working channel" (or aspiration lumen) lumen 7a, from a
smaller irrigation lumen 7b. In Fig. 7B, the irrigation lumen
7b is shown in its expanded state, that is, while it is filled
with irrigation fluid (such as saline). In Fig. 7A, the
irrigation lumen is shown in its collapsed state (7b') after
the irrigation fluid has been removed from said lumen, by
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means of a negative pressure source which has been connected
to its proximal end. It may be seen from Fig. 7A that when the
irrigation lumen 7b' is in its collapsed state, internal wall
is shrunk (7s') and the larger aspiration (or "virtual working
channel") lumen 7a' has a significantly larger volume, thereby
permitting said lumen to fulfill its intended functions
(aspiration and/or passage of surgical tools) with greater
efficiency.
In one preferred embodiment, the collapsible wall(s) of the
multi-lumen conduit may be constructed of a flexible, non-
compliant material (e.g. Nylon or Pebax) . Alternatively, said
collapsible wall(s) may be made of a compliant material such
as silicone rubber.
A perspective view of the bilumen embodiment 8, with the
irrigation. lumen internal wall 8s in a partly-collapsed state,
is shown in Fig. 8.
An alternative embodiment of a bilumen catheter 9 of the
present invention, in which the internal wall 9s of the
irrigation lumen (also referred to as the bilumen partition)
is perforated by a series of-apertures 9p, is depicted in Fig.
9. Apertures 9p permit the passage of a portion of the
irrigation fluid from the smaller, irrigation lumen 9b into
the larger aspiration lumen 9a. The irrigation fluid which
streams through apertures 9p will assist in the breakdown of
fecal material which has been aspirated into aspiration lumen
9a. This further breakdown of particulate matter will inter
alia assist in preventing blockages of aspiration lumen 9a and
the negative pressure line and apparatus connected at the
proximal end thereof.
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The multi-lumen catheter tubes of the present invention may be
produced by means of incorporating internal partitions within
a single tube, or alternatively, by connecting two or more
single lumen tubes in a side-by-side manner.
Control of distal jet spray
In addition to providing externally-collapsible conduits
(first main embodiment) or internally-collapsible conduits
(second main embodiment), for the purpose of allowing
expansion of the aspiration (or virtual working channel)
lumen, the present invention also provides various novel
solutions for the control of the irrigation jet spray through
the distal spray head and the portion of the catheter that is
located immediately proximal to said distal. spray head.
Fig. 10A schematically depicts the distal spray head region of
one preferred embodiment of the invention. Whilst generally
similar to the first main embodiment of the invention
described hereinabove (and illustrated in Fig. 1-6), the
presently-described embodiment also comprises a number of
additional features. Thus, referring to Fig. 10A, the distal
spray head gl may be seen comprising a plurality of spray
nozzles g3 in its distal part. The rigid wire g6 differs from
that described hereinabove, in that in the presently-described
embodiment, wire g6 has an internal lumen which is in fluid
contact at its distal extremity with a balloon g2, and is in
fluid contact at its proximal extremity with a source of
inflation fluid and a pumping apparatus (not shown). Adjoining
the distal head on its proximal side is a sleeve g7 fitted
with a series of lateral apertures g4. The collapsible
catheter sheath g10 is affixed to sleeve g7 with a
biocompatible glue (e.g. UV glue) and further mechanically
affixed with a pressure ring (g5). Thus, when it is desired
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to direct the jet spray in a forward (distal) direction, the
balloon g2 is left in its non-inflated state, thereby
permitting free flow of irrigation fluid through both the
distal spray nozzles g3 and the lateral apertures g4, as shown
in Fig. 10A.
However, when the operator desires the jet spray to exit via
the lateral apertures g4 only, the balloon g2 is inflated such
that it blocks the distal jet apertures g3, as shown in Fig.
10B. The operator may choose to pump irrigation fluid distally
through the catheter for a prolonged period with occasional
inflation or deflation of balloon g2, in order to direct the
fluid as required. Alternatively, during the irrigation the
balloon may be inflated/deflated at a high frequency (for
example -10-20 Hz) thereby enabling the irrigation fluid to
apply a vibration force, thus enhancing the cleansing
operation.
In a further preferred embodiment, the device of the invention
further comprises means for blocking the lateral apertures
described hereinabove, thus allowing the operator to either
permit or prevent an irrigation fluid jet spray exiting said
lateral apertures. These means may be used in conjunction with
the above-described balloon element, thereby permitting the
selection of jet spray through:
i. distal spray nozzles only;
ii. distal spray nozzles and lateral apertures; or
iii. lateral apertures only.
Alternatively, the device may comprise the lateral blocking
means only, that is, the aforementioned balloon element is not
incorporated therein.
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In one preferred embodiment, the lateral aperture blocking
means comprise a slideable overtube (11t) assembled around the
catheter tube (11c) in the region of the lateral apertures
(11p). Figs. 11A to 11C schematically illustrate three
different positions of this overtube 11t in relation to
apertures 11p. Thus, in Fig. 11A, overtube 11t is in its
proximal-most position, thereby exposing all of the lateral
apertures 11p, and thus permitting the jet spray to leave the
side of the distal portion of the catheter tube. In Fig. 11B,
overtube 11t has been moved such that it partially covers the
side apertures 11p, thereby reducing the area of the distal
part of the catheter which is available for emitting a jet
spray. Finally, in Fig. 11C, overtube 11t has been drawn into
its distal-most position, thereby completely blocking all of
the lateral apertures 11p.
In an alternative embodiment, as shown in Figs. 12A to 12C, a
rotatable (rather than slideable) overtube h2 is fitted with
its own series of lateral apertures h4 corresponding exactly
to apertures hl present in the catheter tube h3. Thus, in Fig.
12A, the rotatable overtube h2 is positioned such that the
apertures hl therein are located such that they are not in
alignment with the lateral apertures h4 of catheter tube h3,
thereby preventing any jet spray from leaving said lateral
apertures hi. In Fig. 12B, however, the overtube h2 has been
rotated into an intermediate position, such that the two sets
of apertures, hl and h4, partially overlap, leading to a
series of reduced-area jet spray channels. Finally, Fig. 12C
illustrates the situation after overtube h2 has been rotated
further, such that the apertures hl therein are in precise
alignment with the lateral apertures (h4, not shown) of the
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catheter tube h3, thereby permitting the maximal volume of jet
spray through said apertures.
One of the key advantages offered by the nozzle-blocking
mechanisms described hereinabove is that aspiration and
irrigation operations may be performed independently (together
or separately), thus enabling flexibility and higher
efficiency of liquid usage. Consequently:
= When it is required to irrigate the colon it is desirable
that there should be the maximal momentum of flow passing
through the distal spray head. In such a case, the
lateral apertures would be blocked.
= When it is required to aspirate the fecal material
through the working channel it is desirable that the
spray jets be focused sideways, in order to effect
maximal fecal breakdown and dilution while passing
through the working channel.
It should be noted that the aspiration and dilution of fecal
material using the lateral apertures may be done continuously
(aspirating diluted/broken down feces while the lateral
apertures are exposed and functioning with the catheter sleeve
in its 'inflated' state). Alternatively, it is possible to
switch between aspiration and lateral aperture spray, such
that each time aspirate is performed, the catheter sleeve
collapses (due to the application of internal negative
pressure) and then inflated again in order to cause fecal
breakdown. This process is then repeated until the desired
result is obtained.
In other preferred embodiments of the present invention the
following two configurations may be used either separately or
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together, in order to increase the efficiency of aspiration of
broken-down fecal material:
1) Using jet sprays emanating from the lateral apertures for
breaking down the feces that have been aspirated through
the working channel.
2) Using a spring-like configuration made of thin mesh wires
that employ a high frequency 20-50 Hz linear movement to
dismantle the feces in a manner similar to that of a food
processor.
The second of the above two configuration is illustrated
schematically in Fig. 13 showing a possible embodiment
employing spring-like thin mesh wires q1 and q2.
The present invention also encompasses distal spray head units
that are capable of directing the flow of irrigation fluid,
either inwardly or outwardly:
Inward direction of flow
The configuration illustrated in Figs. 14A to 14D may be used
to direct the flow of irrigation fluid out of the distal spray
head p4 in a predefined convergent (i.e. inwardly-pointing)
direction. The flow p6 may pass through an optimization
entrance p3 to avoid local turbulences. It then passes through
a fine nozzle pl (e.g., having a diameter of about 0.2-0.4 mm)
and finally exits spray head P4 by flowing across the surface
of nipple p2 using the tension surface principle.
Substantially all of the irrigation fluid is thus directed
inwardly toward a focusing point p5.
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In an alternative configuration, as shown in Fig. 15, the flow
p6 may be directed by means of a pre-set internal nozzle angle
p7.
Outward direction of flow
The configuration shown in Figs. 16A to 16D may be utilized to
direct the flow out of the distal spray head y4 in a divergent
manner. The flow y6 may pass trough an optimization entrance
y3 designed to avoid local turbulences. It then passes through
a fine nozzle y2 (e.g., having a diameter of about 0.2-0.4 mm)
and finally exits spray head y4 by flowing across the surface
of nipple yl using tension surface principle. As shown in Fig.
16D, substantially all of the irrigation fluid is thus
directed in a divergent manner.
In an alternative configuration, as shown in Fig. 17, the flow
y6 may be directed by means of a pre-set internal nozzle angle
y8.
Fig. 18 depicts one preferred embodiment of a distal spray
head 8h that may be used as part of the present invention.
This particular version of the spray head comprises a
combination of jet spray apertures (8a, 8b, 8c, 8d, 8e)
located at different points along the surface of the head, and
angled at various directions. The apertures and nozzles
labeled in the figure are as follows:
A. Forward-pointing jets (via apertures 8a) to cleanse the
colonic lumen (or other body cavity) distal to the
leading edge of the device;
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B. Jet nozzles 8b directed at an angle other than 90 degrees
to the distal face of the device (e.g. angled out toward
the colonic wall);
C. Radially outward-pointing jets 8c;
D. The force of the irrigation water provides sufficient
force to cause a ring comprising slanted apertures 8d to
rotate and thus propel the washing liquids radially;
E. Backward-pointing jets (via apertures 8e) either for
device advancement or for breaking up fecal material just
before it is aspirated through the working channel and/or
cleansing the endoscope lens and illumination LEDs.
Filtering and breakdown/dilution of fecal material
In another preferred embodiment, as depicted in Figs. 19A and
19B, the device may further comprise a filter unit 9c which is
assembled on the distal part of catheter tube 9g. Filter 9c is
capable of blocking any material that is larger than the
filter pore size. Using the lateral apertures 9b, which may be
directed backwards, the feces that arrive to the filter are
broken down until they are sufficiently diluted such that they
are able to pass through the filter pores with the assistance
of negative pressure applied at the proximal end of the
working channel 9f of colonoscope 9e.
Further technical features
In an additional configuration, the rigid wire disclosed
hereinabove may have an internal lumen (as described in the
context of the embodiment fitted with a distal balloon) . In
this particular embodiment, said wire lumen may be used to
insert air into the distal spray head, thereby enabling a
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mixture of air and irrigation fluid to be used for cleansing
the colon or other body cavity.
In yet another embodiment of the device nozzles or apertures
are located along at least the distal 2-5 cm, or alternatively
along the entire length of the tube. The presence of such
nozzles permit:
= the insertion and maneuverability of the device through
the colon and working channel;
= self propelling navigation through the colon or other
body cavity;
= Internal working channel cleansing, i.e. causing
breakdown of fecal material that was aspirated into the
working channel and may potentially obstruct the
aspiration channel.
In a still further embodiment, the device may comprise an
asymmetric collapsible tube which, when inflated with water,
is capable of pushing the fecal material that is still inside
the working channel outwards by a peristaltic force. Such a
working arrangement may be achieved either by inflating the
tube one sections at a time (in -1 cm sections, for example)
from the distal part to the proximal part of the colonoscope.
In a yet further embodiment, the device may be
inflated/deflated in such a way that it is capable of applying
a peristaltic force onto the internal wall of the colonoscope
working channel, thereby assisting the breakdown of the
remaining fecal material inside the working channel.
In a still further embodiment of the invention, the device may
further comprise an additional, parallel, lumen running along
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the length of the collapsible catheter sheath. This additional
lumen may be used for a number of purposes including:
injection of therapeutic agents, injection of iodine (for
chromo-endoscopy), application of very cold water in order to
arrest bleeding, and delivery of tumor-specific bio-markers.
In addition, the extra lumen may be used to introduce air for
insufflation of air mixture with the irrigation fluid. It is
to be noted that the additional lumen may have a very small
diameter (e.g. 0.2 - 1mm) and may be contained within a
collapsible tube.
In one alternative embodiment, the distal spray head unit
described above may be connected to a flexible tube that does
not change its diameter under the liquid pressure (i.e. it is
non-collapsible).Such a configuration may be advantageous
when it is required mainly to irrigate a specific location
without necessarily allocating more space to the working
channel. This configuration may also be advantageously
employed in situations wherein the space between the working
channel and the lumen of the irrigation water is sufficiently
large to allow aspiration and/or insertion of additional
tooling through the working channel. This particular
embodiment, while employing a conventional catheter tube is
characterized by the following notable features:
= Miniaturization of the distal spray head unit to 2-3mm
overall diameter enables insertion through small lumens
such as the working channel of a colonoscope.
= The irrigation fluid is directed through the distal spray
head cap assembled on the distal part of the tube and
through holes in the tube.
= It is required to design specific nozzles to optimize the
pressure flow and avoid turbulences wherever possible.
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= The invention apparatuses described above are intended to
enable MAXIMUM LIQUID MOMENTUM WITH MINIMAL LIQUID
VOLUME. For example, if the irrigation liquid is
transformed to a spray wherein the liquid drops are very
small no cleansing effects can be achieved.
Alternatively, if the nozzle is too large (e.g. 0.8mm -
3.8 mm) to provide the cleansing momentum required for
irrigation an impractically-large volume of irrigation
fluid will be required.
= The irrigation nozzles are focused forward (in an inward,
outward angles or straight), thus enabling the physician
maximum efficiency and maximum effective force (liquid
momentum) in the direction where the colonoscope camera
is directed.
= Automatic cleansing in 360 to enable irrigation where no
vision is available (for example, out of the FOV or in
diverticulosis).
DISTAL PLUG-GUIDEWIRE APPROACH:
As explained above, the present invention aims to provide
means and techniques for supplying cleaning fluid to a spray
head or nozzle situated at the distal end of an endoscope
working channel, at a pressure that is sufficiently high in
order to permit generation of a jet spray that will allow
efficient cleaning of the colon or other body cavity which
lies distally to the distal end of said endoscope without
causing trauma and tissue injury. The key technical problem
that needs to be solved in fulfilling this aim is the
generation of a sufficiently high pressure head in order that
a jet spray may be formed, without the need for a separate
catheter to supply the irrigation fluid to the spray head. As
explained hereinabove, the use of such fluid-supply catheters
within the working channel is undesirable, since the presence
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of such a catheter reduces the working channel cross section
and volume which are required for aspiration of solids and
liquids and increase the friction surface.
The solutions provided by these embodiments of the present
invention further comprise,, in their most general form, a
distal spray head unit or plug which is mounted on a thin
guidewire (e.g., having a diameter of about 0.3-0.8mm) or (in
some embodiments) a very small diameter tube (e.g., having a
diameter of about 0.4-1.5 mm). This spray head effectively
functions as a perforated plug that may be caused to partially
or completely block the distal exit of the working channel.
Thus, when partially blocking said distal exit, irrigation
fluid is supplied through the working channel, said fluid
being caused to exit the spray head at a higher pressure, in
the form of a jet scatter directed towards the region of the
body cavity (e.g. colon) located immediately distal to the
distal end of said working channel.
The irrigation fluid may be supplied to the spray head unit in
the following manner: the irrigation fluids fed into the
endoscope working channel using a positive pressure water pump
(peristaltic, centrifugal pump, dosing pump, gearwheel pump,
etc.) at a pump outlet pressure of between 2 and 10
atmospheres, resulting in a pressure range of 2-8 atm in the
outlet nozzle. The flow rate may range between 0.2 and 2
1/min. Sealing elements, adaptors and connectors using
standard Luer components may be used. It is to be emphasized
that the abovementioned pressure and flow parameters are for
the purpose of illustration only, and do not limit the
invention in any way.
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It is to be noted that throughout the disclosure and
description of the distal head-guidewire solution, the terms
"distal plug", "distal head spray unit" and the like are used
interchangeably.
A typical arrangement is shown in Fig. 31, illustrating
endoscope 31f having a working channel 31g into which the
cleansing device 31k of the invention is introduced via
endoscope port 31e. Cleansing device 31k comprises
guidewire/tube 31j having a distal head 31i attached at its
distal end and a proximal handle 31a to which the proximal end
of the guidewire/tube 31j is attached. Guidewire/tube 31j
passes through a tube 31t attached to proximal handle 31a and
which is capable of being sealably connected to endoscope port
31e. Tube 31t comprises irrigation ports 31b and 31c for
supplying irrigation fluid into working channel 31g
therethrough, and aspiration port 31d to which a vacuum pump
may be connected. As will be discussed in details herein
later, proximal handle 31a advantageously comprises control
mechanism capable of setting several working states
(designated by letters A, B and C) of the endoscope/cleansing
device assembly (31f/31k).
In order to fulfill this function, the distal plug is
constructed such that it may be caused to move between the
following two conformations:
a) A first conformation, wherein the spray head unit has a
size that permits its distal passage through the working
channel prior to irrigation and aspiration, and its
proximal passage following the end of those procedures.
This conformation is also used for sealing the distal
exit of the working channel, such that it may assist in
cleansing the endoscope working channel utilizing a
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partial length tube or sleeve (the distal end of which
ends a few centimeters from the distal end of the
guidewire) to supply high pressure irrigation fluid to
the distal part of the endoscope working channel. In
this way, positive hydrostatic pressure forces are added
to the vacuum pressure, thereby significantly increasing
the efficiency with which particulate matter may be
moved proximally from the distal end of the working
channel and thus preventing and/or clearing blockages
therein. Generally, this first conformation is adopted
when the device is contained within the confines of the
endoscope working channel (other other narrow instrument
channel). The external diameter of the distal plug is
generally constructed to be only slightly larger (by a
few millimeters) than the internal diameter of the
working channel, such that when said plug is contained
within the channel, its outer diameter becomes reduced,
and the previously open channels and apertures in the
plug become closed.
b) a second conformation, wherein the spray head unit has
larger external dimensions than in the first- position.
This occurs when the spray head unit (distal plug)
leaves the confines of the working channel (at its
distal end). A proximally-directed force is then
applied such that the distal plug makes contact with the
distal exit of the working channel, effectively
providing a fluid seal over said exit, such that the
only fluid transfer between the working channel and the
region of the body cavity located beyond the distal end
thereof is~by way of channels, apertures and/or nozzles
formed within said spray head unit;
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All of the abovementioned conformations may be incorporated
into one device.
In use, the spray head unit, while in its second, expanded
conformation may be moved distally from its seated position
over the working channel exit (as described immediately
hereinabove) such that free fluid transfer between said
working channel and the region of the body cavity located
beyond the distal end thereof is once again possible. In this
state, the working channel may be employed as a suction
channel for the aspiration of fluid and solid debris from the
body cavity, as well as for the passage of endoscopic tools.
It is to be emphasized that the potential use of the working
channel as an aspiration channel is facilitated by the fact
that the spray head unit is mounted on the aforementioned very
small diameter wire or tube made of either metal or plastic
resin), rather than on a fluid-supply catheter that would
occupy a correspondingly larger fraction of the available
working channel volume. This wire or small diameter tube is
sufficiently rigid that it allows the operator to advance the
distal plug through the working channel and out into the body
passage lumen. However, it also needs to be sufficiently
flexible in order to negotiate bends and 'convolutions within
said body passage. is to The present invention also overcomes
another problem of the latter device, namely that a fluid-
supply catheter having a very small diameter would require the
use of a much higher pressure pump than is currently used, due
to the high resistance.
The presently-disclosed device may also be used to fulfill the
second of the principle aims of the present invention that
were mentioned hereinabove, namely irrigation and cleansing of
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the working channel of an endoscopic instrument, in a manner
such that blockages of said channel by fecal material may be
prevented or removed. Thus, whenever the working channel
becomes blocked by feces (and/or other solid and semi-solid
material), or alternatively before it is thus blocked, a spray
head unit of the present invention (as will be described in
more detail hereinbelow) is mounted on a flexible wire, which
in turn passes through a hollow tube through which irrigation
fluid can pass. This tube may have side apertures formed along
its entire length or a portion thereof and/or an aperture at
the distal end. As an alternative to the above-described wire
within tube assembly, an additional embodiment comprising a
hollow wire or thin tube having side apertures formed along
either its entire length or a portion thereof and/or aperture
at the distal end, may also be used. A cleaning fluid (such as
water or a special dissolving solution) is pumped or injected
into the proximal end of the hollow wire/tube such that said
fluid is caused to exit through the apertures, thereby causing
reduction in the size of the solid debris. In the case of
large obstructions caused by the accumulation of solid
material within the working channel, the distal spray unit
head can be repeatedly advanced (either manually or
automatically) and retracted, thereby making a mechanical
contribution to the breakup of said obstruction. The
combination of this mechanical effect and the fluid spray
thereby permits the effective removal of solid material that
may otherwise obstruct the working channel.
In addition to the fluid causing reduction in the size of the
solid debris an additional usage of the fluid is to create a
positive hydrostatic pressure force (e.g. between 3 and 8atm)
in order to help push the feces and blockage backwards, in
addition to the vacuum force which is limited to a maximum of
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-1 atm of pressure. In practice, the vacuum pressure actually
achieved at the distal part of the endoscope may be much less
than -1 atm. In this configuration it is necessary to seal the
distal end of the endoscope.
In another particularly preferred embodiment of the present
invention, the above-defined aim of preventing or disrupting
blockages within the working channel during use of the
presently-disclosed device is achieved using a version of said
device in which the guidewire, for most (but not all) of its
length passes through a partial-length tube or sheath. The
proximal end of said partial-length tube is fixed within a
proximal handle (as will be described in more detail
hereinbelow). The distal end of the partial-length tube ends
a few centimeters before (i.e. proximal to) the distal end of
the guidewire, to which is affixed a distal head spray unit of
the present invention. While any of the distal head spray
units that will be described hereinbelow may be used to
implement this particularly preferred embodiment, the spray
head referred to as the "second spray head unit embodiment" is
especially suitable.
Since (as will be described) the distal-proximal location of
the distal end of the guidewire is altered during use, while
the position of the partial-length tube is fixed (with
reference to the proximal handle), the precise distance
between the distal end of the partial-length tube and the more
distally placed distal end of the guidewire will also alter,
and will generally be in the range of about 1 cm to about 4
cm. In general, the total length of the guidewire (which is
typically constructed of 0.5 - 0.6 mm diameter) will be in the
range of about 150cm-210cm, depending on the endoscope length
used as well as the external extension tubing length.
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Extension tubing is assembled between the endoscope working
channel adaptor and the handheld device, typically having a
length of 50-70cm with an internal diameter of similar to the
working channel diameter (commonly 3.8 mm). The distal end of
the guidewire is attached to the distal spray head unit by
means of glueing, bonding or laser welding/soldering of the
metal guide wire and the distal plug. The partial-length tube.
is generally constructed of PTFE tubing (for low friction) or
ETFE, depending on the sterilization method of the device to
be used, and has an external diameter of about 1-mm - 1.6 mm
and a wall thickness of about 0.25 mm. It is to be
recognized, however, that these measurements are given only as
a general guide and do not limit the scope of the present
invention in any way.
In some embodiments of this version of the device, said device
incorporates means for assisting the operator to recognize and
detect the position of the distal spray head during use. In
one such embodiment, one half of a ratchet mechanism is fitted
to the distal face of the endoscope adjoining the distal exit
of the working channel. A complementary ratchet surface is
incorporated into the proximal face of the spray head unit,
such that when said unit is brought into contact with the
distal exit of the working channel a clicking sound (caused by
the ratchet mechanism) is emitted, thus informing the operator
that the distal head unit is in close apposition with the
endoscope distal face. Other embodiments incorporate
different mechanisms for signaling the position of the distal
head, including remote sensors or transmitters located on the
distal face of the endoscope that communicate with receivers
or transmitters located on the proximal handle.
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This particularly preferred embodiment of the device of the
present invention is illustrated in Figs. 32A to 32C. Thus,
Fig. 32A depicts the distal spray unit 32a (mounted on
guidewire 32d) located in the distal exit 32b of the
colonoscope working channel 32c. Irrigation of the colonic
lumen is achieved by passing the irrigation fluid through the
working channel 32c. The irrigation jets (32j) pass through
spray nozzle apertures 32e located between the spray head unit
32a and the working channel circumference (32b).
In Fig. 32B, the spray head unit 32a is located outside of the
working channel 32c enabling free aspiration (32s) of
irrigation liquid and solid and semi-solid debris through the
large space that exists between the guidewire (or tube) 32d
and the working channel 32c.
Fig. 32C depicts the manner in which the nozzle seals the
endoscope working channel 32c to enable the fluid pressure
force coming from the irrigation fluid that is diverted
distally through the lumen of the partial length sleeve 32i to
actively push the liquids and fecal remains in a distal-to-
proximal direction through the lumen of the working channel
32c, between the partial length tube 32i and the inner wall of
the working channel.
In order to move between the three different operational modes
of this particularly preferred embodiment of the device (i.e.
irrigation, aspiration and working channel clearing), it has
been found most convenient to incorporate a dedicated proximal
handle into the device, whereby the operator is able to adjust
the mode of operation by means of operating manual controls
that cause change in the position of the distal spray head
unit as well as the path by which the irrigation fluid is
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brought to the distal end of the device. Details of a
suitable device will be described hereinbelow and illustrated
in Figs. 40A and 40B.
The spray head unit of the present invention is capable of
being moved between the various above-described conformations
by virtue of possessing one or more structural or functional
features that permit the dimensions of the head unit to be
altered by the operator, for example, by using linear shift of
the head unit from inside the endoscope working channel to
outside and vice versa. The present invention, is not,
however, limited to such a mechanism but rather encompasses
further embodiments that may include other mechanical
mechanism or inflatable mechanisms that can be used to alter
the spray head conformation and the use of flexible resin
silicone or rubbers.
Several different embodiments of the distal spray head unit
will now be described. It is to be recognized, however, that
there may be many other structural variants which may fulfill
the .functional requirements set out hereinabove, and that said
variants are equally considered to be within the scope of the
present invention.
First spray head unit embodiment
In this embodiment, as shown in Figs. 20 to 22, the distal
spray head unit 20 is constructed of a central portion 20c
surrounded by series of wings 20w or petal-like elements that,
when in their resting state (illustrated in Figs. 21A and
21B), are arranged to form a generally conical or frusto-
conical structure. However, when the device is inserted into
the working channel, the petal-like elements are caused to
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adopt a closed, reduced-diameter, conformation as shown in
Figs. 20A and 20B. In order to bring the device into its
second, open conformation (as defined hereinabove), the head
unit 20 is further advanced distally such that it leaves the
working channel through its distal exit. As shown in Figs. 22A
and 22B, the petal-like elements 20w are then further opened.
This is achieved by a combination of forces that are exerted
during withdrawal of the head and the resistance of the
working channel exit] such that they adopt a second frusto-
conical conformation that has a directionality opposite to
that shown in Figs. 21A and 21B. The head unit 20 is then
moved proximally (i.e. backwards towards the operator) such
that it finally comes to rest over the distal exit of the
working channel 32c, as shown in Figs. 23A and 23B. In
conformation, the narrow spaces between the lateral portion of
the petal-like elements 20w and the wall of the working
channel distal exit, as well as the narrow spaces between each
of said elements, form "virtual nozzles" (indicated by 20n in
Fig. 23b). Thus, when cleaning fluid is pumped through the
working channel 32c, said fluid will be caused to leave the
head unit 20 through these "virtual nozzles" 20n in the form
of a high-pressure spray which may be used to cleanse the
portion of the colon or other body cavity that is located
immediately distally to the distal exit of the working channel
32c.
As illustrated in Figs. 22A and 22B distal head unit 20
further comprises an internal passage 20g adapted to receive a
distal portion of a guidewire, or suitable tube, thereinside
via proximal opening 20p. The inner passage 20g may be further
employed for applying an irrigation stream via nozzle 20z
provided at the distal end of distal head unit 20 by
connecting a hollow guidewire or tube, to opening proximal
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20p. On the proximal portion of central portion 20c there may
be fixedly attached stabilizing members 20q adapted to
facilitate the movement of distal head unit 20 inside the
working channel.
It is to be emphasized that the "virtual nozzles" (20n)
described hereinabove provide only one example of spray-
forming exits that may be formed within this embodiment of the
distal head unit 20, and that other nozzle or aperture forms
may be incorporated therein without deviating from the scope
of the present invention.
Second spray head unit embodiment
A further embodiment of the distal spray head unit 24u of the
present invention is illustrated in Figs. 24A to 24D. As shown
in Fig. 24A, this embodiment comprises two concentrically
arranged portions, the first of which is an inner rigid (for
example plastic or metal) portion 24p that is tubular in its
proximal (lower) part and is formed into a frusto-conical cap
at its distal (upper) end. As seen in Fig. 24C, the spray head
unit 24u is mounted on a guidewire 24r which passes through
the inner lumens 24m of both the tubular and cap parts of the
inner rigid portion 24p. The second portion is a flexible plug
24t containing a central lumen (through which the tubular part
of the inner rigid portion 24p is inserted) and is fitted on
its external aspect with an angled skirt-like element 24k. The
inner portion 24p is fitted within the lumen of the outer
portion 24t such that it may be caused to slide distally or
proximally therein. This relation between the inner and outer
portions of this embodiment is shown in the longitudinal
section view provided in Fig. 24B. It will be noted from this
figure that the tubular part of the inner, rigid portion 24p
of the device 24u is fitted with lateral wings 24g that are
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sized such that they do not interfere with the distal-proximal
movement of said inner portion 24p within the lumen of the
outer portion 24t. In the view provided in Fig. 24B, the
lateral wings 24g are situated approximately half way along
the length of the lumen of the outer, flexible portion 24t of
device 24u.
Fig. 24C is a longitudinal section view showing the spray head
unit 24u placed within the lumen of a working channel 32c,
close to the distal exit of said channel. It will be noted
that as device 24u is advanced manually by the operator in a
distal direction, the inner portion lateral wings 24g are
caused to move distally in relation to the outer, flexible
portion 24t, such that they come to rest on the. inner surface
of the upper (distal) face of said outer portion. It will also
be seen from this figure that the angled skirt element 24k of
the outer, flexible portion 24t of device 24u is compressed by
the inner wall of the endoscopic working channel 32c.
As shown in Fig. 24D, device 24u'may be advanced still further
in a distal direction, such that it leaves working channel 32c
through the distal exit thereof 32x. On leaving the channel
32c, the previously-compressed angled skirt element 24k is
allowed to return to its expanded, rest position, such that
upon slight proximal retraction of device 24u, said skirt
element 24k acts as a mechanical stop, blocking off the distal
exit 32x of working channel 32c and preventing the proximal
return of device 24u back into said channel. In this first
working position (also termed herein as "irrigation mode"),
irrigation fluid may be pumped through working channel 32c
such that it leaves said channel in the form of a high-
pressure spray through the nozzles (24z, Fig. 24E) present in
the upper and lateral surfaces of the rigid cap 24p. Examples
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of suitable nozzles 24z are shown in the transverse section
view of the upper region of device 24u provided in Fig. 24E.
When the operator wishes to perform aspiration (hereinafter
also referred to "aspiration mode", also illustrated in Fig.
33C) of the irrigation fluid and/or debris through the working
channel he or she will simply advance the spray head unit 24u
slightly in the distal direction such that the distal exit of
the working channel becomes unblocked, thereby "freeing" the
working channel, and permitting aspiration.
Following the irrigation and aspiration procedures, the
operator can then manually withdraw the device through the
working channel 32c, as shown in Fig. 24F. This stage
initially requires the application of a briefly-applied force
of greater magnitude than previously used in the procedure, in
order to compress the skirt element 24k such that it can once
more enter the working channel 32c. In this state the
compressed skirt 24k blocks the passage via working channel
32c and which may advantageously be exploited for washing the
working channel 32c (herein after "clearing mode") with a
stream of fresh water supplied via an inner tube (32i in
Figs.32-33) of the cleansing catheter of the invention.
Additional three-dimensional views of the above-described
embodiment are shown in Figs. 33A to 33C, wherein Figs. 33A
and 33B respectively show front and perspective views of the
spray head unit 24u in the irrigation mode, wherein it is
placed over exit opening 32x of working channel 32c, and Fig.
33C show a perspective view showing the state of spray head
unit 24u in the aspiration mode, wherein it is advanced
further distally away (e.g., about 40mm) from exit opening 32x
of working channel 32c.
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In another version of this embodiment of the spray head unit,
said unit comprises an external o-ring constructed of a
flexible material such as silicone. The presence of this o-
ring assists in providing a smooth transition between the
various head unit positions when moving from one operational
mode to another. The use of such an o-ring is of particular
value when the device of the present invention is used in
conjunction with an endoscope that has an internal taper at
the distal end of the working channel. In such a case, the
passage of the distal head unit through the working channel
will largely be friction-free until said head unit enters the
narrowed distal portion of the working channel.
Third spray head unit embodiment
In another preferred embodiment of the present invention,
schematically illustrated in Figs. 27A to 27 D, the spray head
unit is provided in the form of a small balloon 27b with a
predefined shape, such that the outer surface of said balloon
does not form a smooth unbroken arc, but rather has a
furrowed, or rugose outline. This head unit is then assembled
on the distal part of a small diameter tube or hollow wire 27t
which serves both as a guiding wire and for inflating the
balloon 27b. The balloon 27b is navigated to the distal part
of the endoscope through the working channel 32c in its
deflated state (27b) until it reaches the distal exit of said
channel. At this point, the balloon is inflated (27bb) to
partially block the flow and to form virtual nozzles 27z
between the recessed outer surface of the balloon 27bb and the
working channel 32c. Fluid supplied through the working
channel will then leave said channel via the aforementioned
virtual nozzles 27z, in the form of a high pressure jet spray.
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After irrigation is completed the balloon can be deflated in
order to allocate space for aspiration. The shape of the
balloon may be designed such that it incorporates various
special design features, such as: different wall thicknesses,
different inflation shapes, etc.
The advantage of such an embodiment is that it is not required
to push forward the nozzle in order to allocate the space for
aspiration, and thus may simplify the user interface mechanism
by using only an inflation pump with an optional pedal instead
of mechanically moving a device into and out from the
endoscope.
The balloon 27b for use in this embodiment may be constructed,
for example, from silicone rubber or latex by means of molding
and/or heat extrusion techniques and/or use of pebax,
polyester, etc... as are well known in the art.
To enable cleansing of the aspiration channel and/or assisting
the aspiration an additional balloon may be assembled before
or after-the shaped nozzle balloon to seal the exit of the
endoscope, thus enabling the high pressure water flushed in
the distal part of the endoscope through the inner tube to
flush back the irrigation liquid. This embodiment (containing
an additional sealing balloon) is depicted in Figs. 34A to
34E.
To operate both balloons a multilumen/bi-lumen tube may be
used to operate independently all of the options. Thus, Fig.
34A shows this embodiment of the device with both the spray
head unit balloon 34b (nozzle balloon) and the sealing balloon
34s in their deflated sate. Also shown is the inflation tube
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34t, the lumen of which is connected to the lumen of said
balloons.
In Fig. 34B, the nozzle balloon 34b has been inflated into its
working position, i.e. in the distal most portion of the
working channel lumen 32c. It is to be noted that at this
stage, the sealing balloon 34s is still in its deflated state.
Fig. 34C illustrates the use of the device in this
conformation for irrigation (illustrated as doted lines 34j)
of the body passage (irrigation mode) that is situated distal
to the distal end of the device.
In Fig. 34D, both the nozzle balloon 34b and the sealing
balloon are in their deflated states, thereby increasing the
space available within the distal portion of the working
channel 32c and permitting aspiration (illustrated by arrows
34a) of fluid and fecal debris therethrough (aspiration mode).
In Fig. 34E, the drawing shows the sealing balloon 34s in its
inflated state (with the nozzle balloon 34b deflated), and
illustrates the way in which this configuration may be used to
assist the aspiration of fluid and fecal debris through the
working channel 32c by means of high pressure flushing in a
proximal direction (clearing mode).
Fourth spray head unit embodiment
In this preferred embodiment of the present invention, shown
in Figs. 28A to 28D, the spray head unit 28u is provided in
the form of a flexible mushroom-shaped valve (Fig. 28A), which
is designed to increase its overall diameter upon increase in
hydraulic pressure within the working channel (Fig. 28B).
Thus, upon pumping irrigation fluid into the working channel
(illustrated by arrows 28w in Fig. 28E) the mushroom-shaped
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head unit 28u expands until it causes partial obstruction of
the distal exit of. the working channel, the only flow that is
possible being via the nozzles (28z shown in Fig. 28D) and/or
"virtual nozzles" (28v shown in Fig. 28C) that are formed in
said spray head unit. The mushroom-shaped valve used in this
embodiment may be constructed, for example, from a flexible
resin such as polyurethane or flexible silicon rubber of shore
A 20-60.
Fifth spray head unit embodiment
In one preferred version of the device of the present
invention, a distal spray head unit (for example, in
accordance with the first or fourth embodiments described
hereinabove, and which may also incorporate the mechanism
enabling improved aspiration described above) may be
constructed such that it incorporates biopsy forceps (or other
surgical instruments) as indicated as item 29f in Figs. 29A to
29E. This modified spray head unit permits the cleansing of
the colon (or other body cavity) at specific locations
immediately prior to taking a tissue biopsy. In one variant of
this embodiment, the forceps opening mechanism will enable the
creation of spray nozzles. Such an arrangement is particularly
advantageous in endo-surgery procedures where it is necessary
to replace the endoscopic tools by an irrigation nozzle and/or
allocate room for aspiration. Additionally the inner tube (32i
in Fig. 29D) may be assembled to enable increased aspiration
force and working channel clearing together with the sealing
mechanism described above.
The device described herein may be incorporated within any
endosurgery device (snare, forceps, biopsy forceps, injection
needle, cutter etc) where the guidewire will be replaced by
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the shaft of the endosurgery device and the other sub
assemblies of the device (nozzle, inner tube, sealing) will be
assembled as well (Fig. 29D items 28v and 32i). Item 28v
describes the nozzle and the optionally sealing.
In the various embodiments described hereinabove, it is
clearly necessary for the operator to control the position of
distally-placed elements (such as various elements of the
spray head unit, biopsy scissors etc.) from the proximal end
of the endoscope. This may be achieved in various ways, by the
use of various different elements including:
1. Simple handle to hold the wire and tubes to pull/push the
distal head in and out of the working channel distally as
well as place the nozzle on the distal part exit.
2. Control strings to hold the device in its closed state
and/or open state.
3. Trigger to fix the distal part in place at one or more
positions.
4. Proximal part - wire connected to a plug.
5. Torque mechanisms.
As explained hereinabove, one of the advantages of the device
of the present invention is that it permits aspiration of
solid and thick materials through the working channel of the
endoscope with a reduced probability to obstruct the channel.
An example of one type of aspiration system 35 is shown
schematically in Fig. 35. It may be seen from this figure that
this embodiment of the aspiration system 35 provides a pathway
allowing the transfer of aspirated liquids and fecal material
from the patient's body cavity 35a through the endoscope
working channel 35b to the waste container 35d. Of particular
note is the fact that system 35 does not require the use of a
special pump filter. Rather, the waste container 35d functions
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as a pressure buffer. Thus, the vacuum applied by vacuum pump
35e is allowed to build up within the waste container 35d and
connected tubing, thereby enabling the operator to perform
aspiration by means of simply opening a valve 35c.
Vacuum system 35 may be operated such that the aspiration
forces are repeatedly turned on and off, thereby creating
rapid pressure changes enabling aggregations of solid debris
to advance proximally in a step-wise manner.
As explained hereinabove, certain embodiments of,the guidewire
device of the present invention (notably those that comprise a
partial-length tube or sleeve surrounding the guidewire for
most of its length), permit enhanced clearance of particulate
and liquid material from the working channel, thereby
preventing blockage thereof. In this case, the method involves
pulling the distal head (32a in Fig. 32C) into the working
channel (32c) to a greater degree than described above (i.e.
in relation to the irrigation stage), such that O-ring 32g is
pulled into the working channel, thereby totally blocking the
exit of the working channel. Once the exit is blocked and the
working channel is partially filled with feces and other
debris, a high positive pressure pulse of liquid (or air) may
be directed distally through the lumen of the partial-length
sleeve (32i in FIG. 32C), thereby applying positive pressure
to the distal part of the working channel, and thus applying
much higher forces to the solid debris than would otherwise be
possible (i.e. by the use of a maximum negative 1 atm produced
by the vacuum force), as illustrated in Fig. 32C.
In addition to the vacuum forces and the side jets used for
irrigating the fecal debris inside the working channel (as
described hereinabove), additional mechanisms may be employed
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in order to apply mechanic forces to the solid debris. One
example of such a mechanism is shown in Figs. 25A to 25C.
This mechanism will apply a mechanical force on the feces and
debris and will push the debris backwards. Such a mechanism is
possible as long as the friction forces applied on the blades
25b correlate with the moment applied on the shaft 25s from
the exterior without reaching plastic deformation.
Alternatively, as explained hereinabove, it is possible to use
linear motion where the wire moves back and forth for a few mm
or cm thus creating mechanical vibration and mechanical
dismantling action helping to avoid the creation of
obstruction and pushing the solid debris chunks downward (i.e.
proximally).
The linear motion described above can be made more effective
if some mechanical elements, such as small deflectors (30d)
are mounted on the wire (32d), as exemplified in Figs. 30A and
30B. As shown in Fig. 30A, in case a hollow wire or tube 32d
is used it may further include washing apertures 30n located
adjacent to deflectors 30d for washing debris during a
clearing mode by streaming a washing liquid inside hollow wire
or tube 32d.
Additional embodiments of the device may include washer like
filters assembled on the distal part of the wire to prevent
large particles of feces and/or blood clots from entering the
working channel, which may otherwise potentially obstruct said
channel. In some embodiments the nozzle head may also function
as a built-in filter.
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Sixth spray head unit embodiment
In one preferred version of the device of the present
invention, depicted in Figs. 37A to 37C, a distal spray head
unit 37u is constructed such that the direction of the jet
spray that leaves the nozzles may be controlled by means of
pulling or pushing the distal part 37d of said unit in
relation to the distal exit of the working channel 32c and
thereby modifying the angle of flexible wing 37w comprising
spray channels 37c. This has the effect of diverting the jet
spray , such that it is possible to achieve wide-angle forward
spray (37j in Fig. 37A), narrow-angle forward spray (37k in
Fig. 37B) and lateral spray (37r in Fig. 37C) . The latter
spray direction may be usefully employed to clean the optical
devices located on the distal tip of the endoscope. In order
to achieve this directional effect, the distal head spray unit
37u is constructed such that it comprises a flexible wing 37w
that becomes deformed upon re-entry into the working channel
32c.
Seventh spray head unit embodiment
The sealing of the distal end of the endoscope working channel
may be accomplished using a balloon mechanism (compliant
and/or non compliant materials) using a pressure difference
mechanism. This embodiment, schematically illustrated in Figs.
38A to 38C, is characterized by the presence of two series of
apertures along the distal portion of the inner tube 38c. As
shown in Fig. 38B, the apertures 38h situated in the region
where the inner tube 38c is overlaid with balloon 38f are
larger in diameter than the second set of apertures 38g which
are formed in a region of the distal tube that is not overlaid
by balloon 38f. This arrangement enables balloon 38f to be
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inflated first and only afterwards the creation of the
hydrostatic pressure that will result in jet sprays leaving
the smaller apertures 38g.
This design is advantageous because it is single operating
(automatic) and because no bi-lumen or additional inflation
tube is required (i.e. the same conduit both inflates and
irrigates backwards)
This embodiment may also be used in vascular applications
where suction may collapse the arteries, or alternatively, in
any case in which one requires a regulated system with a
balance between the pressure in the lumen and in the balloon.
The various elements of one example of this embodiment
illustrated in Figs. 38A to 38C are as follows:
38a - Working channel
38b - Guide wire
38c - Inner tube (deflated)
38d - Sealing balloon (deflated)
38e - Inner tube distal end blocked
38f - Balloon (inflated)
38g - Pressure apertures
38h - Inflation balloon apertures
38i - Direction of hydrostatic positive pressure
38j - Hydrostatic pressure advancement
Operating handle
In order to control the distal spray head-guidewire device and
switch between its various modes of operation, the present
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invention further provides a proximal control handle, which is
capable of switching between the following three modes:
1. Irrigation Mode - as described hereinabove, the nozzle
(spray head unit) is located at the distal edge of the
working channel creating the virtual nozzle spray.
Irrigation fluid is caused to flow through the working
channel in the space between the device and the channel.
Control of the flow may be accomplished either semi
automatically by pressing a button with predefined flow
and pressure levels, or by pressing a pedal switch.
2. Aspiration Mode - the nozzle is located outside of the
working channel, preferably 5-20mm on the distal side
thereof. Vacuum pressure is activated and liquid and
feces remains are aspirated through the working channel
while the device is still inside the body cavity that is
being cleansed.
3. Working Channel Clearing Mode - the distal head is
positioned such that it completely seals the distal exit
of the endoscope working channel. In addition to the
vacuum pressure, a distally-directed positive flow
pressure is activated through the lumen of the partial-
length tube, in order to assist in the aspiration process
and prevent or clear blockage of the working channel by
debris.
It may thus be appreciated from the foregoing summary of the
three different operating modes that the proximal handle
possesses elements that are capable of serving two key
functions:
a) movement of the distal spray head between three different
locations; and
b) diversion of the irrigation fluid into the desired route
(i.e. into the lumen of the partial-length tube during working
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channel clearing and directly into the working channel during
irrigation).
While specifically intended for use in conjunction with the
irrigation/aspiration device of the present invention, it is
to be noted that the proximal control handle may also be used
for other purposes during endoscopic procedures, for example
the injection of ink or other marker material into the colonic
lumen.
In one preferred embodiment, schematically illustrated in
Figs. 36A to 36D, the control handle 31a may be constructed
such that it may be used to switch between three different
positions or modes. For example, linear motion of a handle
component 31h may be used to switch the device between these
various modes, such that the distal head unit 31i will be
fully outside the working channel 31g (i.e. distal to the
distal working channel exit) in mode 2 (aspiration, shown in
Fig. 36B), pulled backwards to mode 1 (irrigation, shown in
Fig. 36A) and pulled further backwards to mode 3 (strong
aspiration or working channel clearance, shown in Fig. 36C).
In an .alternative embodiment, illustrated in Fig. 36D, a
handle 31y with linear motion 31h between two mode positions
and a trigger 31q to activate the third mode, may be used. In
such an embodiment, the handle 31y may be moved linearly
between modes 1 and 2. Mode 3 can then be activated by setting
the. handle in mode 2 and pressing the trigger 31q, this action
causing an additional linear or rotational movement to seal
the endoscope at the distal working channel exit.
The operator may recognize the position of the handle to
control and switch between the modes either by: fixed linear
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positions, or by differentiating between the modes using
different forces according to the position the distal spray
head unit is located. The force feedback may be controlled by
manual operator sensory feedback or by using a mechanism that
is sensitive to the different forces and blocks.
Figs. 40A to 40B schematically illustrate one particularly
preferred embodiment of a proximal control handle 40
comprising a proximal thumb ring 40r attached to a proximal
housing 40d comprising a mechanism employed for changing the
cleansing device of the invention between its different states
of operation. An outer tube 40t, the proximal end of which is
contained within proximal housing 40d, extends distally
therefrom. Guidewire 40w passes distally from said proximal
housing, and has distal head unit 40h mounted on its distal
end. For most of its length, guidewire 40w is surrounded in a
co-axial manner by partial length tube 40f which ends distally
on the proximal side of head unit 40h at a distance of between
2 and 8 cm, preferably 4cm, therefrom. In the proximal
portion of outer tube 40t located within housing 40d is a
slidable plunger 40g having, for example, an hourglass-like
shape and comprising two seals 40c placed over each of its
broad bases. The distal end of slidable plunger 40g is
mechanically linked at 40q to slider element 40e placed over
housing 40d, such that said slider element 40e may be used for
sealably sliding plunger 40g distally or proximally inside the
proximal portion of outer tube 40t.
Proximal housing 40d further comprises a spring 40s attached
inside outer tube 40t to the proximal wall of housing 40d, a
fluid inlet 40i, and two fluid passages 40a and 40b. The lumen
of tube 40t is sealably divided into first and second sections
by a sealing partition 40p through which the guidewire 40w of
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device 40 is sealably passed, wherein the proximal section of
the outer tube comprises slidable plunger 40g and its distal
section comprises a proximal portion of partial length tube
40f. The distal spray head of the invention 40h is attached at
the distal end of guidewire 40w, and sidable plunger 40g is
attached to the proximal end of guidewire 40w. Ideally,
sealing partition 40p is provided by a dynamic seal mechanism
which seals the guidewire during the channel clearing mode
only (and not during normal aspiration or irrigation, wherein
minimal guidewire friction is desirable and sealing at 40p is
not required).
Fluid passages 40a and 40b communicate between the first and
second sections of outer tube 40t, such that the inlet of
fluid passage 40b is provided between fluid inlet 40i and
proximal wall of housing 40d and the inlet of fluid passage
40a is located distal to fluid inlet 40i. The outlet of fluid
passage 40a is provided in a portion of outer tube 40t located
between sealing partition 40p and location wherein the
proximal end of inner tube 40f is sealably attached to outer
tube 40t.
This arrangement of proximal control handle 40 provides the
mechanism required for moving the cleansing device of the
invention between its different modes of operation. In the
irrigation mode illustrated in Fig. 40A slider element 40e is
placed distally within the proximal unit such that the
proximal seal 40c of slidable planger 40g is located between
fluid inlet 40i and the inlet of fluid passage 40a, thus
preventing fluid flow through said fluid passage. In this
state distal spray head 40h is located at the distal end of
the working channel, and a stream of irrigation fluid
introduced into outer tube 40t via fluid inlet 40i flows
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through fluid passage 40b into the lumen formed between
partial length tube 40f and outer tube 40t in the proximal
portion of the device, and in the space between partial length
tube 40f and the working channel wall in the distal portion of
the device. Finally, in the most distal portion of the device,
the irrigation fluid passes through the apertures in distal
head unit 40h in the form of a spray into the region of the
colonic (or other body passage) lumen that is situated distal
to the distal end of the colonoscope (or other endoscope).
When the operator wishes to perform aspiration of the
irrigation fluid and disrupted solid debris in the colonic (or
other body passage) lumen, the slider 40e is moved further
distally, such that distal head unit 40h is moved beyond the
distal end of the endoscope, thereby leaving the distal exit
of the working channel completely open. Suction pressure is
then applied in order to cause aspiration of fluid and
dislodged debris into the working channel of the endoscope,
and therethrough in a proximal direction, exiting the working
channel of the endoscope through a one-way valve and finally
being collected in an external waste container.
In the working channel clearing mode illustrated in Fig. 40B,
the slider element 40e is pulled proximally until movement of
the slidable plunger 40g is gradually resisted by the now-
compressed spring 40s, which indicates to the operator that
the device has now been placed in the clearing mode. In this
mode, the proximal seal 40c is placed between fluid inlet 40i
and the inlet of fluid passage 40b, thus preventing fluid flow
therethrough. In this state, distal spray head 40h is pulled
proximally over the exit of the working channel, into the
distal portion of said channel such that said exit becomes
completely blocked by the spray head. A stream of irrigation
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fluid is then introduced via fluid inlet 40i and fluid passage
40a into the lumen of partial length tube 40f, exiting
therefrom into the distal portion of the now sealed working
channel. The irrigation fluid stream introduced in this way
then passes in the reverse direction (i.e. proximally) in the
space between partial length tube 40f and the wall of the
working channel under the dual influence of the proximal-to-
distal flow through the lumen of said partial length tube and
the distal-to-proximal suction pressure applied to the working
channel. In this way the efficiency of the aspiration process
is increased, thereby preventing the formation of blockages in
the working channel and/or disrupting any such blockages that
may have already formed.
Housing 40d may be manufactured from ABS, polycarbonate,
Delrin and other plastic resins depending on the compatibility
with the sterilization method to be used (autoclaving, Gamma
radiation or ETO, preferably, by means of casting in mass
production The length of housing may generally be about 80-
120mm, and the diameter of fluid passages 40a and 40b provided
therein may generally be in the range of 2mm-4mm . Outer tube
40t may be made from ETFE, PTFE, and Nylon etc., preferably
from PTFE, having a length of about 50-70cm, depending on the
endoscope length used as well as the external extension tubing
length, an inner diameter generally similar to the working
channel diameter in the range of 2mm-4mm preferably smaller to
reduce hysteresis effects (around AWG8), and wall thickness of
about 0.5-1mm. Partial length tube 40f may be made from ETFE,
PTFE or other plastic resins which are compatible with the
applicable sterilization method with low friction coefficient
and sufficient rigidity to support the device without
collapsing. In an alternative flexible configuration, said
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partial length tube may be made of silicon or rubber resin,
preferably from PTFE for low friction between the guidewire
and tube as well as between the tube and the working channel,
having a length of about 150cm-210cm, depending on the
endoscope length used as well as the external extension tubing
length, and having an inner diameter generally in the range of
lmm preferably smaller to reduce hysteresis effects (around
AWG16), and a wall thickness of about 0.25mm to 0.4mm.
Guidewire 40w is preferably made from stainless steel 304V
with an optional configuration of PTFE coating to reduce
potential friction between the wire and the inner PTFE tube
and its diameter may generally be in range of 0.5-0.7 mm,
preferably about 0.6 mm.
As described hereinabove, in the channel clearing and
aspiration modes the washing fluid flows proximally in the
working channel. In order. to prevent this stream of fluid
from entering fluid passage 40b, said fluid passage preferably
includes a one-way valve 40v which permits flow in the distal
direction only, thereby preventing washing fluid streamed
inside working channel during the clearing mode from flowing
therethrough in the proximal direction. It is important to
include such one way flow restricting means (40v) in fluid
passage 40b since the introduction of pressurized fluid into
the proximal portion of the outer tube during the clearing
mode could result in a rapid distal displacement of slidable
plunger 40g which would cause the distal spray head 40h to
move distally and out of the working channel, thereby causing
an unintentional alteration in the mode of operation of the
device. Examples of suitable valve devices that may be used
for this purpose include ball valves and duck-bill valves.
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It should be recognized that the above-described proximal
handle is only one possible, non-limiting embodiment of
proximal units that may be used in conjunction with the
guidewire-mounted distal spray head units of the present
invention.
Fig. 39 is a block diagram illustrating a preferred console
implementation for the cleansing device of the invention,
comprising housing 39 enclosing an irrigation pump 39p, (e.g.
FLOJET diaphragm pump, peristaltic pump or a gear wheel pump)
a vacuum pump 39v (e.g. THOMAS diaphragm pump, piston pump)
transformer 39m (e.g., medical grade transformer Mean well/
200W Medical series), safety timer 39t, irrigation pump relay
39y and vacuum pump relay 39k.
Housing 39 is connected by suitable piping to a water tank 39a
used for supplying the washing fluid to the cleansing device
of the invention 31k also being in fluid communication with
the console. In a preferred embodiment of the invention
irrigation pump 39p is capable of providing positive pressures
in the range of 2 to 10 atmospheres and flow rates of about 1
liter/min. The streamed washing fluid may be controlled by the
operator by means of pedal switch 39d electrically connected
to the console. The console is also connected to the working
channel of colonoscope 31f for applying vacuum therethrough by
means of vacuum pump 39v and aspirating debris, fecal material
and other particulate matter into waste tank 39k.
Additional features of the device and method of the present
invention
In a further embodiment of the present invention, the fluid
spray jets produced by the distal head unit nozzles may be
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employed to facilitate the insertion of the endoscope into the
body passage. Thus, the spray jets may assist by moving the
GI tract folds and straightening the folds, thereby enabling
easier pushing and pulling of the endoscope. The spray jets
may also assist in endoscope insertion in some instances by
means of their use to clear the GI tract lumen of large
polyps, stones or other obstructions that may be located
distally of the advancing distal tip of the endoscope. In
addition to moving said obstructions, in some circumstances
(e.g. in the case of certain stones) the fluid spray jets will
also be able to cause their disintegration.
It is to be noted that although the various embodiments of the
present invention have been described hereinabove as devices
which may be inserted into the working channel of a
colonoscope or other endoscope, all of said embodiments may
equally be used in any other lumen that enables access to the
body cavity (e.g. dedicated catheter).
In an alternative version of the device of the present
invention, part or all of the length of the guidewire is
provided in the form of a helical spring. This embodiment is
advantageous in that it prevents the guidewire and attached
distal head unit exerting potentially damaging forces on the
colonic wall tissues, in the event that said head unit
inadvertently slips laterally upon exit from the working
channel during aspiration mode.
In other preferred embodiments of any of the above-described
implementations of the device of the present invention, the
distal head units of said device may be constructed as an
integral part of a colonoscope or other endoscope, rather than
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as a separate, distinct instrument that is then inserted into
the working channel of said endoscope.
