U.S. patent application number 10/746286 was filed with the patent office on 2004-09-23 for apparatus and methods for achieving endoluminal access.
This patent application is currently assigned to USGI Medical Corp.. Invention is credited to Chen, Eugene G., Ewers, Richard C., Reydel, Boris, Saadat, Vahid.
Application Number | 20040186349 10/746286 |
Document ID | / |
Family ID | 32994106 |
Filed Date | 2004-09-23 |
United States Patent
Application |
20040186349 |
Kind Code |
A1 |
Ewers, Richard C. ; et
al. |
September 23, 2004 |
Apparatus and methods for achieving endoluminal access
Abstract
The present invention provides methods and apparatus for
pleating at least a portion of a patient's body lumen, such as the
colon. Pleating is achieved via relative motion between an
endoscope and a flexible conduit having an engagement element
configured to reversibly engage the body lumen.
Inventors: |
Ewers, Richard C.;
(Fullerton, CA) ; Reydel, Boris; (West Caldwell,
NJ) ; Chen, Eugene G.; (Carlsbad, CA) ;
Saadat, Vahid; (Saratoga, CA) |
Correspondence
Address: |
TOWNSEND AND TOWNSEND AND CREW, LLP
TWO EMBARCADERO CENTER
EIGHTH FLOOR
SAN FRANCISCO
CA
94111-3834
US
|
Assignee: |
USGI Medical Corp.
Saratoga
CA
|
Family ID: |
32994106 |
Appl. No.: |
10/746286 |
Filed: |
December 23, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60436518 |
Dec 24, 2002 |
|
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Current U.S.
Class: |
600/114 ;
600/115 |
Current CPC
Class: |
A61B 1/00147 20130101;
A61B 1/00149 20130101; A61B 1/00148 20220201; A61B 1/00082
20130101; A61B 1/31 20130101 |
Class at
Publication: |
600/114 ;
600/115 |
International
Class: |
A61B 001/00 |
Claims
What is claimed is:
1. Apparatus for pleating at least a portion of a patient's body
lumen, the apparatus comprising: a first flexible conduit; and a
second flexible conduit comprising an engagement element, wherein
the second flexible conduit is configured for sliding axial
movement relative to the first flexible conduit, and wherein the
engagement element is configured to reversibly engage the patient's
body lumen.
2. The apparatus of claim 1, wherein the body lumen comprises a
lumen chosen from the group consisting of the patient's colon,
gastrointestinal lumen, small bowel, vascular lumens, and
combinations thereof.
3. The apparatus of claim 1, wherein the first flexible conduit
comprises an endoscope.
4. The apparatus of claim 1, wherein the second flexible conduit
comprises a sheath coaxially disposed about the first flexible
conduit.
5. The apparatus of claim 1, wherein the first flexible conduit
comprises a lumen, and wherein the second flexible conduit is
configured for sliding axial movement within the lumen.
6. The apparatus of claim 1, wherein the first flexible conduit
comprises a deflection tip.
7. The apparatus of claim 1, wherein the engagement element is
chosen from the group consisting of expandable spines, balloons,
distensible balloons, non-distensible balloons, expandable meshes,
expandable braids, cut tubing, expandable anchors, expandable
helices, suction elements, extendable elements, malcots, corrugated
tubes, spiral ribs, continuous engagement elements, pleat capture
elements, and combinations thereof.
8. The apparatus of claim 1, wherein the second flexible conduit is
configured to pleat the body lumen.
9. The apparatus of claim 1, wherein the first flexible conduit is
configured to pleat the body lumen and the second flexible conduit
is configured to maintain pleats formed by the first flexible
conduit.
10. The apparatus of claim 1, wherein the second flexible conduit
is adapted to transition between a flexible configuration and a
substantially rigid configuration in a desired arrangement.
11. A method for pleating a least a portion of a patient's body
lumen, the method comprising: advancing a first flexible conduit
into the body lumen; advancing a second flexible conduit having an
engagement element along the first flexible conduit; actuating the
engagement element to reversibly engage the body lumen; and
retracting the second flexible conduit relative to the first
flexible conduit, thereby pleating at least a portion of the body
lumen.
12. The method of claim 11, wherein advancing a first flexible
conduit further comprises advancing an endoscope.
13. The method of claim 11, wherein advancing the second flexible
conduit along the first flexible conduit further comprises
advancing the second flexible conduit over the first flexible
conduit.
14. The method of claim 11, wherein advancing the second flexible
conduit along the first flexible conduit further comprises
advancing the second flexible conduit through the first flexible
conduit.
15. The method of claim 11 further comprising advancing the first
flexible conduit further into the body lumen.
16. The method of claim 11 further comprising disengaging the
engagement element from the body lumen.
17. The method of claim 16 further comprising advancing a third
conduit over the first and second conduits, and maintaining body
lumen pleats with the third conduit.
18. A method for pleating a least a portion of a patient's body
lumen, the method comprising: advancing a first flexible conduit
into the body lumen; advancing a second flexible conduit having an
capture element along the first flexible conduit; engaging the body
lumen with the first flexible conduit; retracting the first
flexible conduit relative to the second flexible conduit, thereby
pleating at least a portion of the body lumen; and actuating the
capture element of the second flexible conduit to maintain body
lumen pleats.
19. The method of claim 18 further comprising advancing the first
flexible conduit further within the body lumen.
20. The method of claim 18 wherein advancing the first flexible
conduit further comprises advancing an endoscope into the body
lumen.
Description
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application claims benefit of the filing date of U.S.
Provisional Patent Application Serial No. 60/436,518, filed Dec.
24, 2002, which is incorporated herein by reference in its
entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to methods and apparatus for
achieving endoluminal access for instruments, e.g. tubular,
fiberoptic instruments, such as colonoscopes, gastroscopes, and the
like. More particularly, the present invention relates to methods
and apparatus for achieving endoluminal access via anatomical
pleating.
[0004] 2. Description of the Background Art
[0005] A physician performing a gastrointestinal examination or
treatment commonly advances a colonoscope through a patient's anus
into the patient's colon. In order to permit full examination of
the colon, the colonoscope must be advanced up to the cecum.
Advancement may be directed via a steerable distal end portion of
the colonoscope. However, at bends in the colon--namely at the
sigmoid, and especially at the two colonic flexures--advancement
problems regularly occur, including a risk of injury, pain to the
patient, cramp-like contractions of the colon, and even an
inability to further advance the colonoscope.
[0006] Such problems stem from the fact that the colon is soft and
weakly adhered to the abdomen. After a first deflection of the
colonoscope, a principal direction of force by which the
colonoscope is advanced no longer points towards the distal end of
the colonoscope, but rather points towards the readily yielding
wall of the colon. Force application is unpleasant to the patient
and precludes access to the cecum in about 10% to 15% of all
cases.
[0007] The concept of pleating or "accordionizing" the colon to
facilitate advancement of the colonoscope is described by Eubanks
et al. in Mastery of Endoscopic and Laparascopic Surgery, Eubanks,
Swantrom, Soper, pg. 337, 2000, Lippincott Williams &
Wilkins.
[0008] "If the colon were a simple noncompliant tube without
redundancy or irregularity, colonoscopic intubation would be a
rather simple endeavor of advancing the scope while following the
tip. Occasionally, especially if there has been a prior sigmoid
resection, colonoscopy may be no more demanding than simple scope
advancement. However straight advancement usually promotes the
development of loops, stretching the colon. When progression of the
scope is not impeded by severe tip deflection, the colon can be
encouraged to accordionize along the length of the scope. This is
most likely to occur if the scope is repeatedly advanced and
withdrawn. In some areas, particularly distally, this is most
effective if it is performed with small rapid strokes, referred to
as dithering the scope. Elsewhere, such as the transverse colon,
this maneuver is performed with long, gentle strokes of 30 to 50
cm."
[0009] FIGS. 1-3 describe Prior Art methods of accomplishing such
accordionization or pleating, as described by Eubanks et al. In
FIG. 1, elongation intubation of colon C through anus A is
described using colonoscope 10 having steerable deflection tip 12.
In FIG. 1A, scope 10 is advanced into proximal sigmoid S.
Deflection tip 12 then is turned into the distal descending colon
DC, as in FIG. 1B. In FIG. 1C, sigmoid S is accordionized onto
scope 10 via simultaneous clockwise torqueing, shaft withdrawal and
flattening of deflection tip 12. Further distal advancement of
scope 10 then is achievable without causing pain to the patient,
etc.
[0010] FIG. 2 describe intubation via looping. In FIG. 2A, scope 10
is inserted into sigmoid S with counterclockwise torqueing during
scope advancement. In FIG. 2B, the broad loop in the sigmoid
flattens the sigmoid-descending colon junction. Subsequent
clockwise rotation of scope 10 with concurrent withdrawal
accordionizes sigmoid S onto the scope.
[0011] FIG. 3 describe intubation of ascending colon AC. In FIG.
3A, scope 10 has a view of the ascending colon with sharp
angulation in the right colic flexure F. In FIG. 3B, transverse
colon TC is elevated into the upper abdomen via clockwise torqueing
and withdrawal of scope 10. As seen in FIG. 3C, scope 10 is then
advanced via clockwise torqueing of the scope, flattening of
deflection tip 12 and evacuation of air from the distended colon C,
thereby accordionizing the colon onto the scope. Complete
intubation of cecum Ce then is achieved by further advancing scope
10, as in FIG. 3D.
[0012] According to Eubanks et al., accordionization most
consistently enables examination of the greatest length of colon
with the least amount of scope. In contrast to techniques where the
scope is advanced up into the colon, accordionization should be
viewed as bringing the colon down over the scope.
[0013] "This technique employs simultaneous application of both
dithering and torqueing. While the shaft is being advanced
approximately 6 to 10 cm, a small amount of counterclockwise torque
of about 45 to 60 degrees is applied. The process is reversed by
applying clockwise torque and simultaneous withdrawal of the scope
for the same length. This cycle is repeated in a rhythmic manner at
a rate of about one cycle per second, but without advancement of
the shaft. It is useful to hold the shaft of the scope close to the
anus to avoid over-advancing. Although the first few
dithering/torquing cycles may appear to accomplish little, by
rhythmically continuing this motion, the cumulative effect is to
pleat a short segment of sigmoid colon onto the scope. As one
acquires experience with this technique, it soon becomes apparent
that the cyclic rhythm, amount of torque, degree of tip deflection,
and shaft advancement distance are all variables that can by
altered to achieve maximum effect. If this technique is successful,
the descending colon can be readily intubated as far as the splenic
flexure by applying clockwise torque during shaft advancement with
minimal deflection of the tip. With this approach, the endoscopist
is attempting to straighten the colon as he or she progresses,
rather than intentionally creating a loop that has to be removed
later. Several principles should be kept in mind when this
technique is performed:
[0014] 1. This method should be started early in the process of
intubation in the rectosigmoid to minimize the deflection
angle.
[0015] 2. It is not always necessary to see the entire lumen, but
one should avoid pushing directly into the colonic wall.
[0016] 3. The endoscopist should resist the temptation to advance
the scope as soon as the lumen is seen, and should continue with
this process to maximize the accordionization of the entire sigmoid
colon.
[0017] 4. Excessive gas insufflation is a deterrent to
accordionization.
[0018] 5. If this technique is not successful, one can proceed with
intentional looping."
[0019] As will be apparent, the accordionization technique
described by Eubanks et al. requires significant skill and
experience on the part of the endoscopist in order to be
successful. Furthermore, many variables must be taken into account
in order to properly accordionize the colon, including cyclic
rhythm, amount of torque, degree of tip deflection, and shaft
advancement distance. It is expected that these limitations will
hamper broad acceptance of accordionization techniques.
[0020] In view of the aforementioned limitations, it would be
desirable to provide methods and apparatus for pleating the colon
that require less skill and experience on the part of the
endoscopist.
[0021] It also would be desirable to provide methods and apparatus
that simplify and expedite pleating.
BRIEF SUMMARY OF THE INVENTION
[0022] In view of the foregoing, it is an object of the present
invention to provide methods and apparatus for pleating the colon
that require less skill and experience on the part of the
endoscopist.
[0023] It is another object of the present invention to provide
methods and apparatus that simplify and expedite pleating.
[0024] These and other objects of the present invention are
accomplished by providing apparatus that facilitates formation and
retention of colonic pleats, thereby allowing physicians to use the
scope as a tool for diagnosis and therapy, rather than as an access
tool. The apparatus engages a proximal portion of the lumen to be
intubated, and withdraws the lumen proximally over a relatively
stationary endoscope or other device. This shortens an elongated
section of luminal anatomy by compressing it in an accordion-like
fashion over the endoscope or other device.
[0025] In a first embodiment, an endoscope is partially advanced
with an external engagement sheath. The sheath then is activated to
engage the lumen wall. Once engaged, the lumen is pulled proximally
by withdrawing or rotating the sheath. In an alternative
embodiment, the scope is extended distally of the external sheath
to "hook" tissue with its deflectable tip. The scope then is
withdrawn towards the sheath, forming a pleat that is pulled back
over the sheath. Once a pleat has been formed, an engagement member
is activated on the sheath to retain the pleat.
[0026] In yet another embodiment, engagement catheters are provided
that may be advanced through the scope's working channel. The
engagement catheters are extended beyond the scope to engage tissue
and withdraw it towards the scope. The engagement catheters
optionally may be used in conjunction with an external engagement
sheath to initiate, position, and/or capture a pleat. Single
anchoring/engagement members may be used, a plurality of engagement
members may be used, a continuum of engagement members may be used,
multiple sheaths may be used, etc.
[0027] Pleating apparatus and methods of the present invention may
be utilized to gain full access into a human colon. In contrast to
known colonoscopic maneuvering techniques to shorten/straighten the
colon and aid in intubation, the present invention provides
separate pleating apparatus that may be used in conjunction with
the endoscope to replace or reduce difficult prior art scope
maneuvering techniques.
[0028] Methods of using the apparatus of the present invention also
are provided.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] The above and other objects and advantages of the present
invention will be apparent upon consideration of the following
detailed description, taken in conjunction with the accompanying
drawings, in which like reference characters refer to like parts
throughout, and in which:
[0030] FIGS. 1A-1C are side views, partially in section,
illustrating a prior art method of intubating and accordionizing
the colon via elongation;
[0031] FIGS. 2A-2C are side views, partially in section,
illustrating a prior art method of intubating and accordionizing
the colon via looping;
[0032] FIGS. 3A-3D are side views, partially in section,
illustrating a prior art method of intubating and accordionizing
the ascending colon;
[0033] FIGS. 4A-4C are side views, partially in section,
illustrating a method of intubating and pleating the colon with a
first embodiment of balloon apparatus of the present invention;
[0034] FIG. 5 is a side-sectional view of the apparatus of FIG.
4;
[0035] FIG. 6 is a side view, partially in section, illustrating
the conformable nature of the apparatus of FIG. 4;
[0036] FIG. 7 is a side view, partially in section, illustrating
pleating via an alternative, non-conforming embodiment of the
balloon apparatus of FIG. 4;
[0037] FIGS. 8A and 8B are side-sectional views of another
embodiment of apparatus in accordance with the present invention
comprising expandable spines, shown, respectively, in a collapsed
configuration and in an expanded configuration;
[0038] FIGS. 9A-9C are side views, partially in section,
illustrating a method of pleating the colon with the apparatus of
FIG. 8;
[0039] FIGS. 10A and 10B, respectively, are side and isometric
views of alternative expandable spine apparatus shown collapsed and
expanded;
[0040] FIGS. 11A-11C are side views, partially in section,
illustrating a method of pleating the colon with expandable mesh
apparatus in accordance with the present invention;
[0041] FIGS. 12A and 12B are side views of an alternative
embodiment of the apparatus of FIG. 11 comprising a multi-humped
expandable mesh, shown collapsed and expanded;
[0042] FIGS. 13A-13D are isometric and side views of an alternative
embodiment of oversheath pleating apparatus of the present
invention comprising an expandable helix;
[0043] FIGS. 14A-14C illustrate a method of pleating the colon with
a pleat capture sheath of the present invention used in conjunction
with a colonoscope;
[0044] FIGS. 15A-15C are, respectively, isometric, side-sectional,
and cross-sectional views of suction pleating apparatus of the
present invention;
[0045] FIG. 16 is a schematic view of an illustrative vacuum source
and shut-off valve for use with the apparatus of FIG. 15;
[0046] FIGS. 17A-17C are side views, partially in section,
illustrating a method of pleating the colon utilizing the apparatus
of FIG. 15 as an oversheath pleater;
[0047] FIG. 18 is a schematic view of alternative suction pleating
apparatus comprising a shape-lockable overtube;
[0048] FIGS. 19A-19D are isometric views of further alternative
suction pleating apparatus comprising various extendable
anchors;
[0049] FIG. 20 is a schematic view of pleating apparatus of the
present invention configured for delivery through the working
channel of a colonoscope;
[0050] FIGS. 21A-21D are schematic views of various alternative
engagement tips for the apparatus of FIG. 20;
[0051] FIGS. 22A-22D are side views, partially in section,
illustrating a method of using the through-scope pleating apparatus
of FIG. 20 in conjunction with the pleat capture apparatus of FIG.
14 to form and capture pleats;
[0052] FIGS. 23A-23C are side views, partially in section,
illustrating a method of pleating the colon according to the
present invention.
[0053] FIGS. 24A-24C are side views, partially in section,
illustrating a method of pleating the colon with continuous
engagement apparatus of the present invention;
[0054] FIGS. 25A-25C are side views, partially in section,
illustrating a method of pleating with alternative continuous
engagement apparatus comprising a corrugated tube;
[0055] FIGS. 26A and 26B are side views, partially in section,
illustrating a method of pleating with braided continuous
engagement apparatus;
[0056] FIG. 27 is an isometric view of continuous engagement
apparatus comprising a braided mesh and a split sheath;
[0057] FIGS. 28A and 28B are side views of cable-actuated braided
engagement apparatus of the present invention; and
[0058] FIGS. 29A and 29B are, respectively, a side view, partially
in section, and an isometric view of an alternative embodiment of
the apparatus of FIG. 28.
DETAILED DESCRIPTION OF THE INVENTION
[0059] The present invention relates to methods and apparatus for
achieving endoluminal access for instruments, e.g. tubular,
fiberoptic instruments, such as colonoscopes, gastroscopes, and the
like. More particularly, the present invention relates to methods
and apparatus for achieving endoluminal access via anatomical
pleating.
[0060] One aspect of the invention comprises a pleating sheath that
is advanceable over a colonoscope. The sheath, which preferably is
fabricated from an extrusion of plastic material, is placed over
the scope prior to use. Rounding off a leading edge or overmolding
of the sheath may provide the sheath with a soft tip of foam or
elastomer that acts as an atraumatic tip. Preferably, a metal
spring coil is embedded in the wall of the sheath to provide
flexibility in combination with kink-resistance. Alternatively, the
sheath may be fabricated with a braided component embedded in the
wall. This too allows good flexibility while maintaining
strength.
[0061] The sheath may be configured to minimize friction between
itself and the colonoscope. This may be achieved by a variety of
techniques, for example, the sheath may have internal ridges or
nubs to reduce surface contact area, roller wheels or ball bearings
may be provided in the wall to create rolling friction instead of
sliding friction, or preferably a hydrophilic coating may be
applied to the sheath's inner surface. The coating is activated by
wetting with, e.g., water or saline, and significantly reduces the
coefficient of friction between the scope and the sheath's internal
surface.
[0062] In use, the colonoscope preferably is advanced into the
colon to a desired or achievable depth. Then, the pleating sheath
preferably is back loaded up the scope or is introduced
simultaneously with the scope. An anchoring feature preferably is
provided at the tip of the sheath to engage the colon wall. The
sheath then is withdrawn while the scope is held in place or
further advanced. Withdrawal of the activated sheath pulls the
colon proximally. The sheath-engaged colon pleats along the scope
towards the anus. This shortens the colon by taking its
stretched-out natural length and "bunching up" a portion of it.
[0063] With reference to FIGS. 4-6, a pleating sheath embodiment is
described comprising an engagement member having a distensible
balloon. In FIG. 4A, pleating sheath 50 is shown advanced over
scope 10 to a bend within a patient's colon C. In FIG. 4B,
distensible balloon 60 of sheath 50 is inflated to releasably
engage the patient's colon in the vicinity of the bend. With colon
C engaged, sheath 50 is retracted relative to scope 10, thereby
pleating the colon over the scope and facilitating further
advancement of the scope, as seen in FIG. 4C. Balloon 60 then may
be deflated to disengage sheath 50 from colon C, and the sheath may
be further translated relative to scope 10. Balloon 60 may be
re-inflated, as desired, to engage the colon at additional
locations, for example, to facilitate additional pleating.
[0064] FIG. 5 illustrates lumen 52 of sheath 50, which is sized for
advancement over scope 10, as well as inflation lumen 54, which
facilitates inflation and deflation of balloon 60, e.g., via a
standard syringe coupled to a proximal region of the sheath (not
shown). The physician inflates the balloon by injecting a
prescribed amount of liquid or gas via the syringe. As seen in FIG.
6, distensible balloon 60 has the advantage of achieving a minimal
collapsed profile to aid in easy insertion, and also complies with
the anatomy wherever it is inflated. The surface of said balloon
optionally may have a texture to aid in engaging the wall of the
colon.
[0065] As seen in FIG. 7, a non-distensible balloon alternatively
may be provided. Non-distensible balloon 70 advantageously may be
preformed into a desired shape. For example, the balloon may be
formed to take on the inflated shape of a cone or "barbed"
structure that preferentially engages the colon wall upon
withdrawal. It also may have a maximum expansion size that could
not be overridden by excessive inflation volume.
[0066] Similar to the balloons described hereinabove, mechanical
structures may be used to form the expanding anchor/engagement
member. For example, as seen in FIG. 8, concentric sheaths may be
provided. Apparatus 100 comprises concentric, thin-walled inner
sheath 110 and outer sheath 120. Inner sheath 110 extends slightly
distal of outer sheath 120, and comprises inner lumen 112
configured for advancement over scope 10. Spines 130, which may
comprise slits formed in outer sheath 120 and/or may, for example,
comprise plastic, elastomeric, or metallic spines, connect the tip
of inner sheath 110 with the tip of outer sheath 120. Relative
translational motion between the two sheaths approximates the
connected tips and causes the spines to "elbow out" or expand from
the collapsed delivery profile of FIG. 8A to the expanded
engagement profile of FIG. 8B.
[0067] This relative motion may be achieved with a handle/slider
mechanism, per se known, that the user operates to expand or
contract the anchoring spines as desired. Alternatively, the
mechanism for forming the "elbowed out" spines may use
temperature-activated memory metal or plastic, in which flushing
with a particular temperature liquid causes the spines to take on a
desired profile. Electrical heating may also be used.
[0068] With reference to FIG. 9, a method of using apparatus 100 to
pleat colon C is described. In FIG. 9A, apparatus 100 is advanced
over scope 10 to a tortuous bend in the colon. Outer sheath 120 is
then advanced relative to inner sheath 110, which causes spines 130
to expand outward and reversibly engage colon C, as in FIG. 9B. In
FIG. 9C, apparatus 100 is withdrawn relative to scope 10, thereby
pleating the colon over the scope and facilitating further distal
advancement of the scope. Outer sheath 120 may then be retracted
relative to inner sheath 110 to disengage spines 130 from colon C.
This cycle of relative motion between scope 10, inner sheath 110
and outer sheath 120 may be repeated as desired at additional
distal locations within the colon to further pleat the colon.
[0069] With reference to FIG. 10, a particularly atraumatic
expanded spine structure is described. Apparatus 150 comprises
spines 160 that not only "elbow out," they also "loop out"
simultaneously to create a smooth edged expanded profile. FIG. 9A
illustrates the collapsed configuration, while FIG. 9B illustrates
the expanded configuration.
[0070] Referring now to FIG. 1, expandable, tubular-braid like
material also may be used. Braided mesh 180 of apparatus 170 is
extremely porous and compliant, yet exceptionally strong due to the
composition of numerous interlaced fibrous elements. Braid 180 is
made from individual monofilament elements combined in an opposing
helical pattern. The nature of the braided tubular structure allows
it to have two diameter states. Axial tension of opposing ends of
the braid causes it to elongate and reduce in diameter, as in FIG.
11A. Axial compression causes the braid to reduce in length while
simultaneously expanding in diameter, as in FIGS. 11B and 11C. A
disk-like anchor is made by forming two ends of a short length of
braid into small diameter collars 182A and 182B. This may be
accomplished by heat forming the mesh into continuous,
diametrically fixed bushings that transition into the braid tube.
Alternatively, the braid may be glued, overmolded, soldered, welded
onto separate bushings. These bushings are then connected to, e.g.,
co-axial sheaths 110 and 120 described above. Bringing the sheath
ends in closer proximity causes braided spines 180 to expand
outwardly into the anchoring disk of FIGS. 11B and 11C.
[0071] In FIG. 11A, apparatus 170 is coaxially advanced over scope
10 to a bend in colon C. Mesh 180 is then expanded to engage the
colon, as in FIG. 11B. Next, apparatus 170 is retracted relative to
scope 10, as in FIG. 11C, thereby pleating the colon over the scope
and facilitating further distal advancement of the scope. Mesh 180
is then collapsed, and the pleating technique may be repeated, as
needed.
[0072] With reference to FIG. 12, an alternative embodiment of
apparatus 170 is described. Apparatus 170' comprises `accordion`
mesh 180' that forms multiple humps upon expansion, as seen in FIG.
12B, but that may be reduced for coaxially translation about scope
10, as in FIG. 12A. It is expected that the multiple humps of
accordion mesh 170' will facilitate pleating of the colon by
contacting the colon over an increased surface area.
[0073] Referring now to FIG. 13, much like the expanding spines and
braid meshes described hereinabove, resilient helix 192 of
apparatus 190 may be drawn down to a low profile by attaching the
ends of the helix to concentrically-disposed inner sheath 110 and
outer sheath 120. Bringing the tube ends together expands helix
192, as in FIG. 13B, while pulling them apart collapses the helix,
as in FIG. 13A. As seen FIGS. 13C and 13D, optional elastomeric
jacket 194 may be placed over helix 192 in order to spread the
contact area over a wider location than just the helix, thereby
making the helix less traumatic. The spiral nature of expanding
helix 192 also promotes some rotational motion of the tip, like an
auger, which may help induce colon engagement or proximal motion of
the colon. Alternatively, the helix may be made of
temperature-activated memory metal or plastic, in which expansion
of the helix is activated by exposure to a liquid of a
predetermined temperature or electrical heating. Apparatus 190, as
well as the other mechanically expanding structures described
hereinabove, may be used like the balloon embodiments to engage the
colon wall, after which proximal motion of the sheath causes
pleating.
[0074] Apparatus of the present invention described with respect to
FIGS. 4-13 illustrate use of an activated pleating sheath to
actively pull back the colon wall. With reference to FIG. 14, pleat
capture sheath 200 is described, wherein colon C is pleated via
engagement anchor 210, which is used to capture pleat P formed by a
hooking maneuver conducted with deflection tip 12 of scope 10. In
FIG. 14A, scope 10 is advanced beyond a distal end of apparatus
200, deflection tip 12 is steered into a hook shape, engaged to the
colon wall, and then drawn back. The colon thereby forms pleat P
over apparatus 200, as seen in FIG. 14B. As seen in FIG. 14C,
engagement anchor 210 then may be activated to engage colon C and
create a physical stop point so that pleat P cannot spontaneously
slide forward on its own. Forming the pleat with scope 10 and
capturing it with apparatus 200 may be repeated multiple times
until the desired section of colon is available. Engagement member
210 of apparatus 200 may employ any of the engagement structures
described and illustrated previously, as well others, per se known.
In FIG. 14, engagement member 210 illustratively comprises an
expandable balloon.
[0075] Referring now to FIG. 15, suction is used commonly in the GI
tract to bring an endoscope into contact with mucosa. Accordingly,
as seen in FIG. 15A, apparatus 220 may comprise suction anchor 222
having one or more suction ports 224 disposed on a distal region of
sheath 226, for example, to pleat the colon or capture pleats
formed by scope 10. Scope 10 may be translated within lumen 227 of
sheath 226, as seen in FIG. 15B. Preferably, one or more evacuation
lumens 225 run through the sheath and attach externally to a vacuum
source (see FIG. 16). FIG. 15C illustrate exemplary alternative
cross-sections of sheath 226 along section line A-A of FIG. 15B.
Additional evacuation lumens 225 may be provided, as needed, to
couple additional suction ports 224 of suction anchor 222 to the
vacuum source. Suction-based engagement may replace any of the
expandable anchors shown and described above.
[0076] When numerous suction ports 224 are provided, a system of
vacuum shut off valves may be used to block the continuation of
suction through ports not in contact with tissue. For example, as
shown in FIG. 16, each port 224 may be coupled to vacuum source 230
via a vacuum line 232 having a valve 234. Each valve may comprise
chamber 235 having aperture 236 through which cork 237 may be
removably disposed to prevent flow therethrough. Cork 237 may be
coupled to compression spring 238 that biases the cork from
occluding aperture 236 when its associated port 224 is in contact
with tissue. When associated suction port 224 is not in contact
with tissue, vacuum source 230 aspirates cork 237 against the
biasing force of compression spring 238 to occlude aperture 236,
thereby decoupling vacuum source 230 from the non-contacting port
224. This prevents apparatus 220 from spontaneously adhering to
different places after an initial acceptable anchoring occurs.
Also, this feature prevents a continual evacuation of insufflation
gas after anchoring is achieved. Generally, a quantity of gas
pressure is desired in the colon to help tent it so that it is more
easily accessed and visualized.
[0077] With reference to FIG. 17, a method of using apparatus 220
as a pleating oversheath to pleat the colon is described. As will
be apparent, apparatus 220 alternatively may be used to capture
pleats formed via deflection tip 12 of scope 10. In FIG. 17A,
apparatus 220 is translationally advanced over scope 10. Activation
of vacuum source 230 causes distal vacuum ports 224 of vacuum
anchor 222 to attach to mucosa along the wall of colon C, as in
FIG. 17B. As seen in FIG. 17C, vacuum-anchored sheath 226 then is
withdrawn relative to scope 10, thereby pleating the colon as
described previously.
[0078] Advantageously, vacuum anchor 222 provides apparatus 220
with a small profile, even while engaging tissue. A degree of
anchoring achievable with apparatus 220 may be specified, for
example, by controlling the size of vacuum ports 224, the strength
of suction applied by vacuum source 230, and inclusion of safety
vents. An optional release mechanism (not shown) may also be
provided, whereby suction anchor 222 releases colon C when sheath
226 is retracted with sufficient force.
[0079] Suction anchor 222 may have numerous configurations. For
example, suction port(s) 224 may be configured as a single point,
an elongated window, or multiple windows. Furthermore, port(s) 224
may be located at a specific position along the wall of sheath 226,
or may be distributed about the diameter or circumference.
[0080] Referring now to FIG. 18, alternative suction anchoring
apparatus in accordance with the present invention is described.
Apparatus 240 comprises shape-lockable overtube 250 having suction
anchor 222 disposed on a distal end of the overtube. Apparatus 250
further comprises actuation handle 260 disposed at a proximal end
of overtube 250 for reversibly transitioning the overtube from a
flexible configuration to a substantially rigid configuration while
the overtube is disposed in a desired arrangement. Shape-lockable
overtubes are described in greater detail in Applicant's co-pending
U.S. patent application Ser. No. 10/281,462, filed Oct. 25, 2002,
which is incorporated herein by reference in its entirety. Suction
activation valve 252, as well as suction conduit 254 for attaching
to vacuum source 230, is also coupled to handle 260.
[0081] Apparatus 240 may be used to pleat a patient's colon in a
manner similar to that described for apparatus 220 in FIG. 17.
Handle 260 may then be actuated to reversibly rigidize overtube 250
and maintain the colon in the pleated configuration. Scope 10 may
be advanced through handle 260 and overtube 250.
[0082] Referring to FIG. 19, to enhance engagement of suction ports
to the colon wall, the suction ports may be configured to extend
beyond the sheath. Such deployable ports advantageously facilitate
contacting of the colon wall over a larger surface area, thereby
enhancing holding force. Various low profile or deployable
appendages may be utilized. In FIG. 19A, apparatus 270 comprises a
plurality of ported coils 272 that may be extended out of sheath
271 to "find" and engage the colon wall. In FIG. 19B, apparatus
270' comprises thin, elongated suction pad 274 that extends from
sheath 271. In FIG. 19C, apparatus 270" comprises pre-shaped,
ported tube 276 that may be advanced out of sheath 271 to form a
helical suction pad. In FIG. 19D, apparatus 270'" comprises
elastomerically coated mesh hose or braid 278 that may be extended
from sheath 271 to form a large-surface-area suction funnel.
Additional extendable suction anchors will be apparent to those of
skill in the art.
[0083] Apparatus and methods of the present invention described
thus far comprise apparatus configured for advancement over scope
10 in order to pleat the colon. An alternative method for engaging
the colon and creating pleats employs tools disposed through the
working channel of the scope. With reference to FIG. 20, catheter
300 with expanding tip 310 may be advanced through working channel
14 beyond the distal tip of scope 10, and then activated to engage
the colon distal of the scope. Withdrawal of the catheter relative
to the scope pulls the colon back towards the scope tip, thereby
causing a pleat to form on the scope. Expanding tip 310 may
comprise any of the expanding structures described previously,
including suction.
[0084] FIG. 21 illustrate various embodiments of catheter 300. In
FIG. 21A, expandable tip 310 of catheter 300' comprises Malcot 312.
In FIG. 21B, tip 310 of catheter 300" comprises helix 314. Catheter
300'" of FIG. 21C comprises hook 316, while catheter 300"" of FIG.
21D comprises pre-shaped suction tube 318. Additional engagement
tip will be apparent to those of skill in the art.
[0085] Engagement catheter 300 may be used in conjunction with
oversheath pleating apparatus and/or pleat engagement/capture
sheaths described previously to induce and/or capture colon pleats.
In FIG. 22, a balloon engagement tip embodiment of catheter 300 is
used in conjunction with scope 10 and pleat capture sheath 200 of
FIG. 14 to pleat colon C. In FIG. 22A, catheter 300 is advanced
through working channel 14 of scope 10, such that balloon
engagement tip 310 is disposed distal of the scope. Sheath 200 is
advanced over scope 10 to a position proximal of the distal end of
the scope. Balloon engagement tip 310 of catheter 300 then is
activated to engage and anchor against the colon, as in FIG. 22B.
In FIG. 22C, catheter 300 is withdrawn relative to scope 10 and
sheath 200, thereby pleating the colon. Engagement anchor 210 of
pleat capture sheath 200 then is activated to capture pleat P, as
seen in FIG. 22D. Catheter 300 then may be de-activated and
advanced again to engage a new section of colon C.
[0086] Referring now to FIG. 23, an embodiment of the present
invention is described comprising multiple external sheaths and
anchors. Apparatus 350 comprises a balloon-tipped, Mother-Daughter
sheath assembly having mother sheath 352 with balloon 353 and
daughter sheath 354 with balloon 355. Sheaths 352 and 354 may be
used to "hand over hand" pull the colon proximally, in which each
sheath operates similar to the balloon tipped sheath initially
described. Providing multiple engagement sheaths facilitates more
intricate pleating of the colon.
[0087] The Mother-Daughter sheath assembly of apparatus 350 may be
introduced over scope 10, as seen in FIG. 23A. In FIG. 23B, balloon
353 of mother sheath 352 is activated to anchor colon C to the
mother sheath, and daughter sheath 354 is advanced with scope 10.
Simultaneously, mother sheath 352 is withdrawn, thereby pleating a
portion of the colon. Balloon 355 of daughter sheath 354 then is
activated, as seen in FIG. 23C, and the daughter sheath is
withdrawn relative to the scope. Immediately after activation of
daughter balloon 355, mother balloon 353 is deflated. As daughter
sheath 354 completes its withdrawal, a new section of colon C is
pleated over deflated mother balloon 355. The mother balloon then
is re-inflated, capturing the two sections of colon in a pleat.
Daughter balloon 355 then is deflated, and daughter sheath 354 is
advanced again into a new section of the colon. This procedure may
be repeated as many times as desired, and the sheaths may be
advanced and inflated as far as, and as much as, desired.
[0088] Such stepwise formation of a pleat alternatively may be
achieved in a similar mother-daughter manner using any of the other
expanding or suction anchors described previously. Furthermore, the
sheaths of apparatus 350 optionally may be moved relative to one
another, and/or the balloons inflated and deflated, using a
mechanical or electromechanical actuator. The actuator may include
a handle/slider that is coupled to reciprocating inflation
bladders. The arrangement may be actuated by repeatedly engaging a
trigger or slide by the user.
[0089] With reference now to FIG. 24, a continuous anchor/pleating
engagement sheath is described. Apparatus 400 comprises sheath 410
having external thread-like spiral rib 420. The spiral rib may
comprise, for example, an elongated balloon that is introduced in a
low profile deflated state. Once in a desired position, rib 420 may
be activated by inflation, and then used to rotationally draw the
colon into a pleat.
[0090] As seen in FIG. 24A, sheath 410 is slid into place over
scope 10. In FIG. 24B, a secondary twisting rotation engages colon
C along rib 420, which draws the colon down the length of sheath
410 like an auger and pleats the colon, as in FIG. 24C. Colon C
alternatively may be pleated by initially screwing apparatus 400
into position, with no linear advancement of sheath 410 over scope
10. The sheath would be positioned slightly in the rectum and
rotated to bring the colon down over it. Preferably, a hybrid
motion comprising some linear advancement and some twisting would
be used to achieve pleating.
[0091] With reference to FIG. 25, another embodiment of a
continuous engagement sheath is described comprising an expandable
corrugated tube. In FIG. 25A, expandable tube 452 of apparatus 450
is inserted into colon C in its extended collapsed form. Apparatus
450 comprises a thin walled inner sheath (not shown) attached to
the distal tip of tube 452. Retracting the inner sheath while
holding the outer corrugated tube stationary causes the
corrugations to expand outward and engage the colon wall, as in
FIG. 25B. Tube 452 may be used to actively engage the mucosa, or
the enhanced frictional surface of the compressed corrugations may
engage the length of the colon wall. As corrugations form along
tube 452 due to withdrawal of the inner sheath, the sheath tip
moves proximally, bringing with it the engaged colon, as in FIG.
25C. Apparatus 450 may be further retracted after
expansion/corrugation of tube 452 to further pleat the engaged
colon.
[0092] FIG. 26 illustrate yet another embodiment of apparatus of
the present invention that continuously engages the colon wall.
Apparatus 470 comprises expanding braid tube or sleeve 480 that is
disposed over inner sheath 490. As the inner sheath is pulled
proximal while the braid sleeve is held at anus A, as in FIG. 26A,
the distal tip junction of sleeve 480 and sheath 490 is withdrawn
down the colon. This is accompanied by the textured braid sleeve
expanding to engage the colon wall. Continued withdrawal of the
inner sheath pulls the tip back further and continues braid
expansion, thereby engaging and pleating the colon, as in FIG. 26B.
Apparatus 470 is similar to apparatus 170 of FIG. 11, as well as
apparatus 170' of FIG. 12, except that engagement braid 480 is
disposed over a substantially greater longitudinal distance along
the apparatus.
[0093] With reference to FIG. 27, apparatus 500 comprises braid
tube or sleeve 510 coupled at its distal end to inner sheath 520.
The inner sheath comprises optional split or seam 522, such that as
it is removed from the colon it can be "pealed" away from scope 10.
Split 522 may comprise a thinning in the wall of sheath 520 to
facilitate tearing thereof, or may comprise a zipper or other
similar mechanism to permit the sheath to be reformed even after it
has been split. The split sheath is beneficial in that it would not
occupy space over the scope's shaft outside of the patient; many
colonoscopists value the ability to hold the scope shaft directly
near the anus to obtain adequate feel of the scope and optimum
scope maneuvering.
[0094] Another feature demonstrated by a braid pleating sleeve is
its ability to be very flexible in its elongated state. When it is
compressed it has a tendency to straighten and feel much firmer.
The braid pleating sheath therefore may act as a flexibly placed
pleating sheath that transforms into a sturdy, more conventional
straightening tube after activation.
[0095] Referring now to FIG. 28, further alternative pleating braid
apparatus is described. When pleating with apparatus 470', inner
sheath 490' is left in position, and pleating braid 480' is
withdrawn or extended by activating opposing cables A and B. Distal
bushing C of the pleating braid may be coupled to one or more
pleat-forming cables B and one or more return cables A, as seen in
FIG. 28A. When cable B is tensioned, distal collar C is drawn in
the proximal direction towards the proximal bushing, thereby
pleating the braid and inducing the colon to pleat. When cable A is
tensioned and cable B is released, distal bushing C may be pulled
in the distal direction to return the braid to its elongated,
non-pleated state. To reciprocate tension between cables A and B,
lever arm Ar having pivot P may be coupled to the cables. As
illustrated in FIG. 28B, when a user turns the lever arm in the
counterclockwise direction, cable B is tensioned, taking up slack
within cable A. Similarly, when the lever arm is turned in the
clockwise direction, cable A is tensioned, and slack within cable B
is taken up.
[0096] With reference to FIG. 29, an alternative cable-controlled
pleating sleeve is shown. Apparatus 550 comprises pleat-forming
cables C and D, which extend from distal slide collar 552, through
proximal fixed collar 554 and out of the patient. Apparatus 550
further comprises return cables A and B, which extend from distal
slide collar 552 through sheath 560 and out of the patient. It may
be preferential to have this arrangement mirrored to better balance
the cable forces. For clarity of the sketch, mirrored cables are
not shown in FIG. 29.
[0097] Although preferred illustrative embodiments of the present
invention are described above, it will be evident to one skilled in
the art that various changes and modifications may be made therein
without departing from the invention. For example, although the
apparatus has been described as suited for pleating the colon, it
should be understood that the apparatus alternatively may be used
to pleat any other suitable body lumen, for example, alternative
portions of the gastrointestinal lumen, the small bowel, vascular
lumens, etc. It is intended in the appended claims to cover all
such changes and modifications that fall within the true spirit and
scope of the invention.
* * * * *