U.S. patent application number 12/175274 was filed with the patent office on 2009-01-29 for overtube introducer for use in endoscopic bariatric surgery.
Invention is credited to Daniel J. Balbierz, Carlos E. Castro, David Cole, Samuel T. Crews, Melanie L. Harris, Jason S. Stewart.
Application Number | 20090030284 12/175274 |
Document ID | / |
Family ID | 39791305 |
Filed Date | 2009-01-29 |
United States Patent
Application |
20090030284 |
Kind Code |
A1 |
Cole; David ; et
al. |
January 29, 2009 |
OVERTUBE INTRODUCER FOR USE IN ENDOSCOPIC BARIATRIC SURGERY
Abstract
This application describes an overtube device that gives
diagnostic and/or therapeutic access to body cavities using natural
orifices of the body. The overtube includes an elongate flexible
body having a distal portion deflectable in response to activation
of a control cable. Proximal features of the overtube include an
insufflations port and seals for minimizing loss of insufflations
pressure around the shafts of instruments passed through the tube.
In some embodiments, retractor elements are including on the distal
portion of the overtube.
Inventors: |
Cole; David; (San Mateo,
CA) ; Harris; Melanie L.; (Mountain View, CA)
; Castro; Carlos E.; (San Jose, CA) ; Stewart;
Jason S.; (Redwood City, CA) ; Crews; Samuel T.;
(Woodside, CA) ; Balbierz; Daniel J.; (Redwood
City, CA) |
Correspondence
Address: |
STALLMAN & POLLOCK LLP
353 SACRAMENTO STREET, SUITE 2200
SAN FRANCISCO
CA
94111
US
|
Family ID: |
39791305 |
Appl. No.: |
12/175274 |
Filed: |
July 17, 2008 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
60950584 |
Jul 18, 2007 |
|
|
|
Current U.S.
Class: |
600/206 |
Current CPC
Class: |
A61B 17/0218 20130101;
A61B 1/00135 20130101; A61B 1/00078 20130101; A61B 1/2736 20130101;
A61B 1/0051 20130101 |
Class at
Publication: |
600/206 |
International
Class: |
A61B 1/32 20060101
A61B001/32 |
Claims
1. An endogastric overtube for use in a stomach of a patient,
comprising: a flexible elongate tube having a proximal end and a
distal end, the tube proportioned such that when the distal end is
in the stomach, the proximal end is positioned outside the patient,
the tube including at least one lumen extending from the proximal
end to the distal end, the tube having a maximum outer diameter of
at least approximately 10 mm; and a control cable extending through
a wall of the tube, the control cable coupled to a distal portion
of the tube such that engagement of the control cable causes
deflection of the distal portion.
2. The endogastric overtube of claim 1, wherein the tube further
includes a reinforcement on a distal portion of the tube.
3. The endogastric overtube of claim 2, wherein the tube is a
formed of polymeric material and wherein the reinforcement is
embedded within the polymeric material.
4. The endogastric overtube of claim 2, wherein the tube is a
formed of polymeric material and wherein the reinforcement is
positioned on an inner surface of the lumen or an outer surface of
the tube.
5. The endogastric overtube of claim 2, wherein the reinforcement
is a resilient coil.
6. The endogastric overtube of claim 2, wherein the reinforcement
is at least one resilient ring.
7. The endogastric overtube of claim 2, wherein the reinforcement
is at least one partial ring.
8. The endogastric overtube of claim 6, wherein the resilient ring
is circular.
9. The endogastric overtube of claim 6, wherein the resilient ring
is elliptical.
10. The endogastric overtube of claim 2, wherein the reinforcement
includes a mesh element.
11. The endogastric overtube of claim 2, wherein the lumen has a
diameter, and wherein the tube is expandable from a first position
to a second position in response to introduction of an instrument
having a diameter exceeding the lumen diameter into the lumen, and
wherein the reinforcement is configured to restore the tube to the
first position upon removal of the instrument from the lumen.
12. The endogastric tube of claim 1, further including a removable
atraumatic tip on the distal end.
13. The endogastric tube of claim 12, wherein the atraumatic tip is
positioned on an elongate member extending through the lumen.
14. The endogastric tube of claim 12, wherein the atraumatic tip is
a cap at least partially covering the distal end of the tip.
15. The endogastric tube of claim 12, wherein the elongate element
is retractable in a proximal direction to invert the cap into the
lumen.
16. The endogastric tube of claim 12, wherein the elongate element
is advanceable in a distal direction to collapse the cap into a
collapsed position, and wherein the elongate element is
retractactable to withdraw the cap in the collapsed position
through the lumen.
17. The endogastric tube of claim 5, wherein the control cable is
coupled to the spring element.
18. The endogastric tube of claim 1, further including a retractor
element on the distal end of the tube, the retractor element
moveable from a first position to a second position in which the
retractor element extends laterally from the tube.
19. The endogastric tube of claim 18, wherein the retractor element
extends longitudinally when in the first position.
20. The endogastric tube of claim 18, wherein the retractor element
includes a first portion coupled to a first ring and a second
portion coupled to a second ring, and wherein relative movement of
the second ring towards the first ring moves the retractor element
from the first position to the second position.
21. The endogastric tube of claim 20, wherein the retractor element
includes a hinge, and wherein the first portion and the second
portion are on opposite sides of the hinge.
22. The endogastric tube of claim 20, wherein the first portion is
an elongate member, and wherein the second portion is a pivot
element pivotably coupled between the elongate member and the
second ring.
23. The endogastric tube of claim 18 wherein the retractor element
includes a mount for receiving an implant to be implanted in the
stomach.
24. The endogastric tube of claim 1, further including a retractor
element on the distal end of the tube, the retractor element
including a plurality of segments and a cable extending between the
segments, the retractor having a first, flexible, position and a
second, more rigid, position, the cable retractable to move the
retractor from the first to the second position.
25. The endogastric tube of claim 24, wherein the segments are
positioned on a cable loop and wherein the retractor element in the
second position forms a retractor hoop.
26. The endogastric tube of claim 25, further including a second
retractor element including a plurality of second segments and a
second cable extending between the segments, the second cable
retractable to move the second retractor from a flexible position
to a more rigid position.
27. The endogastric tube of claim 26, wherein the second retractor
in the second position forms a retractor hoop.
28. The endogastric tube of claim 1, wherein the tube includes a
seal positioned to seal against an instrument inserted into the
lumen.
29. The endogastric tube of claim 1, wherein the proximal portion
of the tube includes a port positionable in fluid communication
with a source of insufflation gas.
30. The endogastric tube of claim 1, wherein the tube has a maximum
outer diameter of between approximately 10 mm-20 mm.
31. The endogastric tube of claim 30, wherein the tube has a
maximum out diameter of between approximately 15 mm-20 mm.
32. The endogastric tube of claim 30, wherein the tube has a
maximum outer diameter of approximately 20 mm.
33. The endogastric tube of claim 1, wherein the tube has a maximum
outer diameter of approximately 18-22 mm.
34. The endogastric tube of claim 1, wherein the tube has a maximum
wall thickness of 0.1-0.2 mm.
35. An endogastric overtube for use in a stomach of a patient,
comprising: a flexible elongate tube having a proximal end and a
distal end, the tube proportioned such that when the distal end is
in the stomach, the proximal end is positioned outside the patient,
the tube including at least one lumen extending from the proximal
end to the distal end, the tube having a maximum outer diameter of
at least approximately 10 mm; and a retractor element on the distal
end of the tube, the retractor element moveable from a first
position to a second position in which the retractor element
extends laterally from the tube.
36. The endogastric tube of claim 35, wherein the retractor element
extends longitudinally when in the first position.
37. The endogastric tube of claim 35, wherein the retractor element
includes a first portion coupled to a first ring and a second
portion coupled to a second ring, and wherein relative movement of
the second ring towards the first ring moves the retractor element
from the first position to the second position.
38. The endogastric tube of claim 37, wherein the retractor element
includes a hinge, and wherein the first portion and the second
portion are on opposite sides of the hinge.
39. The endogastric tube of claim 37, wherein the first portion is
an elongate member, and wherein the second portion is a pivot
element pivotably coupled between the elongate member and the
second ring.
40. The endogastric tube of claim 37, wherein the retractor element
includes a mount for receiving an implant to be implanted in the
stomach.
41. The endogastric tube of claim 35, further including a retractor
element on the distal end of the tube, the retractor element
including a plurality of segments and a cable extending between the
segments, the retractor having a first, flexible, position and a
second, more rigid, position, the cable retractable to move the
retractor from the first to the second position.
42. The endogastric tube of claim 41, wherein the segments are
positioned on a cable loop and wherein the retractor element in the
second position forms a retractor hoop.
43. The endogastric tube of claim 42, further including a second
retractor element including a plurality of second segments and a
second cable extending between the segments, the second cable
retractable to move the second retractor from a flexible position
to a more rigid position.
44. The endogastric tube of claim 43, wherein the second retractor
in the second position forms a retractor hoop.
45. The endogastric tube of claim 35, wherein the tube includes a
seal positioned to seal against an instrument inserted into the
lumen.
46. The endogastric tube of claim 35, wherein the proximal portion
of the tube includes a port positionable in fluid communication
with a source of insufflation gas.
47. The endogastric tube of claim 35, wherein the tube has a
maximum outer diameter of between approximately 10 mm-20 mm.
48. The endogastric tube of claim 47, wherein the tube has a
maximum out diameter of between approximately 15 mm-20 mm.
49. The endogastric tube of claim 35, wherein the tube has a
maximum outer diameter of approximately 20 mm.
50. The endogastric tube of claim 35, wherein the tube has a
maximum outer diameter of approximately 18-22 mm.
51. The endogastric tube of claim 35, wherein the tube has a
maximum wall thickness of 0.1-0.2 mm.
Description
PRIORITY
[0001] This is application claims priority to U.S. Provisional
Application No. 60/950,584, filed Jul. 18, 2007
BACKGROUND OF THE INVENTION
[0002] This application describes an overtube/introducer device
that gives access to body cavities using natural orifices of the
body (e.g., esophagus, anus, vagina) for a variety of therapeutic
and/or diagnostic procedures. In a particular application, the
overtube/introducer enables the introduction of devices into the
gastrointestinal tract of a patient via the mouth and esophagus.
Therapies to be carried out using the introducer can include
procedures designed for the treatment of obesity. The disclosed
overtube provides in and out access to the targeted procedural site
and protects the body tissue during the procedure from trauma.
[0003] The disclosed overtube is suitable for use in an exemplary
procedure in which the geometry of the stomach is modified and
implantable devices are deployed. The procedure is preferably
performed entirely through the naturally existing orifice of the
mouth, without additional external incisions.
[0004] The exemplary procedure is initiated with the introduction
of an overtube into the mouth and, at a minimum, past the pharynx
of a patient but preferably reaching and sealing against the lower
esophageal sphincter (LES). For reference, FIG. 1 shows the anatomy
of the human head and stomach, with reference numerals identifying
the following features: [0005] 1. Body of stomach [0006] 2. Fundus
[0007] 3. Anterior wall [0008] 4. Greater curvature [0009] 5.
Lesser curvature [0010] 6. Lower esophageal sphincter
(LES)/gastroesophageal junction [0011] 9. Pyloric sphincter [0012]
10. Pyloric antrum [0013] 11. Pyloric canal [0014] 12. Angular
notch [0015] 13. Gastric Canal [0016] 14. Rugal folds
[0017] The entire exemplary procedure is preferably performed under
direct endoscopic visualization, obtained by inserting a flexible
endoscope into the overtube prior to its introduction into the
patient, though the procedure (or individual steps of the
procedure) may also be performed without direct visualization. In
cases where an endoscope is used, the endoscope's distal tip may be
inserted into a flexible Bougie that incorporates a central lumen
allowing direct line-of-sight for the endoscope's illumination and
visualization optics. The endoscope with the installed Bougie may
then be inserted into the overtube's central lumen until the Bougie
protrudes just past the overtube's distal end. This provides a
gentle leading edge that facilitates insertion of the Bougie,
overtube and endoscope into the patient's esophagus.
[0018] Alternatively the overtube may be inserted over a guide
wire; the guidewire inserted under direct visualization using a
standard endoscope. A transition member is positioned between the
inside diameter of the overtube and the outside diameter of the
guidewire providing for a smooth transition. This transition is
preferably a long taper, and composed of a soft, flexible material
such as silicone.
[0019] Once the overtube, endoscope and Bougie have reached the
desired position within the esophagus, the endoscope and Bougie are
withdrawn from the overtube, and the overtube is left in position.
The overtube is now in a position to facilitate the introduction of
other tools and devices needed to perform subsequent steps.
[0020] With the overtube in the desired position, a special-purpose
stapler is inserted which will be used to prepare sites within the
stomach wall tissue that will serve as mounting points for
implantable devices to be installed in later steps. Staplers
suitable for this procedure include those disclosed in the
following U.S. Applications: [0021] U.S. application Ser. No.
11/542,457, filed Oct. 3, 2006, Attorney Docket BARO-1110; [0022]
U.S. application Ser. No. 11/900,757, filed Sep. 13, 2007, Attorney
Docket BARO-1310. [0023] U.S. application Ser. No. 12/119,329,
filed May 12, 2008, Attorney Docket BARO-1610. [0024] U.S.
application Ser. No. 12/050,169, filed Mar. 18, 2008, Attorney
Docket BARO-1900.
[0025] In one such stapler, the leading distal tip of the stapler
mechanism is covered with a compliant, bullet-shaped, Bougie end
cap, and incorporates a side-looking window. The smooth Bougie
shape of the end cap facilitates introduction of the stapler into
the overtube and past the distal end of the overtube into the
patient's esophagus or stomach. The side window allows stomach wall
tissue to be drawn between the stapler jaws prior to the
application of staples. The stapler incorporates a passive flexible
length which allows the device to bend freely between the user
controls at the proximal end and the stapler mechanism at the
distal end. Insertion of the stapler is preferably performed under
direct endoscopic visualization, with an endoscope positioned next
to the stapler such that its camera optics are located slightly
proximal of the stapler's distal end. In this way, the position of
the stapler may be visualized at all times, relative to its
position within the overtube, esophagus and stomach. However,
insertion of the stapler may optionally be performed without using
an endoscope for visualization.
[0026] With the stapler inserted into the stomach, it may then be
positioned relative to the stomach wall near the lower esophageal
sphincter as desired. In order to achieve the desired position and
visualization, it may be necessary to withdraw or further insert
the overtube, or to manipulate certain features of the overtube, in
such a way that it advantageously alters the geometry of the tissue
and/or the overtube's relative position. When the position of the
stapler is judged to be correct, suction is applied to draw stomach
wall tissue into the stapler end cap's side-looking window. This
positions the stomach wall tissue between the jaws of the stapler,
which are then approximated via a physician-controlled actuator to
clamp the tissue firmly in position. Once the tissue has been
securely fixtured, the suction may be released, as it is no longer
needed to retain the stomach tissue. Staples are then deployed by
means of a second physician-controlled actuator through the
plication, or fold, of stomach tissue between the stapler's jaws to
create circular rings about a central point. A hole is created in
the plication of stomach tissue at the center of the pattern of
stapes simultaneous to the application of the staples. The hole and
surrounding circular array of staples create a secure and durable
mounting point (e.g., for implantable devices), and will be used in
later steps of the procedure. Once the staples have been deployed
and the mounting point has been created, the physician releases the
plication from the stapler's jaws and any remaining suction. The
stapler and endoscope are then withdrawn from the overtube.
[0027] For staplers that must be re-loaded prior to the creation of
the next mounting point, the stapler is withdrawn from the overtube
and the distal stapling mechanism is then reloaded. For
self-reloading stapler mechanisms, this step is not required. If
reloading is required and has been performed, the reloaded device,
Bougie end cap and endoscope are reinserted into the overtube. The
process of positioning the stapler mechanism within the stomach
described above is repeated so that the next mounting point is
identified and created. This process is repeated to produce one or
more anchor points, but preferably four mounting points are
created. These mounting points may be anywhere within the stomach,
but they are preferably located at the 3, 6, 9 and 12 o'clock
positions, a fixed distance away from the lower esophageal
sphincter. If the mounting points are to be used as anchor points
for a flow restrictor of the type used to restrict/obstruct passage
of food from the esophagus into the stomach, the preferential
distance of the mounting points is such that the position of the
exit of a restrictor attached at the mounting points will be
immediately adjacent the lower esophageal sphincter. Exemplary
restrictor devices include but are not limited to those disclosed
in U.S. Pat. Nos. 6,675,809, 6,845,776, 7,097,665, and 7,146,984,
U.S. application Ser. No. 10/345,666, filed Jan. 16, 2003, Attorney
Docket No. BARO-300, and U.S. application Ser. No. ______,
Endoscopic Implant System and Method, Attorney Docket BARO-2010,
filed Jul. 17, 2008.
[0028] Once the desired mounting points have been created with the
stapler, the stapler is withdrawn. Next, highly compliant anchors
are installed through the hole at the center of each of the
mounting points. The anchors have a rivet-like shape with large
retaining heads on either end. The anchors are intended to be
installed in the holes at the center of the mounting points, remain
in position indefinitely or until removed, and be easily removable.
The anchors are configured such that they may be grasped and pulled
from one end (herein referred to as the "leading end"), and the
resulting tension causes the leading end retaining head to change
profile so that it may be drawn through the hole in a mounting
point. The other end of the anchor (herein referred to as the
"following end") is designed so that tension resulting from drawing
it through the mounting hole does not result in a change to its
profile, so it cannot be drawn through the mounting hole. Anchors
of this type are described in U.S. application Ser. No. ______,
Endoscopic Implant System and Method, Attorney Docket BARO-2010,
filed Jul. 17, 2008
[0029] Anchors are positioned in each of the mounting holes by
means of graspers or similar instruments, which pull them, leading
end first, through the mounting holes. Once the anchors are
installed, the instruments required to insert them are withdrawn
from the overtube.
[0030] Finally, a restrictor is inserted into the stomach via the
overtube. The restrictor is attached to the anchors, and will
remain in the stomach after the procedure for an indefinite period
of time, such as the point in time when a physician determines the
patient has achieved sufficient weight loss. The restrictor is
attached to the anchors by drawing the leading end of the anchors
through mounting holes in the restrictor using graspers or other
instruments, as appropriate.
[0031] When the restrictor is attached to the anchors, the
procedure is complete and the overtube may be withdrawn from the
patient, along with any tools remaining in the lumen it defines
(e.g., endoscope, graspers, etc.).
[0032] Upon completion of the procedure, the overtube has enabled
the deployment of a restrictor, which is attached to anchors that
have been implanted into stapled plications in the stomach wall.
The passage of food into the stomach from the esophagus has been
restricted, altering the patient's feelings of satiety and eating
habits.
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] FIG. 1 schematically illustrates certain aspects of the
anatomy of the head and stomach;
[0034] FIG. 2 is a side elevation view of an embodiment of an
overtube
[0035] FIG. 3 is a side elevation view of a distal portion of the
overtube of FIG. 2.
[0036] FIG. 4A is a side elevation view of an alternate portion of
an overtube, showing expansion of the distal portion in response to
introduction of an instrument into the overtube.
[0037] FIG. 4B illustrates a reinforcing ring suitable for use in
the deformable overtube of FIG. 4A and shows degrees of deformation
of the reinforcement ring in response to instrument advancement
through the overtube.
[0038] FIG. 4C is a cross-section view of the tube of FIG. 4A,
shown as transparent to permit viewing of an alternate
reinforcement. The figure shows deformation of the reinforcement
ring in response to instrument advancement through the overtube.
FIG. 4D is similar to FIG. 4C and shows yet another alternate
reinforcement.
[0039] FIG. 5A-5C are a sequence of steps illustrating one
embodiment of an overtube manufacturing technique
[0040] FIG. 6A shows three cross-section views of arrangements of
alternating thermoplastic elements with and without wire cores that
may be used to form a wall of an overtube in the method of FIGS.
5A-5C.
[0041] FIG. 6B is a longitudinal cross-section view of one
embodiment of an overtube made using thermoplastic and wire core
arrangements of the type shown in FIG. 6A.
[0042] FIGS. 6C and 6D is similar to the drawings of FIG. 6A but
shows an alternate arrangement of thermoplastic elements and wire
core elements.
[0043] FIG. 7 illustrates an alternate method of making an overtube
using a thin sheet of thermopolymer or other suitable material.
[0044] FIGS. 7A-7B are cross-section views illustrating various
lumen arrangements for the overtube.
[0045] FIG. 8 is a side elevation view of a distal portion of an
overtube having a bougie positioned at its distal end.
[0046] FIG. 8A is a side elevation view of a distal portion of an
overtube having a transition member and endoscope extending from
its distal end.
[0047] FIG. 8B is a side elevation view of a distal portion of an
overtube having a transition member and a guidewire endoscope
extending from its distal end.
[0048] FIG. 9A is a side elevation view of a distal portion of an
overtube having an umbrella-shaped leading element.
[0049] FIG. 9B is similar to FIG. 9A and illustrates inversion of
the umbrella element for withdrawal.
[0050] FIG. 9C is similar to FIG. 9A and illustrates advancement
and collapse of the umbrella element for withdrawal.
[0051] FIG. 10 is a side elevation view of a distal portion of an
overtube having spreadable finger elements.
[0052] FIG. 11A is a side elevation view of a distal portion of a
second embodiment of an overtube having spreadable finger elements,
showing the finger elements in the retracted position.
[0053] FIG. 11B is similar to FIG. 11A and shows the finger
elements in the expanded position.
[0054] FIG. 12A shows an alternative arrangement of finger elements
which may be positioned on the distal end of an overtube as in FIG.
10.
[0055] FIG. 12B shows the finger elements of FIG. 12A in a
partially expanded position.
[0056] FIG. 12C shows the finger elements of FIG. 12A in the fully
expanded position.
[0057] FIGS. 13A and 13B are perspective views of the distal
portion of an overtube showing alternative shapes finger elements
at the distal end of an overtube.
[0058] FIG. 13C is a perspective view of a vacuum cup positioned on
a finger element.
[0059] FIG. 13D is a perspective view of a distal portion of an
overtube showing an implant device mounted to the finger
elements.
[0060] FIG. 14 is a perspective view illustrating a control
mechanism for use with expandable members such as the finger
elements of FIGS. 10-13D.
[0061] FIG. 15 is a perspective view illustrating a distal portion
of an overtube having an alternate arrangement of expandable
elements in the form of a pair of expandable hoops.
[0062] FIG. 16 is a side elevation view of an embodiment of an
overtube having an articulating distal portion.
[0063] FIG. 17A illustrates an embodiment of a spring assembly
suitable for use in the overtube of FIG. 16.
[0064] FIG. 17B shows the spring assembly of FIG. 17A in an
articulating position.
[0065] FIG. 18A is a side view of a distal portion of an overtube
utilizing a stacked ring construction for the articulating
section.
[0066] FIG. 18B is similar to FIG. 18A and shows the articulating
section in an articulated position.
[0067] FIGS. 18C and 18D are similar to FIGS. 18A and 18B and show
an alternate configuration of stacked ring elements.
[0068] FIG. 19 is a perspective view showing an alternate
arrangement of ring elements suitable for use in the articulating
section.
[0069] FIG. 20 is a side elevation view of a distal portion of an
overtube illustrating optional inner and outer sheaths covering the
articulating section.
[0070] FIG. 21 is a cross-sectional side view of an overtube with
an instrument positioned in the lumen of the overtube, and
illustrates the use of magnetic indexing.
[0071] FIG. 22 is a cross-sectional side elevation view showing a
distal portion and intermediate portion of an overtube together
with proximal control features for use in controlling the
articulating section of the overtube.
[0072] FIG. 23 illustrates articulating control features utilizing
separate spools for each pullwire cable.
[0073] FIG. 24A is a perspective view of a portion of a spool and
knob having a selection of cable attachment points allowing for
selection and/or adjustment of cable length.
[0074] FIG. 24B is a side elevation view showing a barrel adjuster
suitable for fine tuning cable length.
[0075] FIG. 25 shows perspective view and proximal end views of an
overtube having depth and angle markings.
[0076] FIG. 26 shows a distal end view, side elevation view, and
proximal end view of an overtube and illustrates color coding of
angle markings.
[0077] FIG. 27 is a side view of a distal portion of an overtube,
illustrating the use of color coded markers positioned within the
field of view of an endoscope used in combination with the
overtube.
[0078] FIG. 28 is a perspective view of a proximal end of an
overtube and illustrates a terminating end ring.
[0079] FIG. 29 is a plan view of a proximal end of an overtube and
illustrates an iron intern ring.
[0080] FIG. 30 is a perspective view of a proximal portion of an
overtube showing the use of steering controls and expandable
element controls on iron an intern ring of the type shown in FIG.
29.
DETAILED DESCRIPTION
[0081] The present invention comprises an overtube intended to be
inserted trough the mouth into the esophagus of a patient, and
extend at least past the pharynx, but preferably far enough for the
distal end to seal against the lower esophageal sphincter (LES) at
the junction between the stomach and the esophagus. The overtube
incorporates features that enable it to facilitate the procedure
described in the Background section above though is not restricted
to that single procedure. The primary purpose of the present
invention is to create and maintain a patent lumen that provides
access from the mouth of a patient to the stomach. The outer
diameter of the overtube's insertable length allows it to fit
within, and be insertable into, a patient's gastrointestinal tract
from the mouth to the stomach. The outer surface of the insertable
length of the overtube is sufficiently lubricious to allow for its
introduction into the esophagus and subsequent manipulations (e.g.,
further insertion or withdrawal, rotation), and/or is compatible
with lubricants commonly used for such procedures. The inner
diameter of the overtube's insertable length is sufficiently large
to accommodate the insertion of the instruments described in the
Background section (e.g., stapler, endoscope, graspers, etc.).
Alternatively, the Overtube may be composed of multiple lumens
allowing multiple tools to be inserted without interfering with
each other. The inner surfaces of the overtube's insertable length
are sufficiently lubricious to allow the insertion of instruments
and devices, and/or are compatible with lubricants commonly used
for such purposes. The overtube conforms to the patient's anatomy
and protects anatomical features (e.g., the pharynx, esophagus,
lower esophageal sphincter, etc.) from injury that may result from
the insertion and manipulation of instruments during the procedure.
Further, the overtube provides a means to control the position
relative to the LES along the axis of insertion. The position of
the distal end of the overtube may be controlled by means of
insertion and withdrawal of the instrument (the "Z-level"), by
means of rotation of (torquing) the insertable length of the
overtube, and by optionally incorporating an articulatable,
steerable, lockable section somewhere within the insertable length.
The overtube assembly may also incorporate expandable elements at
or near the distal tip that assist in creating a volume within the
stomach, reshaping the walls to facilitate visualization and
access. The overtube possesses sufficient tensile, compressive and
hoop strength to resist excessive deformation (e.g., extension,
compression, collapse, kinking) during use. Materials suitable for
short-term mucosal tissue contact are preferable for use in the
overtube, e.g., stainless steel, nitinol, silicone, urethanes,
PEEK, PVC, etc.
Overview and System Layout
[0082] FIG. 2 shows a general system diagram of the overtube 100,
and indicates the configuration and names of system components. The
insertable length of the overtube 101 is comprised of at least one
passive section 102 and optionally at least one articulatable,
lockable section 103, which may be steered by means of controls 104
at the proximal end 105 of the assembly. The proximal end also
incorporates a terminating end piece 106 and an iron intern ring
107, which serve to support and orient the device during use. At
the distal end 108 of the overtube, spreadable fingers 108 may be
incorporated to facilitate maneuvers during a procedure. The
configuration of the spreadable fingers is determined by controls
104 at the proximal and 105. The construction of the overtube may
include some or all of these elements, in different combinations,
or it may omit elements, depending on the configuration. This
disclosure is intended to include all combinations of inclusion or
exclusion of these elements.
Insertion Tube Characteristics
[0083] One embodiment of the present invention's insertable length
101 (FIG. 3) consists of a compliant, flexible, hollow tube. The
preferred dimensions of the tube are approximately 38-42 cm
(15-16.5 in.) in length (L), with outer diameter (OD) of
approximately 1.0-2.0 cm (0.780 in.) (preferably 2.0 cm, but up to
approximately 2.2 cm), inner diameter (ID) approximately 1.8 cm
(0.700 in.) and wall thickness (T) approximately 0.1-0.2 cm. Larger
diameters are preferable when the anatomy will accommodate it,
however tubes having smaller dimensions (including those having a
diameter proportioned to only accommodate small instruments or
endoscopes) are also considered within the scope of this invention.
The tube is supported internally at least part of its length by a
springform wire 112, intended to support the compliant material
comprising the tube 110, and to improve the tube's patency when
bent, and to improve the tube's torsional rigidity to facilitate
rotating the overtube when in situ during a procedure (its
"torquability"). The springform wire reinforcement may extend the
full length of the tube, or it may optionally terminate some
distance short of the distal or proximal tip. The reinforcement 112
may be encapsulated within the overtube's wall in a thermopolymer
or thermoset polymer matrix. The overtube is designed to be
compliant and flexible, enabling it to follow the contours and
navigate around features of the patient's anatomy, and is capable
of conforming to curves with a radius of curvature of at least 1.5
in.
[0084] The tube 110 may also incorporate a thin woven mesh,
encapsulated within the compliant material as described above,
either in conjunction with the springform wire 112 or in lieu of
such a wire. The woven mesh may be made of stainless steel, for
instance, or aluminum, or any of a variety of polymeric materials.
The purpose of embedding mesh within the tube is to substantially
increase its torquability while having a minimal effect on its
resistance to bending or its minimum radius of curvature.
[0085] The outer surface of the insertable length of the overtube
should be sufficiently lubricious to allow for its introduction
into the esophagus and subsequent manipulations (further insertion
or withdrawal, rotation), and/or be compatible with lubricants
commonly used in such procedures. The inner surfaces of the
overtube's insertable length should also be sufficiently lubricious
to accommodate the insertion of instruments and devices, and/or be
compatible with lubricants typically used in such applications. In
order to achieve sufficient lubricity, inherently lubricious
materials may be selected (e.g., PTFE), or coatings may be applied
to base materials (e.g., hydrophilic or hydrophobic coatings).
Features that prevent locking or binding between components may
also be incorporated, such as serrations or surface features
similar to those seen on knives designed for slicing meat. Such
features facilitate sliding, rather than binding, when elements are
moved relative to one another.
[0086] The tube 110 may include a single or large central lumen
114a as shown in FIGS. 7A and 7B, or multiple smaller lumens 114b
as in FIG. 7C. Additionally, the tube may incorporate numerous
channels 114c completely or partially within the wall. (FIG. 7B).
In this way, it comprises a multi-lumen tube, with at least one
large central lumen whose primary purpose is facilitating the
introduction of instruments and devices to the stomach, and at
least one much smaller lumen, through which control cables, fluids,
etc. may be routed between the proximal and distal end of the
device, or to intermediate points between the ends. In this way,
the device presents a single, smooth outer surface to the patient,
rather than having any ancillary elements separate from the
overtube's insertable section itself in contact with a patient's
gastrointestinal tract tissue. This provides protection for the
components that may be routed within these lumens, and increases
control of cleanliness and thus device function, as well as
reduction of requirements for biocompatibility. In some cases, the
small channels or lumens 114c within the wall of the overtube may
serve more than one purpose: for example, the compressive housing
of a Bowden cable may be unnecessary when the control cable is
routed within one of the small lumens in the overtube itself,
eliminating a component and simplifying the design. For reference,
a Bowden cable is comprised of an inner control cable which is
housed in an outer housing designed to withstand compressive loads,
often a coil tube. Displacements at the proximal end of the inner
cable relative to the coil tube housing of a Bowden cable are
transmitted to the distal end of the inner cable, and can be used
as an actuator to create useful forces and motion relative to the
cable housing.
[0087] The construction of the overtube may also be such that it
may be expanded as necessary after it has been placed within a
patient's anatomy. In the event that large instruments or devices
are to be inserted through the overtube into the stomach, it may be
beneficial to allow the overtube to expand to accommodate such
large components that may otherwise fit too tightly or not at all,
and to then return to its unexpanded diameter following passage of
the large device. This is illustrated in FIG. 4A. One means of
accomplishing this is to form the reinforcing wire rings 112a or
coil used to support the overtube structure into elliptical shapes,
rather than a circular profile. Such rings could also be
encapsulated within a thermopolymer or thermoset polymer matrix, as
described above. If the elliptical reinforcing rings are tilted in
aspect ratio, as shown in FIG. 4B, the cross sectional shape of the
overtube's insertable length is circular under normal
circumstances. However, when a large instrument is inserted into
the overtube's central lumen to the stomach, the elliptical
reinforcing rings comprising the overtube's structural supports can
change aspect to present a larger cross sectional area, thus
allowing the large instrument to pass through. FIG. 4C shows
another embodiment, which relies upon support rings 112b which are
not continuous closed forms, but rather are partial rings which
have a shape resembling the letter "C". The shape of the partially
ring can optionally be in a closed default configuration to
resemble the letter "O", with the ends of the ring touching or
overlapping, which then dilate and open a gap when expansion forces
are applied. Alternatively, more than one wire shape 112c can be
combined to create a structure which spans the full circumference
of the tube (FIG. 4D). In cases where the ends of the wire
endpoints overlap, a fold 116 may be introduced in the
thermopolymer or thermoset polymer matrix encapsulating the support
to facilitate such dilation (FIG. 4D).
[0088] One means of manufacturing the insertable length of the
overtube assembly as described (with reinforcing elements
encapsulated within a matrix) is to start with a wire 112 which is
coated with a thermopolymer 113. This wire may be coiled around a
mandrel 118 having the desired outer diameter or profile (the
mandrel's outer diameter need not be consistent). This is depicted
in FIG. 5A Heat shrink 120 may then be placed over the entire wound
wire and mandrel 118 and heat applied, for example with a heat gun
122 or hot box, causing the heat shrink to relax over the wire
(FIG. 5B). With the appropriate amount of heat addition, the heat
shrink material and any coatings on the wire core will then flow
around and encapsulate the wire 112 (FIG. 5C). Once the wire and
thermopolymer assembly is complete, the supporting mandrel 118 may
be removed, leaving a flexible, hollow tube. The same technique can
be performed with a wire mesh in addition to the coil of wire, or
instead of the coil of wire. The pitch of the wire wound around the
mandrel 118 may also be varied prior to the application of heat
shrink. This may be accomplished by alternating thermoplastic
elements that have no wire core between windings 113 of those that
have the wire core 112, as shown in FIG. 6A. After the application
of heat and the flow of the thermopolymer, this results in
differences in the space between each turn of wire, affecting the
overall pitch (FIG. 6B). The profile of the thermopolymer elements
that have no wire core may be round, square, rectangular, or any
other desired shape, and the wire 112 need not be originally coated
with thermoplastic, nor are they necessarily the same size (FIG.
6C). The cross sectional area of the thermopolymer-only elements
need not have the same cross-sectional area as those containing
wire (FIG. 6D).
[0089] Another means of manufacturing the insertable length of the
overtube is to wrap at least one layer of a thin rolled sheet 120a
around a mandrel 118, and then fuse the layers together using heat,
adhesives or chemical means. This is shown in FIG. 7. Reinforcing
elements, e.g., wire and/or mesh, may be incorporated underneath,
in between or on top of the rolled sheets in order to create an
overtube with encapsulated support elements.
Bougie at Distal End
[0090] The distal tip may maintain the same outer diameter
(herinafter "OD"), inner diameter (hereinafter "ID") and wall
thickness as the rest of the tube, or it may taper slightly to form
a gentle curve. When an optional taper is incorporated into the
distal tip, this serves to facilitate introduction into a patient's
gastrointestinal tract, as well as helping to prevent tissue from
being drawn into, and potentially pinched between, the overtube and
any loose fitting components inserted into its inner lumen. As
illustrated in the embodiments of FIGS. 8 and 8A, the distal end of
the overtube 100 may be used in combination with a Bougie 124
attached to the distal tip of instruments, such as a flexible
endoscope 126 for visualization, inserted to the distal end of the
overtube. For reference, a Bougie is a smooth bullet-shaped leading
tip that facilitates introduction into a lumen. The Bougie OD
should be sized such that it creates a snug fit with the ID of the
overtube's distal end.
[0091] Alternatively the overtube may be inserted over a guide wire
128 (FIG. 8B); the guidewire inserted under direct visualization
using an endoscope. A transition member 130 is positioned between
the inside diameter of the overtube and the outside diameter of the
guidewire providing for a smooth transition. This transition member
preferably includes a long taper, and is composed of a soft,
flexible material such as silicone. As shown in FIG. 8A, a similar
transition member may be used in place of the Bougie of FIG. 8.
[0092] An alternate means of achieving a gently curved leading edge
is by means of a protective, thin walled umbrella-like cap 132
positioned at the distal end of the overtube. During insertion, the
umbrella is positioned so that it fits snugly over the distal
opening of the overtube, maintaining a dome shape and creating the
gently curved bullet shape that facilitates insertion and prevents
damage to tissue (FIG. 9A). When the desired insertion depth has
been achieved with the overtube, the umbrella may be removed by
either pulling it back using an element such as a wire 134 or cable
and thus inverting it so that it fits into the overtube's lumen
(FIG. 9B), or by pushing it forward with an element such as a wire
134 or cable from the distal end of the overtube, causing the
umbrella to close before withdrawing it through the overtube (FIG.
9C).
Expandable Elements
[0093] FIG. 10 illustrates how the distal end of the overtube
assembly 100 may optionally include attachments or features, such
as an array 136 of spreadable fingers 138. Such an expandable
element can be used to push the stomach wall away from the
overtube, expanding and increasing the amount of space available
within the stomach to perform a procedure. An overtube may
incorporate or omit such expanders. The benefits of increasing the
volume within the stomach include improvements in the ability to
introduce and manipulate tools, improvements in the ability to
locate plications and staples, improved ability to deploy
implantable devices and improved visualization. Essentially, there
is more room to work, and this simplifies many of the tasks. In
addition to increasing the volume within the stomach, the expanders
may be used to reshape the stomach in a way that facilitates the
performance of the procedure. For instance, when the expander is at
least partially expanded, the overtube may be pulled back slightly
to pull up on the LES and reshape the stomach from its normal
dome-like shape into something more resembling a cone. During
introduction of the overtube into the esophagus, the expander is
preferably in its fully retracted state, so that it presents a
smooth cone shape that facilitates insertion. Once the desired
location has been reached with the distal end of the overtube
(e.g., once past the LES), the expander may be caused to open
partially or fully to increase the available working volume and
reshape the stomach as desired. Expansion of such elements also
serves to help position and support the distal end of the overtube
relative to the stomach, stabilizing it and helping it maintain
position.
[0094] FIG. 11 shows one embodiment of the expandable elements, in
the form of spreadable fingers 138. The position of the fingers may
be adjusted and maintained anywhere between a fully closed position
(FIG. 11A) and a fully expanded position (FIG. 11B). In this
embodiment, this motion is created by changing the relative
position of two control rings 140, 142 by means of at least one
actuator, for example a Bowden cable. In the illustrated
embodiment, movement of ring 140 pivots a hinge 144 coupled to
fingers 138. At least part of the more distal control ring 140 may
be sized slightly smaller than the more proximal control ring 142
so that it fits or nests at least partially within the proximal
control ring 142. During introduction of the overtube into the
esophagus, the fingers are preferably in their fully retracted
state, so that they present a smooth Bougie-like leading edge that
facilitates insertion (FIG. 11A). Once in the desired location, the
fingers may be expanded partially or fully to increase the
available working volume and reshape the stomach (FIG. 11B). The
fingers may be left in this position for the duration of the
procedure, or they may be adjusted at any time as desired by the
user.
[0095] An additional embodiment of spreadable fingers is shown in
FIG. 12. This version of the expandable element again incorporates
two control rings, one distal 140a and one proximal 140b. However,
this design differs in that the spreadable fingers do not reach
forward (more distal) of the distal control ring when they are
fully retracted. Rather, these spreadable fingers include a hinge
146 at or near the midpoint so that they form a link located
between the control rings, in effect forming a tube-like, scaffold
structure. Like the embodiment described in the previous paragraph
and depicted in FIG. 11, pulling the distal control ring 140a
towards the proximal control ring 140b causes the fingers to spread
and deploy. The rings may be approximated by any number of actuator
types, such as the pullwires/Bowden cables 148 depicted in FIG. 12
which can be used to draw the rings 140a, 140b together, such as by
drawing the distal ring 140a towards the proximal ring 142a. At
least one Bowden cable may be used, however using two or more
Bowden cables allows for balancing the actuation forces more evenly
around the control ring. FIG. 12A shows this version of the
spreadable fingers in its fully retracted position, FIG. 12B shows
it partially expanded, and FIG. 12C shows it fully extended. The
control rings may optionally incorporate features that mate when
the fingers are fully deployed to provide a positive stop when the
full range of motion has been achieved.
[0096] Another embodiment of a mechanism that may be used to
control the degree of expansion of such spreadable fingers employs
a Bowden cable attached at the distal end to each finger in order
to determine its position. When tension is applied to each Bowden
cable, either separately or simultaneously, the corresponding
finger moves radially outward, creating a larger working space.
[0097] In cases where an array of spreadable fingers are used to
create the expandable element, such as that shown in FIG. 11, these
fingers may also be used to maintain orientation during a
procedure. Because the image from an endoscope may be rotated and
may change unpredictably during the course of a procedure, features
that aid in determining location and orientation are helpful. Using
landmarks such as the spreadable fingers, especially when they have
been individually identified, e.g., with color codes or other
markings, aids in determining position of instruments and
visualization components. They are especially useful for
determining angular position, or "clocking".
[0098] In addition to facilitating introduction of the overtube and
enabling users to increase the working volume and reshape the
stomach during a procedure, the expandable elements, such as the
fingers described above and in FIG. 11, may serve as attachment
points for a variety of additional devices. In one case, they may
have pads 150 attached at their distal ends that increase the
surface area they present to the stomach wall when deployed,
resulting in a more desirable distribution of forces and a more
desirable shape (FIG. 13A). In another case, the pads 150a may be
shaped to form a cone when the expandable elements are retracted to
their closed position, facilitating introduction of the overtube
into the patient (FIG. 13B). In another case, the pads may be
configured to form suction cups 150b, which may be applied to the
stomach wall and fixed in place when suction is supplied (FIG.
13C). The use of suction immobilizes the stomach tissue relative to
the distal end of the overtube. In another case the pads may have a
deployable implant 152, such as the restrictor discussed above,
temporarily mounted that, from this lead position at the distal tip
of the overtube, may be delivered to one or more desired sites
(FIG. 13D). Expansion of the fingers may then be used to deploy the
implant within the stomach.
[0099] One embodiment of a mechanism that may be used to control
the degree of spread of such expandable fingers, or any other
embodiment that may be effectively controlled by means of Bowden
cables 148, is shown in FIG. 14. This control handle serves to
adjust the position of an inner control cable relative to an outer
compressive housing of a Bowden cable 148. To accomplish this, an
outer cup 154 is used in conjunction with a slidable plate 156. The
slidable plate 156 is threaded, and acts like a nut when used in
combination with a thumbscrew 158, which moves the slidable plate
156 towards or away from the outer cup 154 when it is turned. The
thickness of the slidable plate and the clearance between its outer
edge and the inside edge of the outer cup serve to keep the
slidable plate aligned and prevent it from binding within the cup
as it moves. Binding and misalignment may be further prevented via
the addition of alignment slots 160, mated to pins 162 that
protrude from the slidable plate. The controller may act on at
least one Bowden cable, and the cables may be, but are not
necessarily, centered or balanced with respect to the slidable
plate. Adjustment of the Bowden cable may be accomplished with a
barrel adjuster, or similar component. If a barrel adjuster is
used, it may be comprised primarily of a screw which has a hole
drilled through its central axis. The Bowden cable's compressive
housing terminates against the screw head while the inner control
cables runs through the screw. When the screw is inserted into a
threaded hole, and the cable is attached to a component (such as
the slidable plate shown in FIG. 14), the relative positions of the
inner cable and outer compressive housing are adjusted.
[0100] When retraction of the expandable elements is desired, it
may be advantageous or required, depending on the construction, to
incorporate components within the mechanism of the expanders to
ensure that they reliably retract. For instance, in cases where
Bowden cables are used to actuate an expandable element, friction
between the control cable and the compressive housing may prevent
the expandable element from returning to a retracted position. For
the embodiment shown in FIG. 11, this may be accomplished by means
of a compression spring that pushes the two control rings apart.
Alternately, nitinol spring elements may be incorporated to act
upon the outer face of each of the fingers when they are extended,
so that they push the fingers back to the retracted position when
tension is removed from the Bowden cable that pulls the control
rings together.
[0101] An alternate embodiment of an expandable element located at
the distal end of the overtube or on a separate elongate member
passed through the overtube, is shown in FIG. 15. In this
embodiment, a fully expanded pair of hoops are comprised of
numerous piecewise sections 166 which have central tensioning
cables 168 running through their centers. When the tensioning
cables are relaxed, the hoop sections are free to move relative to
each other, and the result is a flexible chain of short elements.
This configuration is well suited for insertion of the device
through the overtube. When the tensioning cable is placed in
tension, the hoop sections are forced to join together and organize
into a shape that creates additional volume within the stomach,
such as the hoops, or globe, shape shown. In this example, a hoop
shape is depicted, however other shapes are possible and may be
desirable, such as triangles, squares, umbrellas, etc.
Articulatable Section
[0102] At least one articulatable, lockable section may optionally
be incorporated within the insertable length of the overtube. FIG.
16 shows a version of the overtube that incorporates such an
articulatable length, labeled 103. The purpose of the articulatable
section is to facilitate positional control of instruments and
devices inserted through the lumen defined by the overtube. For
instance, an articulatable section may be steered (caused to bend
at a desirable angle and direction), to impart a "hockey stick"
shape to the insertable length of the overtube. Additionally, the
shape of the articulatable section may be locked in place by
immobilizing or otherwise constraining the actuating elements that
determine its shape. The simplest embodiments of the overtube may
incorporate no such articulating section, being comprised entirely
of a passive tube, as described above and depicted in FIG. 3.
However, at least one articulatable section may be incorporated in
such a way that it is coaxial and continuous with other passive,
non-articulatable sections of the overtube. The articulatable
section(s) have an OD, ID and wall thickness similar, but not
necessarily equal, to those of the passive overtube sections. FIG.
16 shows the configuration of the articulatable section(s), which
may be located at the distal end of the overtube, such that the
section 108 has minimal length or zero length. Alternately, the
articulatable sections may be located between passive sections of
the overtube, such that the length of sections labeled 108 and 102
are non-zero. Similarly, the articulating section may be located at
the proximal end of the overtube so that the length of the passive
section 102 has minimal or zero length. In cases where more than
one articulating section is incorporated, they may be located in
any of the positions defined above, and they may be located next to
each other or separated by passive sections. The preferred number
of articulating sections is either zero or one, and the preferred
location of the articulating section is near the distal end of the
overtube, such that the length of the passive section 108 is
between 0-6 in.
Steering Controls
[0103] Steering control of the articulatable section may be
achieved by a variety of methods. The preferred method is to
control articulation with at least one pull cable, such as a Bowden
cable, acting within a coil tube compression housing. A single such
control cable can be used to control the shape of the articulatable
section in one direction (e.g., to the right), or a single cable
can be used in combination with an opposing spring element to cause
articulation in two directions (e.g., the spring pulls to the left
and the cable pulls to the right). Alternately, two control cables
can be used to control articulation in two directions (e.g., left
and right). Extending this further, three control cables can be
used in combination to allow for articulation in all directions
(e.g., left, right, up and down), or four control cables can be
used, each directly controlling bending of the articulatable
section in each direction. The use of four control cables is the
preferred method, as the resulting control is simple and intuitive
for the user.
[0104] The control cables may be used to steer, or determine the
curvature of, the articulating section of the overtube. FIG. 22
shows an example where two control cables are used to control the
articulation angle .THETA. of a distal articulatable section in two
directions, up (U) and down (D). The coil tube housings associated
with the control cables are routed from a rotating control knob 170
located at the proximal end of the overtube assembly, down the
length of the overtube to the junction between the length of
passive overtube 102 and the articulatable section 103 controlled
by the knob 170. Rotating the control knob in one direction results
in one control cable being pulled in and an opposing control cable
being spooled out. Similarly, rotating the control knob in the
opposite direction reverses these motions. The resulting motion and
forces are transmitted down the length of the control cables and
compression housings to the articulatable length of overtube, and
determine the major (inner) and minor (outer) arc lengths of the
articulating section. As an example, FIG. 22 illustrates the case
where the control knob is rotated clockwise by the user. This
results in the upper control cable 172 being pulled relative to its
compression coil tube housing 174, and this defines the minor arc
length (l) along the top edge of the articulating length.
Simultaneously, the rotation of the knob 170 releases tension on
and feeds out the bottom control cable 176 relative to its
corresponding compression coil tube housing 178, defining the major
arc length (L) along the bottom edge of the articulating section.
Variations of this design may incorporate four control cables, each
determining the bending of the articulatable section in a different
direction, such as left, right, up and down. For this case, two
knobs are used. One knob controls one pair of control cables, e.g.,
the left-right pair, and the other knob controls the other pair of
control cables, e.g., the up-down pair. The steering control knobs
may optionally be oriented so that their position relates to the
direction of steering they control. For example, when two knobs are
used with one knob controlling left-right bending and the other
knob controlling the up-down bending, the knobs may be rotated
relative to one another by 90.degree.. Further, the knobs may be
oriented so that the position of the knob controlling bending in
the left-right directions is horizontal and the position of the
knob controlling bending in the up-down directions is vertical.
[0105] The length of each of the Bowden cables is critical to their
correct performance, and for this reason elements that facilitate
their adjustment are helpful. Even in cases where they have been
cut to the exact length required and perfectly installed, cables
typically stretch over time and use, and will require periodic
adjustment. For this reason, the control knob assemblies may
incorporate a number of means of cable adjustment. One useful
characteristic of a control knob is to incorporate a means to deal
individually with each control cable that terminates there. For
instance, if the control knob determines the shape of the
articulatable section in the left-right direction, the cable
controlling bending to the left can be managed and kept separate
and adjusted independently of the cable controlling bending to the
right. This may be accomplished by incorporating two completely
separate sections 170a, 170b of the control knob, one for each
terminating control cable, as illustrated in FIG. 23. In this
figure, the 2-part spool is indicated with the reference numerals
171a, 171b. Coarse cable adjustment can be provided by
incorporating a multitude of attachment points between the knob
described in the paragraph above and the Bowden cable. The spool
around which the control cable is wound requires a single potential
attachment point, such as a pin, for a control cable, however if
multiple potential attachment points are provided, the length of
the cable may be adjusted relative to the position of the spool and
knob. The example shown in FIG. 24A has potential attachment point
173 spaced every 15.degree., however this spacing may be any useful
interval. The route of the control cable wire to the control knob
termination point is preferably but not necessarily smooth, so that
it does not present any hard corners or sharp edges to the cable,
extending its operating life. Fine cable adjustment may be
accomplished with the addition of a barrel adjuster or similar
element. In the case of a barrel adjuster, a screw is drilled
through its central axis, and the cable's compressive housing
terminates against the screw head while the inner control cable
runs through the screw. When the screw is inserted into a threaded
hole 182, and the cable is attached to a component (such as the
spool shown in FIG. 24A), the relative positions of the inner cable
and outer compressive housing may be adjusted by the position of
the screw. Turning the screw so that it moves towards the cable's
termination point (e.g., clockwise for right-handed threads)
loosens the cable. Conversely, turning the screw so that it moves
away from the cable's termination point (e.g., counter-clockwise
for right-handed threads) tightens the cable. This is depicted in
FIG. 24B.
[0106] Control of an articulating section may also be achieved by
means other than Bowden cables. Any appropriate alternate actuation
method and energy source may be used, such as hydraulic or
pneumatic actuators, which could be used to create the motion and
forces needed to bend the articulatable section.
Articulatable Section Construction
[0107] The articulatable sections may be constructed using a
variety of techniques. One simple embodiment consists of a single
coil spring element 112 capable of bending as desired, and is shown
in FIG. 17A. The proximal 184 and distal 186 ends of the spring are
fitted with end caps 188 that provide termination points for
actuating elements (described below) and mounting features for
attaching them to other parts of the overtube's insertable length.
Additional features may be useful for routing components that
traverse through the articulatable section, such as Bowden cables
running between the user controls at the proximal end and the
expandable elements at the distal tip. The spring element 112 may
have significant space between the coil windings so that it bends
freely when a moment is applied between the distal and proximal
ends without changing length significantly. To cause the spring to
articulate, a Bowden cable may be used, attached across one side of
the outside of the spring element. If the Bowden cable's
compressive housing terminates at the proximal end cap 188a of the
spring element, and the control cable terminates at the distal end
cap 188b of the spring element, pulling on the cable relative to
the compressive housing results in the spring bending in the
direction of the cable, as shown in FIG. 17B. A backbone 190
extending through the overtube prevents collapse of the spring
during bending. Bending the spring element in other directions is
achievable by attaching additional Bowden cables in other locations
around the outside of the spring element. A benefit of this
construction is that the spring element comprising the
articulatable section returns to a straight shape when tension is
released from the control cables: its relaxed configuration is
straight. The spring element comprising the articulatable section
of this construction may be created by attaching a separate spring
to passive sections of the overtube to create the full insertable
length of the overtube, or it may be formed from the same materials
used as the supporting structure of the passive sections of the
insertable overtube. This can be accomplished by altering the
winding pitch and/or the diameter locally, if needed, where the
articulatable section is required.
[0108] An alternative means of constructing an articulatable
section is to create it by stringing together on cables 194 a
succession of rings shaped in such a way that they are allowed to
rock relative to one another. The rocking motion can again be
controlled through the use of Bowden cables. This construction
technique is illustrated in FIG. 18A through D. The shape of each
ring is such that it forms an inner lumen, and is preferably (but
not necessarily) round. The inner radius r is sized so that it is
approximately the same as the inner radius of the rest of the
insertable length of the overtube. The outer radius R and the wall
thickness T are equal to or as close as possible to the outer
radius of the rest of the insertable length of the overtube. Four
small through holes are drilled through each ring's wall parallel
to the central axis of the overtube, at the 3, 6, 9 and 12 o'clock
positions. These holes accept the control cables 194, which run
through each ring and hold the assembly together. When viewed from
the side, as shown in FIG. 18A, each ring is flat along the bottom
surface and has two aligned raised arches along the top surface. In
the figure, these are shown in the 12 and 6 o'clock orientation.
The raised sections are oriented so that their peaks are coincident
with the small holes drilled through the wall. To assemble the
articulatable section, a number of rings are strung together using
control cables 194. At the distal end of the assembly of rings,
each cable is terminated, e.g., with a crimp 196. At the proximal
end of the assembly of rings, each compressive housing is
terminated. When sufficient tension is applied to a control cable,
it will pull back and move into its compressive housing, and the
corresponding side of the distal end of the assembly of rings is
pulled towards the proximal end. The cables themselves constrain
the relative motion of the rings so that the result is piecewise
bending. This is shown in FIG. 18B and FIG. 18D. The rings are
prevented from sliding relative to each other and losing
organization by the cables that connect them. Such rings may be
comprised of any of a variety of materials that possess adequate
strength, however stainless steel or polycarbonate are
preferred.
[0109] The arrangement of the rings relative to each other in the
assembly determines whether bending in two directions results
(e.g., left and right) or whether bending in four directions (e.g.,
left, right, up and down) is allowed. FIGS. 18A and B show the
construction that results in articulation in two directions (left
and right). For this construction, the raised portions of each of
the rings are all oriented similarly, e.g., from the 12 o'clock
position to 6 o'clock position. When control cables are actuated at
the 3 o'clock position or the 9 o'clock position, the assembly is
caused to rock in the direction of the cable under tension. For
this construction, all of the rings contribute to the bending of
the assembly. The other two cables (at 12 o'clock and 6 o'clock)
are always held at a fixed length and pretension, and applying
further tension to them would not result in bending the
articulatable section. Instead, these cables serve primarily to
string the rings together and stabilize the assembly. They may
terminate immediately at the proximal end of the articulatable
section, without the use of compressive housings, or they may
optionally extend back to the proximal controls.
[0110] FIGS. 18C and D show a variation of the construction that
enables the assembly of rings to articulate in four directions
(left, right, up and down). For this construction, the raised
portions of each of the rings are alternated, rotated 90.degree.
between successive rings. When any of the four control cables is
actuated, or combinations of control cables, the assembly is caused
to rock in the direction of the cable(s) under tension. For this
construction, each ring contributes to the bending of the assembly
in two of the four possible directions, such as the left and right
pair. Every other ring contributes bending in the left-right
directions, alternating with rings that contribute bending in the
up-down directions. FIG. 18D illustrates the contributions of each
of the rings in the assembly when a single cable is pulled.
[0111] These stacked ring embodiments of the articulatable section
may also be used to construct unarticulatable sections. Such
sections are flexible, but their articulation is not selectable or
controllable by a user. When this approach is used, the entire
length of the overtube may be constructed using a continuous
assembly of rings, oriented in at least one of the ways described
above. The shape of at least one region of the assembly may be
controllable (e.g., articulatable or steerable) via Bowden cables,
as described, while the remaining regions of the assembly which are
not controllable have no Bowden cables determining their shape.
[0112] Another embodiment of an articulatable section is shown in
FIG. 19. In this version, rings 198 that are joined with hinge
joints 200 are combined to form an assembly that may be caused to
articulate in a desired direction by means of an actuator that
pulls differentially in a given direction, such as a Bowden cable.
The orientation of successive hinges may alternate in increments of
90.degree. as shown, which enables bending in four directions
(e.g., left, right, up and down), or all hinges may be aligned in
the same orientation, which will allow for bending in two
directions (e.g., left and right). As with the previously described
embodiment, the balance of the insertable length of the overtube
may also optionally be made using this construction. A single
section, multiple sections, or no section may then optionally be
made articulatable by means of actuators such as Bowden cables.
[0113] Regardless of the construction of the articulatable section,
it may have either a continuous outer sheath 202 or surface, a
continuous inner sheath 204 or surface, or both (e.g., sheaths
positioned over the inner and outer surfaces of the articulating
rings, coil or other articulating features, or an
encapsulation/positioning of such articulating features within the
walls of a sheath). This is shown in FIG. 20. The material used to
create the sheath preferably offers little resistance to the
bending of the articulatable section. For this reason, soft
materials, such as a low durometer, thin wall urethane, silicone or
similar material are preferred. The overtube's terminating end
piece provides an air tight seal against devices inserted through
the inner lumen for the purpose of facilitating and maintaining
insufflation of the stomach during a procedure, and if the overtube
is not a continuously sealed tube along its insertable length, air
leaks are likely to occur. Insufflation facilitates visualization
and access by increasing the volume of the stomach where the
procedure is performed, and when insufflation is not adequate, the
procedure may be negatively impacted.
[0114] Components may be added to or incorporated within the
overtube to provide tactile feedback to users when instruments
within the overtube's inner lumen are moved. For example, elements
may be used that provide the sensation of indexing, such as a
ratcheting feel of engagement and disengagement, when an instrument
is inserted into the overtube to specific depth intervals, or
rotated relative to the overtube 100 at angular intervals. One
embodiment of such a feature makes use of magnetic interactions. If
at least one magnet 206 or magnetically attractive element is
incorporated into the overtube, and a corresponding magnet 208 or
magnetically attractive element is incorporated into an instrument
210 that moves relative to the overtube, the elements will attract
or repel each other as they move into and out of proximity. This is
illustrated in FIG. 21. These forces may be useful to the user to
indicate that a location of interest has been achieved, or that a
certain increment of motion has occurred. Another embodiment of
such a feature involves a ball detent, mounted either in the
overtube or in an insertable instrument that indexes against
indentations in a mating surface. The indentations may be either
circular or elongate in shape.
Depth and Angle Markings
[0115] The proximal end of the overtube may incorporate graduated
markings indicating depth and radial angle (FIG. 25). The depth
markings 212a enable users to quantitatively track and control the
depth of insertion of the overtube into the patient, as well as the
depth of insertion of instruments, tools and devices into the
overtube. The radial angular markings 212b similarly enable users
to quantitatively track and control the angular position (also
called "clocking") of the overtube and the instruments, tools and
devices inserted into the overtube. The depth and angle markings
also enable users to repeatedly return an instrument or device to a
previously achieved location when required. Additionally, the depth
and angle markings enable users to reposition instruments and
devices at a known location relative to a previously achieved
location. For example, if a physician wishes to create a new
stapled mounting point in the stomach wall at a location 90.degree.
clockwise and at an equivalent distance from the LES relative to a
previously placed stapled mounting, he or she would ensure that the
overtube was inserted to the same depth and angular position into
the patient for both sequences of operations, that the instruments
used were inserted into the overtube at the same depth, and that
the instruments were rotated 90.degree. clockwise as indicated on
the overtube's angular markings.
Color Coding to Indicate Orientation
[0116] The angular markings at the proximal end of the overtube may
be further identified by means of color coding (FIG. 26). For
instance, the quadrant from 0.degree. to 90.degree. may be
indicated with the color green (G), the quadrant from 90.degree. to
180.degree. with red (R), 180.degree. to 270.degree. with blue (B),
and 270.degree. to 0.degree. with no color (NC) added. These color
codings may be coordinated with similar markings at the distal end
of the overtube 110 which will be visualized with an endoscope.
This improves the ability of the user to maintain proper
orientation and obtain the desired result when manipulating
instruments at the proximal end of the overtube, since it directly
corresponds to what he or she observes visually at the distal end
of the overtube. The color coding at the distal end of the overtube
may be applied anywhere that may be visualized by an endoscope
placed inserted through the inner lumen, such as to the overtube
itself (including passive and/or articulatable sections), or to
components attached to and extending beyond the distal end of the
overtube. For instance, expandable elements such as spreadable
fingers may be added to the end of the overtube which may each be a
unique color. Alternately, components may be extended from the
distal end of the overtube for the express purpose of placing color
coded markings within the field of view of the endoscope (FIG. 27).
These forward-extending components may be of any useful shape,
e.g., a tubular antenna, or a garden-hoe-like flag.
[0117] The steering controls that determine the angle and direction
of the articulatable section may also be marked to correspond to
the markings on components at the distal end of the overtube. If,
for instance, the spreadable finger located at the top of the
overtube (at the 12 o'clock position) is red, the control knob that
determines the up-down position of the articulatable section will
have a red marking on it indicating which direction it should be
turned to cause the articulatable section to bend in the up
direction. Similarly, if the spreadable finger located at the
bottom of the overtube (at the 6 o'clock position) is blue, then
markings on the same knob will incorporate an indication of which
direction it should be turned to cause the articulatable section to
bend down. This may be done, for example, by marking the knobs with
different color arrows.
[0118] In addition to indicating which direction to turn each knob
to achieve the desired bend angle with the articulatable section,
each knob may be marked with an indication of when the
articulatable section is approximately straight. A marking
indicating the "neutral" position of the articulatable section
allows a user to straighten the articulatable section with high
confidence, rather than relying on "feel" or for the articulatable
section to return to a straight configuration if tension is
released on the controlling Bowden cables.
[0119] A positive retention force and tactile feedback may also be
provided in the steering control knobs by incorporating ball detent
components and a sequence of mating indentations. When a user turns
a steering control knob, the ball detents can prevent the knob from
turning freely, thus preventing the articulatable section from
unintentionally returning to its relaxed neutral position. The
indexing that occurs as the ball detent moves through the
succession of indentations may also provide useful tactile feedback
to the user, indicating increments of rotation of a knob and/or
certain positions of the articulatable section, such as straight or
neutral.
Terminating End Ring
[0120] The proximal end of the overtube incorporates a terminating
end ring (FIG. 28). The end ring is attached to, and is not free to
move relative to, the insertable length of the overtube. The end
ring incorporates at least one sealing feature for the purpose of
creating and maintaining an air-tight seal against components
inserted into its inner lumen. When insufflation or suction is
applied through the overtube or by instruments passing within the
overtube, this seal prevents flow between the inside and the
outside of a patient. The sealing feature may take the form of at
least one o-ring, but preferably two o-rings. Additionally, the end
ring incorporates a port for the introduction of insufflation. This
port accepts tubing through which insufflation air may flow.
Optionally, a clamp valve may be installed over the insufflation
tubing to control the flow of air, or the flow may be controlled by
means of turning the insufflation pump on and off.
Fixturing Ring
[0121] Over the terminating end ring, a fixturing ring 220 (FIG.
29) may be fitted that facilitates attachment to a clamping or
fixturing device, such as an iron intern. For this reason, this
device may also be referred to as an "iron intern ring". The iron
intern ring fits loosely over the terminating end ring, so that it
is possible to rotate them relative to each other. The fixturing
ring also incorporates at least one tensioning element that, when
active, immobilizes the terminating end ring relative to the
fixturing ring. This tensioning element may be embodied, for
example, by at least one screw 222 that, when tightened, locks the
terminating end ring relative to the iron intern ring, preventing
rotation and axial motion. Preferably, more than one screw is used
to distribute the clamping load. For example, three clamping screws
are shown in FIG. 29. This screw may also incorporate features that
facilitate frequent adjustment without requiring the use of tools.
For instance, large knobs may be located on the screw heads to
enable users to tighten and loosen them by hand. The iron intern
ring is also the mounting point for elements of the overall device
that are inconvenient to rotate in the event that the insertable
length of the overtube is torqued. This includes the steering
controls for the articulatable, lockable section of the overtube
and the position control from the expandable elements, such as the
embodiment shown in FIG. 14. In one embodiment, the steering
controls (e.g., left-right control 226 and up-down control 228) and
the expandable element controller 230 are incorporated into a
single component, and this component is attached to the iron intern
ring (FIG. 30).
[0122] An overtube may be packaged alone or as a system in
combination with related components such as staplers and implants
of the type referenced in the application, as well as any
combination of the following: Bougies, transition members,
guidewires, endoscopes etc. The system might further include
instructions for use instructing a user to employ the system in
accordance with the methods disclosed herein.
[0123] As is apparent from the forgoing disclosure, in some
embodiments described above, the overtube comprises an articulating
section, an actuator for effecting articulation of the articulating
section, and an optional locking mechanism allowing the
articulating section to be locked in a desired position. In other
embodiments described above, the overtube comprises an elongate
tube having one or more retraction elements on its distal end,
allowing the overtube to create working space within the body
(e.g., stomach) while giving access to instruments passed through
its lumen.
[0124] It should be recognized that a number of variations of the
above-identified embodiments will be obvious to one of ordinary
skill in the art in view of the foregoing description. Accordingly,
the invention is not to be limited by those specific embodiments
and methods of the present invention shown and described herein.
The applications and methods listed are not limited to the
treatment of diseases or procedures listed. Modifications of the
above described methods and tools and variations of this invention
that are obvious to those of skill in the art are intended to be
within the scope of this disclosure. Moreover, the disclosed
embodiments may be combined with one another in varying ways to
produce additional embodiments.
[0125] Any and all patents, patent applications and printed
publications referred to above, including those relied upon for
purposes of priority, are incorporated herein by reference.
* * * * *