U.S. patent application number 16/142974 was filed with the patent office on 2019-01-24 for apparatus and methods of inducing weight loss using blood flow control.
The applicant listed for this patent is Mayo Foundation for Medical Education and Research. Invention is credited to Samuel J. Asirvatham, Juliane Bingener-Casey, Charles J. Bruce, Navtej S. Buttar, Gianrico Farrugia, Paul A. Friedman, Michael J. Levy, Elizabeth Rajan, Louis-Michel Wong Kee Song.
Application Number | 20190021890 16/142974 |
Document ID | / |
Family ID | 54055872 |
Filed Date | 2019-01-24 |
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United States Patent
Application |
20190021890 |
Kind Code |
A1 |
Farrugia; Gianrico ; et
al. |
January 24, 2019 |
APPARATUS AND METHODS OF INDUCING WEIGHT LOSS USING BLOOD FLOW
CONTROL
Abstract
Methods and apparatus for inducing weight loss using blood flow
control are described herein. The apparatus and methods operate by
controlling blood flow to the stomach and/or small bowel.
Inventors: |
Farrugia; Gianrico;
(Rochester, MN) ; Friedman; Paul A.; (Rochester,
MN) ; Rajan; Elizabeth; (Rochester, MN) ;
Bruce; Charles J.; (South Ponte Vedra Beach, FL) ;
Asirvatham; Samuel J.; (Rochester, MN) ; Levy;
Michael J.; (Rochester, MN) ; Wong Kee Song;
Louis-Michel; (Rochester, MN) ; Bingener-Casey;
Juliane; (Rochester, MN) ; Buttar; Navtej S.;
(Rochester, MN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Mayo Foundation for Medical Education and Research |
Rochester |
MN |
US |
|
|
Family ID: |
54055872 |
Appl. No.: |
16/142974 |
Filed: |
September 26, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15123094 |
Sep 1, 2016 |
10123896 |
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PCT/US2015/018965 |
Mar 5, 2015 |
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16142974 |
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61949024 |
Mar 6, 2014 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61B 2018/00494
20130101; A61B 17/12013 20130101; A61B 18/1492 20130101; A61F 7/123
20130101; A61B 2017/00199 20130101; A61F 5/0013 20130101; A61B
2090/063 20160201; A61B 2090/064 20160201; A61F 2005/0016 20130101;
A61B 2017/00818 20130101; A61B 2018/00404 20130101; A61N 1/3606
20130101; A61B 5/4238 20130101; A61B 5/026 20130101; A61B 5/03
20130101; A61B 18/1815 20130101; A61B 2017/00106 20130101; A61F
2007/0261 20130101; A61B 2018/0022 20130101; A61B 5/4205 20130101;
A61B 2018/00613 20130101; A61B 2018/00863 20130101; A61B 5/6876
20130101; A61N 1/36007 20130101; A61N 1/0556 20130101; A61F
2007/126 20130101; A61B 2018/00434 20130101; A61B 2018/00577
20130101 |
International
Class: |
A61F 5/00 20060101
A61F005/00; A61F 7/12 20060101 A61F007/12; A61B 5/026 20060101
A61B005/026; A61B 5/03 20060101 A61B005/03; A61B 5/00 20060101
A61B005/00; A61N 1/05 20060101 A61N001/05; A61N 1/36 20060101
A61N001/36; A61B 17/12 20060101 A61B017/12; A61B 18/14 20060101
A61B018/14; A61B 18/18 20060101 A61B018/18 |
Claims
1-12. (canceled)
13. A method of inducing weight loss, the method comprising
reducing blood flow to the gastrointestinal tract by ablating one
or more blood vessels that supply the stomach and/or small bowel to
limit dilation of the blood vessels to increase flow after the
ablating.
14. A method according to claim 13, wherein the ablating is
configured to cause fibrosis of the one or more blood vessels that
supply the stomach and/or small bowel, wherein the fibrosis limits
dilation of the blood vessels to increase flow.
15-18. (canceled)
19. A system for inducing weight loss, the system comprising: a
controller operably connected to one or more input devices, wherein
the controller is configured to determine that a patient is
ingesting food; and one or more blood flow constriction devices
operably connected to the controller, the one or more blood flow
constriction devices configured to reduce blood flow to the
gastrointestinal tract.
20. A system according to claim 19, wherein the one or more input
devices comprise one or more of: a sensor configured to detect
distention and/or increased pressure in a stomach, a sensor
configured to detect swallowing, and a sensor configured to detect
flow into a stomach.
21. A system according to claim 19, wherein the one or more input
devices comprise a direct input device actuated by a patient to
provide a signal to the controller that food is being ingested.
22. A system according to claim 19, wherein the one or more blood
flow constriction devices comprises a device configured to
mechanically constrict one or more blood vessels that supply the
stomach and/or small bowel.
23. A system according to claim 19, wherein the one or more blood
flow constriction devices comprises a device configured to cool an
exterior surface of one or more blood vessels that supply the
stomach and/or small bowel.
24. A system according to claim 23, wherein the one or more blood
flow constriction devices is coiled around the exterior surface of
the one or more blood vessels that supply the stomach and/or small
bowel.
25. A system according to claim 19, wherein the one or more blood
flow constriction devices comprises a perfusion balloon configured
to cool blood flowing through a blood vessel in which the perfusion
balloon is located.
Description
RELATED APPLICATION
[0001] The present application claims the benefit under 35 U.S.C.
.sctn. 119(e) of U.S. Provisional Patent Application No.
61/949,024, filed on Mar. 6, 2014 and titled APPARATUS AND METHODS
OF INDUCING WEIGHT LOSS USING BLOOD FLOW CONTROL, which is hereby
incorporated by reference in its entirety.
[0002] Apparatus and methods of inducing weight loss using blood
flow control are described herein. The apparatus and methods
operate by controlling blood flow to the stomach and/or small
bowel.
[0003] Morbid obesity and its concurrent health risks (including
diabetes, heart disease and other ailments) are of near-epidemic
proportions in industrialized societies. A wide variety of
treatments have been proposed and attempted to treat morbid obesity
with a wide variety of efficacy and associated morbidity. These
treatments include techniques to reduce stomach volume, alter
gastric and intestinal motility, and alter the absorption of
nutrients in the small intestine.
[0004] Clearly, obesity is a complex disease having physiologic,
social and psychological components which are not fully understood.
The complex nature and the enormous societal implication of obesity
require a wide variety of treatment options be available to permit
a physician to select a most appropriate option for a particular
patient.
[0005] Even if all treatments were proven effective, no one
treatment can meet the clinical needs presented by a diverse
population. For example, bariatric surgeries, such as the Roux-en-Y
procedure as will be described, is not considered suitable for only
so-called mildly obese patients (e.g., those with a Body Mass Index
less than 35).
[0006] Less invasive procedures (such as gastric banding) have
reduced surgical risk. Unfortunately, they suffer from reduced
efficacy (and they are not without risks). Further, efficacy may be
culturally biased. Namely, gastric banding studies show reduced
efficacy in North American patients compared to European
patients.
[0007] Surgical approaches may include, e.g., minimally invasive
surgery, open surgery and endoscopic approaches to gastric volume
reduction. Gastric volume reduction procedures include vertical and
horizontal gastroplasty in which sutures, staples or other fixation
devices are used to join opposing surfaces of the stomach to create
a reduced volume pouch and thereby reduce caloric intake. Less
invasive techniques for restricting the volume of the stomach also
include a gastric partition in which the stomach wall is
endoscopically cinched together to form a reduced size pouch. Other
techniques for reducing gastric volume size include placement of
obstructions within the stomach.
[0008] To address deficiencies associated with gastric volume
reduction, treatments have been suggested and developed for
reducing the amount of nutrient absorption in the small intestine
(particularly in the upper and middle portions of the small
intestine--the duodenum and jejunum, respectively). Techniques to
reduce nutrient absorption (commonly referred to as malabsorption
treatments) include drug therapies for reducing lipids
absorption.
[0009] Other malabsorption treatments include surgical techniques
for rerouting the intestinal system to bypass an extended portion
of the small intestine. These include a so-called jejunoileal
bypass. Not commonly used due to unacceptable mortality rates, a
jejunoileal bypass typically results in effective weight loss.
Other techniques include the gastric bypass (or Roux-en Y) and
duodenal switch. As a result, the absorptive length of the small
intestine is significantly shortened thereby reducing the amount of
nutrients which are absorbed into the body and which support or
lead to weight gain. These procedures combine the benefits of
gastric volume reduction with malabsorption.
[0010] Less invasive techniques are suggested for placing a band
(referred to as LAP bands) around an upper portion of the stomach
to act as a belt to reduce the size of the stomach and create a
small passageway (a stoma) from a small upper pouch to the
remainder of the stomach.
[0011] US Patent Application Publication No. US 2013/0184635
describes a variety of techniques for treating obesity which may
include one or more of reducing the rate of stomach emptying,
creating a fistula between the stomach and another portion of the
gastrointestinal tract two limit nutrient absorption, etc.
[0012] US Patent Application Publication No. US 2013/0096580
describes another approach to obesity treatment which involves
occluding a blood vessel to interfere with normal gastrointestinal
function.
SUMMARY
[0013] Methods and apparatus for inducing weight loss using blood
flow control are described herein. The apparatus and methods
operate by controlling blood flow to the stomach and/or small
bowel.
[0014] In a first aspect, one or more embodiments of a method of
inducing weight loss as described herein may include: making a
determination that a patient is ingesting food; and reducing blood
flow to the gastrointestinal tract after making the determination
that a patient is ingesting food.
[0015] In one or more embodiments of methods according to the first
aspect, making a determination that a patient is ingesting food
comprises one or more of: sensing distention of the patient's
stomach, sensing increased pressure in the patient's stomach,
sensing swallowing by the patient, receiving direct feedback from
the user, and Doppler flow measurements to measure flow
velocity.
[0016] In one or more embodiments of methods according to the first
aspect, reducing blood flow to the gastrointestinal tract comprises
mechanically constricting one or more blood vessels that supply the
stomach and/or small bowel.
[0017] In one or more embodiments of methods according to the first
aspect, reducing blood flow to the gastrointestinal tract comprises
cooling an exterior surface of one or more blood vessels that
supply the stomach and/or small bowel. In one or more embodiments,
cooling an exterior surface of one or more blood vessels that
supply the stomach and/or small bowel comprises coiling a cooling
device around the one or more blood vessels that supply the stomach
and/or small bowel.
[0018] In one or more embodiments of methods according to the first
aspect, reducing blood flow to the gastrointestinal tract comprises
cooling blood flowing through one or more blood vessels supplying
blood to the stomach and/or the small bowel. In one or more
embodiments, the cooling comprises locating a perfusion balloon in
a blood vessel and supplying cooling fluid within the perfusion
balloon to reduce the temperature of blood flowing through the
blood vessel past the perfusion balloon.
[0019] In one or more embodiments of methods according to the first
aspect, reducing blood flow to the gastrointestinal tract
comprises: sensing an increase in blood flow in one or more gastric
supply blood vessels; and diverting flow away from the one or more
blood vessels that supply the stomach and/or small bowel after
sensing the increase in blood flow in the one or more blood vessels
that supply the stomach and/or small bowel.
[0020] In one or more embodiments of methods according to the first
aspect, reducing blood flow to the gastrointestinal tract comprises
eluting a drug to reduce flow through one or more blood vessels
that supply the stomach and/or small bowel.
[0021] In one or more embodiments of methods according to the first
aspect, reducing blood flow to the gastrointestinal tract comprises
expanding one or more blood vessels that do not that supply the
stomach and/or small bowel.
[0022] In one or more embodiments of methods according to the first
aspect, reducing blood flow to the gastrointestinal tract comprises
reducing the flow of blood away from the gastrointestinal
tract.
[0023] In one or more embodiments of methods according to the first
aspect, reducing blood flow to the gastrointestinal tract comprises
cooling one or more of: stomach, small bowel, and nerves associated
with the stomach and/or small bowel.
[0024] In a second aspect, one or more embodiments of a method of
inducing weight loss as described herein may include reducing blood
flow to the gastrointestinal tract by ablating one or more blood
vessels that supply the stomach and/or small bowel to limit
dilation of the blood vessels to increase flow after the
ablating.
[0025] In one or more embodiments of methods according to the
second aspect, the ablating is configured to cause fibrosis of the
one or more blood vessels that supply the stomach and/or small
bowel, wherein the fibrosis limits dilation of the blood vessels to
increase flow.
[0026] In a third aspect, one or more embodiments of a method of
inducing weight loss as described herein may include reducing blood
flow to the gastrointestinal tract by ablating one or more nerves
selected from the group of: celiac ganglion, superior mesenteric,
inferior mesenteric, and hepatic.
[0027] In one or more embodiments of methods according to the third
aspect, the ablating comprises ablating the one or more nerves
using one or more of: direct current electroporation, microwave
energy, and radio-frequency energy.
[0028] In a fourth aspect, one or more embodiments of a method of
inducing weight loss as described herein may include reducing blood
flow to the gastrointestinal tract by stimulating one or more
peri-arterial nerves to cause vasoconstriction of one or more blood
vessels that supply the stomach and/or small bowel.
[0029] In a fifth aspect, one or more embodiments of a method of
inducing weight loss as described herein may include reducing blood
flow to the gastrointestinal tract by pacing one or more
peri-arterial nerves to cause vasoconstriction of one or more blood
vessels that supply the stomach and/or small bowel.
[0030] In a sixth aspect, one or more embodiments of a system for
inducing weight loss as described herein may include: a controller
operably connected to one or more input devices, wherein the
controller is configured to determine that a patient is ingesting
food; and one or more blood flow constriction devices operably
connected to the controller, the one or more blood flow
constriction devices configured to reduce blood flow to the
gastrointestinal tract.
[0031] In one or more embodiments of systems according to the sixth
aspect, the one or more input devices comprise one or more of: a
sensor configured to detect distention and/or increased pressure in
a stomach, a sensor configured to detect swallowing, and a sensor
configured to detect flow into a stomach.
[0032] In one or more embodiments of systems according to the sixth
aspect, the one or more input devices comprise a direct input
device actuated by a patient to provide a signal to the controller
that food is being ingested.
[0033] In one or more embodiments of systems according to the sixth
aspect, the one or more blood flow constriction devices comprises a
device configured to mechanically constrict one or more blood
vessels that supply the stomach and/or small bowel.
[0034] In one or more embodiments of systems according to the sixth
aspect, the one or more blood flow constriction devices comprises a
device configured to cool an exterior surface of one or more blood
vessels that supply the stomach and/or small bowel. In one or more
embodiments, the one or more blood flow constriction devices is
coiled around the exterior surface of the one or more blood vessels
that supply the stomach and/or small bowel.
[0035] In one or more embodiments of systems according to the sixth
aspect, the one or more blood flow constriction devices comprises a
perfusion balloon configured to cool blood flowing through a blood
vessel in which the perfusion balloon is located.
[0036] As used herein and in the appended claims, the singular
forms "a," "an," and "the" include plural referents unless the
context clearly dictates otherwise. Thus, for example, reference to
"a" or "the" component may include one or more of the components
and equivalents thereof known to those skilled in the art. Further,
the term "and/or" means one or all of the listed elements or a
combination of any two or more of the listed elements.
[0037] It is noted that the term "comprises" and variations thereof
do not have a limiting meaning where these terms appear in the
accompanying description. Moreover, "a," "an," "the," "at least
one," and "one or more" are used interchangeably herein.
[0038] The above summary is not intended to describe each
embodiment or every implementation of the obesity treatment
apparatus or methods described herein. Rather, a more complete
understanding of the invention will become apparent and appreciated
by reference to the following Description of Illustrative
Embodiments and claims in view of the accompanying figures of the
drawing.
BRIEF DESCRIPTION OF THE VIEWS OF THE DRAWING
[0039] FIG. 1 is a flowchart depicting one illustrative embodiment
of a method of inducing weight loss as described herein.
[0040] FIG. 2 depicts one illustrative embodiment of an apparatus
that may be used to induce weight loss as described herein.
[0041] FIG. 3 depicts one illustrative embodiment of an apparatus
and method for cooling blood within a blood vessel as described
herein.
DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS
[0042] In the following description of illustrative embodiments,
reference is made to the accompanying figures of the drawing which
form a part hereof, and in which are shown, by way of illustration,
specific embodiments. It is to be understood that other embodiments
may be utilized and structural changes may be made without
departing from the scope of the present invention.
[0043] On illustrative embodiment of a method of inducing weight
loss is depicted in a flowchart in FIG. 1. In one or more
embodiments, the method includes (10) making a determination that a
patient is ingesting food, followed by (12) reducing blood flow to
the gastrointestinal tract after making the determination that a
patient is ingesting food. In other words, control over blood flow
to the gastrointestinal tract is based on making a determination
that a patient is ingesting food.
[0044] That determination, i.e., that a patient is ingesting food
can be made by any of a variety of techniques. In one or more
embodiments, determining that a patient is ingesting food may be
accomplished through a variety of techniques such as, e.g., using a
sensor to detect distention of and/or increased pressure in the
stomach (using, e.g., pressure sensors, etc.), sensing swallowing
by the patient, detecting flow of food into the stomach, detecting
changes in luminal fluid (e.g. acidity, bile acid content, fluid
volume, solid material), detecting patient activity or movement
versus a resting state, detecting gastrointestinal (GI) luminal
wall characteristics (e.g. stiffness, thickness), detecting
positional changes of recumbency versus standing, etc., and
combinations of one or more of these techniques. In one or more
alternative embodiments, a patient may provide direct feedback,
i.e., an indication that he or she is ingesting food directly as
described elsewhere herein. In one or more alternative embodiments,
the system can also be selectively and automatically triggered
based on time.
[0045] Once a determination is made that a patient is ingesting
food, one or more embodiments of the methods described herein may
include reducing blood flow to one or more portions of the
gastrointestinal tract. Reducing blood flow to one or more portions
of the gastrointestinal tract may, in one or more embodiments, slow
the passage of food through the gastrointestinal tract. Slowing the
passage of food out of the stomach may increase the feelings of
satiety experienced by the patient which may, in turn, lead to a
reduction in food consumption.
[0046] In one or more embodiments of the methods described herein,
reducing blood flow to the gastrointestinal tract may include
mechanically constricting one or more blood vessels that supply the
stomach and/or small bowel. Although US Patent Application
Publication No. US 2013/0096580 describes obesity treatment methods
that involve occluding a blood vessel to interfere with normal
gastrointestinal function, those methods are static. In other
words, those methods do not include restricting blood flow in
response to determining that a patient is ingesting food. The
various apparatus and techniques for mechanically constricting
blood vessels that supply the stomach and/or small bowel described
in that reference may, however, be useful in connection with the
methods described herein. Other methods of mechanical constriction
may also be used for occluding blood flow, for example, air or
fluid filled inflatable cuffs, magnetic devices, a lever- or
hinge-based system, vessel retraction toward an anchored structure
(e.g. spine), etc.
[0047] In one or more embodiments, flow manipulating devices used
to reduce blood flow to the gastrointestinal tract may be placed
internally or externally in or around a target vessel. These
placements could be, e.g., percutaneous, transmural by traversing
intestinal wall, via the vasculature or through a laparoscopic or
retroperitoneal approach. In one or more embodiments, the flow
manipulating devices could include a stimulation system
(electrodes, wires, or pneumatic cuff) that, e.g., stimulates
nerves that, in turn, constrict the vessel. In one or more
embodiments, the flow manipulating devices could include a
stimulation system that stimulates the smooth muscle of the vessel
and give rise to constriction. In one or more embodiments, the flow
manipulating devices may also be utilized in a non-muscular
constriction system made up of conformable metals, metalloids, or
engineered materials that result in constriction and apposition
when electrically stimulated.
[0048] Another option for one or more embodiments of a flow
manipulating device involves the use of a pneumatic compression
device with the air compression chamber involving a diaphragm with
one surface exposed to the ring around the vessel of interest and
the other to an external compression chamber that could, e.g., be
placed subcutaneously or within the abdominal cavity. In one or
more embodiments, the pneumatic chamber may involve a system where
there is no direct air transport, but rather an electronic system
that initiates a biochemical reaction that releases one or more
gasses (including, e.g., air) to effect compression or
decompression.
[0049] In one or more embodiments of the methods described herein,
reducing blood flow to the gastrointestinal tract may include
cooling an exterior surface of one or more blood vessels that
supply the stomach and/or small bowel. Such cooling may, for
example, cause the blood vessels to constrict and, thereby, reduce
flow. In one or more embodiments, the cooling may be performed by
coiling a cooling device around one or more of the blood vessels
that supply the stomach and/or small bowel as described in more
detail herein. In one or more embodiments of the methods described
herein, blood in blood vessels supplying blood to the stomach
and/or the small intestine may be selectively directly cooled to
restrict flow.
[0050] In one or more embodiments, cooling may be used in ways that
do not involve direct cooling of blood. In one or more embodiments,
the cooling of nerves could result in reflex vasodilation and, in
turn, increase the gradient for flow. Cooling also may simply be
used to directly suppress appetite by cooling the blood around the
stomach and also increase caloric needs and possibly increase
metabolic rate as a result of the body needing to increase
temperature in response to the cooling.
[0051] One illustrative embodiment of a system that may be used to
induce weight loss in a patient according to one or more of the
methods described herein is depicted in FIG. 2. The system includes
a controller 20 that is configured to perform the actions described
in connection with the methods described herein.
[0052] In one or more embodiments, the controller 20 may be
connected to an input device 22 that is configured to receive input
from a user/patient. The input device 22 may be a wireless input
device that communicates wirelessly with the controller 20 which
may be implanted subcutaneously within the patient. Some potential
embodiments of wireless input devices 22 may include, e.g., smart
phones, personal computers, dedicated wireless input devices, etc.
In one or more alternative embodiments, the input device 22 may be
connected to the controller 20 by wired connection with the input
device 22 being in the form of a switch, pushbutton, etc. In those
embodiments in which the input device 22 is connected to the
controller 20 by wired connection, input device 22 may implanted
subcutaneously within the patient.
[0053] In one or more embodiments in which the controller 20 is
configured to perform a method that includes a determination that a
patient is ingesting food, the system may include one or more
sensors configured to detect that a patient is ingesting food. In
the illustrative embodiment depicted in FIG. 2, the system may
include one or more of: a sensor 23 configured to detect distention
of and/or pressure increases in the stomach of a patient, a sensor
24 configured to sense swallowing by a patient, and a sensor 25
configured to detect flow of food into the stomach of a patient.
Each of the sensors is operably connected to the controller 20 to
provide input signals indicative of the ingestion of food by a
patient.
[0054] The system depicted in FIG. 2 also includes an optional
blood vessel constriction device 26 configured to constrict blood
flow through a blood vessel 14. The constriction device 26 is
operably connected to the controller 20 which is, as described in
connection with the methods described herein, configured to operate
the constriction device to constrict blood flow through the blood
vessel 14.
[0055] Another optional device which may be provided in a system
such as that depicted in FIG. 2 is a cooling device 28 configured
to cool blood flowing through a blood vessel 14 as described in
connection with one or more of the methods described herein. The
cooling device 28 is operably connected to the controller 20 which
is, as described in connection with the methods described herein,
configured to operate the cooling device to cool blood flowing
through the blood vessel 14. In the depicted illustrative
embodiment, the cooling device 28 is in the form of a coiled device
coiled around the blood vessel 14, with coolant passing through the
coiled device 28 two remove thermal energy from the blood vessel 14
and, therefore, from the blood passing through the blood vessel
14.
[0056] In one or more embodiments of the methods described herein,
the blood flowing through a blood vessel may be cooled as opposed
to cooling the exterior surface of the blood vessel. For example,
in one or more embodiments, the cooling may be performed by
locating a perfusion balloon in a blood vessel and supplying
cooling fluid within the perfusion balloon to reduce the
temperature of blood flowing through the blood vessel past the
perfusion balloon. One illustrative embodiment of a perfusion
balloon used to cool blood flowing through a blood vessel is
depicted in FIG. 3. In that figure, blood flows through the blood
vessel 114 in which a perfusion balloon 128 is located. The
direction of blood flow is indicated by the arrow located within
the interior 130 of the perfusion balloon 128. The perfusion
balloon 128 includes an outer jacket 132 through which a cooling
fluid flows to remove thermal energy from the blood flowing through
the interior 130 of the perfusion balloon 128. The cooling fluid
flowing through jacket 132 may flow in the same direction as the
blood flowing through the interior 130 of the perfusion balloon 128
or in the opposite direction. In one or more embodiments, the
perfusion balloon 128 may operate to both mechanically constrict
flow through the blood vessel 114 as well as cool the blood flowing
through that blood vessel.
[0057] In one or more embodiments of the methods described herein,
reducing blood flow to the gastrointestinal tract may include
sensing an increase in blood flow in one or more blood vessels that
supply the stomach and/or small bowel; and diverting flow away from
the one or more blood vessels after sensing (based on, e.g.,
dynamic change in vessel size, actual vessel caliber, implantable
perivascular ultrasound or laser Doppler, electromagnetic
intravascular sensor, etc.) the increase in blood flow in the one
or more blood vessels thereby decrease the blood flow to the
stomach.
[0058] In one or more embodiments of the systems and methods
described herein in which Doppler sensing techniques are used to
measure velocity of blood flow in a blood vessel, the velocity is
related to diameter of the blood vessel. The more a blood vessel is
constricted (for a given flow rate), the higher the velocity of
blood flowing through that vessel, and the more the blood vessel is
dilated, the lower the velocity of blood flowing through the vessel
for the same flow rate. Doppler sensing could, in one or more
embodiments, be used to make sure that blood flow velocity is set
at a certain level. A potential advantage of that approach could
include avoiding the need for a separate sensor to detect, e.g.,
gastric motility, food intake, etc. A potential disadvantage of
this approach is that it presupposes that the total amount of blood
flow through a blood vessel is constant. However by incorporating
vessel diameter measurements, flow rate can be easily calculated.
In one or more embodiments of the systems and methods described
herein, the Doppler sensor may be advantageously placed in the
venous system intravascularly to detect flow either through the
vein or from the neighboring artery while an external device could
be placed for compression using any of the iterations mentioned
herein for the artery. If a sensing device is placed
intravascularly, one or more embodiments could be to prepare these
sensors with material that prevents blood clotting.
[0059] In one or more embodiments of the systems and methods
described herein, warming of the surrounding vessels may be needed
to increase blood flow other than to the organ of interest, e.g.,
the stomach. At the same time, cooling may be desired, as described
herein, along the artery (or vein--see below) of interest to
control blood flow. To achieve these dual purposes and, at the same
time, provide for rapid (e.g., near instantaneous) cooling, one or
more embodiments of the systems and methods described herein may
use the Peltier/Seebeck effects.
[0060] Using the Seebeck approach would, e.g., be primarily for
generating an electrical signal as feedback when the temperature
difference is sufficient between the surrounding tissue (warmer)
and the periarterial surface (cooler). This temperature difference
using a simple Seebeck generator would, in one or more embodiments,
give rise to a signal that would, in turn, shut the device off or
reduce the rate of thermal control/regulation. In effect, placement
of Seebeck generator in such embodiments could function as a
detector of blood flow through a vessel and/or into selected
tissue. As the blood flow increased, an electric current (signal)
could, in one or more embodiments, be generated as a function of
the difference in temperature between the two sides of the element.
This temperature change could, therefore, be used in one or more
embodiments as an electronic switch or control mechanism as
described herein.
[0061] The Peltier component of such a system and/or method would,
in one or more embodiments, cause the cooling itself using, e.g., a
standard battery-capacitor and generator system or simple power
supply that might be implanted (potentially inductively charged
nocturnally via a charger under the mattress, etc.). One potential
disadvantage of thermoelectric generators is that warming occurs on
one surface as cooling occurs on another surface (typically on two
opposing surfaces). This phenomenon may be used, in one or more
embodiments, to advantage by cooling the vessels and/or tissue that
are closest to one surface of the device (to, e.g., limit blood
flow) and warming vessels and/or tissue the other (e.g., opposite)
surface to cause vasodilation. The result may be, in one or more
embodiments, reduced blood flow to the stomach and enhanced early
satiety. This effect may be amplified if the device is
strategically placed, for example, cooling a blood vessel and/or
tissue near one surface of the device to limit blood flow, while
warming appropriate nerve bundles near the other surface of the
device to modulate nerve traffic. Alternatively, the reverse
effects could be employed, e.g., the nerve bundles could be cooled
to impede conduction, while the blood vessels and/or other tissues
are warmed.
[0062] In one or more embodiments of the methods described herein,
reducing blood flow to the gastrointestinal tract comprises eluting
a drug (e.g., vasodilators and/or vasoconstricting agents depending
on the particular vessel) to reduce flow through one or more blood
vessels that supply the stomach and/or small bowel.
[0063] In one or more embodiments, direct electrical stimulation
of, e.g., a stent coated with one or more drugs, could give rise to
vessel constriction and/or or directly promote satiety could be
released on receipt of the electrical impulse (e.g., electrical
mediation of drug elution).
[0064] In one or more embodiments of the methods described herein,
reducing blood flow to the gastrointestinal tract comprises
expanding one or more blood vessels that do not supply the stomach
and/or small bowel but rather supply other organs, as well as blood
vessels (i.e., veins) that drain blood from the GI tract. This
diversion will functionally limit the blood flow to the stomach
and/or small bowel. One example of such an approach could be timed
according to gut distention, where blood goes to the small
intestine when food is in the stomach and vice versa. This approach
may create a relative deficiency to the area where food needs to be
absorbed.
[0065] In one or more embodiments of the methods described herein,
reducing blood flow to the gastrointestinal tract comprises
reducing the flow of blood away from the gastrointestinal tract. It
is theorized that reducing the flow of blood away from the
gastrointestinal tract may reduce the rate at which blood is
delivered to the gastrointestinal tract.
[0066] In one or more embodiments of the methods described herein,
reducing blood flow to the gastrointestinal tract comprises cooling
one or more of: stomach, small bowel, and one or more nerves (e.g.,
vagus) or ganglia (e.g., celiac) associated with the stomach and/or
small bowel. In the methods described thus far, inducing weight
loss has been discussed in the context of detecting when a patient
is ingesting food and reducing blood flow to one or more portions
of the gastrointestinal tract in an effort to induce weight loss.
In another approach, one or more embodiments of methods of inducing
weight loss may involve reducing blood flow to the gastrointestinal
tract by ablating one or more gastric supply blood vessels to limit
dilation of the blood vessels to increase flow after the ablating.
It is theorized that limiting dilation of the blood vessels will
reduce flow that would normally increase after the ingestion of
food and during processing of that food within the gastrointestinal
tract.
[0067] In one or more embodiments of the systems and methods
described herein, the autonomic modulation, either through
stimulation blockade or ablation may potentially be used alone to
control blood flow. In one or more embodiments, a device could be
internal/intravascular (vein or artery) or external with, e.g., a
cuff-type electrode around the vascular trunks that would include
neural bundles which therefore can be stimulated. In such an
embodiment, the sensing arm could be a separate sensor that senses
one or more of blood flow, gastric motility, glucose, etc.
(although in one or more embodiments, the sensor could be
incorporated into the effector arm of the device). In other words,
the system/method could be configured to monitor neural traffic in
a template that is kept normal for that patient during rest,
eating, sleep, etc. When a characteristic trigger associated with
food ingestion is sensed, stimulation/blockade will be performed
and, in turn, have reflex vascular changes that may promote early
satiety.
[0068] In one or more alternative systems/methods, the functioning
may not be based on feedback indicative of the patient eating. In
one or more embodiments, for example, the system/method may involve
baseline phasic stimulation to increase afferent signaling of
satiety, as well as, e.g., increasing vascular tone through the
efferent autonomic nerves. The same device could, in one or more
embodiments, be used also for direct constriction of the vascular
smooth muscle.
[0069] In one or more embodiments of systems/methods using
ablation, this could be done by a one-time procedure or an
implanted device where the ablation is done by the same battery
that does the stimulation (DC and DC phasic waveforms). In one or
more embodiments, the ablation is not necessarily permanent. It may
involve stunning of neurotransmission because of, e.g., reversible
electroporation.
[0070] In one or more embodiments of inducing weight loss by
ablating one or more blood vessels, the ablating (using, e.g.,
radiofrequency energy, high intensity ultrasound energy, microwave
energy, cryothermal energy, transection, photodynamic therapy
(PDT), intravascular sclerosant, etc.) is configured to cause
fibrosis of the one or more blood vessels that supply the stomach
and/or small bowel, wherein the fibrosis limits dilation of the
blood vessels to increase flow.
[0071] In one or more embodiments of the systems and methods
described herein, fibrosis could be facilitated on the vascular
wall by ablating either internally or externally. The extent of
fibrosis may cause no fixed limitation in terms of blood flow
(e.g., stenosis is not necessarily caused), but may limit blood
flow by stiffening the vessel wall and limiting the vasodilation
and promotional blood flow that occurs as a reflex on, e.g.,
ingesting food.
[0072] In addition to inducing weight loss in methods that involve
detecting when a patient is ingesting food and reducing blood flow
to one or more portions of the gastrointestinal tract or by
ablating one or more blood vessels supplying the gastrointestinal
tract, another approach to inducing weight loss as described herein
may involve reducing blood flow to the gastrointestinal tract by
ablating one or more nerves selected from the group of: celiac
ganglion, superior mesenteric, inferior mesenteric, and
hepatic.
[0073] In one or more embodiments in which one or more nerves are
ablated to induce weight loss, the ablation may be performed using
one or more of: direct current electroporation, microwave energy,
and radio-frequency energy.
[0074] In addition to inducing weight loss in methods that involve
detecting when a patient is ingesting food and reducing blood flow
to one or more portions of the gastrointestinal tract, by ablating
one or more blood vessels supplying the gastrointestinal tract, or
by ablating one or more nerves as described herein, another
approach to inducing weight loss as described herein may involve
reducing blood flow to the gastrointestinal tract by stimulating
one or more peri-arterial nerves to cause vasoconstriction of one
or more gastric supply blood vessels. Yet another potential method
for inducing weight loss as described herein may include reducing
blood flow to the gastrointestinal tract by pacing one or more
peri-arterial nerves to cause vasoconstriction of one or more blood
vessels that supply the stomach and/or small bowel.
[0075] In one or more embodiments of the systems and methods
described herein, stimulation, electroporation, direct
radiofrequency energy application, and other thermal approaches,
including cooling, of the ganglia (e.g., celiac, mesenteric,
hepatic, etc.) could provide indirect effects on satiety by, e.g.,
changing cellular glucose intake, promoting glycogenolysis, and
possibly gluconeogenesis from fat breakdown that may be similar to
the effects seen during starvation, exercise, and adrenergic
stimulation (via, e.g., the hepatic and related ganglia). These
effects may be beneficial and intended/purposeful beyond effects of
satiety. In one or more embodiments, improvement of metabolism may
indirectly help with obesity, diabetes, possibly hypertension and
the metabolic syndrome could potentially be affected through the
direct neuroregulatory systems and methods.
[0076] In one or more embodiments of the systems and methods
described herein, cooling of tissue may be used for the autonomic
nerves to produce electroporation without the use of DC current. In
one or more embodiments, this effect could result in increased
vascular tone at certain locations and decreased vascular tone in
others where blood flow is to be promoted. In some instances, there
may be combined effects here with cooling directly affecting the
vessel, and providing beneficial effects on the perivascular
nerves.
[0077] Disclosure of any patents, patent documents, and
publications identified herein are incorporated by reference in
their entirety as if each were individually incorporated. To the
extent there is a conflict or discrepancy between this document and
the disclosure in any such incorporated document, this document
will control.
[0078] Illustrative embodiments of the systems and methods are
discussed herein some possible variations have been described.
These and other variations and modifications in the invention will
be apparent to those skilled in the art without departing from the
scope of the invention, and it should be understood that this
invention is not limited to the illustrative embodiments set forth
herein. Accordingly, the invention is to be limited only by the
claims provided below and equivalents thereof. It should also be
understood that this invention also may be suitably practiced in
the absence of any element not specifically disclosed as necessary
herein.
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