Related Applications

[0001] The present application is a continuation in part of U.S. Patent Application Serial No. 12/144,575, filed on June 23, 2008, by Edwards et al, entitled "Devices and Methods for Treatment of Hollow Organs," which is a continuation in part of U.S. Patent Application Serial No. 12/108,499, filed on April 23, 2008, by Edwards et al., entitled "Treating Medical Conditions of Hollow Organs," which is a continuation in part of U.S. Patent Application Serial No. 12/099,349, filed on April 8, 2008, by Edwards et al., entitled "Treating Medical Conditions of Hollow Organs;" all of which applications are assigned to the assignee of the present application; the full disclosures of which are all incorporated herein by reference. All patents and published patent applications referred to herein are incorporated herein by reference in their entirety.

Technical Field

[0002] The present invention is generally related to devices and methods for treating medical conditions of hollow anatomical structures, and more particularly, and by way of example, to devices and methods for treating the hollow anatomical structures of the digestive system to treat body-weight related conditions.

Background Art

[0003] The human body has several anatomical structures that are considered hollow, such as but not limited to: hollow anatomical structures ("HAS") of the GI tract (e.g., esophagus, stomach, small and large intestines), bladder, ear canal, nasal sinuses, female reproductive system (e.g., vagina, vaginal canal, uterus, fallopian tubes), and the lungs; as well as various veins and arteries.

[0004] Each of these and other hollow anatomical structures can be subject to medical conditions such as cancer or conditions resulting from loosening of the muscles underlying the HAS, tissue proliferation, and the like. Treatment for these medical conditions range from pharmaceutical therapies to highly invasive surgeries.

[0005] As an example, obesity is one major medical condition that affects several hollow structures of the GI tract. Obesity is directly associated with other medical disorders, such as: osteoarthritis (especially in the hips), sciatica, varicose veins, thromboembolism, ventral and hiatal hernias, hypertension, insulin resistance, and hyperinsulinemia; premature death; type 2 diabetes, heart disease, stroke, hypertension, gall bladder disease, GI tract cancers, incontinence, psychological disorders, sleep apnea, gastro esophageal reflux disease (GERD), and liver disease. Reducing obesity reduces the effects of these conditions provided the weight loss is significant and enduring. This, of course, is the challenge to the patient and practitioner. Current obesity treatments include behavior modification, pharmaceutical interventions, and invasive surgeries.

[0006] One problem with behavior modification is patient compliance. Significant and maintained weight loss demand enormous levels of patient compliance over a long time.

[0007] Problems with pharmaceutical intervention include drug dependence and adverse side effects. Amphetamine analog treatments involve habitual use of addictive drugs to produce and maintain significant weight loss. Dexfenfluramine and fenfluramine treatments often result in primary pulmonary hypertension and cardiac valve abnormalities. Drugs such as sibutramine substantially increase blood pressure in many patients.

[0008] Surgical obesity treatments include invasive surgical procedures such as: gastric banding, bariatric surgery, and liposuction. While current surgical procedures can be effective, the overall rates of surgical mortality and associated hepatic dysfunction are so high that surgical treatments are only indicated for younger patients who are morbidly obese.

[0009] The following table outlines various conventional treatments for obesity and issues associated therewith:

[0010] USP 7,326,207 proposes treating obesity by mapping (for example, using a visualization apparatus, such as but not limited to endoscopes or fluoroscopes) and ablating nerves in targeted stomach areas by creating patterns of thermal lesions. The nerves are ablated using electrodes that penetrate the nerves during energy application. Mapping is required to properly position the electrodes where they can penetrate the nerves.

Physiological changes caused by tissue ablation create a sense of satiety in the patient by directly modulating nerves responsible for hunger sensation or by modulating the nerves inhibiting the let-down reflex of the stomach muscles that are digestion precursors.

[0011] Despite the treatment described in the '207 patent, there is room for further improvement in the field of obesity treatment and as well treatment of other medical conditions that affect hollow anatomical structures.

Summary

[0012] The present invention relates to devices and methods for treatment of hollow anatomical structures ("HAS"). In an embodiment, the present invention relates to devices and methods for treatment of the digestive system, such as the stomach, for weight-related conditions. Although the apparatus and methods of the present invention are described in the context of treating the stomach, it should be appreciated that the present devices and methods are applicable and useful in treatment of other hollow anatomical structures and may be adapted to suit the particular hollow anatomical structure under treatment. Exemplary hollow anatomical structures include, but are not limited to, the lungs, urinary tract, nasal passages, the reproductive tract, as well as body lumens and blood vessels such as, but not limited to, the perforator veins which connect the superficial veins to the deep veins in the leg, truncal superficial veins of the leg (e.g., great saphenous vein, short saphenous vein, and the like), superficial tributary veins of the leg, internal spermatic veins (varicoceles), ovarian veins, gonadal veins, hemorrhoidal vessels, fallopian tubes, a-v malformations, a-v fistula side branches, esophageal varices, and the like.

[0013] Methods of treatment embodying features of the present invention include applying energy to, among other things, any one or more of muscles, nerves, mucosa (or tissue), or glands associated with and/or underlying the hollow anatomical structure (including vessels) to alter any one or more of the muscular profile of the structure, its biomechanical operation, or physiological properties (e.g., shrinkage, coagulation, ablation, constriction). The treatments embodying features of the present invention enable the modification of any one or more of the nerve signal transmission, muscle profile to reaching treatment goals, or the gland's enzyme release. As used herein, the term "ablative energy" denotes energy to bring about any of such physiological or other changes mentioned above.

[0014] In each such application and others to treat the various hollow anatomical structures, the point of entry for the introduction of the present devices to access the structures, the accompanying components (e. g., visualization device), physical shape of the delivery system, as well as the treatment assemblies embodying features of the present invention may differ to suit the particular application. The present apparatus and methods may be adapted for use in various endoluminal, percutaneous, surgical, or laparoscopic procedures.

[0015] In the case of the stomach, in an embodiment, the desired treatment sites of the hollow anatomical structure, are those of the stomach's and include any one or more areas corresponding to or in the vicinities of the greater curvature of the stomach, smaller curvature of the stomach, cardiac zone, gastric/fundic zone, pyloric zone, or the vagal nerve within the stomach, as well as the small intestine. In an embodiment, the nerves, muscles, and/or glands are exposed to a source of ablative energy by expanding the structure beyond its normal volume until the structures mucosa (or tissue) is separated and the underlying nerves, muscles, and/or glands are exposable to the energy. The nerves, muscles, mucosa, and/or glands are exposed by way of expanding an expandable member ("expander member") sized and configured to expand within the structure, and conforming the structure's inner volume to that of the expanded member. In one embodiment, the expandable expander member is formed from non-compliant or semi-compliant material such that it cannot, at least substantially, expand beyond a pre-defined size. The expandable member, upon expansion, expands the structure to a size greater than its normal (e.g., as it is at least prior to the treatment) size, thus conforming the hollow structure's volume to that of the expandable member in the expanded configuration. The methods of treatment provide for guided delivery of energy to the desired treatment areas of the hollow anatomical structure.

[0016] An apparatus for treating medical conditions of hollow anatomical structures embodying features of the present invention may include a treating assembly having an expander assembly including an expandable member configured for expansion in the structure to expose at least a portion of either or both the hollow structure's underlying nerves or muscle. The expandable member is configured to conform the hollow structure's volume to that of the expandable member in the expanded configuration. In an exemplary

configuration, the expandable member, such as an expandable balloon, is disposed at a distal end of an elongate body such as a catheter.

[0017] The expandable balloon includes treatment areas corresponding to any one or more of desired treatment sites of the hollow anatomical structure. In an embodiment, the desired treatment sites are those of the stomach's and include any one or more areas corresponding to or in the vicinities of any one or more of the greater curvature of the stomach, smaller curvature of the stomach, cardiac zone, gastric/fundic zone, pyloric zone, or the vagal nerve within the stomach, or the small intestine.

[0018] The balloon treatment areas may be formed in any direction along the expandable balloon, e.g., circumferential, longitudinal; and include channels (e.g., pockets formed in the material constituting the balloon (e.g., where portions of the balloon are formed from two layers with a hollow interior therebetween for the flow of fluid therethrough)) adapted to receive an energized fluid medium therein. The channels are in fluid communication with one another as well as a fluid source though inlet and outlet conduits. The inlet conduit delivers the energized fluid medium from an energized fluid source to the channels with the outlet conduit providing a return path for the spent fluid medium. The fluid flows from the inlet conduit through the channels and exits the balloon through the outlet conduit. The returned fluid may be re-energized (e.g., reheated) by an external source and returned to the channels for further use during the treatment. Alternatively, fresh energized fluid may be used in a continuous or intermittent manner, as necessary, with the returned fluid being discarded. As used herein, the terms energized fluid and/or fluid energy medium refer to a source of energy (e.g. thermal energy), such as but not limited to hot fluids such as water, saline, air, steam, and the like.

[0019] The energy source, such a thermal energy source, is controllable by a control assembly, normally external to the patient's body. The temperature of the energized fluid at its source is sufficiently high to provide a sufficiently high fluid temperature at the point of treatment. In the case of treatment of the stomach, the temperature of the energized fluid at its source may range from about 60 ^° to about HO C, from about 70 ^° to about 105 C, from about 75 ^° to about 85 C. The temperature at the point of treatment is sufficiently high to effectuate the desired treatment. The temperature at the point of treatment in the stomach may range from about 50 ^° to about lOO C, from about 60 ^° to about 95 C, from about 60 ^° to about 80 ^° C.

[0020] In order to monitor the amount of energy delivered and the amount of heat generated, the apparatus may also include one or more sensors. These sensors can be used to detect a variety of operating parameters including the amount of energy delivered, and the

temperature of a region adjacent the apparatus. These sensors can also be used to provide feedback for controlling the operation of the energy source which delivers energy to the energy delivery device. In addition, chemical or biochemical sensors can be used to detect ablation.

[0021] In one embodiment, the apparatus includes at least one temperature sensor, such as a thermocouple or thermistor. The temperature sensor is coupled to a communication link (such as a conductor), which is coupled to a processor. For example, in the case where the temperature sensor is a thermocouple, the communication link may comprise a D/A converter coupled to a register disposed for reading by the processor. The processor reads a sensor value from the sensor and, responsive thereto, controls the signal generator so as to achieve delivery of an effective amount of energy (e.g., by way of energized fluid) to a desired section of tissue to be ablated. The processor thus uses information from the signal generator, the channels, energy delivery device, and temperature sensor, as a feedback loop for controlled delivery of energy to a section of a stomach (or other treatment areas of a hollow anatomical structure). For example, the processor may control the delivery of energized fluid to achieve delivery of a selected amount of energy, to achieve a selected temperature, or to achieve a selected amount of ablation of a section of a stomach. A variety of positionings for the sensors are possible. In one embodiment, the sensor is coupled to the expandable member.

[0022] As described above, the temperature or some other property of the tissue being ablated, or of the energy delivery device (e.g., source for generating the energized fluid, the delivery mechanism, and the like) can be monitored using a variety of sensors. By way of example, open and a closed loop feedback systems may be utilized for coupling a sensor used in the apparatus to an energy source so that the output energy of the energy source is adjusted in relation to the property sensed by the sensor. One or more sensors may be located within or about the expandable member, or at or about the channels. It should be appreciated that the sensor may take any appropriate form, as for example formed of wireless construction, and may further be configured to sense and convey the necessary information in any number of ways and formats and is not limited to direct thermal sensors. By way of example and not limitation, the temperature may be sensed by optical means which can assess a change in the color of at least a portion of expandable member (e.g., channels). In this configuration, colorants may be present in the material forming the expandable member/channels or be painted or deposited on its material (on the inner or outer surface). Once the colored area is exposed to the elevated temperature, the colorant may change its characteristics. Information as to the temperature may then be conveyed to the practitioner. The information may be conveyed automatically by instrumentation or by direct visualization through the endoscopic device. As stated, such sensors may also be present on or in the expandable member.

[0023] The treatment assembly may further include a visualization device, such as an endoscope (or bronchoscope in the case of the hollow structure being the lung), disposed within the elongate body (e.g., catheter), or deliverable though any other suitable means. The endoscope may include an illumination source such as lights for visualization of the structure. In an embodiment, the endoscope is disposed within the expander assembly prior to advancement into the structure. The expander assembly and the endoscope are accessible through a hand-piece disposed at a proximal end of the treatment assembly.

[0024] The expandable expander member may be formed from any suitable material such as, but not limited to expandable, noncompliant (or semi-compliant) material including Mylar, Nylon, PET, PeBax, IEBA. In a preferred embodiment, the material for balloons is formed from non-compliant material. For example, Mylar, while expandable, is noncompliant and restricts expansion of the expandable balloon within the stomach. Therefore, an expandable balloon formed from Mylar cannot infinitely expand and patient injury resulting from unintended over-inflation of expandable balloon can be reduced. In an embodiment, when used for obesity treatment, expandable balloon is constructed such that when inflated within the stomach, the stomach expands from its empty volume (about 1 liter) to at least about twice the stomach's empty volume (e.g. 2 liters). However, for other hollow anatomical structures and other species, the expandable member may have different profiles or volumes. In an embodiment, the expandable member is pre-shaped such that as the expandable member is expanded within the hollow anatomical structure, the interior of the hollow anatomical structure conforms to the profile of the expandable member.

[0025] Optional visual markings, corresponding to desired target sites of the HAS, may be located on the expandable member. The visual markings are used to aid in locating the desired treatment target sites. Such visual markings may be incorporated into or deposited on or within the material forming the expandable expander member. In an embodiment, the visual markings may take the form of colorant, metallic or polymeric material. Although some sort of visual marking may be preferred, the practitioner may identify the necessary areas for transfer of energy using practitioner's experience. The visual markings may be positioned to correspond to any one or more areas corresponding to or in the vicinities of the greater curvature of the stomach, smaller curvature of the stomach, cardiac zone,

gastric/fundic zone, pyloric zone, or the vagal nerve within the stomach, or the small intestine.

[0026] In another embodiment, a treatment assembly may include a reference point positioner disposed at a distal end of the expander assembly. Preferably, reference point positioner comprises a positioning balloon adapted for inflation in the patient's body using means such as a conventional air or liquid tube that may also acts as a catheter guide. In operation, positioning balloon is inflated after passing through the pyloric sphincter and seats against the distal side of the pyloric sphincter. Once seated, the inflated positioning balloon sets a reference point for the tube and allows proper positioning of the balloon assembly without necessarily using a visualization apparatus. In an embodiment, the expanding balloon and its treatment sites may extend into the small intestine to provide treatment to at least a portion of the small intestine.

[0027] In an embodiment, the treatment assembly further includes an external treatment controller (portions of which were described above) for controlling various parameters useful in the treatment procedure. The external treatment controller comprises any one or more of the following subassemblies: treatment energy source for providing source of treatment energy such as energized fluid source (e.g., steam, hot water, hot saline), input/output (I/O) device, inflation fluid delivery unit for inflating/deflating the expandable member, or the positioning balloon when present.

[0028] In an exemplary method for treating the hollow anatomical structures embodying features of the present invention includes using a source of energy positionable in the HAS to apply energy to at least one surface of the HAS to affect its operation. In an embodiment, energy is thermal energy provided from a source of hot fluid, such as steam, hot water, or hot saline. An exemplary hollow anatomical structure is the stomach and the at least one surface of the HAS to which energy is applied is either or both stomach's muscle surface or the surface in the vicinity of at least a portion of a nerve communicating with the stomach and brain. In an embodiment, the treatment includes applying energy to at least one surface of the stomach's underlying glands to affect glandular emissions, such as ghrelin, pepsin, rennin, and/or HCl. In an exemplary method, the treatment includes transferring energy from an energy delivery member (e.g., the expandable expander member), such as the channels, positionable within the HAS, to the hollow anatomical structure's surface (or underlying muscles, nerves, glands, etc), by way of, direct or indirect, preferably physically nonpenetrating, surface contact.

[0029] In an exemplary embodiment, a method for treating the hollow anatomical structure, such as the stomach in the digestive tract, includes introducing an expandable expander member into the hollow anatomical structure; expanding the hollow anatomical structure with the expandable expander member to bring into surface contact at least a portion of a surface of the expandable member with at least a portion of a surface of the hollow anatomical structure to expose any one or more of the underlying nerves, muscles, or glands of the HAS. A source of energy, such as energized fluid, is controllably introduced into a portion of the expandable member, e.g., the channels in the material forming the expander member, and energy (e.g., thermal energy) from the energized fluid is delivered to at least a portion of the surface of the expandable member, e.g., surface of the channels, and to at least a portion of the surface of the hollow anatomical structure. At least one or more of underlying nerve, muscle, or gland of the stomach are treated (e.g., ablated). In an embodiment, the at least one or more of underlying muscle is at least in one of the greater curvature of the stomach, smaller curvature of the stomach, cardiac zone, gastric/fundic zone, pyloric zone, or the vagal nerve within the stomach, or the that of the small intestine.

[0030] In an embodiment for treatment of the gastric tract, and in operation, a gastric introducer is positioned in the patient's throat and protects the esophageal walls during the procedure. The expander assembly, preloaded with the endoscope (when present) is inserted into patient's body through the introducer. The expandable balloon is advanced distally, positioning a shaped distal portion of the expander member against the distal side of the pyloric sphincter. Using an inflation conduit, the expandable member is inflated until the stomach's volume reaches the desired volume, such as at least about twice its empty volume (e.g. to about 2 liters). The pre-shaped distal portion, at the expanded configuration, seats against the distal side of the pyloric sphincter, providing an anchor and aiding in position and placement of the expander assembly within stomach.

[0031] Once the expandable member has been positioned at the treatment site and expanded to the desired volume, the optional endoscope may be pulled back completely or partially into the introducer.

[0032] In an embodiment, the practitioner using a control unit and foot pedal, introduces energized fluid (e.g., hot fluid such as hot saline or water), from an energized fluid source through inlet conduit 350, into the channels extending along at least a portion of the expandable balloon. As hot water (or other source of energy) is introduced into the channels, thermal energy is transferred from the channels and the expandable member to the desired treatment site/s of the target hollow anatomical structure. In an embodiment, the expanded expandable member comes into direct surface contact with the desired target sites of the hollow anatomical structure. In an embodiment, the desired treatment site/s include any one or more areas corresponding to or in the vicinities of the greater curvature of the stomach, smaller curvature of the stomach, cardiac zone, gastric/fundic zone, pyloric zone, or the vagal nerve within the stomach, or the small intestine.

[0033] In an embodiment, the transferred energy is sufficiently high to cause a change (e.g., physical, biochemical, physiological change) in the treatment target sites as described earlier.

[0034] It should be noted that the energized fluid may be further augmented by delivery of energy to the targeted areas in other forms such as electromagnetic energy (e.g., RF, microwave), ultrasonic energy, infrared energy, visible laser energy, other sources of thermal energy, or the like. Such augmenting energies may be deliverable to the surface of the hollow anatomical structure by way of surface contact electrodes, preferably non-penetrating electrodes. In an embodiment, such electrodes are formed on a surface, exterior and/or interior, of the expandable balloon, or in between layers of material forming the expander member. The electrodes may be associated with the channels or formed in, on or about other portions of the balloon or other structures disposable within the hollow anatomical structure. For example, and as described in co-pending US Application Serial No. 12/108,499 entitled Treating Medical Conditions of Hollow Organs, filed on April 23 ^rd , 2008 and assigned to the assignee of the present invention, the full disclosure of which is incorporated herein by reference; the various assemblies may further be modified to allow the practitioner to activate an RF generator (not shown), resulting in additional energy being emitted from electrodes positionable in, on, or about the expandable member to treat (e.g., ablate) the tissue in the treatment zones. During this time, using GUI and feedback from corresponding sensor associated with such electrodes, the practitioner can monitor the temperature at the site. The duration of time and frequency of applied energy are, of course, responsive to judgments of medical personnel. [0035] After the practitioner is satisfied that the desired amount of tissue has been treated (for example ablated) and/or the pulse transmissions between nerves and the brain have been affected by the desired amount, energy application is stopped. The energized fluid and the spent fluid are removed from the channels by way of outlet conduit 355. The expandable member is deflated, the expander assembly is withdrawn from the patient, as is the gastro introducer.

[0036] In another embodiment embodying features of the present invention, after patient sedation, the endoscope introduces the reference point positioner (e.g., reference point balloon), into the patient's alimentary canal. The endoscope forwards positioning balloon through the stomach and onto the distal side of the pyloric sphincter. The endoscope is retracted and positioning balloon inflated to seal against the distal side of the pyloric sphincter. This sets a fixed reference point for the tube. A gastric introducer positioned in the patient's throat, protects the esophageal walls during the next steps in the process.

[0037] The expander assembly is now introduced into the patient's digestive system through the gastric introducer and by the catheter riding over tube. When distal tip of the catheter contacts the positioning balloon and the closed pyloric sphincter, the practitioner stops inserting the stomach expander into the patient. Balloon member 320 is then inflated until the stomach's volume becomes about twice its empty volume. The desired target sites are treated as described above.

[0038] After the practitioner is satisfied that the desired amount of tissue has been treated (for example ablated) and/or the pulse transmissions between nerves and the brain have been affected by the desired amount, energy application is stopped. The energized fluid and the spent fluid are removed from the channels by way outlet conduit. The reference positioner and the expandable member are deflated and withdrawn from the patient, as is the gastro introducer.

Brief Description of Drawings

[0039] FIGs. IA and IB are simplified illustrations of a mammalian digestive system.

[0040] FIG. 2A illustrates an exemplary assembly embodying features of the present invention for treating hollow anatomical structures.

[0041] FIGs. 3 A and 3B are schematic representations of different expandable members embodying features of the present invention.

[0042] FIG. 4 A is a schematic representation of a treatment assembly embodying features of the present invention and for treating hollow anatomical structure.

[0043] FIGs. 4AA- AC are cross sectional views of portions of the HAS expander assembly, endoscope, and the introducer of FIG. 4A.

[0044] FIG. 4B is a schematic representation of another treatment assembly embodying features of the present invention and for treating hollow anatomical structure.

[0045] FIG. 5 illustrates a schematic of an exemplary external control unit embodying features of the present invention for use with the stomach treatment assembly of FIG. 3.

[0046] FIGs. 6A and 6B are schematic representations of neural communication between the stomach and the brain.

[0047] FIG. 7 illustrates a schematic profile of a treated stomach about 8-12 weeks, post-op.

Description of Embodiments

Anatomical Background

[0048] In describing features of the present invention, the hollow organ of the digestive system, such as the stomach, will be used. However, it should be appreciated by those skilled in the art that the use of this exemplary hollow structure is not intended to limit the scope of the present invention.

[0049] FIGs. IA and IB are simplified depictions of a mammalian digestive system. These FIGs. are not intended to be strictly accurate in an anatomic sense or imply that the teachings of this patent application are limited strictly to treating the digestive system. The drawings show the digestive system in somewhat diagrammatic form for purposes of discussion.

[0050] FIG. IA, illustrates esophagus 10, a muscular tube, for carrying food from the mouth to the stomach 12, by way of wavelike contractions of the muscles in the walls of the esophagus 10. The interior esophagus walls include glands that secrete mucus, which further aid the movement of food by acting as lubricants.

[0051] Stomach 12, located in the upper left hand side of the abdomen, lies between the esophagus 10 and the small intestine 14. In humans and most other animals, stomach 12 is a simple baglike organ.

[0052] FIG. IB depicts branches 15 of the vagal nerve that connect stomach 12 with the hindbrain H which is believed to be the neurological source for the hunger sensation. The upper end of stomach 12 connects with the esophagus 10 at cardiac notch 16 (FIG. IA). The muscular ring called the lower esophageal sphincter 18 surrounds the opening between the esophagus 10 and the stomach 12. The funnel-shaped region of the stomach 12 immediately next to sphincter 18 is the cardia. The cardia (also known as Z-line or esophagogastric junction or gastroesophageal junction) is the anatomical term for the junction orifice of the stomach and the esophagus. At the cardia, the mucosa of the esophagus transitions into gastric mucosa. The cardia is also the site of the lower esophageal sphincter 18 (LES which is also termed cardiac sphincter). The greater curvature of the stomach, 26, starts from the cardiac orifice at the cardiac notch, and forms an arch backward, upward, and to the left; the highest point of the convexity is on a level with the sixth left costal cartilage. The lesser curvature 27 of the stomach is opposite the greater curvature and extends between the cardiac and pyloric orifices, forming the right or posterior border of the stomach. It descends as a continuation of the right margin of the esophagus in front of the fibers of the right crus of the diaphragm, and then, turning to the right, it crosses the first lumbar vertebra and ends at the pylorus.

[0053] From this level it may be followed downward and forward, with a slight convexity to the left as low as the cartilage of the ninth rib; it then turns to the right, to the end of the pylorus. Positioned below the cardia is the fundus 25 of the stomach.

[0054] The volume of an average adult stomach, an organ for storing and digesting food, is a little over one quart (-0.95 liter). Pyloric sphincter 22, located distal of pylorus 23, surrounds and controls the size of the duodenal opening disposed between stomach 12 and small intestine 14. Pyloric sphincter 22 keeps non- liquid food in stomach 12 until the food is processed into a more flowable liquid form, thereafter allowing for the flow of the liquefied food from stomach 12 into the intestine 14. The time food spends in stomach 12 varies and usually ranges from about three to about five hours.

[0055] Using these anatomical features as landmarks or guides, the human stomach is often described as having three zones, namely: cardiac zone, gastric/fundic zone, and pyloric zone. In an embodiment, A treatment according to the body-weight related conditions, according to the present invention, is achieved by applying energy to or in the vicinities of any one or more of:

[0056] (1) nerve tissue which allows nerve pulse communication between the hindbrain H and stomach 12; or

[0057] (2) stomach tissue to ablate tissue in one or more areas where food is either processed and/or absorbed by the body, for example, the cardiac, gastric/fundic, and pyloric zones.

[0058] Additionally, treatment may be expanded to other areas, such as the small intestine (and associated nerves), where about 95% of all food absorption occurs. Ablation, or causing cell death, produces lesions which when large enough, evoke tissue -healing and intervention of fibroblasts, myofibroblasts, macrophages, and other cells. Healing results in tissue contraction (shrinkage), decreased volume, and/or altered biomechanical properties. In contrast with other treatments for conditions such as obesity which merely try to prolong patient satiety, the current devices and methods embodying features of the present invention, further provide for directly affecting the digestive process and may reduce food absorption. Without intending any limitations on the scope of the present invention, it is believed by the present inventors that ablation of cells in the cardiac, gastric/fundic, and/or pyloric zones enables treatment of weight-related conditions and reduces a patient's body weight, among other things, for the following reasons:

[0059] CARDIAC AND FUNDIC-GASTRIC ZONES - The cardia and fundic-gastric zone contain, respectively, the cardiac glands (not shown) and the fundic glands (not shown). The cardiac and fundic glands release digestive enzymes (e.g., ghrelin, pepsin and rennin) and hydrochloric acid (HCl) which are used during digestion to break down food. Ablating a portion of the cardiac and gastric-fundic zones, e.g., the cardiac and fundic glands, therefore, reduces the release of ghrelin, pepsin, rennin and HCl, thereby reducing the amount of food digested by the body and resulting in more undigested food particles passing through the patient's body.

[0060] PYLORIC ZONE - The pyloric sphincter controls the size of food particles and their flow from the stomach (emptying cycle). The wider the opening of the sphincter, the larger the size of the food particles that may flow out of the stomach. Without limiting the scope of the present invention, it is believed that ablating the pyloric muscle tissue decreases the size of the pyloric opening and the size of food particles that may flow out, thereby lengthening the emptying cycle (longer sensation of satiety).

[0061] The gastric zone also includes the lesser curvature of the stomach which contains nerves that control peristalsis of the stomach walls. Peristalsis contributes to digestion by physically reducing the size of food particles in the stomach. It is also believed, without limiting the scope of the present invention, that ablating portions of the muscles of the lesser curvature reduces peristalsis and increases food particle size. These larger food particles, when passed through the pyloric sphincter, cannot be digested through the small intestine and therefore would pass through the patient's body undigested. Finally, ablating gastric zone tissue may also affect the gastric glands and reduce HCl production in the stomach (see above).

[0062] Against this anatomical and physiological background, exemplary apparatus, assemblies, and methods for treating body-weight related medical conditions associated with the digestive hollow organs will be described. It should be appreciated by those skilled in the art that using the digestive hollow organ, such as the stomach, for describing features of the present invention, is not intended to limit the scope of the present invention.

Treatment Apparatus

[0063] FIGs. 2A through 5 show features of an exemplary embodiment of apparatus 80 for treating hollow anatomical structures ("HAS"). For purposes of describing the present invention the digestive tract, e.g., stomach 12 (FIGs. IA and IB) will be used. Although the apparatus and methods of the present invention are described in the context of treating the digestive tract (e.g., stomach), it should be appreciated that the present devices and methods are applicable and useful in treatment of other hollow anatomical structures. Furthermore, it should be appreciated that the shape, size, and specific configuration of the various components may be modified and adapted for use in the particular application and the anatomical structure (e.g., respiratory tract, lung, reproductive tract and/or organ, urinary tract and organs, nasal passage, sinus, veins, artery, tunsile, tempanic membrane, or joints).

[0064] Assembly 80 (FIG. 2) includes a hollow anatomical structures treating assembly 100 (FIG. 3A and 4A) and an external control assembly 500 (FIG. 5). At least a portion of the HAS treating assembly 100 works inside the patient's body for treatment of the hollow anatomical structures such as hollow organs and blood vessels. External control assembly 500 (FIG. 5) includes components for, among other things, providing energy, controlling, monitoring, and viewing, at least parts of the HAS treating assembly 100.

[0065] Now referring to FIG. 3 A, portion of a HAS treating assembly 100, such as treatment assembly 100, is shown including; an expander assembly 300, such as balloon assembly 310; embodying features of the present invention. As shown in FIG. 3 A, the balloon assembly 310 including an expandable member such as expandable balloon 320, is disposed, in an expanded configuration, in the stomach 12. The expandable balloon is adapted for expansion within the interior of the HAS conforming an inner wall 123 of the HAS 120 to the shape and volume of the expanded expandable member such that at least portions of the outer surface 325 of the balloon 320 are in surface contact with the inner wall 123 of the HAS.

[0066] An interior 330 of balloon 320 is in fluid communication with an inflation/deflation source (FIG. 4A) through a conduit, such as lumen of an elongate body, such as catheter 400 (by way of example and not limitation, inflation deflation may be achieved through the same or different lumens). Balloon 320, as shown, is disposed at a distal end 403 of the catheter 400.

[0067] Now returning to FIG. 3A, a distal portion 335 of the balloon 320 is shaped to conform, upon expansion, to a portion of the HAS, preferably, distal to the desired treatment site; such as the pyloric sphincter 22. In operation the shaped distal portion 335 is inflated and seats against the distal end of the pyloric sphincter.

[0068] Balloon 320 includes treatment areas 340 (shown as dashed pattern) corresponding to any one or more of desired treatment sites of the HAS. In the embodiment shown, the desired treatment sites are those of the stomach's and include any one or more areas corresponding to or in the vicinities of the greater curvature of the stomach, smaller curvature of the stomach, cardiac zone, gastric/fundic zone, pyloric zone, or the vagal nerve within the stomach. The balloon treatment areas 340, as shown, are formed in radial direction and include channels 345 (e.g., pockets formed in the material forming the balloon as for example in a balloon where portions of the balloon are formed from two layers with a hollow interior therebetween for the flow of fluid therethrough) adapted to receive a fluid energy medium therein. The channels 345 are in fluid communication with one another. An inlet conduit 350 delivers fluid energy medium from an energized fluid source to the channels with an outlet conduit 355 providing a return path for the spent fluid medium. It should be appreciated that the treatment areas 340 are not limited to those extending in the radial dimension of the balloon 320 and that they may take any shape and be extended in any suitable direction. The fluid flows from the inlet conduit through the channels and exits the balloon from the outlet conduit. The returned fluid may be re-energized (e.g., reheated) by an external source and returned back to the channels for further use during the treatment. Alternatively, fresh energized fluid may be used in a continuous or intermittent manner, as necessary, with the returned fluid being discarded. As used here, the terms energized fluid and fluid energy medium refer to a source of thermal energy, such as but not limited to hot fluids such as water or saline, steam, and the like.

[0069] As shown in FIG. 3 A, the expanded balloon 320 extends from a distal end 606 of an introducer 600, such as gastric introducer 603. In an embodiment, the expanding balloon and its treatment areas may extend into the small intestine to provide treatment to at least a portion of the small intestine.

[0070] In another embodiment, as shown in FIG. 3B, a HAS treatment assembly 100 may include a reference point positioner 700 disposed at a distal end 103 of the expander assembly 300. Preferably, reference point positioner 700 comprises a positioning balloon 703 adapted for inflation in the patient's body using means such as a conventional air or liquid tube 710 that may also acts as a catheter guide. In operation, positioning balloon 703 is inflated after passing through the pyloric sphincter 22 and seats against the distal side of the pyloric sphincter 22. Once seated, inflated positioning balloon 703 sets a reference point for tube 710 and allows proper positioning of the balloon assembly 310 without necessarily using a visualization apparatus. In an embodiment, the expanding balloon and its treatment sites may extend into the small intestine to provide treatment to at least a portion of the small intestine.

[0071] Now referring to FIG. 4A, the expander assembly 300 of FIG. 3 A is shown as part of a HAS treating assembly 100. In the embodiment shown, the expander assembly 300 includes an elongate body such as catheter 400 (FIG. 4B) with proximal and distal ends, 406 and 403, respectively; and at least one lumen (not shown) extending along at least a distal portion thereof. The balloon member 320 is disposed at the distal end of the catheter 400 (FIG. 4B) and extends from a distal end 606 of the introducer 600 (FIG. 4A). As also shown in cross-section FIGs. 4AA and 4AB, an endoscope 800 may optionally be disposed within the catheter 400. Endoscope (or other visualization tool) 800, during a procedure, may be extended into the interior 330 of the expandable balloon 320 for better visualization of the treatment site. Endoscope 800 may include an illumination source such as lights (not shown) for visualization of the HAS when it is disposed within the HAS interior 130. The expander assembly and endoscope are accessible through (FIG. 4A) hand-piece 750 disposed at the proximal end 110 of the treatment assembly 100. For purposes of clarity in FIGs. 4AA-4AC, only the overall structure of the introducer, catheter, and/or endoscope are shown (e.g., the channels are not shown).

[0072] Now referring to FIG. 4B, wherein like references denote like elements, expander assembly of FIG. 3B is shown as part of a HAS treating assembly 100. A distal end 103 of HAS treating assembly 100 includes the reference point positioner 700 with the positioning balloon 703 adapted for inflation in the patient's body using the conventional air or liquid tube 710 that also acts as a catheter guide.

[0073] The expander assembly 300 comprises, for example, the balloon assembly 310 integrated with the catheter 400 having a distal tip 420. In FIG. 4B, balloon assembly 310 is collapsed. Catheter 400 allows balloon assembly 310 to be inserted into the patient's body over tube 710. Then, using an air line in handpiece 750 disposed at the proximal end 110 of the treating assembly 100, balloon member 320 is inflated to expand the stomach's volume. The HAS expander assembly, the reference point positioner, and tube 710 (and the endoscope when present) are accessible through hand-piece 750 disposed at the proximal end of the HAS treatment assembly.

[0074] The fluid inlet conduit is configured for fluid communication with an energy source 900. Energy source 900, such a thermal energy source 903, may include, but is not limited to, hot fluids such as hot water, hot saline, hot air, steam; and is controllable by the control assembly 500. The temperature of the energy at its source is sufficiently high to provide a sufficiently high fluid temperature at the point of treatment. In the case of a stomach, the temperature of the energy at its source may range from about 60 ^° to about HO C, from about 70 ^° to about 105 C, from about 75 ^° to about 85 C. The temperature at the point of treatment is sufficiently high to effectuate the desired treatment. The temperature at the point of treatment, for the stomach, may range from about 50 to about lOO C, from about 60 ^° to about 95 ^° C, from about 60 ^° to about 80 ^° C.

[0075] One or more sensors may be located within or about the expandable member, or at or about the channels. In an embodiment, the sensor is a thermocouple or thermistor. The temperature sensor is coupled to a communication link (such as a conductor), which is coupled to a processor. For example, in the case where the temperature sensor is a thermocouple, the communication link may comprise a D/A converter coupled to a register disposed for reading by the processor. The processor reads a sensor value from the sensor and, responsive thereto, controls the signal generator so as to achieve delivery of an effective amount of energy (e.g., by way of energized fluid) to a desired section of tissue to be ablated. The processor thus uses the information from the signal generator, the channels, energy delivery device, and temperature sensor, as a feedback loop for controlled delivery of energy to a section of a stomach (or other treatment areas of a hollow anatomical structure). For example, the processor may control the delivery of energized fluid to achieve delivery of a selected amount of energy, to achieve a selected temperature, or to achieve a selected amount of ablation of a section of a stomach. A variety of positionings for the sensors are possible. In one embodiment, the sensor is coupled to the expandable member.

[0076] As described above, the temperature or some other property of the tissue being ablated, or of the energy delivery device (e.g., source for generating the energized fluid, the delivery mechanism, and the like) can be monitored using a variety of sensors. By way of example, open and a closed loop feedback systems may be utilized for coupling a sensor used in the apparatus to an energy source so that the output energy of the energy source is adjusted in relation to the property sensed by the sensor. One or more sensors may be located within or about the expandable member, or at or about the channels. It should be appreciated that the sensor may take any appropriate form, as for example formed of wireless construction, and may further be configured to sense and convey the necessary information in any number of ways and formats and is not limited to direct thermal sensors. By way of example and not limitation, the temperature may be sensed by optical means which can assess a change in the color of at least a portion of expandable member (e.g., channels). In this configuration, colorants may be present in the material forming the expandable member/channels or be painted or deposited on its material (on the inner or outer surface). Once the colored area is exposed to the elevated temperature, the colorant may change its characteristics. Information as to the temperature may then be conveyed to the practitioner. The information may be conveyed automatically by instrumentation or by direct visualization through the endoscopic device. As stated, such sensors may also be present on or in the expandable member.

[0077] Regardless of the configuration, HAS expandable member 320 may be formed from any suitable material such as, but not limited to expandable, noncompliant (or semi- compliant) material including Mylar, Nylon, PET, PeBax, IEBA. In a preferred embodiment, the material for balloons 320 is formed from non-compliant material. For example, Mylar, while expandable, is noncompliant and restricts expansion of the expandable balloon within the stomach. Therefore, an expandable balloon formed from Mylar cannot infinitely expand and patient injury resulting from unintended over-inflation of expandable balloon can be reduced. In an embodiment, when used for obesity treatment, expandable balloon is constructed such that when inflated within the stomach, the stomach expands from its empty volume (about 1 liter) to at least about twice the stomach's empty volume (e.g. 2 liters). However, for other hollow anatomical structures and other species, the expandable member may have different profiles or volumes. In an embodiment, the expandable member is pre- shaped such that as the expandable member is expanded within the hollow anatomical structure, the interior of the hollow anatomical structure conforms to the profile of the expandable member.

[0078] Optional visual markings, corresponding to desired target areas of the HAS, may be located on the expandable member. The visual markings are used to aid in locating the desired treatment target areas. Such visual markings may be incorporated into or deposited on or within the material forming the member. In an embodiment, the visual markings may take the form of colorant, metallic or polymeric material. Although some sort of visual marking may be preferred, the practitioner may identify the necessary areas for transfer of energy using practitioner's experience. The visual markings may be positioned to correspond to any one or more areas corresponding to or in the vicinities of the greater curvature of the stomach, smaller curvature of the stomach, cardiac zone, gastric/fundic zone, pyloric zone, or the vagal nerve within the stomach.

External Control

[0079] Now referring back to FIGs. 2 and 5, the external control portion 500 for apparatus 80 is shown and including a control unit 510. Control unit 510 may include any one or more of the following subassemblies: treatment energy source 520 for providing and controlling fluid source 900, controller 530, I/O device 540, inflation fluid delivery unit 250, and GUI 560.

[0080] Summarily, control unit 510 governs the power levels, cycles, and duration of energy transmitted through line 512 to the fluid source and the channels to achieve and maintain temperature levels that achieve treatment objectives. Foot switch 511 allows hands-free control of energized fluid delivery (e.g., heating and delivery of hot fluid). In tandem, control unit 510 controls delivery of processing (inflation) fluid and, if needed, the removal of aspirated material through fluid lines 555.

[0081] Controller 510 includes an Input/Output (I/O) device 540. The I/O device 540 allows practitioners to enter control and processing factors enabling control unit 510 to generate correct command signals. The I/O device 540 also receives real time processing feedback information from the one or more sensors associated with the expandable member or the inlet/outlet conduits, as well as the endoscope (e.g., visualization data) when present. The feedback information is processed by the controller 530, to govern energy application and processing inflation fluid as well as energized fluid delivery. The I/O device 540 also includes a graphical user interface (GUI) 560 that graphically presents processing

information to the practitioner for viewing and/or analysis. The energy may be in the form of electromagnetic energy (e.g., RF, microwave) and ultrasonic energy, infrared energy, visible laser energy, heat energy, or the like.

Therapeutic Procedure/Method

[0082] For purposes of discussion, exemplary therapeutic methods embodying features of the present invention will be described in the context of the treatment of the stomach. However, it should be noted that the methods of the present invention are equally applicable in the treatment of other hollow anatomical structures and variations as to the steps, complementary components, visualization tools, introducers, and points of access to the anatomical structure may be modified as necessary. Because practitioners need not make any incisions (or in the case of transcutaneous or laparoscopic procedures the incision is minimal), and in far contrast to the complex and highly invasive bariatric surgeries currently practiced, the treatment according to the present invention is minimally invasive. In an embodiment, the procedure takes about one hour, including preparation and minimal recovery times. In an embodiment, patients can be treated on an out-patient basis using conscious sedation and since the risk of serious problems during the treatment is low it does not necessarily require the complete back-up of a hospital for emergencies.

[0083] In an embodiment for treatment of the gastric tract, and in operation, a gastric introducer is positioned in the patient's throat and protects the esophageal walls during the procedure.

[0084] The expander assembly, preloaded with the endoscope (when present) is inserted into patient's body through the introducer. The expandable balloon is advanced distally positioning the shaped distal portion against the distal side of the pyloric sphincter. Using an inflation fluid line, such as an air line (e.g., extending along an inner lumen of catheter 400), through a hand-piece disposed at the proximal end of the HAS treatment assembly, expandable member is inflated until the stomach's volume reaches the desired volume, such as at least about twice its empty volume (e.g. to about 2 liters). The pre-shaped distal portion, at the expanded configuration, seats against the distal side of the pyloric sphincter, providing an anchor and aiding in position and placement of the expander assembly within stomach.

[0085] Once the expandable member has been positioned at the treatment site and expanded to the desired volume, the optional endoscope may be pulled back completely or partially into the introducer.

[0086] In an embodiment, the practitioner using control unit 510 and a foot pedal introduces energized fluid (e.g., hot fluid such as hot saline or water) from an energized fluid source through inlet conduit 350, into the channels extending along at least portions of expandable balloon 320. As hot water (or other source of energy) is introduced into the channels, thermal energy is transferred from the channels and the expandable member to the desired treatment area/s of the target hollow anatomical structure. In an embodiment, the expanded expandable member comes into direct surface contact with the desired target areas of the hollow anatomical structure. In an embodiment, the desired treatment area/s include any one or more areas corresponding to or in the vicinities of the greater curvature of the stomach, smaller curvature of the stomach, cardiac zone, gastric/fundic zone, pyloric zone, or the vagal nerve within the stomach.

[0087] In an embodiment, the transferred energy is sufficiently high to cause a change (e.g., physical, biochemical, physiological change) in the treatment target areas as described earlier.

[0088] It should be noted that hot fluid energy may be further augmented by delivery of energy to the targeted areas in other forms such as RF, other heat sources, microwaves, infrared energy, visible laser energy, or the like. For example, and as described in co- pending US Application Serial No. 12/108,499 entitled Treating Medical Conditions of Hollow Organs, filed on April 23 ^rd , 2008 and assigned to the assignee of the present invention, the full disclosure of which is incorporated herein by reference; the various assemblies may further be modified to allow the practitioner to activate an RF generator (not shown), resulting in additional energy being emitted from electrodes positionable in, on, or about the expandable member to treat (e.g., ablate) the tissue in the treatment zones. During this time, using GUI and feedback from corresponding sensor associated with such electrodes, the practitioner can monitor the temperature at the site. The duration of time and frequency of applied energy are, of course, responsive to judgments of medical personnel.

[0089] After the practitioner is satisfied that the desired amount of tissue has been treated (for example ablated) and/or the pulse transmissions between nerves and the brain have been affected by the desired amount, energy application is stopped. The energized fluid and the spent fluid are removed from the channels by way outlet conduit. The expandable member is deflated, the expander assembly is withdrawn from the patient, as is the gastro introducer.

[0090] In another embodiment embodying features of the present invention, after patient sedation, the endoscope introduces the reference point positioner (e.g., reference point balloon), into the patient's alimentary canal. The endoscope forwards positioning balloon through the stomach and onto the distal side of the pyloric sphincter. The endoscope is retracted and positioning balloon inflated to seal against the distal side of the pyloric sphincter. This sets a fixed reference point for the tube. A gastric introducer positioned in the patient's throat, protects the esophageal walls during the next steps in the process.

[0091] The expander assembly is now introduced into the patient's digestive system through the gastric introducer and by the catheter riding over tube. When distal tip of the catheter contacts the positioning balloon and the closed pyloric sphincter, the practitioner stops inserting the stomach expander into the patient. Balloon member 320 is then inflated until the stomach's volume becomes about twice its empty volume. The practitioner using a method similar to that described above treats the desired areas within the hollow structure.

[0092] After the practitioner is satisfied that the desired amount of tissue has been treated (for example ablated) and/or the pulse transmissions between nerves and the brain have been affected by the desired amount, energy application is stopped. The energized fluid and the spent fluid are removed from the channels by way outlet conduit. The reference positioner and the expandable member are deflated and withdrawn from the patient, as is the gastro introducer.

[0093] FIGs. 6A and 6B very schematically show the disruption and slowing of the travel of nerve pulses S, S' between the stomach 12, the small intestine 14, and the brain. In FIG. 6A, smaller ablated portions Q of exemplary nerve 15 disrupt the straight flow of nerve signal impulses S between the stomach, small intestine, and brain. In FIG. 6B, larger ablated portions Q' of exemplary nerve 15 more greatly disrupt the straight flow of nerve signal impulses S' between the stomach, small intestine, and brain. The size of ablated portions Q, Q' and the desired degree of associated signal disruption are left to the sound judgment of the practitioner after considering, for example, the degree of patient's obesity, strength of patient's hunger sensations, and variation in nerve size from patient to patient.

[0094] FIG. 7 is an exemplary depiction of the appearance of the muscle profile of a treated stomach about 3 months post-op. There will now be major muscular constrictions and lesions (dead tissue) 121 in the areas of the fundus 25, peritoneum 30 and pylorus 23. These muscular constrictions and associated lesions should cause patient weight loss for the reasons discussed above. Because the procedure does not cause complete cell death in the treated areas, over long periods of time continued healing may cause the stomach's muscle profile to return to normal. Accordingly, follow-up treatments may be required. However, due to the process' simplicity, this should not pose any undue risk or inconvenience to the patient.

Conclusion

[0095] While this application describes certain exemplary embodiments of treatments for weight-based medical conditions and apparatus useful for carry out the treatments, only the attached claims define the scope of the invention.