Implantable adjustable sphincter system

An implantable adjustable sphincter system is comprised of a band configured to encircle a portion of an anatomical passageway, a manual pump, a reservoir in fluid communication with the pump, and a valve assembly in fluid communication with the band and the manual pump. The valve assembly is comprised of a first configuration and a second configuration, and is operable to be manually switched between configurations. The first configuration only permits fluid to flow from the band toward the reservoir. The second configuration only permits fluid to flow from the reservoir toward the band. The manual pump is in fluid communication with the valve assembly and the reservoir, and is manually operable to transfer fluid between the reservoir and the band when the valve assembly is in the second configuration.

TECHNICAL FIELD

The present invention relates in general to surgically implantable device systems, and more particularly, to an implantable adjustable band system.

BACKGROUND OF THE INVENTION

Since the early 1980s, adjustable gastric bands have provided an effective alternative to gastric bypass and other irreversible surgical weight loss treatments for the morbidly obese. The gastric band is typically wrapped around an upper portion of the patient's stomach, forming a stoma that restricts food passing from an upper portion to a lower portion of the stomach. When the stoma is of the appropriate size, food held in the upper portion of the stomach provides a feeling of fullness that discourages overeating. However, initial maladjustment or a change in the stomach over time may lead to a stoma of an inappropriate size, warranting an adjustment of the gastric band. Otherwise, the patient may suffer vomiting attacks and discomfort when the stoma is too small to reasonably pass food. At the other extreme, the stoma may be too large and thus fail to slow food moving from the upper portion of the stomach, defeating the purpose altogether for the gastric band.

In addition to a latched position to set the outer diameter of the gastric band, adjustability of gastric bands is generally achieved with an inwardly directed inflatable balloon, similar to a blood pressure cuff. The inner diameter of the gastric band may thereby be adjusted by adjusting the pressure in the balloon. Typically, a fluid such as saline is injected into the balloon through a fluid injection port to achieve a desired diameter. Since adjustable gastric bands may remain in the patient for long periods of time, the fluid injection port is typically installed subcutaneously to avoid infection, for instance in front of the sternum. Adjusting the amount of fluid in the adjustable gastric band is typically achieved by inserting a Huber tip needle through the skin into a silicon septum of the injection port. Once the needle is removed, the septum seals against the hole by virtue of compressive load generated by the septum. A flexible conduit communicates between the injection port and the adjustable gastric band.

The traditional surgical technique for securing a fluid injection port developed for vascular uses has been applying sutures through a series of holes spaced about a peripheral base flange. While generally effective, suturing often proves to be difficult since adjustable gastric bands are intended for the morbidly obese. A significant thickness of fat tissue may underlie the skin, causing difficulties as the surgeon attempts to apply sutures to deeply recessed tissues (e.g., 10-12 cm) to secure the port, often requiring 10-15 minutes to complete.

In addition to the difficulty of installing an injection port, the use of injections and injection ports for adjusting gastric bands has other disadvantages apparent to those of ordinary skill in the art. For example, port-site infections are a common complication arising from the use of injection ports. In addition, the use of needles or other invasive techniques to adjust a gastric band may subject a patient to unnecessary discomfort.

The art includes some gastric band adjustment systems that do not require the use of injections or injection ports, such as employing an electrical motor that adjusts the volume of a bellows accumulator. Power to such an implant is generally provided by transcutaneous energy transfer (TET), with control and/or feedback provided by telemetry. Such TET systems have to overcome design challenges associated with electromagnetic interference and compatibility (EMIC). In addition, a clinician who adjusts the adjustable gastric band has to invest in the external equipment necessary for TET.

Implant systems exist that employ the use of manually palpable pumps and valve assemblies in the context of penile implant systems. An example of such a system is disclosed in U.S. Pat. No. 4,404,968, issued to Evans. However, in contrast to the present invention, such penile implant systems employ the use of generally linear bladders as opposed to adjustable sphincters. In addition, such penile implants provide obvious visual feedback as to which direction the fluid in the implant system is flowing. The pumps in many conventional penile implant systems are bulbs located in the scrotum, such that the pump may be easily palpated by hand through relatively thin skin by squeezing both sides of the bulb.

Accordingly, it would be advantageous to have an implantable system whereby an adjustable sphincter, such as a gastric band, may be adjusted without the use of an injection or injection port. It would be further advantageous to have such a system that avoids the inconveniences of conventional TET implant systems. Consequently, a significant need exists for an implantable adjustable sphincter system that is percutaneously adjustable without the use of injections, an injection port, or TET.

BRIEF SUMMARY OF THE INVENTION

The present invention addresses these and other problems in the prior art by providing an implantable adjustable sphincter system comprising a band, a reservoir, a valve assembly, and a manual pump that may be simply palpated to increase and/or decrease the size of a stoma formed by the band acting as a sphincter.

In one aspect of the invention, there is an implantable adjustable sphincter system for treatment of a medical condition. The system is comprised of a band configured to encircle a portion of an anatomical passageway and to resiliently receive and hold fluid. The system is further comprised of a manual pump responsive to manual palpation and a reservoir in fluid communication with the manual pump. The system is further comprised of a valve assembly in fluid communication with the band and the manual pump. The valve assembly is comprised of a first configuration and a second configuration. The first configuration permits fluid from the band to flow toward the reservoir. The first configuration also prevents fluid from flowing from the reservoir toward the band. The second configuration permits fluid from the reservoir to flow toward the band. The second configuration also prevents fluid from flowing from the band toward the reservoir. The valve assembly is operable to be manually switched between the first configuration and second configuration. The manual pump is in fluid communication with the valve assembly and the reservoir. The manual pump is manually operable to transfer fluid between the reservoir and the band in response to manual palpation when the valve assembly is in the second configuration. Thus, neither an injection port nor the use of injections or TET is required to adjust the size of the stoma created by the band.

These and other objectives and advantages of the present invention shall be made apparent from the accompanying drawings and the description thereof.

Reference will now be made in detail to the present preferred embodiment of the invention, an example of which is illustrated in the accompanying drawings.

DETAILED DESCRIPTION

Referring now to the drawings in detail, wherein like numerals indicate the same elements throughout the views,FIG. 1shows an adjustable gastric band system2. The system2is comprised of a reservoir4, a pump6, a valve assembly12, and an adjustable gastric band8. In the present example, a flexible conduit10connects the reservoir4to the pump6, the pump6to the valve assembly12, and the valve assembly12to the band8. Each portion of the conduit10thus serves as a means of fluid communication between each component that the conduit10connects. It will be appreciated, however, that two or more components may be situated and/or constructed such that the components may fluidly communicate without the need for a conduit10. By way of example only, the pump6may be integrally connected to the reservoir4. In addition, or alternatively, the pump6may be integrally connected to the valve assembly12. Such types of alternate configurations of the system2will not result in departure from the scope of the present invention.

In the present example, the reservoir4is configured to hold fluid, such as saline for example. The reservoir4may be made of silicone, for example, or any other suitable biocompatible material. Preferably, the reservoir4will be generally deformable or resilient. The function of the reservoir4relative to the system2as a whole will be apparent to those of ordinary skill in the art.

As is known in the art, the adjustability of a gastric band8may be a function of band8fluid pressure or volume. In the present example, the pump6may be used to increase band8pressure or volume when the valve assembly12is configured to allow fluid to be pumped into the band8without allowing fluid to escape from the band8. The pump6in the present example is a silicone bulb, however any suitable biocompatible alternative may be used. With the valve assembly12properly configured, the pump6in the present example may be manually palpated to draw fluid from the reservoir4toward the band8, thereby increasing the band8pressure or volume. As will be apparent to those of ordinary skill in the art, this increase in band8pressure or volume will result in a reduction in the size of the stoma in the stomach in the present example.

As the pump6may be located subcutaneously, the pump6may be palpated by manually applying pressure on the skin above the site where the pump6is located. Alternatively, the pump6may be palpated by the flexing of the abdominal muscles or other bodily function. Preferably, the pump6should be sized to pump an appropriate amount of fluid while not being too obtrusive to the patient.

The valve assembly12may be comprised of two one-way valves. Alternatively, the valve assembly12may be comprised of a single one-way valve configured such that its direction may be switched. Still other possible ways of making the valve assembly12will be apparent to those of ordinary skill in the art.

The valve assembly12is comprised of one or more configurations, such that each configuration may dictate whether and in which direction fluid may flow through the system2. A first configuration may permit fluid from the band8to flow toward the reservoir4, while preventing fluid from flowing from the reservoir4toward the band8. This first configuration would thus be used when the band8pressure or volume is to be decreased, thereby allowing the size of the stoma in the stomach to increase. This flow of fluid may occur as a result of a pressure differential across the valve assembly12. This flow of fluid may also be made to occur by pumping. As will be apparent to those of ordinary skill in the art, the pump2may be constructed such that it is operable to pump fluid from the band8toward the reservoir4when the valve assembly12is in this first configuration.

Alternatively, there could be a plurality of pump-valve systems such as, by way of example only, two pumps and two valves, each being operable to draw fluid from or toward the band8, respectively.

Following the present example having one valve assembly12, a second configuration of the valve assembly12may permit fluid from the reservoir4to flow toward the band8, while preventing fluid from flowing from the band8toward the reservoir4. This second configuration would be used when the band8pressure or volume is to be increased, thereby causing the size of the stoma in the stomach to decrease. In the present example, this flow of fluid would be made to occur as a result of manual palpation of the pump6.

It is understood that, in the present example, manual palpation of the pump6, while the valve assembly12is in the first configuration, may result in fluid circulating within the reservoir4and/or fluid flowing from the reservoir4toward the pump6and/or toward the valve assembly12. Incidentally, this flow may be in the general direction of the band8. Nevertheless, such flow will not result in departure from the scope of the language defining the first configuration in part as preventing fluid from flowing from the reservoir toward the band. Ultimately, the first configuration would prevent fluid from flowing through the entire valve assembly12into the band8.

In addition, while the manual pump6may be described as being manually operable to transfer fluid between the reservoir4and the band8, it will be apparent to those of ordinary skill in the art that such language should not be read as limiting the invention to require the pump6to actually transfer fluid from the reservoir4into the band8. In other words, pressure in the band8may be increased by the mere shifting of fluid in the reservoir4toward the band8, as such shifting will cause similar shifting of fluid “upstream” of the reservoir4when the valve assembly12is in the second configuration. It is not necessary for fluid being introduced into the band8by palpation of the pump6to have actually come from the reservoir4. Consistent with the present invention, this additional fluid may originate from any part of the system2between the band8and the reservoir4.

A third configuration of the valve assembly12may prevent fluid from flowing through the valve assembly12at all. This third configuration may thereby prohibit fluid from flowing into or out of the band8. In other words, the third configuration may be considered as the valve assembly12being bi-directionally “closed.” Thus, this third configuration may be used when the band8pressure or volume is sought to be maintained. Preferably, the valve assembly12will be in this third configuration by default. In other words, it may be desirable to keep the valve assembly12in the third configuration most of the time, only switching it to the first or second configuration when it is desired that the band8pressure or volume be decreased or increased, respectively.

It will be appreciated that, without actual palpation of the pump6, the second configuration of the valve assembly12may be all that is necessary to maintain band8pressure or volume. In other words, a valve assembly12may be constructed within the present invention without having a third configuration. However, having a third configuration of the valve assembly12may be preferable to the extent that it may prevent inadvertent increase in band8pressure or volume. That is, to the extent that the pump6may be unintentionally palpated by incidental pressure on the pump6, such as pressure caused by leaning against a table for example, the third configuration of the valve assembly12would prevent such unintentional palpation from causing the pressure or volume of the band8to increase. Nevertheless, where a valve assembly12is constructed having only a first and second configuration, the valve assembly12may be considered “closed” in the second configuration to the extent that palpation of the pump6is required to create sufficient pressure to overcome and open a valve.

The valve assembly12may be constructed such that the valve assembly12may be switched between the various configurations by way of a mechanism responsive to manual palpation. By way of example only, the valve assembly12may be constructed such that the configuration of the valve assembly12may be switched by percutaneous manipulation of a switch, lever, dial, button, or any other suitable switching alternative or combination thereof. Where the valve assembly12configuration is manually switchable by such a mechanism or mechanisms, the valve assembly12may give tactile feedback indicating the configuration of the valve assembly12based on the position of the switching mechanism or mechanisms.

Alternatively, the valve assembly12may be constructed such that the valve assembly12may be switched between configurations by the transcutaneous transmission of other non-electromagnetic energy to the valve assembly12. By way of example only, a valve assembly12may be constructed such that the valve assembly12may be switched between configurations by way of ultrasound. In other words, a valve assembly12may be made responsive to ultrasound such that valves are actuated or the valve assembly12is otherwise placed in various configurations by mechanical resonance and/or other effects created by ultrasound.

The valve assembly12may be made to respond differently to different frequencies of ultrasound. For example, a first frequency may actuate a first valve or otherwise place the valve assembly12in a first configuration, such that fluid is permitted to flow from the band8toward the reservoir4, while fluid is prevented from flowing from the reservoir4toward the band8. A second frequency may actuate a second valve or otherwise place the valve assembly12in a second configuration, such that fluid is permitted to flow from the reservoir4toward the band8, while fluid is prevented from flowing from the band8toward the reservoir4. A third frequency may place the valve assembly12in a third configuration, such that fluid would be prevented from flowing through the valve assembly12at all. Alternatively, the valve assembly12may be constructed such that the valve assembly12is in such a third configuration by default (i.e. when it is not being exposed to a first or second frequency of ultrasound). In such an embodiment, the response of the valve assembly12to the first and/or second frequency may be substantially temporally limited to the duration of the exposure of the valve assembly12to the first and/or second frequency, respectively. In other words, the valve assembly12may be constructed such that the valve assembly12would be placed in the first or second configuration only for the approximate time of its exposure to the first or second frequency, respectively.

Alternatively, the adjustment may be enabled by a wide range of ultrasonic frequencies, relying upon sufficient strength of ultrasonic energy to avoid inadvertent enablement. Even given brief exposure to ultrasonic energy, such as for a medical diagnostic procedure wherein adjustment is not intended, integrating primary value control with pumping may ensure maintenance of fluid pressure. The ultrasonic energy may assist in overcoming static friction, for instance, within dynamic seals of the pump that enable pumping to occur, which would otherwise resist movement.

In such an ultrasonically enabled valve assembly12, direction of adjustment may be controlled by having the pump6comprised of two parallel pumps, each check valve controlled to allow fluid in opposite directions with each opposing all flow when in an unactuated state. Thus, the ultrasonic enablement avoids inadvertent actuation of the pumps, yet specifically tailored ultrasonic sources need not be used.

As another example inFIG. 2, an electrically-powered valve controller24may be energized or activated by an ultrasonic frequency coming from an ultrasound emitter20, such as with a vibration transducer22, and electromechanically actuate a valve or valves in response thereto, or otherwise change configurations of the valve assembly12in response to an ultrasonic frequency. In this embodiment, the valve assembly12may be coupled with or include such a transducer22and controller24, along with a battery26as a source of power to the valve or valves. As merely providing power to a valve or valves, such a battery26may have a longer life than a battery that supplies power to a pump, such as those found in conventional TET-operated implant systems. Additionally, the valve assembly12, including the transducer22, controller24, and battery26, may all be electrically shielded to avoid EMIC considerations that are typically appurtenant to conventional TET systems.

As to any embodiment where the valve assembly12is responsive to ultrasound, it may be desirable to limit the responsiveness of the valve assembly12to certain patterns of ultrasound. That is, rather than being immediately responsive to a certain frequency or frequencies of ultrasound, the valve assembly12could be made such that the valve assembly12will only respond to a frequency or frequencies of ultrasound being emitted in a certain pattern or patterns. By way of example only, such pattern-based requirements may alleviate concerns that the valve assembly may respond to ultrasound being emitted by unforeseen sources of ultrasound.

The process of implanting conventional gastric band systems is known in the art and therefore needs not be reiterated in detail herein. By way of example, the implantation of gastric band systems using injection ports is described in one or more of the following U.S. patents: U.S. Pat. No. 4,592,339 issued on Jun. 3, 1986 to Kuzmak et al.; U.S. Pat. No. 5,226,429 issued on Jul. 13, 1993 to Kuzmak; U.S. Pat. No. 6,102,922 issued on Aug. 15, 2000 to Jakobsson et al.; and U.S. Pat. No. 5,449,368 issued on Sep. 12, 1995 to Kuzmak. Each of the above-listed patents is assigned to the assignee of the present invention and is incorporated herein by reference. While the gastric bands in the above-cited patents employ the use of injection ports as the sole means to adjust the gastric band, as opposed to a pump6and valve assembly12, the implantation and function of the bands themselves are similar to the band8in the present example.

As to the band8in the present example, the method of securing the band8around the stomach may be accomplished using conventional methods. The rest of the components of the system may also be implanted subcutaneously. By way of example only, the valve assembly12, pump6, and reservoir4may all be implanted anywhere convenient in the abdominal cavity. Alternatively, any or all of the components may be implanted in any other suitable location. Any or all of the components may be attached to a suitable surface within the body. Alternatively, any or all of the components may be attached to no surface within the body.

Preferably, the pump6will be implanted in the abdominal cavity. In this way, the pump6may be percutaneously palpated through relatively thick abdominal skin from one side only. The pump6may be placed against fascia that resists inward pressure to allow pumping by applying pressure on the side of the pump6opposite to the fascia.

Once the band8and the components are in place, the pressure or volume of the band8may be brought to an initial desired level, in accordance with the initial desired size of the stoma created in the stomach by the band8. For example, the system2may be implanted with all of the fluid already inside the system2, such that palpation of the pump6is all that is necessary to bring the pressure or volume of the band8to an initial desired level, such as through an injection port30. Alternatively, the system2may be implanted with less than all desired fluid inside the system2, such that additional fluid is added to the system2shortly following implantation. By way of example only, where additional fluid is to be added to the system2shortly following implantation, such additional fluid may be added by injecting the fluid into a port on a component of the system2. Still other ways of achieving an initial desired band8pressure or volume will be apparent to those of ordinary skill in the art.

In use, a time may come where it is desired to have the band8pressure or volume decreased or increased. Where a decrease in band8pressure or volume is desired, the valve assembly12will be manually switched to the first configuration. Then, due to the fluid pressure being higher on the band8side of the valve assembly12than the fluid pressure on the other side of the valve assembly12, fluid will tend to drain toward the reservoir4end of the system2until the pressure throughout the system2is generally uniform. Alternatively or additionally, fluid may be drawn from the band8toward the reservoir4by manual palpation of the pump6. When the desired amount of pressure or volume has been relieved from the band8, the valve assembly12may then be switched to the second or third configuration to prevent additional fluid from escaping the band8.

Where an increase in band8pressure or volume is desired, and the valve assembly12is not already in the second configuration, the valve assembly12will be manually switched to the second configuration. Then, the pump6will be palpated to draw fluid from the reservoir4and force it toward the band8, thereby increasing the band8pressure or volume. When the desired amount of pressure or volume has been added to the band8, the person palpating the pump6should cease palpating the pump6. The valve assembly12may then be left in the second configuration, or alternatively, switched to the third configuration.

It will become readily apparent to those skilled in the art that the above invention has equal applicability to other types of implantable bands or adjustable sphincters. For example, bands may be used for the treatment of fecal incontinence. One such band is described in U.S. Pat. No. 6,461,292, which is incorporated herein by reference. Bands may also be used to treat urinary incontinence. One such band is described in U.S. Patent Application 2003/0105385, which is incorporated herein by reference. Bands may also be used to treat heartburn and/or acid reflux. One such band is described in U.S. Pat. No. 6,470,892, which is incorporated herein by reference. Bands may also be used to treat impotence. One such band is described in U.S. Patent Application 2003/0114729, which is incorporated herein by reference.

In summary, numerous benefits have been described which result from employing the concepts of the invention. While preferred embodiments of the present invention have been shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. The foregoing description of one or more embodiments of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Obvious modifications or variations are possible in light of the above teachings without departing from the invention. For example, a reservoir may include a pressure differential to the band such that one of the valve positions is sufficient to create a change in fluid volume with the band without manual pumping. A bellows accumulator within a sealed case containing a propellant that asserts a differential pressure is one such reservoir.

It should be understood that every structure described above has a function and such structure can be referred to as a means for performing that function. The one or more embodiments were chosen and described in order to best illustrate the principles of the invention and its practical application to thereby enable one of ordinary skill in the art to best utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. Accordingly, it is intended that the invention be limited only by the spirit and scope of the appended claims.