US20110098702A1 - Apparatus to treat esophageal sphincters - Google Patents

Abstract

A sphincter treatment apparatus has an introducer means including a distal portion means. An expandable device means includes a plurality of arm means. Each arm means of the plurality has a distal section means and a proximal section means. Each of distal sections means of the arm means are coupled and each of the proximal sections means of the arm means are coupled to the introducer means distal portion means. The expandable device means is configured to at least partially dilate a sphincter in a deployed state. An energy delivery device means is introduceable from the introducer means into a selected site of the sphincter. The energy delivery device means is configured to deliver sufficient energy to reduce a frequency of relaxation of the sphincter.

Description

RELATED APPLICATIONS
• This application is a divisional of co-pending U.S. patent application Ser. No. 11/638,952, filed 14 Dec. 2006, which is a divisional of co-pending U.S. patent application Ser. No. 10/838,292, which is a divisional of U.S. patent application Ser. No. 09/971,085, filed Oct. 4, 2001 (now U.S. Pat. No. 6,749,607), which is a continuation of U.S. patent application Ser. No. 09/036,092, filed Mar. 6, 1998, now abandoned.
FIELD OF THE INVENTION
• This invention relates generally to an apparatus to treat sphincters, and more particularly. to an apparatus to treat esophageal sphincters.
DESCRIPTION OF RELATED ART
• Gastroesophageal reflux disease (GERD) is a common gastroesophageal disorder in which the stomach contents are ejected into the lower esophagus due to a dysfunction of the lower esophageal sphincter (LES). These contents are highly acidic and potentially injurious to the esophagus resulting in a number of possible complications of varying medical severity. The reported incidence of GERD in the U.S. is as high as 10% of the population (Castell D O; Johnston B T: Gastroesophageal Reflux Disease: Current Strategies For Patient Management. Arch Fam Med, 5 (4):221-7; (1996 April)).
• Acute symptoms of GERD include heartburn, pulmonary disorders and chest pain. On a chronic basis, GERD subjects the esophagus to ulcer formation, or esophagitis and may result in more severe complications including esophageal obstruction, significant blood loss and perforation of the esophagus. Severe esophageal ulcerations occur in 20-30% of patients over age 65. Moreover, GERD causes adenocarcinoma, or cancer of the esophagus, which is increasing in incidence faster than any other cancer (Reynolds J C: Influence Of Pathophysiology, Severity, And Cost On The Medical Management Of Gastroesophageal Reflux Disease. Am J Health Syst Pharm, 53 (22 Suppl 3):S5-12 (1996 Nov. 15)).
• Current drug therapy for GERD includes histamine receptor blockers which reduce stomach acid secretion and other drugs which may completely block stomach acid. However, while pharmacologic agents may provide short term relief, they do not address the underlying cause of LES dysfunction.
• Invasive procedures requiring percutaneous introduction of instrumentation into the abdomen exist for the surgical correction of GERD. One such procedure, Nissen fundoplication, involves constructing a new “valve’ to support the LES by wrapping the gastric fundus around the lower esophagus. Although the operation has a high rate of success, it is an open abdominal procedure with the usual risks of abdominal surgery including: postoperative infection, herniation at the operative site, internal hemorrhage and perforation of the esophagus or of the cardia. In fact, a recent 10 year, 344 patient study reported the morbidity rate for this procedure to be 17% andmortality 1% (Urschel, J D: Complications Of Antireflux Surgery, Am J Surg 166 (1): 68-70; (1993 July)). This rate of complication drives up both the medical cost and convalescence period for the procedure and may exclude portions of certain patient populations (e.g., the elderly and immuno-compromised).
• Efforts to perform Nissen fundoplication by less invasive techniques have resulted in the development of laparoscopic Nissen fundoplication. Laparoscopic Nissen fundoplication, reported by Dallemagne et al. Surgical Laparoscopy and Endoscopy, Vol. 1, No. 3, (1991), pp. 138-43 arid by Hindler et al. Surgical Laparoscopy and Endoscopy, Vol. 2, No. 3, (1992), pp. 265-272, involves essentially the same steps as Nissen fundoplication with the exception that surgical manipulation is performed through a plurality of surgical cannula introduced using trocars inserted at various positions in the abdomen.
• Another attempt to perform fundoplication by a less invasive technique is reported in U.S. Pat. No. 5,088,979. In this procedure, an invagination device containing a plurality of needles is inserted transorally into the esophagus with the needles in a retracted position. The needles are extended to engage the esophagus and fold the attached esophagus beyond the gastroesophageal junction. A remotely operated stapling device, introduced percutaneously through an operating channel in the stomach wall, is actuated to fasten the invaginated gastroesophageal junction to the surrounding involuted stomach wall.
• Yet another attempt to perform fundoplication by a less invasive technique is reported in U.S. Pat. No. 5,676,674. In this procedure, invagination is done by a jaw-like device and fastening of the invaginated gastroesophageal junction to the fundus of the stomach is done via a transoral approach using a remotely operated fastening device, eliminating the need for an abdominal incision. However, this procedure is still traumatic to the LES and presents the postoperative risks of gastroesophageal leaks, infection and foreign body reaction, the latter two sequela resulting when foreign materials such as surgical staples are implanted in the body.
• While the methods reported above are less invasive than an open Nissen fundoplication, some still involve making an incision into the abdomen and hence the increased morbidity and mortality risks and convalescence period associated with abdominal surgery. Others incur the increased risk of infection associated with placing foreign materials into the body. All involve trauma to LES and the risk of leaks developing at the newly created gastroesophageal junction.
• Besides the LES, there are other sphincters in the body which if not functionally properly can cause disease states or otherwise adversely affect the lifestyle of the patient. Reduced muscle tone or otherwise aberrant relaxation of sphincters can result in a laxity of tightness disease states including, but not limited to, urinary incontinence.
• There is a need to provide an apparatus to treat a sphincter and reduce a frequency of sphincter relaxation. Another need exists for an apparatus to create controlled cell necrosis in a sphincter tissue underlying a sphincter mucosal layer. Yet another need exists for an apparatus to create controlled cell necrosis in a sphincter and minimize injury to a mucosal layer of the sphincter. There is another need for an apparatus to controllably produce a lesion in a sphincter without creating a permanent impairment of the sphincter's ability to achieve a physiologically normal state of closure. Still a further need exists for an apparatus to create a tightening of a sphincter without permanently damaging anatomical structures near the sphincter. There is still another need for an apparatus to create controlled cell necrosis in a lower esophageal sphincter to reduce a frequency of reflux of stomach contents into an esophagus.
SUMMARY OF THE INVENTION
• Accordingly, an object of the present invention is to provide an apparatus that reduces a frequency of sphincter relaxation.
• Another object of the invention is to provide an apparatus to create controlled cell necrosis in a sphincter tissue underlying a sphincter mucosal layer. Yet another object of the invention is to provide an apparatus to create controlled cell necrosis in a sphincter and minimize injury to a mucosal layer of the sphincter.
• A further object of the invention is to provide an apparatus to controllably produce a lesion in a sphincter without creating a permanent impairment of the sphincter's ability to achieve a physiologically normal state of closure.
• Still another object of the invention is to provide an apparatus to create a tightening of a sphincter without permanently damaging anatomical structures near the sphincter.
• Another object of the invention is to provide an apparatus to create controlled cell necrosis in a lower esophageal sphincter to reduce a frequency of reflux of stomach contents into an esophagus.
• These and other objects of the invention are provided in a sphincter treatment apparatus within an introducer means including a distal portion means. An expandable device means includes a plurality of arm means. Each arm means has a distal section means and a proximal section means. Each of the distal section means of the arm means are coupled and each of the proximal section means Of the arm means are coupled to the introducer means distal portion means. The expandable device means is configured to at least partially dilate a sphincter in a deployed state. An energy delivery device means is introduceable from the introducer means into a selected site of the sphincter. The energy delivery device means is configured to deliver sufficient energy to reduce a frequency of relaxation of the sphincter.
• In another embodiment, an expandable device means is coupled to an introducer distal portion means. The expandable device means includes a first arm means with a proximal and distal section means and a second arm means with proximal and distal section means. The first and second arm distal portion means are coupled. The expandable device means is configured to at least partially dilate a sphincter in a deployed state. An energy delivery device means is coupled to the expandable device means. The energy delivery device means is configured to deliver sufficient energy to reduce a frequency of relaxation of the sphincter while minimizing cell necrosis of a mucosal layer of the sphincter.
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG. 1 is an illustrated lateral view of the upper GI tract depicting the position of the sphincter treatment apparatus of the present invention in the lower esophageal sphincter.
• FIG. 2 is a lateral view of the present invention illustrating the introducer, expansion device and energy delivery device.
• FIG. 3 depicts a lateral view of an embodiment of the invention that illustrates the use of a sheath to introduce and deploy the expansion device.
• FIG. 4 illustrates a lateral view of the basket assembly used in an embodiment of the invention.
• FIG. 5 is a lateral view of the basket assembly illustrating the placement of struts on the basket assembly.
• FIG. 6A is a lateral view of the junction between the basket arms and the introducer illustrating a lumen in the basket arm that can be used for the advancement of energy delivery devices.
• FIG. 6B is a frontal view of a basket arm in an alternative embodiment of the invention illustrating a track in the arm used to advance the movable wire.
• FIG. 7A is a cross-sectional view of a section of a basket arm and an energy delivery device illustrating stepped and tapered sections in the basket arm apertures and energy delivery device.
• FIG. 8A is a lateral view of the basket assembly illustrating the use of the advancement member and introducer to position energy delivery devices into the sphincter wall.
• FIG. 8B is a lateral view of the basket assembly illustrating the use of the advancement member and basket arms to position energy delivery devices into the sphincter wall.
• FIG. 9 is a cross sectional view illustrating the use of a needle electrode in combination with an angled aperture segment to select and maintain a constant penetration angle into the sphincter wall.
• FIG. 10 is a lateral view illustrating the placement of needle electrodes into the sphincter wall by expansion of the basket assembly.
• FIG. 11 is a lateral view illustrating the use of an insulation layer on the needle electrode to protect an area of tissue from RF energy.
• FIG. 12 depicts the fluid source and flow path to deliver fluid to treatment site using the introducer.
• FIG. 13 is a cross sectional view illustrating a visualization device coupled to an embodiment of the invention.
• FIG. 14 is an enlarged lateral view illustrating the placement of sensors on/adjacent the energy delivery device and the coupling of sensors to a feedback control system.
• FIG. 15 is a flow chart illustrating a sphincter treatment method using the apparatus of the present invention.
• FIG. 16 is a lateral view of sphincter smooth muscle tissue illustrating electrical foci and electrically conductive pathways for the origination and conduction of aberrant electrical signals in the smooth muscle of the lower esophageal sphincter or other tissue.
• FIG. 17 is a lateral view of a sphincter wall illustrating the infiltration of tissue healing cells into a lesion in the smooth tissue of a sphincter following treatment with the sphincter treatment apparatus of the present invention.
• FIG. 18 is a view similar to that ofFIG. 17 illustrating shrinkage of the lesion site caused by cell infiltration.
• FIG. 19 is a lateral view of the esophageal wall illustrating the preferred placement of lesions in the smooth muscle layer of a esophageal sphincter.
• FIGS. 20A-D are lateral views of the sphincter wall illustrating various patterns of lesions created by the apparatus of the present invention.
• FIG. 21 depicts a block diagram of the feed back control system that can be used with an embodiment of the invention.
• FIG. 22 depicts a block diagram of an analog amplifier, analog multiplexer and microprocessor used with the feedback control system ofFIG. 21.
• FIG. 23 depicts a block diagram of the operations performed in the feedback control system depicted inFIG. 21.
DETAILED DESCRIPTION
• Referring toFIGS. 1 and 2, one embodiment of asphincter treatment apparatus10 delivers energy to atreatment site12 to producelesions14 in asphincter16, such as the lower esophageal sphincter (LES). In this embodiment,sphincter treatment apparatus10 comprises a flexibleelongate shaft18, also calledintroducer18, coupled to anexpansion device20, in turn coupled with one or moreenergy delivery devices22.Introducer18 has a distal extremity also calledintroducer end19.Energy delivery devices22 are configured to be coupled to a power source.
• Expansion device20 comprises a plurality ofarms24, with proximal and distal arms ends25 and26. Proximal arm ends25 are coupled tointroducer end19.Expansion device20 has a centrallongitudinal axis28 and is moveable between contracted and expanded/deployed states substantially there along.Expansion device20 is configured to be positionable in a sphincter16 (such as the LES) or adjacent anatomical structure (such as the cardia of the stomach) and is further configured to partially dilatesphincter16 when in the deployed state.Energy delivery devices22 are configured to be introduceable fromintroducer18 and to contact and/or penetrate a targetedtreatment site12 in asphincter wall30 or adjoining anatomical structure. They are further configured to deliver energy totreatment site12.
• Referring now toFIG. 2,introducer18 is configured to be coupled toexpansion device20 and has sufficient length to positionexpansion device20 in the LES and/or stomach using a transoral approach. Typical lengths forintroducer18 include a range of 40-180 cm.Introducer18 may be circular or oval in cross section. Also,introducer18 may be flexible, articulated, coil-reinforced, or steerable, or any combination thereof. Suitable materials forintroducer18 include polyethylenes, polyurethanes, silicones and other biocompatible polymers known to those skilled in the art.
• Introducer18 may also be coated with a lubricious coating as is well known to those skilled in the art.Introducer18 may have one ormore lumens32, that extend the full length ofintroducer18, or only a portion thereof.Lumens32 may be used as paths for the delivery of fluids and gases, as well as providing channels for cables, catheters, guide wires, pull wires, insulated wires, and optical fibers.
• In another embodiment of the invention depicted inFIGS. 3A and 3B, anintroduction member34, also called asheath34, is used to introducesphincter treatment apparatus10 into the LES.Sheath34 can also function as a sheath forexpansion device20 to keep it in a nondeployed or contracted state during introduction into the LES. To facilitate this function,sheath34 contains asheath lumen36 of sufficient inner diameter to allow free movement ofsphincter treatment apparatus10 withinsheath lumen36.Sheath34,sheath lumen36 andsphincter treatment apparatus10 are configured to allowexpansion device20 to go from a contracted state to an expanded state and vice versa by either i) the retraction or advancement ofsheath34, or ii) the advancement or withdrawal ofsphincter treatment apparatus10.Sheath34 may be flexible, articulated, coil-reinforced or steerable, or any combination thereof Suitable materials forsheath34 include polyethylenes, polyurethanes, silicones, polytetrafluoroethylenes and other biocompatible polymers known to those skilled in the art. Typical diameters forsheath lumen36 include0.1 to 2 inches, while typical lengths include 40-180 cms.
• Referring now toFIG. 4, in another embodiment of the present invention,expansion device20 comprises one or moreelongated arms24 that are joined at their proximal ends25 and distal ends26 to form abasket assembly38.Proximal arm end25 is attached to a supporting structure, which can bedistal end19 ofintroducer18 or aproximal cap40. Likewise,distal arm end26 is also attached to a supporting structure which can be adistal basket cap42 orintroducer18.Arms24 are of a sufficient number, two or more, to sufficiently open and efface the folds ofsphincter16 to allow treatment withsphincter treatment apparatus10, while preventing herniation ofsphincter wall30 into thespaces44 betweenarms24.
• Arms24 may form a variety of geometric shapes including, curved, rectangular, trapezoidal, triangular, or any combination thereof Also,arms24 can have an outwardly bowed shaped memory for expandingbasket assembly38 into engagement withsphincter wall30.Arms24 may be preshaped at time of manufacture or shaped by the physician.Arms24 can have a variety of cross sectional geometries including, circular, rectangular and crescent-shaped. The circumferential spacing ofarms24 can be symmetrical or asymmetrical with respect to a circumference aroundlongitudinal axis28. Suitable materials forarms24 include spring steel, stainless steel, superelastic shape memory metals such as nitinol, or stiff shaft plastic tubing as is well known to those skilled in the art.Arms24 may also be color-coded to facilitate their identification via visual medical imaging methods and equipment, such as endoscopic methods, which are well known to those skilled in the art.
• In another embodiment of the invention depicted inFIG. 5, a supportingmember46 is attached to two ormore arms24. Supportingmember46, also calledstrut46, can be attached toarms24 along a circumference ofbasket assembly38.Strut46 may also containapertures50 in one or more places that extend throughstrut46 toarm24 as will be discussed herein. The cross sectional geometry ofstrut46 can be rectangular, circular or crescent-shaped. Suitable materials forstrut46 include spring steel, stainless steel, superelastic shape memory metals such as nitinol, or stiff shaft plastic tubing as is well known to those skilled in the art.
• Referring now toFIG. 6A,arms24 may be solid or hollow with acontinuous arm lumen48 that may be coupled withintroducer lumens32. Alsoarms24 may have one ormore apertures50 that may coupled toarm lumen48. Coupledlumens32 and48, andapertures50 provide a path for the delivery of a fluid orenergy delivery device22 fromintroducer18 to the surface or interior ofsphincter wall30. As shown inFIG. 6B,arms24 may also have a partiallyopen channel52, also called atrack52, that functions as a guide track for the travel of an advancement member (discussed herein) and/orenergy delivery device22 that permit the controlled placement ofenergy delivery devices22 at or intosphincter wall30. Referring now toFIG. 7,apertures50 may have taperedsections54 and/or steppedsections56 in all or part of their length, that are used to control the penetration depth ofenergy delivery devices22 intosphincter wall30 as will be discussed herein.Energy delivery devices22 may have similar taperedsections54′ and/or steppedsections56′.
• Referring now toFIGS. 8A and 8B, in another embodiment of the invention,energy delivery devices22 can be coupled to an energydevice delivery member57, also called anadvancement member57.Advancement member57 can be an insulated wire, an insulated guide wire, a plastic-coated stainless steel hypotube with internal wiring or a plastic catheter with internal wiring as is well known to those skilled in the art.Advancement member57 is configured to be able to introduceenergy delivery device22 intosphincter wall30 via introducer (seeFIG. 8A) orbasket assembly38 as will be discussed herein (seeFIG. 8B).Advancement member57 is of sufficient length to positionenergy delivery device22 in the LES and/or stomach using a transoral approach. Typical lengths foradvancement member57 include a range of 40-180 cms.
• In another embodiment of the invention depicted inFIG. 9,energy delivery device22 has a distal portion58 that is configured to penetratesphincter wall30 with a minimum amount of tearing of the mucosal andsubmucosal layers60 and62 ofsphincter16. This is facilitated by maintaining a constant angle ofpenetration64, also calledpenetration angle64, of distal portion58 intosphincter wall30 during the time thatenergy delivery device22 is advanced intosphincter wall30. The typical range forpenetration angle64 lies between 1 and 90°. This can be accomplished through the use of a needle58′ for distal energy delivery device portion58, coupled with anangled aperture segment50′ having a preselectedpenetration angle64. Needle58′ is of sufficient sharpness and length to penetrate into the smooth muscle ofsphincter wall30. In a further embodiment, needle58′ can be a needle electrode58. Distal portion58, including needle58′ and needle electrode58 can also be stepped or tapered to enable control of energy delivery device (seeFIG. 7). Suitable materials for needle58′ and needle electrodes58″ include304 stainless steel and other metals known to those skilled in the art.
• In another embodiment of the invention,energy delivery device22 is coupled toarm24. As shown inFIG. 10, this can be accomplished by attaching needle58′ toarm24. Whensphincter treatment apparatus10 is properly positioned at thetreatment site12, needles58′ are deployed by expansion ofbasket assembly38, resulting in the protrusion of needle58′ into the smooth muscle tissue of sphincter wall30 (seeFIG. 10). Referring back toFIG. 9, coupling can also be accomplished by employingarm24 to introduceenergy delivery device22 intosphincter wall30 via use ofarm lumen48.
• Turning now to a discussion of energy delivery, suitable power sources andenergy delivery devices22 that can be employed in one or more embodiments of the invention include or more of the following: (i) a radio-frequency (RF) source coupled to an RF electrode, (ii) a coherent source of light coupled to an optical fiber, (iii) an incoherent light source coupled to an optical fiber, (iv) a heated fluid coupled to a catheter with a closed channel configured to receive the heated fluid, (v) a heated fluid coupled to a catheter with an open channel configured to receive the heated fluid, (vi) a cooled fluid coupled to a catheter with a closed channel configured to receive the cooled fluid, (vii) a cooled fluid coupled to a catheter with an open channel configured to receive the cooled fluid, (viii) a cryogenic fluid, (ix) a resistive heating source, (x) a microwave source providing energy from 915 MHz to 2.45 GHz and coupled to a microwave antenna, or (xi) an ultrasound power source coupled to an ultrasound emitter, wherein the ultrasound power source produces energy in the range of 300 KHZ to 3 GHz. For ease of discussion for the remainder of this application, the power source utilized is an RF source andenergy delivery device22 is one ormore RF electrodes66, also described aselectrodes66. However, all of the other herein mentioned power sources and energy delivery devices are equally applicable tosphincter treatment apparatus10.
• For the case of RF energy,RF electrode66 may be operated in either bipolar or monopolar mode with a ground pad electrode. In a monopolar mode of delivering RF energy, asingle electrode66 is used in combination with an indifferent electrode patch that is applied to the body to form the other electrical contact and complete an electrical circuit. Bipolar operation is possible when two ormore electrodes66 are used.Multiple electrodes66 may be used. These electrodes may be cooled as described herein.Electrodes66 can be attached toadvancement member57 by the use of soldering methods which are well known to those skilled in the art.
• Referring now toFIG. 11,RF electrodes66 can have an insulatinglayer68, covering aninsulated segment70 except for an exposedsegment72. For purposes of this disclosure, an insulator or insulation layer is a barrier to either thermal or electromagnetic energy flow including RF energy flow.Insulated segment70 is of sufficient length to extend intosphincter wall30 and minimize the transmission of RF energy to a protectedsite74 near or adjacent toinsulated segment70. Typical lengths forinsulated segment70 include, but are not limited to, 1-4 mm. Suitable materials for insulatinglayer68 include electrically insulating plastics and other materials well known to those skilled in the art.
• In another embodiment of the invention, the depth of penetration ofenergy delivery device22 intosphincter wall30 is controllable. This can be accomplished by the selection and control of the. dimensional relationships (e.g. the amount of clearance between inner and outer diameters) ofenergy delivery devices22 and/oradvancement member57 to one or more of the following elements:arm lumen48,apertures50 andtrack52. Control of penetration depth can also be accomplished through the use of tapered and/or stepped sections in one or more of the preceding elements as is discussed herein. In another embodiment, penetration depth control can be accomplished by the use of one or more of a variety of positional control means, known to those skilled in the art, that are coupled tosphincter treatment apparatus10. Such positional control means include stepper motor systems, indexing mechanisms and micromanipulators.
• Referring now toFIG. 12, in another embodiment of the invention, fluid can be delivered totreatment site12 viaintroducer18. This is accomplished by the coupling ofintroducer18 to afluid source76 viaintroducer lumen32.
• Referring now toFIG. 13, another embodiment ofsphincter treatment apparatus10 includes avisualization device78 coupled tointroducer18.Visualization device78 can include a combination of one or more of the following: a viewing scope, an expanded eyepiece, fiber optics (both imaging and illuminating fibers), video imaging devices and the like.
• As shown inFIG. 14, one ormore sensors80 may be positioned adjacent to or onelectrode66 for sensing the physical properties of sphincter tissue attreatment site12.Sensors80 permit accurate determination of the physical properties ofsphincter wall30 at an electrode-tissue interface82. Such physical properties include temperature, electrical conductivity, electrical capacitance, thermal conductivity, density, thickness, strength, elasticity, moisture content, optical reflectance, optical transmittance, optical absorption acoustical impedance and acoustical absorption.Sensors80 can be positioned at any position onexpansion device20,electrode66 orbasket assembly38. Suitable sensors that may be used forsensor80 include: thermocouples, fiber optics, photomultipliers, resistive wires, thermocouple IR detectors, thin film sensors, anemometric sensors and ultrasound sensors.Sensor80 can be coupled to afeedback control system84, described herein. The coupling ofsensor80 tofeedback control system84 can be used to regulate the delivery of energy, fluids and gases to one or more of the following locations:treatment site12,sphincter wall30, andelectrode tissue interface82.
• FIG. 15 is a flow chart illustrating a method for usingsphincter treatment apparatus10. First,sphincter treatment apparatus10 is introduced into the esophagus under local anesthesia and positioned attreatment site12.Sphincter treatment apparatus10 can be introduced into the esophagus by itself or through a lumen in an endoscope (not shown), such as disclosed in U.S. Pat. Nos. 5,448,990 and 5,275,608, incorporated herein by reference, or a similar esophageal access device known to those skilled in the art.Basket assembly38 is expanded as described herein. This serves to temporarily dilate the LES sufficiently to efface all or a portion of the folds of the LES. In an alternative embodiment, esophageal dilation and subsequent LES fold effacement can be accomplished by insufflation of the esophagus (a known technique) using gas introduced into the esophagus throughintroducer lumen32, an endoscope, or others esophageal access devices known to those skilled in the art. Once treatment is completed,basket assembly38 is returned to its predeployed or contracted state andsphincter treatment apparatus10 is withdrawn from the esophagus. This results in the LES returning to approximately its pretreatment state and diameter. It will be appreciated that the above procedure is applicable in whole or part to the treatment of other sphincters in the body.
• The diagnostic phase of the procedure then begins and can be performed using a variety of diagnostic methods known to those skilled in the art including the following: (i) visualization of the interior surface of the esophagus via an endoscope or other viewing apparatus inserted into the esophagus, (ii) visualization of the interior morphology of the esophageal wall using ultrasonography to establish a baseline for the tissue to be treated, (iii) impedance measurement to determine the electrical conductivity between esophageal mucosal andsubmucosal layers60 and62 andsphincter treatment apparatus10, and (iv) measurement and surface mapping of electropotential signals of the LES and surrounding anatomical structures during varying time intervals which may include such events as depolarization, contraction and repolarization of gastroesophageal smooth muscle tissue. This latter technique is done to determinetarget treatment sites12 in the LES or adjoining anatomical structures that are acting aselectrical foci107 or electricallyconductive pathways109 for abnormal or inappropriate polarization and relaxation of the smooth muscle of the LES (Refer toFIG. 16).
• After diagnosis, the treatment phase of the procedure begins. In this phase of the procedure, the delivery of energy totreatment site12 can be conducted under feedback control, manually or by a combination of both. Feedback control (described herein) enablessphincter treatment apparatus10 to be positioned and retained in the esophagus during treatment with minimal attention by the physician.Electrodes66 can be multiplexed in order to treat the entire targetedtreatment site12 or only a portion thereof. Feedback can be included and is achieved by the use of one or more of the following methods: (i) visualization, (ii) impedance measurement, (iii) ultrasonography, (iv) temperature measurement; and, (v) contractile force measurement via manometry. The feedback mechanism permits the selected on-off switching ofdifferent electrodes66 in a desired pattern, which can be sequential from oneelectrode66 to anadjacent electrode66, or can jump around betweennon-adjacent electrodes66.Individual electrodes66 are multiplexed and volumetrically controlled by a controller.
• The area and magnitude of cell injury in the LES orsphincter16 can vary. However, it is desirable to deliver sufficient energy to the targetedtreatment site12 to be able to achieve tissue temperatures in the range of 55-95° C. and producelesions14 at depths ranging from 1-4 mms from the interior surface of the LES orsphincter wall30. Typical energies delivered to the esophageal or stomach wall include, but are not limited to, a range between 100 and 50,000 joules perelectrode66. It is also desirable to deliver sufficient energy such that resultinglesions14 have a sufficient magnitude and area of cell injury to cause an infiltration oflesion14 byfibroblasts110,myofibroblasts112,macrophages114 and other cells involved in the tissue healing process (refer toFIG. 17). As shown inFIG. 18, these cells cause a contraction of tissue aroundlesion14, decreasing its volume and/or altering the biomechanical properties atlesion14 so as to result in a tightening of the LES orsphincter16. These changes are reflected in transformedlesion14′. The diameter oflesions14 can vary between 0.1 to 4 mm. It is preferable thatlesions14 are less than 4 mmns in less than 4 mms in diameter in order to reduce the risk of thermal damage to mucosal andsubmucosal layers60 and62. In one embodiment, a 2mm diameter lesion14 centered in the wall of the smooth muscle provides a 1 mm buffer zone on either side oflesion14 to prevent damage to mucosal andsubmucosal layers60 and62 and the adventitia (not shown), while still allowing for cell infiltration and subsequent sphincter tightening on approximately 50% of the thickness of the wall of the smooth muscle (refer toFIG. 19).
• It is desirable thatlesions14 are predominantly located in the smooth muscle layer of selectedsphincter16 at the depths ranging from 1 to 4 mm from the interior surface ofsphincter wall30. However,lesions14 can vary both in number and position withinsphincter wall30. It may be desirable to produce a pattern ofmultiple lesions14 within the sphincter smooth muscle tissue in order to obtain a selected degree of tightening of the LES orother sphincter16. Typical lesion patterns shown inFIGS. 20 A-D include, but are not limited to, (i) a concentric circle oflesions14 all at fixed depth in the smooth muscle layer evenly spaced along the radial axis ofsphincter16, (ii) a wavy or folded circle oflesions14 at varying depths in the smooth muscle layer evenly spaced along the radial axis ofsphincter16, (iii)lesions14 randomly distributed at varying depths in the smooth muscle, but evenly spaced in a radial direction and, (iv) an eccentric pattern oflesions14 in one or more radial locations in the smooth muscle wall. Accordingly, the depth of RF and thermal energy penetration intosphincter16 is controlled and selectable. The selective application of energy to sphincter16 may be the even delivery of RF energy to the entire targetedtreatment site12, a portion of it, or applying different amounts of RF energy to different sites depending on the condition ofsphincter16. If desired, the area of cell injury can be substantially the same for every treatment event.
• A second diagnostic phase may be included after the treatment is completed. This provides an indication of LES tightening treatment success, and whether or not a second phase of treatment, to all or only a portion of the esophagus, now or at some later time, should be conducted. The second diagnostic phase is accomplished through one or more of the following methods: (i) visualization, (ii) measuring impedance, (iii) ultrasonography, (iv) temperature measurement, or (v) measurement of LES tension and contractile force via manometry.
• In one embodiment of the invention,sensor80 is coupled to an open or closed loopfeedback control system84. Referring now toFIG. 21, an open or closedloop feedback system84couples sensor80, now described assensor346, to anenergy source392. In this embodiment, anenergy delivery device314 is one ormore RF electrodes314; however, in various other embodiments,energy delivery device314 may include others described herein. Similarly, in this embodiment,sensor346 senses temperature, but in various other embodiments,sensor346 may sense other physical properties described herein.
• The temperature of the tissue, or ofRF electrode314, is monitored, and the output power ofenergy source392 adjusted accordingly. The physician can, if desired, override the closed oropen loop system84. Amicroprocessor394 can be included and incorporated in the closed or open loop system to switch power on and off, as well as modulate the power. Theclosed loop system84 utilizesmicroprocessor394 to serve as a controller, monitor the temperature, adjust the RF power, analyze the result, refeed the result, and then modulate the power.
• With the use ofsensor346 andfeedback control system84, tissue adjacent toRF electrode314 can be maintained at a desired temperature for a selected period of time without causing a shut down of the power circuit to electrode314 due to the development of excessive electrical impedance atelectrode314 or adjacent tissue. EachRF electrode314 is connected to resources which generate an independent output. The output maintains a selected energy atRF electrode314 for a selected length of time.
• Current delivered throughRF electrode314 is measured bycurrent sensor396. Voltage is measured byvoltage sensor398. Impedance and power are then calculated at power andimpedance calculation device400. These values can then be displayed at user interface anddisplay402. Signals representative of power and impedance values are received by acontroller404.
• A control signal is generated bycontroller404 that is proportional to the difference between an actual measured value, and a desired value. The control signal is used bypower circuits406 to adjust the power output an appropriate amount in order to maintain the desired power delivered atrespective RF electrodes314.
• In a similar manner, temperatures detected atsensor346 provide feedback for maintaining a selected power. Temperature atsensor346 is used as a safety means to interrupt the delivery of power when maximum pre-set temperatures are exceeded. The actual temperatures are measured attemperature measurement device408, and the temperatures are displayed at user interface anddisplay402. A control signal is generated bycontroller404 that is proportional to the difference between an actual measured temperature and a desired temperature. The control signal is used bypower circuits406 to adjust the power output an appropriate amount in order to maintain the desired temperature delivered at thesensor346. A multiplexer can be included to measure current, voltage and temperature, at thesensor346, and energy can be delivered toRF electrode314 in monopolar or bipolar fashion.
• Controller404 can be a digital or analog controller, or a computer with software. Whencontroller404 is a computer it can include a CPU coupled through a system bus. This system can include a keyboard, a disk drive, or other non-volatile memory systems, a display, and other peripherals, as are known in the art. Also coupled to the bus is a program memory and a data memory.
• User interface anddisplay402 includes operator controls and a display.Controller404 can be coupled to imaging systems including, but not limited to, ultrasound, CT scanners, X-ray, MRI, mammographic X-ray and the like. Further, direct visualization and tactile imaging can be utilized.
• The output ofcurrent sensor396 andvoltage sensor398 are used bycontroller404 to maintain a selected power level atRF electrode314. The amount of RF energy delivered controls the amount of power. A profile of the power delivered toelectrode314 can be incorporated incontroller404 and a preset amount of energy to be delivered may also be profiled.
• Circuitry, software and feedback tocontroller404 result in process control, the maintenance of the selected power setting which is independent of changes in voltage or current, and is used to change the following process variables: (i) the selected power setting, (ii) the duty cycle (e.g., on-off time), (iii) bipolar or monopolar energy delivery; and, (iv) fluid delivery, including flow rate and pressure. These process variables are controlled and varied, while maintaining the desired delivery of power independent of changes in voltage or current, based on temperatures monitored atsensor346.
• Referring now toFIG. 22,current sensor396 andvoltage sensor398 are connected to the input of ananalog amplifier410.Analog amplifier410 can be a conventional differential amplifier circuit for use withsensor346. The output ofanalog amplifier410 is sequentially connected by ananalog multiplexer412 to the input of A/D converter414. The output ofanalog amplifier410 is a voltage which represents the respective sensed temperatures. Digitized amplifier output voltages are supplied by A/D converter414 tomicroprocessor394.Microprocessor394 may be a type 68HCII available from Motorola. However, it will be appreciated that any suitable microprocessor or general purpose digital or analog computer can be used to calculate impedance or temperature.
• Microprocessor394 sequentially receives and stores digital representations of impedance and temperature. Each digital value received bymicroprocessor394 corresponds to different temperatures and impedances.
• Calculated power and impedance values can be indicated on user interface anddisplay402. Alternatively, or in addition to the numerical indication of power or impedance, calculated impedance and power values can be compared bymicroprocessor394 to power and impedance limits. When the values exceed predetermined power or impedance values, a warning can be given on user interface anddisplay402, and additionally, the delivery of RF energy can be reduced, modified or interrupted. A control signal frommicroprocessor394 can modify the power level supplied byenergy source392.
• FIG. 23 illustrates a block diagram of a temperature and impedance feedback system that can be used to control the delivery of energy totissue site416 byenergy source392 and the delivery of a cooling medium toelectrode314 and/ortissue site416 byflow regulator418. Energy is delivered toRF electrode314 byenergy source392, and applied totissue site416. Amonitor420 ascertains tissue impedance, based on the energy delivered to tissue, and compares the measured impedance value to a set value. If measured impedance is within acceptable limits, energy continues to be applied to the tissue. However if the measured impedance exceeds the set value, a disablingsignal422 is transmitted toenergy source392, ceasing further delivery of energy toRF electrode314.
• The control of the delivery of cooling medium toelectrode314 and/ortissue site416 is done in the following manner. During the application of energy,temperature measurement device408 measures the temperature oftissue site416 and/orRF electrode314. Acomparator424 receives a signal representative of the measured temperature and compares this value to a pre-set signal representative of the desired temperature. If the measured temperature has not exceeded the desired temperature,comparator424 sends a signal to flowregulator418 to maintain the cooling solution flow rate at its existing level. However if the tissue temperature is too high,comparator424 sends a signal to a flow regulator418 (connected to an electronically controlled micropump, not shown) representing a need for an increased cooling solution flow rate.
• The foregoing description of a preferred embodiment 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 forms disclosed. Obviously, many modifications and variations will be apparent to practitioners skilled in this art. It is intended that the scope of the invention be defined by the following claims and their equivalents.

Claims (11)

1. A sphincter treatment apparatus comprising:

an introducer having an introducer lumen,

an expandable device coupled to the introducer, the expandable device including a first arm with a proximal section and a distal section and a second arm with a proximal section and a distal section, the first and second arm distal sections being coupled, at least one of the first and second arms including an arm lumen coupled in fluid communication with the introducer lumen for delivery of a fluid, the expandable device being configured to at least partially dilate a sphincter in a deployed state, and

an energy delivery device coupled to the expandable device.

2. An apparatus as inclaim 1

wherein at least a portion of the energy delivery device is advanceable into the sphincter.

3. An apparatus as inclaim 1

wherein the at least one of the first and second arms includes an aperture coupled to the introducer lumen and adapted to provide a path for delivery of the fluid from the introducer.

4. An apparatus as inclaim 3

wherein the fluid is cooling fluid.

5. A method of treating a sphincter comprising:

providing an introducer, the introducer carrying an expandable device,

providing an energy delivery device coupled to the expandable device,

deploying the introducer to a targeted tissue site at or near a sphincter,

expanding the expandable device to at least partially dilate the sphincter,

delivering energy from the energy delivery device to the targeted tissue site, and

delivering a cooling fluid from the introducer.

6. A method as inclaim 5

wherein the expandable device includes a first arm with a proximal section and a distal section and a second arm with a proximal section and a distal section, the first and second arm distal sections being coupled.

7. A method as inclaim 6

wherein at least one of the first and second arms includes a lumen.

8. A method as inclaim 5

wherein the introducer includes a lumen.

9. A method as inclaim 5

wherein the cooling fluid is delivered at a sensed flow rate, further comprising,

measuring the temperature of at least one of the tissue site and the energy delivery device, and

comparing the measured temperature to a pre-set desired temperature.

10. A method as inclaim 9, further comprising

maintaining the flow rate if the measured temperature does not exceed the desired temperature.

11. A method as inclaim 9, further comprising

increasing the flow rate if the measured temperature exceeds the desired temperature.

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