Abstract:
A method and system for treating body structures or tissue allows treatment by any of ablation, coating, expansion, plumping, shaping, and shrinking. Treatment sitesinclude any of a sphincter, sinus or orifice. During treatment, electrodes emerge from apertures in a balloon. The balloon with liquid from a circulating bath cools tissue in direct contact with electrodes and immediately adjacent, so that discrete regions are treated, with minimal damage to adjacent structures. Sensors, coupled to electrodes, measure treatment properties such as: temperature, impedance and nervous activity. Measurements are used for: diagnostic assessment, determining treatment parameters, providing nervous stimulation and/or blocking, and feedback for controlling energy delivery. The catheter includes an optical path that can be coupled to external viewing apparatus. Endoscopic methods, including fluoroscopic, fiber optic, or radioscopy allow examining tissue and determining position of electrodes. The catheter includes a suction apparatus used to remove liquids obscuring treatment area and to gently conform treatment area to electrodes.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is a Continuation-in-part of U.S. patent application Ser. No. 08/677,811, filed Jul. 10, 1996, now U.S. Pat. No. 5,921,954, issued Jul. 13, 1999, which document is hereby incorporated by reference as if fully set forth herein. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to treatment of tissue in the urinary, digestive, respiratory, reproductive and circulatory systems. Such treatment can be performed using ablation, coating, expansion, plumping, shaping, shrinking, or related techniques. 
     2. Related Art 
     Human beings and other animals such as livestock and small animals are subject to a number of disorders that affect the digestive, urinary, respiratory, circulatory and reproductive systems. Frequently, these disorders (such as urinary and fecal incontinence) involve the relative tone of sphincters and other muscles. Other disorders (such as aneurysms) involve changes in the integrity of the wall of an artery or other body structure. Still other disorders (such as cancers, hemorrhoids and pilonital cysts) involve uncontrolled or improperly regulated growth of tissue. Many other disorders, particularly reproductive disorders, involve occlusions in otherwise healthy tissue. 
     Known methods for the treatment of these disorders include surgery, pharmaceutical remedies, chemotherapeutic regimens, radiation, photodynamic therapy and lifestyle modification. These methods only occasionally achieve the goal of successful treatment of disorders in circulatory, urinary, respiratory, reproductive and digestive systems. Moreover, these methods suffer from several drawbacks. 
     Drawbacks to surgical treatment include its highly invasive nature, associated risks, possible iatrogenic effects, and high cost. Drawbacks to pharmaceutical and chemotherapeutic treatments include their relative ineffectiveness (particularly in the oral cavity and adjacent respiratory structures) and associated side effects. Moreover, these approaches are contraindicated for many patients. Drawbacks to lifestyle modification include relatively poor patient compliance and relative ineffectiveness. Drawbacks to photodynamic therapy include its frequent unavailability and limited applicability. Drawbacks to radiation include side effects such as exhaustion, radiation burns, chronic dry mouth and permanent distortion of the taste buds. Accordingly, it would be advantageous to provide techniques for treatment of these disorders that are not subject to these known drawbacks. 
     The use of radio frequency (RF) to ablate tissue in the body (such as heart muscle tissue) is known in the art of cardiac treatment. However, known systems that rely on RF energy are still subject to several drawbacks. One drawback is that it can be difficult to target very small areas of tissue for treatment without causing thermal damage to adjacent structures. 
     A second problem involves controlling the flow of bodily fluids and gases into an area of the body where tissue ablation is taking place. Controlling the flow of bodily fluids and gases is critical because they can dissipate and detrimentally absorb the energy to be applied to the tissue to be ablated. 
     A third problem in the art involves directing and positioning the electrodes in the body cavity or orifice. Difficulties in accurately positioning the electrodes in the target orifice detract from treatment. Frequently, unhealthy tissue remains untreated while healthy tissue is removed. Difficulties in directing and positioning the electrodes are particularly problematic because one of the goals of treatment is to minimize collateral damage to healthy tissue and to completely ablate diseased tissue. 
     A fourth problem in the art involves difficulty in the simultaneous use of complimentary technology. Known systems do not provide for optimal, simultaneous use of auxiliary tools for nerve stimulation, visualization, feedback technology and drug administration. 
     A fifth problem in the known art involves the simultaneous heating and cooling of adjacent tissues. Frequently, it is desirable to prevent thermal damage to adjacent tissues. One way of preventing such damage is by controlling the temperature of the adjacent tissues. Known systems to not provide for the simultaneous heating and cooling of adjacent tissues. 
     A sixth problem in the known art involves conforming the interior of an organ such as a bladder to as to be in optimal contact with the electrodes. This inability makes it difficult to predict with any accuracy the overall degree of shrinkage that may result from RF treatment. 
     Accordingly, it would be advantageous to provide improved techniques for treatment of disorders in the circulatory, respiratory, urinary, digestive and reproductive systems. For example, it would be advantageous to provide devices bearing different arrays of curvilinear or straight electrodes such that each electrode is surrounded by saline. It would be particularly advantageous if such devices could also support apparatus for drug administration and tissue visualization. Such devices would allow medical personnel to (1) visualize the tissue to be treated, (2) seal off the area from fluids and gases that would disturb the area to be treated, (3) target very small areas for treatment, (4) treat all diseased tissue while sparing healthy tissue and (5) provide for the localized administration of drugs to numb the area and treat the disorder. These advantages are achieved in an embodiment of the invention in which medical personnel use a catheter bearing multiple controls for visualization and drug administration, balloon-like air sacs for sealing the area and multiple arrays of curvilinear or straight electrodes that extend out of a holes in a multiporous balloon. 
     SUMMARY OF THE INVENTION 
     In one aspect of the invention, an environment proximate to or surrounding the targeted treatment region can be isolated or controlled by blocking the flow of gases or liquids using an inflatable, microporous balloon positioned immediately adjacent to the tissue that is to be ablated. The inflatable microporous balloon also serves to anchor the catheter in place and prevent the catheter from being expelled from-the body. The inflatable microporous balloon can also insure that locally administered drugs remain in the area where most needed. 
     In a second aspect of the invention, straight or curvilinear electrodes emerge out of small apertures in the balloon. Inflation of the balloon with liquid from a constantly circulating bath of chilled fluid has the effect of cooling tissue, including tissue that is immediate adjacent to tissue in direct contact with an electrode. This permits treatment of small, discrete regions while minimizing collateral damage to immediately adjacent structures. 
     In a third aspect of the invention, the electrodes are coupled to sensors that measure properties of the target region such as temperature, impedance and nervous activity. These measurements are useful both in making diagnostic assessments as well as in determining treatment parameters. Moreover, they can be used to provide for nervous stimulation and/or blocking, and permit the use of feedback technique to control delivery of the RF energy. 
     In a fourth aspect of the invention, the catheter includes an optical path that can be coupled to external viewing apparatus. A wide variety of endoscopic methods, including fluoroscopic, fiber optic, or radioscopic techniques can be used to examine tissue and determine the position of the electrodes in the body. 
     In a fifth aspect of the invention, the catheter includes suction apparatus. This suction apparatus can be used to draw away liquids that obscure the treatment area and to gently conform the treatment area to the electrode. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a block diagram of a system for ablating tissue using a catheter and electrode assembly. 
     FIG. 2 is a process flow diagram of a method for treatment for urinary incontinence. 
     FIG. 3 is a process flow diagram of a method for treatment of an occluded fallopian tube. 
     FIG. 4 is a process flow diagram of a method for treatment of an occluded vas deferens. 
     FIG. 5 is a process flow diagram of a method for treatment of Barrett&#39;s esophagus. 
     FIG. 6 is a process flow diagram of a method for treatment of a fecal incontinence. 
     FIG. 7 is a process flow diagram of a method for treatment of a hemorrhoid or pilonital cyst. 
     FIG. 8 is a process flow diagram of a method for treatment of an anal fissure. 
     FIG. 9 is a process flow diagram of a method for treatment of an aortic aneurysm. 
     FIG. 10 shows an alternate embodiment of the system of FIG.  1 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     System Elements 
     FIG. 1 is a block diagram of a system for ablating tissue associated with the circulatory, respiratory, reproductive, digestive, auditory and urinary systems along with their related sphincters and associated musculature using a catheter and electrode assembly. 
     A catheter and electrode assembly  100  for treating tissue includes a catheter  110 , an inflatable microporous balloon  120  and a control and delivery linkage  130 . 
     The catheter  110  includes a short, distal segment  111  and a proximal segment  112 . The distal segment includes a tapered tip  113  for easy insertion into an orifice, a surgically created opening such as a stoma, or though a herniated muscle, body shunt or incision made for the purpose of insertion. The tapered tip  113  may be either flexible or rigid depending upon the orifice or opening into which the catheter  110  is to be inserted. The overall length of the shaft of the catheter  110  (including the inflatable, microporous balloon  120 ) from the tapered tip  113  to the junction where the catheter  110  is coupled to the control and delivery linkage  130  is about 65 centimeters. The diameter of the catheter  110  is about 0.4 centimeters. In an alternative embodiment, the length and diameter of the shaft of the catheter  110  may vary substantially depending upon application and method of treatment. 
     Taken together, the distal segment  111 , the inflatable, microporous balloon  120  and the proximal segment  112  are linearly contiguous and form one continuous unit. 
     The inflatable, microporous balloon  120  can be composed of a biologically non-reactive material that is resistant to high temperatures such as Kevlar. The balloon  120  is shaped so that it contains numerous sealed openings that create a set of apertures  121 . These apertures  121  do not effect the integrity of the walls of the balloon  120  because they are sealed. This unique shape provides for simultaneous application of RF energy and cooling of tissue. 
     One or more electrodes  122  emerge through each member of the plurality of apertures  121 . In a preferred embodiment, one electrode  122  emerges from every aperture  121 . However, in alternative embodiments, two or more electrodes can emerge from a single aperture. Each electrode  122  includes a metallic tube  123  defining a hollow lumen  124 , a temperature sensor  125 , an impedance sensor  126 , a sensor for measuring nervous activity  127 , and a nerve sensor  128  that is responsive to individual nerves. In addition to ablating tissue by delivering RF energy, the electrodes  122  are disposed to deliver at least one flowable substance to the area where ablation is to take place. In a preferred embodiment, the flowable substance includes saline with a concentration of less than about 10% NaCl, which aids in hydration of body structures. However, in alternative embodiments, the deliverable, flowable liquids include other substances, including anesthetic drugs, anti-inflammatory agents, chemotherapeutic agents, systemic or topical antibiotics, collagen and radioactive substances such as labeled tracers. In alternative embodiments, the overall dimensions of the inflatable microporous balloon  120  can vary as long as they are responsive to the dimensions of the targeted tissue. For instance, the dimensions of an inflatable, microporous balloon  120  that is used to ablate tissue in a uterus will be larger than those of an inflatable microporous balloon  120  that is used to ablate tissue in a fallopian tube. In other alternative embodiments, the shape and length of the electrodes may also vary. 
     Exact positioning of the electrodes  122  is achieved through the use of visualization apparatus coupled to port  132 . 
     Simultaneous application of RF energy and cooling is achieved by means of a temperature regulator such as inflating the balloon  120  with liquid from a continuously circulating bath of saline  138  whose temperature is controlled. 
     Manipulating the control and delivery linkage  130  operates the assembly  110 . The control and delivery linkage  130  includes a port  131 , a port  132 , three female couplings  133 ,  134  and  135 , a mechanical switch  136  and a hand set  137 . 
     The port  131  can be coupled to a source of RF energy. The port  132  can be coupled to visualization apparatus, such as fiber optic devices, fluoroscopy equipment and related endoscopic apparatus, to allow internal viewing of the targeted tissue. In a preferred embodiment, female coupling  133  can be connected to biologically nonreactive tubing  139  containing at least a single lument through the microporous balloon  120 . Female coupling  134  can be connected to drug administration apparatus. Female coupling  135  can be connected to suction apparatus. Switch  136  allows for the selection of individual electrodes in a manner that is responsive to the judgment of medical or veterinary personnel. Port  131 , port  132 , female couplings  133 ,  134 ,  135  and switch  136  are all included on the hand set  137  to allow easy operation. 
     First Method of Operation 
     FIG. 2 is a process flow diagram of a method for treatment for urinary incontinence. 
     This method of operation is appropriate for the type of incontinence common to many post-menopausal parous women. In some women, the structure of the pelvic support of the bladder is damaged, either by parturition or urethral atrophy caused by estrogen deprivation. When this occurs, the urethra shortens, and the normal urethovesical angle is lost. The goals of this method of operation include producing uniform shrinkage of submuscosal tissue. This shrinkage helps restore the urethovesical angle that is important for closure of the urethral sphincter. 
     This method of treatment is also appropriate when incontinence is caused by inflammatory lesions of the muscosal tissue in the trigone area of the bladder. These lesions can cause uncontrollable detrusor contractions and unwanted passage of urine, often called urgency incontinence. The goals of this method include shrinkage of muscosal tissue and ablation of the lesions causing incontinence. Other possible uses of this device in the urinary tract include removal of urethral obstructions. 
     A method  200  is performed using a catheter and electrode assembly  100 . The preferred size of the catheter  110  will be responsive to the orifice through which the catheter is inserted. The choice of pharmaceutical agents to be infused prior to or during treatment will be responsive to judgments by medical or veterinary personnel and may include lubricants, anesthetics, antispasmodics, anti-inflammatories, antibiotics or other agents. 
     In a step  201 , the area around the urethral meatus is cleansed. The tapered tip of the catheter  110  is well lubricated and introduced into the urethral meatus in an upward and backward direction, in much the same way one would introduce a Foley catheter. Due to the potential for inducing pain, the outer opening of the urethra may be pretreated with a topical anesthetic before insertion and a muscle relaxant may be administered. The choice of pharmaceutical agents to be infused prior to or during treatment will be responsive to judgments by medical personnel and may include lubricants, anesthetics, antispasmodics, anti-inflammatories, antibiotics or other agents. In an alternative embodiment, the area of the glans penis around the urinary meatus is washed with a cleansing agent such as benzalonium chloride and the lubricated tapered tip  113  of the catheter  110  is inserted. 
     In a step  202 , the catheter  110  is threaded through the female urethra until the tapered tip  113  and the inflatable, microporous balloon  120  extend past the neck of the bladder. Strict aseptic technique is maintained during this step and all subsequent ones. In an alternative embodiment, the catheter is threaded along the anterior wall of a male urethra. 
     In a step  203 , viewing apparatus coupled to port  132  is used to (1) examine the sphincters and the urethrovesical angle (2) determine which areas of the mucosal or submucosal tissue are targeted for shrinkage and which lesions, if any, are targeted for ablation and (3) evaluate the position of the catheter  110 . In male patients, attention is directed toward identifying evidence of lesions or other damage caused by prior surgery, such as prostatic surgery, because this is frequently the cause of incontinence in men. 
     In a step  204 , a temperature controlled bath of cool sterile, saline or other flowable substance is prepared. One end of tubing containing at least one lumen, is attached to female coupling  133 ; the other end of the tubing is attached to a pump which is submerged in the temperature controlled saline bath. Double lumen tubing permits constant circulation of the flowable substance throughout the balloon  120 . The nature, temperature and amount of flowable substance are responsive to judgments by medical personnel. 
     In a step  205 , the balloon  120  is inflated by turning on the pump. Inflation of the balloon  120  serves several purposes. In addition to preventing thermal damage by providing a cool surface, it also snugly positions the electrode  122  against the wall of the bladder and helps anchor the catheter  110  in place. In an alternative embodiment, a blocking element  120   a  is used to help seal off the bladder neck. The blocking element may be a second balloon or a sponge, the blocking element being disposed to present a liquid-tight seal in a region proximal to said selected location. 
     In a step  206 , the parasympathetic and sympathetic nerves that ennervate the base of the bladder are identified using the nerve sensors  127 . 
     In a step  207 , the position of the catheter  110  and the balloon  120  is checked again using the visual apparatus coupled through port  132 . Any correction to the position of the catheter  110  is made at this time by repeating steps  202  through  206 . 
     In a step  208 , suction apparatus connected to female coupling  135  may be used to gently help conform the bladder to the catheter and balloon. This step is optional. 
     In a step  209 , one or more electrodes  122  are selected for activation. Since the goal of treatment includes uniform shrinkage of the submucosal or mucosal tissue, the selected electrodes  122  usually adhere to a uniform pattern. However, when the goal is ablation of lesions, the selected electrodes need not adhere to any pattern. Particular caution is given with respect to the nerves identified in step  207 . There may be instances in which these nerves are to be completely shielded from RF energy using nerve shield  128 ; conversely, there may be cases in which these nerves require application of RF energy. The number and pattern of selected electrodes  122  is responsive to judgement of medical personnel. The mechanical switch  136  is used to select one or more electrodes  122 . 
     In a step  210 , a source of RF energy is coupled to port  131 . RF energy is provided to the electrodes  122  to shrink the targeted tissue and ablate lesions in the bladder, if present. In a preferred embodiment, the RF energy has a frequency between 435 kilohertz and 485 kilohertz. The RF energy is received by the tissues immediately near the electrodes for a period of time less than ten minutes. During this time, the adjacent tissues are cooled by the constant circulation of saline through the balloon. The duration of time and frequency of energy are responsive to judgments of medical personnel. Application of RF energy causes the involuntary sphincter to shrink so that urine does not seep through. In selected areas, it also has the effect of ablating lesions that cause incontinence. In alternative embodiments, the electrodes may deliver other forms of energy, such as heat, microwaves, infrared or visible laser energy. In other alternative embodiments, the electrodes are controlled by a feedback technique using at least one sensor such as temperature sensor  125 , impedance sensor  126  or nervous activity sensor  127 . 
     To perform ablation, the tissue is heated for a short period of time until ablation occurs. Application of RF energy causes cell death by dehydration or denaturation of cellular proteins. 
     To perform expansion, plumping, or shaping, the tissue is suffused with a flowable substance, such as a gas or liquid, a collagen, or another substance that can be absorbed by the body structure or tissue. The flowable substance can be exuded from the catheter, either using a separate flow line, or using the electrodes themselves. In a preferred embodiment, the tissue is heated for a short time, and thereafter cooled, so as to cause the flowable substance to crosslink or otherwise transform into a bulking, plumping, or shaping agent. 
     To perform coating, the flowable substance can be exuded so as to adhere to (or be adsorbed by) an epithelial layer of cells. In a preferred embodiment, the tissue is heated for a short time, and thereafter cooled, so as to cause the flowable substance to crosslink or otherwise transform into a solid mass coating or covering the epithelial layer. 
     To perform shrinking, the tissue is suffused with the flowable substance, with the flowable substance being selected so as to act as a receiving antenna or dielectric for the RF energy. RF energy is applied, which is differentially absorbed by the flowable substance; this causes the flowable substance to heat and to shrink the tissue it suffused, either by cell death, dehydration, or denaturation of cellular proteins. 
     In a step  211 , suction apparatus is connected to female coupling  135 ; suction is applied to remove debrided tissue and body fluids, if necessary. 
     In a step  212 , pharmacological agents can be administered locally using drug administration apparatus connected to female coupling  134 . The type and dosage of drug to be administered is responsive to judgments by medical and veterinary personnel. 
     In a step  213 , all or most of the flowable liquid circulating through the balloon  120  is siphoned off by removing the tubing from the saline bath and applying negative force to female coupling  133 . This has the effect of deflating balloon  120 . 
     In a step  214 , the catheter  110  is carefully withdrawn from the urethra. 
     FIG. 3 is a process flow diagram for a method of treating an occluded fallopian tube. 
     Blockage of the fallopian tube is a frequent cause of infertility in women of reproductive years. Diagnosis of tubal blockage is generally made by hysteroslpingogram and diagnostic laparoscopy. The goals of this method of treatment include restoration of the fallopian tube patency. Other possible uses of this device in the female reproductive system include removal of uterine tumors and fibroids, and endometrial ablation. 
     A method  300  is performed using a catheter and electrode assembly  100 . 
     In a step  301 , the skin of the lower abdomen is cleansed and draped. A small surgical incision is made to allow the insertion of the catheter  110 . Strict aseptic technique is maintained during this step and all subsequent ones. Due to the potential for inducing pain, the surface of the skin may be pretreated with a topical anesthetic before insertion. A mild anesthetizing agent such as VerSed may be indicated. The choice of pharmaceutical agents to be infused prior to or during treatment will be responsive to judgments by medical or veterinary personnel and may include lubricants, anesthetics, antispasmodics, anti-inflammatories, antibiotics or other agents. 
     In a step  302 , both fallopian tubes are located. A second small incision is made in the wall of one the fallopian tubes to permit insertion of the catheter  110 . Care is taken not to abrade the ovaries or damage the broad ligament that supports the fallopian tube. 
     In a step  303 , viewing apparatus coupled to port  132  is used to examine the interior walls of the fallopian tube, search for occlusions, evaluate the position of the catheter  110  and balloon  120 , and determine which areas are targeted for ablation. 
     In a step  304 , a temperature controlled bath of cool sterile, saline or other flowable substance is prepared. One end of a piece of double-lumen tubing is attached to female coupling  133 ; the other end of the tubing is attached to a pump which is submerged in the temperature controlled saline bath. Double lumen tubing permits constant circulation of the flowable substance throughout the balloon  120 . The nature, temperature and amount of flowable substance are responsive to judgments by medical personnel. 
     In a step  305 , the balloon  120  is inflated by turning on the pump. Inflation of the balloon  120  serves several purposes. In addition to preventing thermal damage by providing a cool surface, it also anchors the catheter  110  in place and causes the set of electrodes to be brought into contact with the offending occlusions and blockages. In some instances, the act of inflating the balloon may be sufficient to dilate the fallopian tube and break up the occlusion. 
     In a step  306 , the position of the catheter  110  and the balloon  120  is checked once again using the visual apparatus coupled through port  132 . Any correction to the position of the catheter  110  is made at this time, by repeating steps  303  through  305 . 
     In a step  307 , suction apparatus connected to female coupling  135  may be used to gently help conform the interior of the fallopian tube to the catheter  110  and balloon  120 . In an alternative embodiment, step  208  does not occur. 
     In a step  308 , one or more electrodes  122  are selected for activation. Unlike the previous method, the selected electrodes  122  need not adhere to a uniform pattern. The number and pattern of selected electrodes is responsive to the judgments of medical or veterinary personnel. The mechanical switch  136  is used to select one or more of the electrodes  122 . 
     In a step  309 , a source of RF energy is coupled to port  131 . RF energy is provided to the electrodes  122  to ablate the targeted tissue. In a preferred embodiment, the RF energy has a frequency between 435 kilohertz and 485 kilohertz. The RF energy is received by the tissue immediately near the electrodes for a period of time less than ten minutes. The duration of time and frequency of energy are responsive to judgments of medical or veterinary personnel. 
     In a step  310 , additional suction may be provided using suction apparatus connected to female coupling  135 . 
     In a step  311 , pharmacological agents can be locally administered using drug administration apparatus connected to female coupling  134 . The type and dosage of such drugs is responsive to judgments by medical and veterinary personnel. 
     In a step  312 , all or most of the flowable liquid circulating through the balloon  120  is siphoned off by removing the tubing from the saline bath and applying negative force to female coupling  133 . Application of this negative force deflates the balloon  120 . 
     In a step  313 , the catheter  110  is removed from the fallopian tube and the incision in the fallopian tube is repaired. 
     In a step  314 , the catheter  110  is withdrawn from the incision where it was initially introduced into the body. 
     Steps  301  through  314  may be repeated, if necessary, to treat occlusions on the other fallopian tube. 
     Third Method of Operation FIG.  4  is a process flow diagram of a method for treatment of an occluded vas deferens. 
     Obstruction of the vas deferens accounts for about 3% of male infertility. Obstruction may be congenital or acquired. Congenital obstruction may be an isolated abnormality or may be associated with cystic fibrosis. Acquired obstruction of the vas deferens may be caused by tuberculosis and gonorrhea. The goals of the method of operation include removal of the obstruction and restoration of fertility. 
     A method  400  is performed using a catheter and electrode assembly  100 . 
     In a step  401 , the skin of the lower abdomen is cleaned and draped. A small surgical incision is made to allow the insertion of the catheter  110 . Strict aseptic technique is maintained during this step and all subsequent ones. Due to the potential for inducing pain, the surface of the skin may be pretreated with a topical anesthetic before insertion. A mild anesthetizing agent such as VerSed may be indicated. The choice of pharmaceutical agents to be infused prior to or during treatment will be responsive to judgments by medical personnel and may include lubricants, anesthetics, antispasmodics, anti-inflammatories, antibiotics or other agents. 
     In a step  402 , both of the vas deferens are located. A second small incision is made into the wall of one the vas deferens to permit insertion of the catheter  110 . Care is taken not to abrade the seminal vesicles or supporting structures. 
     In a step  403 , viewing apparatus coupled to port  132  is used to examine the interior walls of the vas deferens, search for occlusions, evaluate the position of the catheter  110  and balloon  120 , and determine which areas are targeted for ablation. 
     In a step  404 , a temperature controlled bath of cool sterile, saline or other flowable substance is prepared. One end of a piece of double-lumen tubing is attached to female coupling  133 ; the other end of the tubing is attached to a pump which is submerged in the temperature controlled saline bath. Double lumen tubing permits constant circulation of the flowable substance throughout the balloon  120 . The nature, temperature and amount of flowable substance are responsive to judgments by medical personnel. 
     In a step  405 , the balloon  120  is inflated by turning on the pump. Inflation of the balloon  120  serves several purposes. In addition to preventing thermal damage by providing a cool surface, it also anchors the catheter  110  in place and causes the set of electrodes to be brought into contact with the offending occlusions and blockages. In some instances, the act of inflating the balloon may be sufficient to dilate the vas deferens and break up the occlusion. 
     In a step  406 , the position of the catheter and the balloon is checked once again using the visual apparatus coupled through port  132 . Any correction to the position of the catheter  110  is made at this time by deflating the balloon and repeating steps  303  through  305 . 
     In a step  407 , suction apparatus connected to female coupling  135  may be used to gently help conform the interior walls of the vas deferens to the catheter  110  and balloon  120 . In an alternative embodiment, step  407  does not occur. 
     In a step  408 , one or more electrodes  122  are selected for activation. The number and pattern of selected electrodes is responsive to the judgments of medical or veterinary personnel. The mechanical switch  136  is used to select one or more of the electrodes  122 . 
     In a step  409 , a source of RF energy is coupled to port  131 . RF energy is provided to the electrodes  122  to ablate the targeted tissue. In a preferred embodiment, the RF energy has a frequency between 435 kilohertz and 485 kilohertz. The RF energy is received by the tissue immediately near the electrodes for a period of time less than ten minutes. The duration of time and frequency of energy are responsive to judgments of medical or veterinary personnel. Application of RF energy has the effect of ablating the offending occlusions. 
     In a step  410 , suction may be applied, if necessary. 
     In a step  411 , pharmacological agents may be administered locally using drug administration apparatus connected to the female coupling  134 . The type of drug and dosage are responsive to judgments of medical or veterinary personnel. 
     In a step  412 , all or most of the flowable liquid circulating through the balloon  120  is siphoned off by removing the tubing from the saline bath and applying negative force to female coupling  133 . Application of this negative force deflates the balloon  120 . 
     In a step  413 , the catheter  110  is removed from the vas deferens and the incision in the wall of the vas deferens is repaired. 
     In a step  414 , the catheter  110  is withdrawn from the incision where it was initially introduced into the body. 
     In a step  415 , the incision where the catheter  110  was introduced is repaired. 
     Steps  401  through  415  may be repeated, if necessary, to treat occlusions on the remaining vas deferens. 
     Fourth Method of Operation 
     FIG. 5 is a process flow diagram of a method for treatment of Barrett&#39;s esophagus. 
     Barrett&#39;s esophagus often accompanies gastroesophegeal reflux disorder. It is diagnosed by esophagoscopy, which reveals the presence of columnar cells lining the lower esophagus. Adjacent peptic strictures may or may not coincide. Patients with Barrett&#39;s esophagus require close follow-up because these abnormal tissues often develop into adenocarcinoma. Other possible uses of this device in the digestive system include RF treatment of the entire gastric cardia to induce a sensation of satiety for the purpose of weight control, mapping of the electric potentials of the stomach for responsive areas when the stomach is stimulated for the purpose of weight control, removal of tumors throughout the digestive track and some disorders affecting the motility of the colon. 
     A method  500  is performed using a catheter and electrode assembly  100 . 
     In a step  501 , the tapered tip  113  of the catheter  110  is inserted into the oral cavity. Due to the potential for inducing pain or a gag reflex, the oral cavity is preferably pretreated with lidocaine spray or other topical anesthetic before insertion; depending upon the circumstances, a muscle relaxant may be indicated. In an alternative embodiment, the tapered tip  113  of the catheter  110  is inserted into a surgically created stoma. 
     The preferred size of the catheter  110  will be responsive to the orifice through which the catheter is inserted. The choice of pharmaceutical agents to be infused prior to or during treatment will be responsive to judgments by medical personnel, and may include lubricants, anesthetics, antispasmodics, anti-inflammatories, antibiotics or other agents. 
     In a step  502 , the catheter  110  is threaded through the throat into the lower esophagus. Precautions are taken to ensure that the catheter  110  is not threaded through the trachea into the lungs. 
     In a step  503 , the catheter  110  is positioned near the Barrett&#39;s esophagus. 
     In a step  504 , viewing apparatus coupled to the port  132  may be used to position the catheter  110 , examine the region, and determine which specific tissues are targeted for ablation. Healthy tissue composed of white squamous cells is distinguished from unhealthy pink columnar cells indicative of Barrett&#39;s esophagus. 
     In a step  505 , a temperature-controlled bath of saline is prepared. This step is similar to step  204 . 
     In a step  506 , the balloon  120  is inflated. This step is similar to step  205 . Inflation prevents thermal damage to the white squamous cells, anchors the catheter  110  in place, positions the electrodes  122  against the invasive columnar cells and prevents gas or liquids arising in the stomach from contaminating the region. 
     In a step  507 , the exact position of the catheter  110  and balloon  120  is rechecked. 
     In a step  508 , suction apparatus may be connected to female coupling  135 . Suction may be employed to help conform the walls of the fallopian tube to the catheter and balloon  120 . 
     In a step  509 , one or more electrodes  122  are selected for activation. Since the treatment goals include ablation of the columnar cells, electrodes that are proximate to these cells are selected. The mechanical switch  136  is used to select one or more electrodes  122 . 
     In a step  510 , a source of RF energy is coupled to port  131 . RF energy is provided to the electrodes so as to ablate the targeted columnar cells. In all other respects, this step is similar to step  210 . 
     In a step  511 , suction may be applied, if necessary to remove debrided tissue and body fluids. 
     In a step  512 , pharmacological agents may be administered. This is similar to step  411 . 
     In a step  513 , the balloon  120  is deflated. This is similar to step  412 . 
     In a step  514 , the catheter  110  is removed from the esophagus by withdrawing the catheter  110  from the oral cavity. In alternative embodiments, it may be removed by withdrawing it, from a stoma. 
     Fifth Method of Operation 
     FIG. 6 is a process flow diagram of a method for treatment of fecal incontinence. 
     A method  600  is performed using a catheter and electrode assembly  100 . The preferred size of the catheter  110  will be responsive to the orifice through which the catheter is inserted. The choice of pharmaceutical agents to be infused prior to or during treatment will be responsive to judgments by medical personnel, and may include lubricants, anesthetics, antispasmodics, anti-inflammatories, antibiotics or other agents. 
     In a step  601 , the rectum and surrounding area are washed with a cleansing agent such as benzalonium chloride. A topical anesthetic may be applied to prevent pain associated with insertion; depending upon the circumstances, a muscle relaxant may be indicated. The tapered tip  113  of the catheter  110  is inserted into the rectum. 
     The preferred size of the catheter  110  will be responsive to the orifice through which the catheter is inserted. The choice of pharmaceutical agents to be infused prior to or during treatment will be responsive to judgments by medical personnel, and may include lubricants, anesthetics, antispasmodics, anti-inflammatories, antibiotics or other agents. 
     In a step  602 , the catheter  110  is threaded into the rectum. 
     In a step  603 , the catheter  110  is positioned near the area of the sphincter targeted for treatment. In the preferred embodiment, viewing apparatus such as an anoscope coupled to the port  132  may be used to examine the region and determine which specific tissues are targeted for treatment. It is important to distinguish between the voluntary and involuntary sphincter because fecal incontinence is frequently caused by defects in the involuntary sphincter. 
     In a step  604 , a temperature-controlled bath of saline is prepared. This step is similar to step  204 . 
     In a step  605 , the balloon  120  is inflated. This step is similar to step  205 . Inflation prevents thermal damage to the walls of the sphincter, anchors the catheter  110  in place, positions the electrodes  122  against the invasive columnar cells and prevents contamination by gas or fecal matter. 
     In a step  606 , the position of the catheter  110  is rechecked using visual apparatus connected to port  132 . Adjustments are made in the position of the catheter, if necessary. 
     In a step  607 , suction apparatus is connected to female coupling  134 . This apparatus can be used, if necessary to conform the tissue to the electrodes. 
     In a step  608 , one or more electrodes  121  are selected for activation. This step is similar to step  209 . 
     In a step  609 , RF energy is provided to the electrodes so as to ablate the targeted tissue. This step is similar to step  210 . 
     In a step  610 , suction may be applied, if necessary to remove debrided tissue and body fluids. 
     In a step  611 , pharmacological agents may be administered. This is similar to step  411 . 
     In a step  612 , the balloon  120  is deflated. This is similar to step  412 . 
     In a step  613 , the catheter  110  is withdrawn from the rectum. 
     Sixth Method of Operation 
     FIG. 7 is a process flow diagram of a method for treatment of a hemorrhoid or pilonital cyst. 
     A method  700  is performed using a catheter and electrode assembly  100 . 
     In a step  701 , the tapered tip  113  of the catheter  110  is well lubricated and the rectum and surrounding area are washed with a cleansing agent. This step is similar to step  601 . 
     In a step  702 , the catheter  110  is introduced into the rectum and advanced along the walls of the sphincter. Since hemorrhoids and pilonital cysts may occur anywhere along this passage, the distance that the catheter is introduced is responsive to the judgment of medical or veterinary personnel. 
     In a step  703 , the catheter  110  is positioned near the internal hemorrhoid, external hemorrhoid or cyst that is targeted for ablation. In the preferred embodiment, viewing apparatus such as an anoscope is coupled to port  132 . This apparatus is used to examine the region and determine which specific tissues are targeted for ablation. 
     In a step  704 , a temperature-controlled bath of saline is prepared. This step is similar to step  204 . 
     In a step  705 , the balloon  120  is inflated. This step is similar to step  205 . Inflation prevents thermal damage to the walls of the sphincter, anchors the catheter  110  in place, positions the electrodes  122  against the invasive columnar cells and prevents contamination by gas or fecal matter. 
     In a step  706 , the position of the catheter  100  and balloon is rechecked using visual apparatus connected to port  1232 . Any corrections in the positioning of the catheter  110  are made at this time, using the anoscope coupled to port  132 . 
     In a step  707 , suction: apparatus is connected to female coupling  134 . This apparatus can be used, if necessary to conform the tissue to the electrodes. 
     In a step  708 , one or more electrodes  121  are selected for activation. This step is similar to step  209 . 
     In a step  709 , a source of RF energy is coupled to port  131 . This step is similar to step  210 . 
     In a step  710 , suction may be applied, if necessary to remove debrided tissue and body fluids. 
     In a step  711 , pharmacological agents may be administered. This is similar to step  411 . 
     In a step  712 , the balloon  120  is deflated. This is similar to step  412 . 
     In a step  713 , steps  703  through  712  are repeated as necessary until all hemorrhoids or cysts are removed. 
     In a step  714 , the catheter  110  is withdrawn from the rectum. 
     Seventh Method of Operation 
     FIG. 8 is a process flow diagram of a method for treatment of an anal fissure. 
     A method  800  is performed using a catheter and electrode assembly  100 . 
     In a step  801 , the tapered tip  113  of the catheter  110  is lubricated and the rectum and surrounding area are washed with a cleansing agent. This step is similar to step  601 . 
     In a step  802 , the catheter  110  is introduced into the rectum and advanced along the walls of the sphincter. This is similar to step  702 . 
     In a step  803 , the catheter  110  is positioned near an anal fissure. In the preferred embodiment, viewing apparatus, such as an anoscope, is coupled to the port  132  may be used to examine the region and determine which specific tissues are targeted for ablation and where collagen should be deposited. 
     In a step  804 , a temperature-controlled bath of saline is prepared. This step is similar to step  204 . 
     In a step  805 , the balloon  120  is inflated. This step is similar to step  205 . Inflation prevents thermal damage to the walls of the sphincter, anchors the catheter  110  in place, positions the electrodes  122  against the invasive columnar cells and prevents contamination by gas or fecal matter. 
     In a step  806 , the position of the catheter  110  and balloon  120  are rechecked. Any adjustments to the position of the catheter  110  and balloon  120  are made at this time, if necessary. 
     In a step  807 , suction apparatus is connected to female coupling  134 . This apparatus can be used, if necessary to conform the tissue to the electrodes  122 . 
     In a step  808 , one or more electrodes  122  are selected for activation. This step is similar to step  209 . 
     In a step  809 , collagen is deposited into the fissure. 
     In a step  810 , a source of RF energy is coupled to port  13   1 . RF energy is provided to the electrodes  121  so as to harden the collagen for filling the fissure. In a preferred embodiment, the RF energy has a frequency between 435 kilohertz and 485 kilohertz. The RF energy is received by the tissue immediately near the electrodes. The tissue is heated for a short period of time until the collagen is sufficiently hardened. In an alternative embodiment, the electrodes are controlled by a feedback technique using at least one sensor  126  such as an impedance or temperature sensor. 
     In a step  811 , suction may be applied, if necessary to remove debrided tissue, body fluids and any excess, unhardened collagen. 
     In a step  812 , pharmacological agents may be administered. This is similar to step  410 . 
     In a step  813 , the balloon  120  is deflated. This is similar to step  411 . 
     In a step  814 , the catheter  110  is withdrawn from the rectum. 
     Eighth Method of Operation 
     FIG. 9 is a process flow diagram of a method for treating of an aortic aneurysm. 
     An aortic aneurysm involves destruction of all three layers of the aortic wall. Thinning of the wall increases the diameter of the aorta, which in turn affects the pressure on the wall. Many aneurysms, known as dissecting aneurysms, include weakened tissue that extends out from the aortic wall. In all instances, the likelihood of rupture increases with time in the absence of treatment. Although often successful, surgical treatment for aortic aneurysm is frequently avoided because of the high morbidity risk. The inventor has discovered that application of RF energy to the wall of the aorta increases the density of the wall. This increase in density has the reverse effect: the diameter of the aortic wall decreases, which in turn decreases the pressure on the aortic wall. The goals of this method of treatment include the increasing the density of the aortic wall. In alternative embodiments, a dissecting aneurysm is treated by depositing collagen into the dissecting region, smoothing over the collagen and hardening it. 
     A method  900  is performed using a catheter and electrode assembly  100 . 
     In a step  901 , the chest and/or abdominal region are cleansed and draped. 
     In a step  902 , a small surgical incision is made in the chest cavity to allow the insertion of the catheter  110 . Strict aseptic technique is maintained during this step and all subsequent ones. Due to the potential for inducing pain, the surface of the skin may be pretreated with a topical anesthetic before insertion. A mild anesthetizing agent such as VerSed may be indicated. The choice of pharmaceutical agents to be infused prior to or during treatment will be responsive to judgments by medical personnel and may include lubricants, anesthetics, antispasmodics, anti-inflammatories, antibiotics or other agents. 
     In a step  903 , the aorta is located. A second small incision is made into the wall of the aorta to permit insertion of the catheter  110 . Care is taken not to abrade or damage adjacent structures. 
     In a step  904 , viewing apparatus is coupled to port  132 . This viewing apparatus is used to examine the interior walls of the aorta, search for aneurysms (including dissecting aneurysms), evaluate the position of the catheter  110  and balloon  120 , and determine which areas are targeted for application of RF energy. 
     In a step  905 , a temperature-controlled bath of saline is prepared. This step is similar to step  204 . 
     In a step  906 , the balloon  120  is inflated. This step is similar to step  205 . Inflation prevents thermal damage to the walls of the aortic wall, anchors the catheter  110  in place and helps position the electrodes  122 . 
     In a step  907 , the position of the catheter and the balloon is checked once again using the visual apparatus coupled through port  132 . Any correction to the position of the catheter  110  is made at this time. 
     In a step  908 , suction apparatus is connected to female coupling  134 . This apparatus can be used, if necessary to gently conform the tissue to the electrodes. 
     In a step  909 , one or more electrodes  121  are selected for activation. This step is similar to step  209 . 
     In a step  910 , RF energy is provided to the electrodes so as to increase the density of the aortic wall. 
     In a step  911 , a mass of collagen may be deposited into a dissected aneursym. This step is optional. 
     In a step  912 , the balloon  120  may be used to present a surface which is used for smoothing the mass of collagen. This smoothing step is performed after the mass of collagen is deposited into the aneurysm and before the mass of collagen is hardened, but in other embodiments, the mass of collagen may be hardened or softened in layers or otherwise repeatedly, so as to achieve a relatively smooth surface layer of collagen. This step is optional. 
     In a step  913 , RF energy is applied to harden the collagen. This step is optional. 
     In a step  914 , suction may be applied, if necessary to remove debrided tissue, body fluids and any excess, unhardened collagen. 
     In a step  915 , pharmacological agents may be administered. This is similar to step  411 . 
     In a step  916 , the balloon  120  is deflated. This is similar to step  412 . 
     In a step  917 , the catheter  110  is removed from the aorta and the incision in the aorta is repaired. 
     In a step  918 , the catheter I  10  is withdrawn from the incision where it was initially introduced into the body. 
     In a step  919 , the initial incision in the wall of the chest or abdomen is repaired. 
     Alternative Embodiments 
     Although preferred embodiments are disclosed herein, many variations are possible which remain within the concept, scope and spirit of the invention, and these variations would become clear to those skilled in the art after perusal of this application.