Abstract:
A catheter for diagnosis of sphincter motility by measuring pressure exerted by the sphincter and, when necessary, ablating the sphincter immediately after diagnosis of a dysfunction. The catheter is in the form of an elongate sheath that has a proximal end, a distal end, and a longitudinal portion therebetween, with a manometry data collecting portion and a sphincterotome portion located at the distal end, and a handle assembly located at the proximal end. Embodiments are shown wherein the distal end can be aimed in a direction that facilitates cannulating the sphincter by moving the handle assembly. The catheter is used by maneuvering the distal end of the catheter into a sphincter. The manometry data collecting portion is first aligned with the sphincter and pressure measurements are taken. If it is determined that the sphincter is dysfunctional, the sphincterotome portion is aligned with and used to ablate the dysfunctional sphincter.

Description:
[0001]    This application claims priority to U.S. Provisional Application Ser. No. 60/338,727, filed Dec. 4, 2001. 
     
    
     
       TECHNICAL FIELD  
         [0002]    This invention relates to medical devices, more particularly to catheters for diagnosis and ablation of dysfunctional sphincters.  
         BACKGROUND OF THE INVENTION  
         [0003]    The sphincter of Oddi is located at the confluence of the bile duct, the pancreatic duct, and the duodenum, where it regulates the flow of bile and pancreatic juices into the small intestine, typically following the ingestion of a meal. Both biliary and pancreatic sphincters are part of the sphincter of Oddi, which is subject to a medical condition known as Sphincter of Oddi Dysfunction (SOD), a motility disorder. SOD can manifest itself as various problems within the bile or pancreatic ducts, such as formation of gallstones that obstruct the biliary duct, pancreatitis resulting from retrograde bile flow into the pancreatic duct, or post-cholecystectomy pain. Sphincter of Oddi Dysfunction has been found to be a leading cause of recurrent pancreatitis. Diagnosis of SOD can be performed by an endoscopist during a Endoscopic Retrograde Cholangiopancreatography (ERCP) by assessing the basal sphincter pressure using a manometry catheter, also called a motility catheter. The catheter, which is designed to be situated within sphincter of Oddi, includes one or more distal ports that infuse saline against the walls of the sphincter. The pressure exerted by the muscles of the sphincter is measured and used to assess the tone of sphincter and help determine if SOD is present. One example of a SOD manometry catheter is the Lehman Sphincter of Oddi Manometry Catheter (Wilson-Cook Medical, Winston-Salem, N.C.). It is a three-lumen catheter with two manometry ports located about the distal end. The two ports communicate with two luer connectors which attach to transducer of a separate recording system for measuring the resistance applied by the sphincter to the saline being infused through the ports by an infusion pump which also has been attached to the manometry catheter. After flushing the wire guide lumen, the catheter is fed over the wire guide pre-positioned in the bile duct and then into the endoscope accessory channel. The manometry catheter is then maneuvered under endoscopy into the cannulated SOD and a series of pressure readings are made to access the condition of the sphincter. A basal tone of more than 40 mm Hg is an indicator that the sphincter cannot effectively regulate bile flow and/or pass smaller stones into the duodenum.  
           [0004]    Typically, a hypertensive SOD is treated by ablation of the sphincter muscles, a procedure called a sphincterotomy, using a second, specialized catheter known as a sphincterotome. A biliary sphincterotome is an endoscopic catheter that includes a wire, typically braided or monofilament stainless steel, that extends from the distal end of the catheter or exits the catheter for only a portion of its length. The wire is connected to a electrosurgical generator that delivers current that allows the wire to ablate tissue with which it comes into contact. A sphincterotomy is often selected as the desired treatment after a manometry catheter has been used to establish that the sphincter is hypertensive. The manometry catheter must first be removed from the scope accessory channel, which is only large enough to accommodate a single device. The sphincterotome is then fed over the wire guide, if used, which remains in the bile duct. After the physician has maneuvered the sphincterotome into the papilla, current is applied to the cutting wire and the sphincter muscles are ablated, thereby creating a larger opening for the drainage of bile and/or passage of stones.  
           [0005]    Depending on the symptoms displayed by the patients, the likelihood of a sphincterotomy being performed can be rather high, once the physician has made the decision that the basal tone of the sphincter should be measured via a manometry catheter. Therefore, in a large number of patients, a sphincterotome will be required to be introduced through the endoscope to the site to replace the manometry catheter. What is needed is a way to more efficiently treat SOD by eliminating the need to replace devices once a confirmation of sphincter hypertension has been made. Ideally, such a solution should reduce the overall duration of the combined diagnostic and therapeutic procedures while including the full ability to perform each. Furthermore, such a device should reduce the risks associated with introducing a second device and be cost effective over a reasonable number of procedures, taking into account that there is a significant percentage of SOD studies that do not result in a sphincterotomy being performed.  
         SUMMARY OF THE INVENTION  
         [0006]    The foregoing problems are solved and a technical advance is achieved in an illustrative sheath or catheter that includes both side ports and dedicated passageways configured for supplying infusate used to acquire manometry data within the sphincter of Oddi, while also including a cutting wire (or needle knife) for performing a subsequent sphincterotomy if indicated by analysis of the manometry data. The combinational manometry catheter and sphincterotome eliminates the need for two separate devices being required, since one device will perform the function of both. Although it is likely that such a device would cost more than a sphincterotome or a manometry catheter alone, it certainly would be less expensive than the combined cost of the two devices. Furthermore, the primary cost advantage is in the reduction of the procedure time by being able to immediately perform a sphincterotomy without having to first remove the manometry catheter. The obvious clinical benefits for the patient include not having to access the papilla and duct a second time and shortening the total time that the devices remain within the patient. Over the course of multiple procedures, the cost and clinical benefits of a dual-function device clearly outweigh any additional cost that the sphincterotome-specific components add in those instances when a sphincterotomy proves unnecessary. In the illustrative embodiment, the deflectable aspect of the sphincterotome portion adds a useful feature for negotiating the manometry data collecting portion into the papilla, especially being that manometry catheters typically lack such a capability.  
           [0007]    The present invention includes an elongate sheath portion having a plurality of passageways that include at least one for infusion of fluids and subsequent measurement of the result fluid pressure, and one to house a cutting wire adapted to ablate adjacent tissue when a current is supplied. Optionally, a lumen is included to accommodate a standard wire guide and/or the infusion of fluids, such as saline or contrast agents. A proximal assembly comprises the proximal portion of the catheter assembly, including a handle portion that is operatively connected to the sheath portion, the handle portion preferably including a electrical connector for connecting to an electrosurgical generator/electrocautery unit for supplying current to the cutting wire; a wire guide port, such as a side arm adaptor; and one or more connectors to attach to a data collection system that includes the necessary components for data acquisition. Typically included in the data collection system is an infusion pump for delivering fluid to the manometric recording ports, one or more transducers for reading the pressure of the individual columns of infusate as they encounter the resistance supplied by the sphincter muscles, and a recording unit, such as a computer and appropriate commercially available function testing software, to analyze and display the manometric data, allowing the physician to access the condition of the sphincter.  
           [0008]    In one preferred embodiment of the invention, the sheath portion comprises a four-lumen polytetrafluoroethylene (PTFE) catheter with three smaller lumens or passageways to accommodate two infusion ports and the sphincterotome cutting wire; and a lumen sized to accommodate a standard wire guide used in the procedure. Some physicians do not use a wire guide to cannulate the papilla as part of the procedure. Therefore, the larger wire guide passageway can be considered optional, leaving a three-lumen catheter. The cutting wire exits the tubing along the distal portion of the sheath for a distance sufficient to allow ablation of the sphincter or papilla when properly positioned. The cutting wire reenters the tubing distally, where it terminates and is affixed to the catheter. The cutting wire can be advanced and retracted longitudinally independent of the catheter portion via the sliding handle. This allows the distal portion of the catheter portion to be deflected in one direction to assist in accessing the papilla. The bowing of the distal portion shortens the cutting portion of the wire and can produce an advantageous configuration for ablation. The two infusion passageways terminate along the distal portion at the respective infusion port of each, which are located approximately 90° with respect to one another. Plugs such as stainless steel wire pieces are placed within each passageway just distal to the port, thereby forcing the fluid to exit at the manometry port. The distal portion of the catheter includes a series of markings that are used as a visual indicator of how far to withdraw the catheter from the papilla of Vater to make a series of successive readings within the sphincter.  
           [0009]    In another preferred embodiment of the present invention, the catheter includes five passageways. One passageway is typically larger for accommodating a standard wire guide. The three smaller passageways are adapted for fluid transport, with the fourth reserved for the cutting wire. Either each of the three are provided for infusion and manometric data collection, or one of the passageways is adapted for aspiration of fluid supplied by the other two to help prevent overfilling of the bile or pancreatic ducts and the associated complications that could result. The aspiration port and passageway can also be present in a sheath with fewer than five passageways, with either the wire guide passageway or one of two infusion passageways being eliminated. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]    Embodiments of the present invention will now be described by way of example with reference to the accompanying drawings, in which:  
         [0011]    [0011]FIG. 1 depicts a side view of an illustrative embodiment of the present invention;  
         [0012]    [0012]FIG. 2 depicts an enlarged, partially sectioned bottom view of the manometry data collecting portion of the embodiment of FIG. 1;  
         [0013]    [0013]FIG. 3 depicts a cross-sectional view taken along line  3 - 3  of FIG. 1;  
         [0014]    [0014]FIG. 4 depicts a cross-sectional view of an alternative embodiment having four passageways; and  
         [0015]    FIGS.  5 - 7  depict a method of using the embodiment of FIG. 1 to both measure and treat the sphincter of Oddi in a patient. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0016]    Referring now to FIGS.  1 - 3 , a first embodiment of the catheter assembly  10  of the present invention is depicted, comprising a sheath portion  90 , including a manometry data-collecting portion  126  and a sphincterotome portion  106 , and a proximal assembly  70 . In the illustrative embodiment intended for biliary use, the overall length of the sheath  90  and proximal assembly  70  is approximately 215 cm, the proximal assembly  70  comprising about 30-35 cm of that length. The sheath portion  90  of the illustrative embodiment comprises a four-lumen, polytetrafluorethylene (PTFE) catheter. PTFE is a preferred material because of its lubricity and pushability within the scope; however, one skilled in the catheter arts would recognize that other polymers may be used. The OUTSIDE DIAMETER (“OD”) of the sheath  90  tubing is approximately 0.094 mm to allow the sheath  90  to pass within the accessory channel of a standard endoscope, such as a duodescope. The distal portion  130  of the catheter advantageously includes a taper  154  that measures approximately 4.5-5.0 Fr at the distal end  156  of the catheter. The distal end  156  includes an opening to a passageway  162  to accommodate a standard wire guide used in a biliary procedure, such as a 0.35″ TRACER® Wire Guide (Wilson-Cook Medical, Inc.). In the illustrative embodiment the wire guide passageway  162 , depicted in FIG. 3, is approximately 0.041 mm. The remaining three passageways  174 ,  178 ,  182 , which do not functionally extend to the distal end  156 , are approximately 0.022 mm, with two passageways  178 ,  182  being for the infusion of fluid (typically saline) used for manometric measurement. The third passageway  174  is adapted for carrying the cutting wire  110  that extends from proximal assembly  70  to the sphincterotome portion  102  of the distal portion  130 , where it exits the passageway  174  at a proximal opening  94  for approximately 20-30 mm, forming the cutting portion  106  of the sphincterotome, before reentering the sheath at a distal opening  122 , where it terminates. Bands  98 ,  118  such as tantalum bands, mark the exit and reentry points  94 , 122  of the cutting wire  110 , respectively. The distal band  118  further serves to secure and anchor the cutting wire  110  as it reenters the passageway  174 . Standard depth markings  114  are provided as a visual guide to aid in ablation, these being located between the distal and proximal markings  98 ,  118 . For the purposes of this application, the sphincterotome portion  102  is defined as that portion of the catheter assembly  10  that is adapted for cutting or ablating a sphincter or papilla, via electrosurgical or other means, for the purposes of facilitating the passage of materials therethrough. While the illustrative embodiment is adapted for biliary use to ablate the sphincter of Oddi, and the papilla of Vater, the present invention would include devices configured for treating other problematic sphincters, e.g., the anal sphincter.  
         [0017]    In another embodiment depicted in FIG. 4, the sheath includes an aspiration lumen  166 , such that there are a total of five passageways. The aspiration lumen  166  communicates with a third proximal connector (not illustrated) at the proximal assembly  70  which is connectable to an automatic or manual aspiration apparatus, such as a vacuum pump, syringe, etc. The aspiration apparatus can be used continually or intermittently to aspirate excess infusate delivery from the manometry recording ports  146 ,  148  to prevent overfilling of the bile and pancreatic ducts.  
         [0018]    Referring now to FIGS. 1 and 2, distal to the sphincterotome portion  102  lies the manometry data collecting portion  126  of the catheter assembly  10 . The length of the manometry data collecting portion  126  and relationship to the sphincterotome portion  102  can be variable, depending on use and preference. In the illustrative embodiment, there is 35-40 mm of catheter tubing beyond the distal opening  122  where the cutting wire  110  enters the tubing, generally a greater length than would be found in a standard sphincterotome. The manometry data collecting portion of the illustrative embodiment comprises the distal 20-25 mm of the distal portion  130  and includes a series of ten radiopaque marker bands  134 , approximately 1 mm in width, located about 2 mm apart. These markings  134  are used as a visual guide to the operator, when viewing through the endoscope, to allow the operator to make notation on the chart when each of the markings correspond to a certain relative position within the duct and sphincter. Generally, the fluid is being infused continually while the catheter is being withdrawn from the sphincter of Oddi. When the first marking becomes visible at the opening of the papilla, the operator can place a mark on the chart to indicate the relative position of the catheter. When the second mark becomes visible, a second mark is made on the chart and so forth until the fourth marking  186  at the distal most manometry recording port  148  is reached. After that port  148  has exited the papilla, there will be rapid drop as the duodenal pressure is then recorded.  
         [0019]    The first and second manometry recording ports  146 , 148  are located on the fifth  190  and fourth  186  marker bands, respectively, counting from the distal end  154 . The ports  146 ,  148  are formed by making a generally circular bore, typically about 0.02″ in diameter, through the outer wall of the sheath  90  and into the respective passageways  178 ,  182 . Just distal to each port  146 ,  148 , a plug  194 , such as short section of stainless steel wire, is placed within the passageway  178 ,  182  which lodges within, and blocks the passageway. The plug forces the infusate that is being delivered through the passageway to exit via the port, where it is encountered by tissue that supplies resistance against the column of infusate, thereby resulting in a measurable back pressure that can be detected by a transducer that is in communication with the passageway containing the infusate. One skilled in the art would understand and appreciate the principles of manometry data collection and the necessary configuration of the manometry instrumentation required to obtain an accurate assessment of the compliance of the sphincter of Oddi.  
         [0020]    Remote operation of the sphincterotome and manometry functions of the present catheter assembly  10  takes place via the proximal assembly  70 , which in the illustrative embodiment of FIG. 1, includes a handle portion  42  that comprises a standard sliding, three-ring handle having a first portion  14  with a single ring to accommodate the operator&#39;s thumb and a second portion  18 , slidable relative to the first portion  14 , that includes a pair of rings, typically to accommodate the index and middle fingers of the operator. In the illustrative handle  42 , cutting wire  110  which extends proximally from the sphincterotome portion  102  is attached inside the second, slidable portion  18  to an electrical connector  30  that is adapted such that the external end conveniently forms a male plug  26  that is received by an electrical cord  22  (sometimes called an ‘active cord’) configured for use with the particular type of sphincterotome, the cord  22  being connectable to a standard electrosurgical generator  34 , such as those manufactured by Valleylab, Inc. (Boulder, Colo.). The operator, via the generator  34 , controls whether current is applied to the catheter assembly  10 , typically using a foot pedal to electrify the cutting wire  110  and ablate tissue coming in contact with the wire. The slidable handle  14  allows tension to be placed on the cutting wire  110  as the handle  14  is retracted, thereby causing the distal portion  130  of the sheath  90  to deflect toward the wire. This permits the distal portion  130 , including both the sphincterotome portion  102  and the manometry data collecting portion  126 , to be directed with increased accuracy to the target region and better orient with the anatomy.  
         [0021]    The portion of the proximal assembly  42  configured for operation of the manometry function of the illustrative catheter assembly  10  comprises a side port assembly  74  by which communication is established with the first, second, and wire guide passageways  174 ,  178 ,  182  of the sheath  90 . A scive or opening (not shown) is established through the tubing into each of the aforementioned passageways. At the access points to the first and second passageways  178 ,  182  which communicate with the manometry recording ports  146 ,  148 , tubing  62 ,  64 , such as standard 4.5 Fr O.D. PTFE tubing, is joined at the scive and secured to the sheath. Typically, a well-known technique is used, whereby a short section of cannula (not shown) is inserted into the scive, with the tubing  62 ,  64  fitted thereover. One or more outer protective sleeves  78 , preferably including shrink tubing, are used to help secure and protect the junction of the tubing  62 ,  64  and sheath  90 , as well as the junction of the wire guide port  66  with the wire guide passageway  170 . The illustrative wire guide port  66  is configured for attachment of a stopcock for infusing contrast media, saline, or other agents. Optionally, the wire guide port  66  can include a Tuohy-Borst adaptor (possibly in combination with a stopcock) which allows the liquid agent to be injected around a wire guide as it is positioned in the wire guide passageway, such that fluid does not leak from the wire guide port. With regard to the manometry tubing  62 ,  64  first and second luer or other standard-type connectors  54 ,  58  are attached to the tubing  62 ,  64  extending from the junctions with first and second passageways  178 ,  182 , respectively. These connectors, which may be conveniently color coded, are connectable to a suitable external manometry operative assembly  46 , which typically includes an infusion pump, such as a Pneumohydraulic Capillary Infusion System available from Arndorfer Medical Specialties, Inc., Greendale, Wis., separate transducers for each recording port  146 ,  148  and a data recording unit for stationary manometry, such as a unit available from Medtronic Synectics, Shoreview, Minn. The particular components used to measure, analyze, and record manometry data are not regarded as an essential part of the present invention. One skilled in this art area should possess knowledge of available and appropriate substitutions that can be made within an exemplary system for obtaining manometry data. For example, placement of the transducers for measuring pressures within the infusate pathway can be alternatively placed within the distal portion of the sheath. As such, the associated conductor wires would extend through the sheath back to appropriate connectors located about the proximal assembly  70 .  
         [0022]    FIGS.  5 - 7  depict typical usage of the embodiment of FIG. 1 being used to diagnosis and treat SOD in a patient. FIG. 5 shows the present catheter assembly  10  being introduced into the common bile duct  200  via a standard duodescope, often after an ERCP procedure has already been performed. A standard wire guide  198  is shown extending distally from the sheath  90  which may be used to cannulate the papilla of Vater  204  and common bile duct  200 . To obtain the manometry readings within the sphincter of Oddi  208 , the distal end  154  of the sheath  90  is introduced through the papilla  204  (by tracking over the pre-existing wire guide  198  in the illustrative example) until the manometry data collecting portion  126  of the sheath  90  is completely within the common bile duct  200  and sphincter of Oddi  208 . As shown in FIG. 6, the sheath is then withdrawn while the saline is being constantly infused by the attached pump (not shown). As discussed previously, the markings  134  are used so that the notations can be made on the data chart as particular marks become visible through the endoscope. The readings are used to form a profile of the muscular compliance along the length of the sphincter of Oddi  208 . Usually, three or four passes are made with the manometry catheter in order to obtain sufficient data for analysis. The number of passes required is partially determined by the number of manometry recording ports with fewer ports requiring additional passes. The pressure readings measured within the sphincter of Oddi  208  help the physician determine if a sphincterotomy (sometimes called a papillotomy if performed by cutting from outside of the papilla into the sphincter) would be an appropriate treatment for the patient. If so, the sheath  82  is further advanced into the common bile duct  200 , as depicted in FIG. 7, until the sphincterotome portion  102  of the sheath  90  is aligned with the sphincter of Oddi  208  with the cutting portion  106  properly oriented to ablate the sphincter  208  and/or papilla  204  and enlarge the opening to the duodenum. The sphincterotomy/papillotomy is performed as it would be with a typical sphincterotome, depending on clinical factors, such as whether the sphincter needs to be pre-cut to allow better access, then the sheath  90  is pulled back into the endoscope and withdrawn from the patient. The described procedure may be varied according to physician preference and the particular needs of the patient. Ablation procedures for other anatomical sites should be based on existing practice and should be already apparent to one skilled in the particular procedure.  
         [0023]    Any other undisclosed or incidental details of the construction or composition of the various elements of the disclosed embodiment of the present invention are not believed to be critical to the achievement of the advantages of the present invention, so long as the element possess the attributes needed for them to perform as disclosed. The selection of these and other details of construction are believed to be well within the ability of one of even rudimentary skills in this area, in view of the present disclosure. Illustrative embodiments of the present invention have been described in considerable detail for the purpose of disclosing a practical, operative structure whereby the invention may be practiced advantageously. The designs described herein are intended to be exemplary only. The novel characteristics of the invention may be incorporated in other structural forms without departing from the spirit and scope of the invention. Unless otherwise indicated, all ordinary words and terms used herein shall take their customary meaning as defined in The New Shorter Oxford English Dictionary, 1993 edition. All technical terms shall take on their customary meaning as established by the appropriate technical discipline utilized by those normally skilled in that particular art area. All medical terms shall take their meaning as defined by Stedman&#39;s Medical Dictionary, 27th edition.