Fluid seal for endoscope

An endoscope seal that effectively inhibits the egress of fluids from the working channel of an endoscope when an elongate device having a non-circular shaft is disposed therein. The endoscope seal includes a body portion having a proximal end adapted for insertion of an elongate device such as a rapid exchange biliary catheter, a distal end adapted for connection to the proximal end of an endoscope, a lumen extending therethrough which is adapted to receive the elongate device and to provide access to the working channel of the endoscope, and a means for conforming to the non-circular shaft of the elongate device to inhibit the flow of fluid from the working channel of the endoscope. The conforming means may, for example, comprise one or more protrusions extending radially inward in the lumen of the body portion, a sealing material such as a surgical foam that is disposed in the lumen of the body portion, or a sealing mandrel. Whether a single protrusion, a plurality of protrusions, a sealing material or a sealing mandrel is utilized, the present invention provides endoscope seals that readily seal about elongate devices having either circular or non-circular profiles.

FIELD OF THE INVENTION

The present invention general relates to endoscopic systems and procedures. More specifically, the present invention relates to seals for use in combination with an endoscope, sometimes referred to as endoscope seals or biopsy seals.

BACKGROUND OF THE INVENTION

Endoscopic procedures for treating abnormal pathologies within the alimentary canal system and biliary tree (including the biliary, hepatic, and pancreatic ducts) are increasing in number. The endoscope provides access to the general area of a desired duct using direct visualization. However, the duct itself must be navigated using a catheter in conjunction with a guidewire under fluoroscopy. A wide variety of catheters are known for treatment of such targeted anatomical regions. Examples of biliary catheters are disclosed in U.S. Pat. No. 5,397,302 to Weaver et al., U.S. Pat. No. 5,320,602 to Karpiel and U.S. Pat. No. 5,921,971 to Argo et al., the disclosures of which are hereby incorporated by reference.

Argo et al. '971 discloses a catheter for use in biliary procedures, wherein the catheter includes a shaft having a proximal end and a distal end. A guidewire lumen extends through the shaft from a proximal guidewire port located proximal of the distal end of the shaft, to a distal guidewire port located at the distal end of the shaft. The shaft may also include a slot or channel extending from a proximal end of the shaft to the proximal guidewire port. By utilizing a slot or channel, the proximal shaft portion has a non-circular profile or cross-section as best seen inFIGS. 5A and 6Aof Argo et al. '971. Catheters incorporating such a guidewire opening and channel are often referred to as rapid exchange or single operator exchange type biliary catheters. One drawback with such rapid exchange or single operator exchange biliary catheters is the inability or relative difficulty in sealing around the non-circular shaft, such that fluid (bile liquid and air) may leak out of the working channel of the endoscope around the non-circular shaft of the biliary catheter.

Conventional endoscope seals are adapted to seal about catheters having circular shafts, and generally do not effectively seal about catheters having non-circular shafts. Such conventional seals are commercially available from Olympus, Fuji and Pentax. An example of a prior art endoscope seal is disclosed in U.S. Pat. No. 4,920,953 to McGown. The endoscope seals commercially available and the endoscope seal disclosed in McGown '953 generally include a body portion having a proximal end adapted to receive an elongate device such as a biliary catheter, a distal end adapted for connection to the proximal end of the endoscope, a lumen extending through the body portion, and a membrane disposed in the lumen, wherein the membrane includes a small circular hole or aperture. The circular aperture is sized to closely fit the elongate device inserted therein such that fluids (bile and air) do not readily escape from the working channel of the endoscope.

However, it can be readily appreciated that when a biliary catheter or other elongate device having a shaft with a non-circular cross section is placed through the circular aperture, at least a portion of the aperture does not engage the non-circular shaft. Accordingly, such prior art endoscope seals do not effectively inhibit the egress of bile liquids and air exiting the working channel of the endoscope when an elongate device having a non-circular cross-section is utilized. Because rapid exchange catheters are becoming more prevalent, and because such rapid exchange catheters have a non-circular shaft cross-section, there is a significant demand for an endoscope seal that effectively seals or inhibits the egress of fluid from the working channel of an endoscope, when a device having a non-circular shaft cross-section is used therewith.

SUMMARY OF THE INVENTION

The present invention satisfies this demand by providing an endoscope seal that effectively inhibits the egress of fluid from the working channel of an endoscope when an elongate device, such as a rapid exchange biliary catheter, having a non-circular shaft is disposed therein. The seal of the present invention is also suitable for other catheters having non-circular shafts such as rapid exchange vascular catheters. In addition, some embodiments of the present invention are perfectly suitable for sealing about elongate devices having shafts with a circular profile. Accordingly, the endoscope seals of the present invention are both versatile and functional, because they effectively inhibit, or at least reduce, the egress of fluids (bile and air) from the working channel of the endoscope when an elongate device having a circular or non-circular shaft is utilized.

The endoscope seals of the present invention include a body portion having a proximal end adapted for insertion of an elongate device such as a rapid exchange type catheter, a distal end adapted for connection to the proximal end of an endoscope, a lumen extending therethrough which is adapted to receive the elongate device and to provide access to the working channel of the endoscope, and a means for conforming to the non-circular shaft of the elongate device to inhibit the flow of fluid from the working channel of the endoscope.

In a first embodiment, the conforming means may comprise a protrusion extending radially inward in the lumen of the body portion. The protrusion may comprise a geometry that mates with the non-circular shaft of the elongate device. In a second embodiment, the conforming means may comprise a plurality of protrusions extending radially inward in the lumen body portion. The plurality of protrusions may be uniformly spaced about the circumference of the lumen and may have sufficient flexibility to conform to a non-circular geometry. In a third embodiment, the conforming means may comprise a sealing material such as a surgical foam that is disposed in the lumen of the body portion or injected therein just prior to use. In a fourth embodiment, the conforming means may comprise a sealing mandrel that it is disposed in the lumen of the body portion. The sealing mandrel conforms to the non-circular geometry to define a collective circular geometry that is readily sealed by a conventional circular aperture in the body portion. Whether a single protrusion, a plurality of protrusions, a sealing material or a sealing mandrel, the present invention provides endoscope seals that readily seal about an elongate devices having either circular or non-circular profiles.

The present invention also provides a variable diameter main body portion and a compression mechanism. The variable diameter main body portion may incorporate a conventional membrane with a circular aperture or may incorporate any of the conforming means described above. The compression mechanism may be used to tighten the variable diameter body portion to compress the membrane therein around a non-circular shaft to establish a fluid seal.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following detailed description should be read with reference to the drawings in which similar elements and different drawings are numbered the same. The drawings, which are not necessarily to scale, depict illustrative embodiments and are not intended to limit the scope of the invention.

Refer now toFIG. 1Awhich illustrates a side view of an endoscope seal in accordance with the present invention. Endoscope seal10includes a main body portion100, a plus portion20and an adapter ring portion30. The details of main body portion100are discussed in more detail with reference toFIGS. 2A and 2B. Main body portions200,300,400, and500as discussed in detail with referenceFIGS. 3A-3B,FIGS. 4A-4B,FIGS. 5A-5B, andFIG. 6D, respectively, may be used in place of main body portion100.

Main body portion100includes a body112having a proximal end and a distal end. An outwardly extending flange114is connected to the distal end of the body112. An inwardly extending flange116is connected to the proximal end of the body112. As best seen inFIG. 1B, a central lumen120extends through body112, and a seal140is disposed in the lumen120. Central lumen120is sized to accommodate the shaft of elongate device such as a biliary catheter (not shown).

The plug portion20is connected to the main body portion100by a flexible arm22. The plug portion20includes a cap24, a middle portion26, and a flange28. The flexible arm22allows the plug portion20to be inserted into the proximal end of the main body portion100and seal the central lumen120in the absence of any devices inserted therein.

The adapter ring portion30is connected to the main body portion100by a flexible arm32. The adapter ring portion30includes an inwardly extending top flange36and an inwardly extending bottom flange38which together define a recess37within the ring30. Adapter ring portion30also defines a central lumen34. The flexible arm32permits the adapter ring portion30to be placed around the flange114of the main body portion100. The adapter ring portion30permits the endoscope seal10to be connected to an endoscope having a larger diameter proximal end as will be discussed in more detail hereinafter.

Refer now toFIGS. 2A and 2Bwhich illustrate the features of main body portion100in greater detail. Central lumen120includes a proximal port121, an upper cavity122, a middle cavity124, a lower cavity126, and a distal port127. The proximal port121has an inside diameter slightly less than the outside diameter of the flange28of the plug portion20. The upper cavity122is sized to accommodate the flange28of the plug portion20. With this arrangement, the flange28may be snapped through the proximal port121into the upper cavity122such that the plug portion20effectively seals the central lumen120when no devices are present therein.

Distal port127is sized to be slightly smaller than the diameter of the proximal end of the endoscope. The lower cavity126is sized to accommodate the flange of the proximal end of the endoscope (not shown). Within the arrangement, the proximal end of the endoscope may be snapped into the distal port127to connect the endoscope seal10to the endoscope and to establish fluid communication between the central lumen120and the working channel of the endoscope.

If the proximal end of the endoscope is to large for the lower cavity126and distal port127, the adapter ring portion30may be placed on the flange114. Specifically, the lumen34of the adapter ring portion30has a diameter that is slightly less than the outside diameter of the flange114. The recess37between the upper flange36and lower flange38of the adapter ring portion30is sized to accommodate the flange114leaving sufficient space to accommodate the proximal flange of the endoscope. With this arrangement, the adapter ring portion30may be snapped into place around the flange114and the proximal flange of the endoscope (not shown) may be snapped into the recess37of the adapter ring portion30. Thus, the adapter ring portion30in combination with the flange114permits the endoscope seal10to fit endoscopes of different sizes.

With this arrangement, the distal end of the main body portion100may be connected to the proximal end of the endoscope (not shown). When the main body portion100is connected to the endoscope, the central lumen120is aligned with and in fluid communication with the working channel of the endoscope. The central lumen120is sized and adapted for insertion of an elongate device such as a biliary catheter. Thus, an elongate device may be inserted into the proximal end of the main body portion100, through the lumen120, and into the working channel of the endoscope.

The middle cavity124of the central lumen120is defined by the seal mechanism140. Middle cavity124is conically shaped to facilitate easy insertion of an elongate device therein. The conically shaped cavity124tapers from a proximal aperture142to a distal aperture144. A plurality of inwardly projecting protrusions146extend from the proximal aperture142to the distal aperture144. Although eight protrusions146are illustrated, it is contemplated that virtually any member of protrusions146may be utilized. Protrusion146is uniformly spaced about the wall148defining the lumen124. The protrusions146are sufficiently flexible to conform to a non-circular shaft of an elongate device inserted therein.

For example, if the non-circular shaft illustrated inFIGS. 5A and 6Aof Argo et al. '971 was inserted into the seal mechanism140, one or more of the protrusions146would be disposed in the non-circular portion (i.e., the C-shaped channel) of the shaft, thereby effectively sealing about the non-circular shaft. Although the protrusions146may not provide a fluid-tight seal about a non-circular shaft, it is believed that any decrease in the amount of fluid (bile and air) escaping from the working channel of the endoscope is a significant improvement. Accordingly, as used herein, the term seal may refer to a fluid-tight seal or a seal which significantly inhibits the egress of fluid. The entire endoscope seal10may be made of conventional materials using conventional techniques. For example, the endoscope seal10may be formed by injection molding a flexible medical grade silicone. From the functional description provided herein, those skilled in the art will readily appreciate that the endoscope seal10may be formed from a wide variety of suitable flexible materials such as rubber, silicon or elastomer. In addition, the endoscope seal10may be made by a variety of different manufacturing methods, but injection molding is preferred.

The endoscope seal10may have an overall length on the order of 3.670 inches. The flexible arms22and32may have a thickness on the order of 0.085 inches and a width on the order of 0.20 inches. The plug portion20may have a thickness of approximately 0.255 inches and an outside diameter of approximately 0.560 inches. The flange28of the plug20may have an outside diameter of approximately 0.400 inches and a thickness of approximately 0.085 inches. The middle portion26of the plug20may have a diameter of approximately 0.320 inches and a thickness of approximately 0.085 inches.

The adapter ring portion30may have an outside diameter portion of approximately 0.780 inches, an inside diameter of approximately 0.500 inches, and a thickness of approximately 0.260 inches. The top flange36and the bottom flange38of the adaptor ring portion30may have a thickness of approximately 0.065 inches, and the recess37may be approximately 0.040 inches deep.

The main body portion100may have an overall height of approximately 0.550 inches. The body112may have a diameter of approximately 0.560 inches and a height of approximately 0.480 inches. The flange114may have an outside diameter of approximately 0.680 inches and a thickness of approximately 0.70 inches. The proximal port121may have an inside diameter tapering from approximately 0.400 inches to an approximately 0.320 inches. Similarly, the distal port127may have an inside diameter tapering from approximately 0.280 inches to approximately 0.200 inches. The upper cavity122may have a diameter of 0.400 inches and a height of approximately 0.110 inches. The lower cavity126may have a diameter of approximately 0.350 inches and a height of approximately 0.130 inches. The middle cavity124may have an inside diameter tapering from approximately 0.170 inches to approximately 0.040 inches. The individual protrusions146may be tapered from the proximal aperture142to the distal aperture144, having a width of approximately 0.020 inches tapering to approximately 0.015 inches. The protrusions146may be separated by slots, each having a width tapering from approximately 0.023 inches to approximately 0.003 inches.

Those skilled in the art will recognize that the endoscope seal10may have dimensions different than the above dimensions, which are provided for purposes of illustration only.

Refer nowFIGS. 3A and 3Bwhich illustrate body portion200in accordance with an alternative embodiment of the present invention. As mentioned previously, body portion200may be used in place of body portion100as described with reference toFIGS. 1A,1B,2A, and2B. Except as described hereinafter and except as shown in the drawings, body portion200is the same in design and function as body portion100.

Main body portion200includes a seal mechanism240. Seal mechanism240includes a single protrusion246extending radially inward. Protrusion246extends from a proximal aperture242to a distal aperture244. Protrusion246may have a wide variety of geometries, but preferably has a geometry that mates with the non-circular portion of the shaft of the elongate device inserted into the central lumen120. For example, if the non-circular shaft illustrated inFIGS. 5A and 6Aof Argo et al '971 were disposed in the central lumen120, the single protrusion246would preferably have a geometry conforming to the slot of the C-shaped channel. Those skilled in the art will recognize that other non-circular shafts may be utilized and that the protrusion246may be modified to mate with the non-circular portion thereof.

Because the single protrusions246will limit rotation of the elongate device inserted through the central lumen120, it may desirable to permit rotation of the main body portion200. This may be accomplished, for example, by providing a low-friction connection between the distal end of the main body portion200and the proximal end of the endoscope. A low-friction connection may be accomplished by a variety of means, such as by utilizing low-friction materials and lubricants.

Refer now toFIGS. 4A and 4Bwhich illustrate main body portion300in accordance with yet another embodiment of the present invention. As mentioned previously, main body portion300may be used in place of main boy portion100described with reference toFIGS. 1A,1B,2A, and2B. Except as described hereinafter and except illustrated in the drawings, main body portion300is the same in design and function as main body portion100. In this particular embodiment, main body portion300utilizes includes a seal140comprising a material having characteristics of easy penetration high-fluid absorption, and tear resistance, such as a surgical foam to seal about the non-circular shaft. Sealing material340is disposed in the upper cavity122, and to accommodate the sealing material340, the height of the upper cavity122is increased at the expense of the height of the middle cavity124. Although not shown, a liquid drainage line and reservoir may be connected to the upper cavity122to drain excess fluid (bile and air) therefrom.

The sealing material340may comprise virtually any suitable medical grade material that has easy penetration, high-fluid absorption, and tear resistance characteristics. Preferably, the sealing material comprises a closed-cell medium density surgical foam commercially available from Rynel of Maine. When a non-circular shaft of an elongate device is inserted through the sealing material340, the sealing material340tends to create a passage conforming to the profile of the non-circular shaft, thereby effective sealing about the non-circular shaft.

The sealing material340may be relatively liquid or relatively solid. For example, the sealing material340may be relatively solid such that it is suitable for molding into a wide variety of desired shapes. The sealing material340may be molded to fit in the upper cavity122and to have a pilot hole extending therethrough. Whether the sealing material340is in the form of a liquid or solid, the plug portion20may be utilized to keep the sealing material340contained in the upper cavity122prior to use.

The sealing material may alternatively comprise fibrous materials that are very compliant and fluid absorbent such as cotton or synthetic fabrics. Alternatively, the sealing material340may comprise a gel-like material to develop a very lubricious and compliant seal. The sealing material340may be cold-molded or insert-molded and a lubricant may be added to the sealing material to reduce friction and increase fluid absorption.

Refer now toFIGS. 5A and 5B, which illustrate main body portion400in accordance with yet another alternative embodiment of the present invention. Except as described hereinafter and except as illustrated in the drawings, main body portion400is the same in design and function as main body portion300described in reference toFIGS. 4A and 4B. Main body portion400includes an injectable sealing material440that may be injected into the upper cavity122just prior to use. To facilitate such injection, the body112may be provided with a thin-walled section412. A suitable injection device such as a syringe450may be used to pierce the thin-walled portion412and inject the liquid sealing material440. Sealing material440may be injected into the upper cavity122with the plug portion20inserted into the proximal end of the main body portion400to contain the sealing material440in the upper cavity122prior to use. Sealing material440has the same properties and performs the same function as sealing material340described with reference toFIGS. 4A and 4B, except sealing material440has a lower initial viscosity.

Refer now toFIGS. 6A,6B,6C, and6D which illustrate a variable diameter main body portion500and tightening ratchet600for use therewith. Except as described herein and except as shown in the drawings, variable diameter body main portion500is the same in design and function as main body portion100described with reference toFIGS. 1A,1B,2A, and2B. The body512includes a central waist portion514that facilitates compression of the lumen124at relatively low forces due to the reduced diameter of the waist514. However, it is contemplated that the compressive forces of the tightening ratchet600may be used with or without the reduced diameter waist portion514. In particular, the tightening ratchet600may be used with a constant diameter body512. By actuating tightening ratchet600disposed about the variable diameter main body portion500as illustrated inFIGS. 6C and 6D, the central cavity124reduces in diameter and seals about the non-circular shaft of the elongate device extending therethrough.

Tightening ratchet600includes a hoop610that may vary in diameter by virtue of the sliding ends612and614. Note that if a reduced diameter waist portion514is provided on the variable diameter main body portion500, the hoop610may include a conforming geometry as illustrated in FIG.6D. Tightening ratchet600further includes a plurality of teeth622that engage a lever arm630to lock the moving ends612and614of the hoop610as the diameter of the hoop610is decreased. The teeth622are disposed on a flexible arm620that is normally biased against the lever arm630but may be deflected to permit the teeth622to disengage the lever arm630, thereby permitting the ends612and614of the loop610to move and thereby increase the diameter of the hoop610. Both the flexible arm620and the lever arm630may include gripping surfaces624and632, respectively, to facilitate easy gripping of the tightening ratchet600. Those skilled in the art will recognize that there are many alternative compression mechanisms to tightening ratchet600, such as a screw-type compression clamp, a spring compression clamp, etc.

Refer now toFIGS. 7A,7B and7C which illustrate main body portion700in accordance with another embodiment of the present invention. Except as described herein and except as illustrated in the drawings, main body portion700is the same in design and function as main body portion200described with reference toFIGS. 3A and 3B. Main body portion700includes a seal mechanism740. Seal mechanism740includes a sealing mandrel746extending through the central lumen120. Sealing mandrel746may have a wide variety of cross-sectional geometries, but preferably has a geometry that mates with the non-circular portion of the shaft of the elongate device inserted into the central lumen120. For example, if the non-circular shaft illustrated inFIGS. 5A and 6Aor Argo et al. '971 were disclosed in the central lumen120, the sealing mandrel746would preferably have a geometry conforming to the slot of this C-shaped channel, as best seen in FIG.7C. The entire length of the sealing mandrel746may have a conforming geometry or only the portion of the sealing mandrel746extending from the proximal aperture742to the distal aperture744may have a conforming geometry while the remainder of the sealing mandrel746has a different cross-sectional geometry, such as a circular cross-section. Those skilled in the art will recognize that other non-circular shafts may be utilized and that the sealing mandrel746may be modified to have a cross-sectional geometry that mates with the non-circular portion thereof. Thus, with the sealing mandrel746disposed in the slot of the biliary catheter (such as biliary catheter disclosed in Argo et al. '971), the collective cross-sectional profile is essentially circular such that the circular aperture744is able to establish a fluid tight seal.