Method and apparatus for biliary access and stone retrieval

Endoscopes, endoscopic instruments, and methods for making and using the same. An illustrative endoscopic instrument includes a catheter that can extend through the working channel of an endoscope. The catheter may include an end effector passing region.

FIELD

The present invention relates to endoscopic medical devices and methods for making and using endoscopic medical devices. More particularly, the present invention relates to endoscopic devices that provide biliary and/or pancreatic access.

BACKGROUND

A wide variety of endoscopes, medical devices for use with endoscopes, and endoscopic procedures have been developed. Of the known endoscopes, medical devices for use with endoscopes, and endoscopic procedures, each has certain advantages and disadvantages. There is an ongoing need to provide alternative endoscopic devices as well as methods for making and using endoscopic devices.

SUMMARY

The disclosure provides design, material, and manufacturing method alternatives for endoscopes, medical devices for use with endoscopes, and for methods for making and using endoscopes and endoscopic devices. An example of a medical device for use with an endoscope is a catheter having a longitudinal slit, slot, or line of weakness formed therein. Some additional details regarding these and other embodiments are described in more detail below.

DETAILED DESCRIPTION

FIGS. 1 and 1Aillustrate an example endoscopic instrument assembly10. Assembly10includes an endoscope12having a shaft portion14and a handle portion16. Shaft portion14includes a distal end region18and a distal port20where one or more medical devices (e.g., a guidewire or shaft22and/or a catheter24) disposed within a working channel29formed in shaft portion14with medical devices are capable of extending out from. Shaft22may include an end effector26disposed at a distal end region thereof. An elevator36can be disposed adjacent port20that, when actuated, alters the angle at which catheter24(and/or shaft22) exits port20. Handle portion16includes one or more openings and/or a control region28where instruments (e.g., endoscopic instruments, guidewires, catheters, and the like) can gain access to working channel29and be extended through shaft portion14and out from port20or where fluids (e.g., contrast media, drugs, etc.) can be passed into a target site within a body lumen. Control region28may also include a control wire (not shown) for controlling elevator36.

A vast number of endoscopic devices exist that have a wide variety of applications. At least some of these applications include advancing the endoscopic device along the biliary and/or pancreatic tract. When accessing the biliary and/or pancreatic tract, the position of the endoscopic device and/or the position of a particular medical device disposed in the endoscopic device may be important. This is because it may be challenging to precisely navigate the endoscope or endoscopic instrument through the anatomy of a patient. For example, when an endoscopic device is used for biliary applications, it may be difficult to advance the endoscopic device through the papilla of Vater and into the bile duct. Moreover, once a device is successfully advanced through the papilla of Vater, subtle movement of the device can result in the device being withdrawn back out from the papilla of Vater, necessitating another round of skilled maneuvering in order to proceed with the intervention.

When the endoscopic device is used to remove an object from a body lumen, for example a stone from the biliary tract, the potential for the endoscope and/or endoscopic device to lose its position can be further complicated. This is because stone removal may include advancing a stone removing device through a catheter disposed in the working channel of the endoscope and the withdrawing of the stone. Typically, it is the catheter that is precisely positioned and that maintains the position of the endoscopic instrument assembly, e.g., at or through the papilla of Vater. Because stones typically are too large to be retracted directly into the catheter itself, it is often necessary to remove the catheter along with the stone so that the stone can be passed from the biliary tract into the digestive tract, where it can be easily eliminated through natural or other interventional processes. This may cause the catheter and, ultimately, the endoscope to lose its desirable position in the biliary tract. A similar conundrum can be appreciated at other body lumens such as along the pancreatic tract.

FIG. 2depicts catheter24(that is configured to address at least some of the issues identified above) disposed in a body lumen30. In some embodiments, body lumen30is adjacent the biliary tract34. For example, catheter24may extend through the duodenum31, pass through the papilla of Vater32, and into the biliary tract34(e.g., adjacent the bile duct) to a position adjacent an object38(e.g., a stone) disposed in the biliary tract34. In other embodiments, body lumen30may be along the pancreatic tract and adjacent the pancreatic duct. Of course, catheter24can likewise be positioned in any number of alternative body lumens30without departing from the spirit of the invention.

Shaft22is disposed in a lumen46(best seen inFIG. 3) formed in catheter24. As mentioned above, shaft22may be provided with an end effector26. End effector26may take a number of different forms. For example, end effector26may include a basket. The basket may have a loop or loop portion40and a basket portion42. A number of alternative end effectors26are contemplated that may be utilized for a number of different interventions. Some of these alternative end effectors26may include loop portion40alone (i.e., without basket portion42). Other end effectors26may include snares, needles, graspers, barbed graspers, forceps, hooks, laparoscopic instruments, arthroscopic instruments, cutting devices, lasers, and the like, or any other suitable device. In general, end effector26is configured to engage and/or remove object38. In at least some embodiments, the shape, form, and/or configuration of end effector26is designed so that it is complementary to catheter24. This may allow the combination of catheter24and end effector26to have a relatively low profile when catheter24is withdrawn, which may ease withdrawal of these devices.

To remove object38from body lumen30, shaft22is advanced through lumen46to a position adjacent object38. When positioned, end effector26can be engaged with object38. In embodiments where end effector26is a loop or a basket, this may include capturing object38within end effector26. Once engaged, shaft22can be proximally retracted so as to remove object38from the biliary tract34.

In order for end effector26to be more easily engaged with stone38, a secondary medical device39(e.g., a camera or optical device, grasper, holder, etc.) may be advanced through a secondary lumen48(best seen inFIG. 3) formed in catheter24. In at least some embodiments, medical device39is an optical catheter that includes a visualization system capable of visualizing the target region within body lumen30. Optical catheter39may extend proximally back to, for example, handle portion16of endoscope12where it may be connected to a suitable visualization monitor (not shown) so that a clinician may visualize the target region.

As described above, it may be desirable to hold or maintain the position of catheter24when it is positioned, for example, near or through the papilla of Vater32. For the reasons set forth above, this may be complicated when catheter24is utilized to remove object38, for example a stone, from body lumen30. In order to improve the ability of catheter24(and/or endoscope12) to hold its position, catheter24is provided with a longitudinal end effector passing region44that is formed therein.

End effector passing region44may take a number of different forms. For example, end effector passing region44may take the form of a slit formed through the wall of catheter24as depicted inFIG. 3. A slit is understood to be an opening that formed in the wall of catheter24such the cut ends are still in close proximity and/or contact with one another. End effector passing region44may extend along at least a portion of catheter24for any suitable distance. For example, end effector passing region44may extend from a distal end45of catheter24in the proximal direction about 1 centimeter to about 30 centimeters or more (including up to the full the length of catheter24). In at least some embodiments, end effector passing region44extends a suitable length so that end effector26can be retracted therethrough from a position adjacent the biliary tract34to a position within the duodenum31.

Alternatively, end effector passing region44may comprise a slot formed in the wall of catheter24′ (that is otherwise the same in form and function as catheter24) as depicted inFIG. 3A. A slot (marked inFIG. 3Aby reference number44′) is understood to be a channel or opening formed in the wall of catheter24′. The outward appearance of slot44′ is that portion of catheter where a piece of the wall is removed. Just like what is described above, slot44′ may extend from a distal end45of catheter24′ in the proximal direction about 1 centimeter to about 30 centimeters or more (including up to the full the length of catheter24′).

In still other embodiments, end effector passing region44may take the form of a horizontal line of weakness formed in catheter24″ (that is otherwise the same in form and function as catheters24/24′) as shown inFIG. 3B. A horizontal line of weakness (marked inFIG. 3Bby reference number44″) is understood to be a closed perforation or other region where the wall of catheter24″ that is weakened, thereby allowing shaft22to relatively easily “tear through”. Horizontal line of weakness44″ may be desirable, for example, because it allows contrast media to be infused through catheter24″ to the target region because the wall of catheter24″ remains essentially closed prior to being torn through. In some embodiments, horizontal line of weakness44″ can be created by placing a weaker polymeric material at the desired location for end effector passing region44. Alternatively, horizontal line of weakness44″ may be defined by a mechanical mechanism or interlock (e.g., similar to the interlocking “zipper” on a ZIPLOC® or other zipper-type of bag), or any other suitable means. Just like what is described above, horizontal line of weakness44″ may extend from a distal end45of catheter24″ in the proximal direction about 1 centimeter to about 30 centimeters or more (including up to the full the length of catheter24″).

FIG. 3Cillustrates that at least some embodiments of catheter24include an enlarged opening43adjacent to end effector passing region (marked generically inFIG. 3Cby reference number44′″ to indicate that any of the previously-described end effector passing regions may include this feature). Enlarged opening43may function as a “funnel” or other type of directional guide that allows shaft22and/or end effector26to be more easily retracted therein in order to facilitate removal of catheter24and/or end effector26. In at least some embodiments, opening43may include or be disposed adjacent an indentation or concave area of catheter24so as to further facilitate this “funneling” function. Opening43may be utilized in combination with any of the other end effector passing regions described herein. Indeed, any combination of slits44, slots44′, and horizontal lines of weakness44″ can be used with or without opening43without departing from the spirit of the invention.

Regardless of which form it takes, end effector passing region44allows shaft22to be retracted back along catheter24while end effector26is engaged with object38. Turning now toFIG. 4, here it can be seen that with end effector26engaged with object38, shaft22can be proximally retracted so that object38is adjacent to distal end region45of catheter24. Because of the design of end effector passing region44, shaft22may be further retracted as shown inFIG. 5. In doing so, end effector26(along with object38) can follow end effector passing region44proximally. This may include end effector26being disposed along the outer wall of catheter24while being proximally retracted. This allows object38to be proximally retracted along catheter24from a position within the biliary tract34, through the papilla of Vater32, and into the duodenum31while the position of catheter24is maintained. Once in the duodenum31, end effector26can be disengaged with object38, thereby allowing object38to be passed through the digestive tract or otherwise removed.

Other than having end effector passing region44, catheter24may be similar in form and function to a number of typical catheters that are suitable for use with an endoscope. For example, catheter24may be sized to fit within the working channel and have a length suitable to extend through the working channel and through the body lumen30to an area of interest. For example, catheter24may have an outside diameter of about 0.008 to about 0.50 inches. Lumens46/48may be sized to accommodate devices having an outside diameter of about 0.008 to about 0.50 inches.

In at least some embodiments, the materials chosen to construct catheter24contribute to at least some of the desirable properties of catheter24. For example, catheter24may include metals, metal alloys, polymers, metal-polymer composites, and the like. Metals and metal alloys may desirably impact the pushability and/or the ability for catheter24to transmit torque. Some examples of suitable metals and metal alloys include stainless steel, such as 304V, 304L, and 316LV stainless steel; mild steel; nickel-titanium alloy such as linear-elastic and/or super-elastic nitinol; other nickel alloys such as nickel-chromium-molybdenum alloys (e.g., UNS: NO6625 such as INCONEL® 625, UNS: NO6022 such as HASTELLOY® C-22, UNS: N10276 such as HASTELLOY® C276®, other HASTELLOY® alloys, and the like), nickel-copper alloys (e.g., UNS: N04400 such as MONEL® 400, NICKELVAC® 400, NICORROS® 400, and the like), nickel-cobalt-chromium-molybdenum alloys (e.g., UNS: R30035 such as MP35-N® and the like), nickel-molybdenum alloys (e.g., UNS: N10665 such as HASTELLOY® ALLOY B2®, other nickel-chromium alloys, other nickel-molybdenum alloys, other nickel-cobalt alloys, other nickel-iron alloys, other nickel-copper alloys, other nickel-tungsten or tungsten alloys, and the like; cobalt-chromium alloys; cobalt-chromium-molybdenum alloys (e.g., UNS: R30003 such as ELGILOY®, PHYNOX®, and the like); platinum enriched stainless steel; combinations thereof; and the like; or any other suitable material. Depending on where along catheter24that the metal is used, some embodiments of catheter24include slits44, slots44′, horizontal lines of weakness44″, and the like that are formed in metallic materials.

In some embodiments, a coating, for example a lubricious, a hydrophilic, a protective, or other type of coating may be applied over portions or all of catheter24, or other portions of assembly10. Hydrophobic coatings such as fluoropolymers provide a dry lubricity which improves guidewire handling and device exchanges. Lubricious coatings improve steerability and improve lesion crossing capability. Suitable lubricious polymers are well known in the art and may include silicone and the like, hydrophilic polymers such as high-density polyethylene (HDPE), polytetrafluoroethylene (PTFE), polyarylene oxides, polyvinylpyrolidones, polyvinylalcohols, hydroxy alkyl cellulosics, algins, saccharides, caprolactones, and the like, and mixtures and combinations thereof. Hydrophilic polymers may be blended among themselves or with formulated amounts of water insoluble compounds (including some polymers) to yield coatings with suitable lubricity, bonding, and solubility. Some other examples of such coatings and materials and methods used to create such coatings can be found in U.S. Pat. Nos. 6,139,510 and 5,772,609, which are incorporated herein by reference.

The sheath or polymeric layer may be formed, for example, by coating, by extrusion, co-extrusion, interrupted layer co-extrusion (ILC), or fusing several segments end-to-end. The layer may have a uniform stiffness or a gradual reduction in stiffness from the proximal end to the distal end thereof. The gradual reduction in stiffness may be continuous as by ILC or may be stepped as by fusing together separate extruded tubular segments. The outer layer may be impregnated with a radiopaque filler material to facilitate radiographic visualization. Those skilled in the art will recognize that these materials can vary widely without deviating from the scope of the present invention.

In at least some embodiments, catheter24may include a radiopaque marker band or coil (not shown). Such structures may be made from, doped with, or otherwise include a radiopaque material. Radiopaque materials are understood to be materials capable of producing a relatively bright image on a fluoroscopy screen or another imaging technique during a medical procedure. This relatively bright image aids the user of catheter24in determining its location. Some examples of radiopaque materials can include, but are not limited to, gold, platinum, molybdenum, palladium, tantalum, tungsten or tungsten alloy, plastic material loaded with a radiopaque filler, and the like. Depending on where along catheter24that the marker is used, some embodiments of catheter24include slits44that are formed in or extend through the marker.

It should be understood that this disclosure is, in many respects, only illustrative. Changes may be made in details, particularly in matters of shape, size, and arrangement of steps without exceeding the scope of the invention. The invention's scope is, of course, defined in the language in which the appended claims are expressed.