Cannulation devices for endoscopic retrograde cholangiopancreatography (ERCP)

Abstract

The cannulation device is adapted to access a patient's common bile duct (14). In some examples, the cannulation device includes a first guidewire lumen (34) extending through the elongate shaft and terminating in a first diagonal guidewire port (36), and a second guidewire lumen (38) extending through the elongate shaft and terminating in a second diagonal guidewire port (40). In some examples, the cannulation device includes an inflatable balloon (72, 80, 92) inflatable from a contracted configuration to an expanded configuration, wherein in the expanded configuration, the inflatable balloon is adapted to occlude the patient's pancreatic duct (16). In some examples, the cannulation device includes an expandable element (118, 140) expandable from a contracted configuration to an extended configuration, wherein in the contracted configuration, the expandable element is disposed within the guidewire lumen, and in the extended configuration, a portion of the expandable element extends distally from the guidewire port.

Description

[Technical Field]

[0001] The present invention relates to medical devices and methods for making and using the medical devices. More particularly, the present invention relates to cannulation devices for ERCP. [Background technology]

[0002] A wide variety of intracorporeal medical devices have been developed for medical applications, such as intravascular applications. These devices can be manufactured by any one of a variety of different manufacturing methods and used according to any one of a variety of methods. Known intracorporeal medical devices and methods for making and using them each have certain advantages and disadvantages. There remains a need to provide alternative intracorporeal medical devices and alternative methods for making and using intracorporeal medical devices. Summary of the Invention

[0003] The present invention provides design, material, manufacturing, and use alternatives for intracorporeal medical devices. One example may be a cannulation device adapted to be advanced through an endoscope to a position proximate a patient's duodenum to access the patient's common bile duct. The cannulation device includes an elongate shaft extending to an atraumatic distal tip, a first guidewire lumen extending through the elongate shaft and terminating in a first diagonal guidewire port, and a second guidewire lumen extending through the elongate shaft and terminating in a second diagonal guidewire port.

[0004] Alternatively or additionally, the first diagonal guidewire port may be adapted to direct a guidewire extending through the first guidewire lumen in a first direction relative to the atraumatic tip.

[0005] Alternatively or additionally, the second diagonal guidewire port may be adapted to guide a guidewire extending through the second guidewire lumen in a second direction relative to the atraumatic tip that is different from the first direction.

[0006] Alternatively or additionally, the atraumatic distal tip may include a tapered outer surface, the first diagonal guidewire port being located on a first portion of the tapered outer surface, and the second diagonal guidewire port being located on a second portion of the tapered outer surface that is circumferentially spaced from the first portion of the tapered outer surface.

[0007] Alternatively or additionally, the first guidewire lumen may be parallel to the second guidewire lumen within the proximal portion of the cannulation device. Alternatively or additionally, the first guidewire lumen may be radially spaced from the second guidewire lumen within a distal portion of the cannulation device.

[0008] Alternatively or additionally, the cannulation device may further include a cutting wire extending through the elongate shaft. Alternatively or additionally, the cannulation device may be adapted to be advanced through an endoscope.

[0009] Alternatively or additionally, the cannulation device may be adapted to access the patient's common bile duct from a location adjacent the patient's ampulla of Vater. Alternatively, a cannulation device may be found that is adapted to be advanced through an endoscope to a position proximate a patient's duodenum to access the patient's common bile duct. The cannulation device includes an elongate shaft extending to an atraumatic distal tip and a guidewire lumen extending through the elongate shaft, the guidewire lumen terminating in a guidewire port disposed within the atraumatic distal tip. An inflatable balloon is disposed relative to the atraumatic distal tip, the inflatable balloon being inflatable from a deflated configuration to an expanded configuration, the inflatable balloon being adapted to occlude the patient's pancreatic duct. An inflation lumen extends through the elongate shaft and is fluidly coupled to the inflatable balloon.

[0010] Alternatively or additionally, the inflatable balloon may be further adapted, upon inflation, to push the atraumatic distal tip away from the patient's pancreatic duct and towards the patient's common bile duct, thereby assisting in aligning the guidewire port with the common bile duct.

[0011] Alternatively or additionally, the inflatable balloon may be positioned along the side of the atraumatic distal tip. Alternatively or additionally, the inflatable balloon may form a portion of the atraumatic distal tip when the inflatable balloon is in a deflated configuration.

[0012] Alternatively or additionally, the cannulation device may be adapted to access the patient's common bile duct from a location adjacent the patient's ampulla of Vater. Alternatively, a cannulation device may be found that is adapted to be advanced through an endoscope to a position proximate a patient's duodenum to access the patient's common bile duct. The cannulation device includes an elongate shaft extending to an atraumatic distal tip and a guidewire lumen extending through the elongate shaft, the guidewire lumen terminating in a guidewire port disposed within the atraumatic distal tip. An expandable element is disposed within the guidewire lumen. The expandable element is expandable from a contracted configuration to an extended configuration, wherein the expandable element is disposed within the guidewire lumen in the contracted configuration and wherein a portion of the expandable element extends distally from the guidewire port in the extended configuration. The expandable element is adapted to allow a guidewire to extend therethrough.

[0013] Alternatively or additionally, the expandable element may be adapted to occlude the patient's pancreatic duct. Alternatively or additionally, the cannulation device may be adapted to access the patient's common bile duct from a location adjacent the patient's ampulla of Vater.

[0014] Alternatively or additionally, the expandable element may comprise an eversion-type soft robot. Alternatively or additionally, the expandable element may include an inverted polymeric sheath.

[0015] Alternatively or additionally, an end of the expandable element may be fixed relative to the distal end of the cannulation device. The above summary of some embodiments is not intended to describe each disclosed embodiment or every implementation of the present invention, although the following figures and detailed description more particularly exemplify these embodiments. [Brief explanation of the drawings]

[0016] The present invention will be more fully understood upon consideration of the following detailed description of various embodiments of the invention in conjunction with the accompanying drawings. [Figure 1] Schematic diagram of some of the anatomical structures proximal to the duodenum and ampulla of Vater. [Figure 2] 1 is a schematic diagram of a portion of an exemplary cannulation device. [Figure 3] 1 is a perspective view of a portion of an exemplary cannulation device. [Figure 4] FIG. 4 is a first end view of a portion of the exemplary cannulation device shown in FIG. 3. [Figure 5] FIG. 4 is a second end view of a portion of the exemplary cannulation device shown in FIG. 3. [Figure 6] 1 is a schematic diagram of an exemplary cannulation device positioned adjacent to the ampulla of Vater. [Figure 7] 1 is a schematic diagram of an exemplary cannulation device positioned adjacent to the ampulla of Vater. [Figure 8] 1 is a schematic diagram of an exemplary cannulation device with an inflatable balloon shown in a deflated configuration. [Figure 9] 9 is a schematic diagram of the exemplary cannulation device of FIG. 8, with the inflatable balloon shown in an inflated configuration. [Figure 10] FIG. 1 is a side view of an exemplary cannulation device including an inflatable balloon shown in a deflated configuration. [Figure 11] 11 is a side view of the exemplary cannulation device of FIG. 10 with the inflatable balloon shown in an inflated configuration. [Figure 12] 11 is a schematic diagram of the exemplary cannulation device of FIG. 10 with the inflatable balloon in a deflated configuration positioned within the anatomical structure. [Figure 13] 11 is a schematic diagram of the exemplary cannulation device of FIG. 10 with the inflatable balloon in an inflated configuration positioned within the anatomical structure. [Figure 14]1 is a schematic diagram of an exemplary cannulation device with an expandable element shown in a contracted configuration. [Figure 15] 15 is a schematic diagram of a portion of the exemplary cannulation device of FIG. 14. [Figure 16] 15 is a schematic diagram of the exemplary cannulation device of FIG. 14 with the expandable element shown in an extended configuration. [Figure 17] 1 is a perspective view of a portion of an exemplary cannulation device. [Figure 18] 18 is a schematic diagram of the exemplary cannulation device of FIG. 17, with the expandable element in a contracted configuration positioned within the anatomical structure. [Figure 19] 18 is a schematic diagram of the exemplary cannulation device of FIG. 17 with the expandable element in the extended configuration positioned within the anatomical structure.

[0017] The invention is susceptible to various modifications and alternative forms, specifics of which have been shown by way of example in the drawings and will be described in detail. It is to be understood, however, that the invention is not limited to the particular embodiments described. On the contrary, it is intended to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. DETAILED DESCRIPTION OF THE INVENTION

[0018] For the following defined terms, these definitions shall be applied unless a different definition is given in the claims or elsewhere in this specification. All numerical values, whether explicitly stated or not, are assumed herein to be modified by the term "about." In general, the term "about" refers to a range of numbers that one of ordinary skill in the art would consider equivalent to the recited value (i.e., having the same function or result). In many instances, the term "about" may include numbers that are rounded to the nearest significant figure.

[0019] The recitation of numerical ranges by endpoints includes all numbers within that range (eg, 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5). As used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the content clearly dictates otherwise. As used in this specification and the appended claims, the term "or" is generally used in its sense including "and / or" unless the content clearly dictates otherwise.

[0020] The following detailed description should be read with reference to the drawings, in which like elements in 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.

[0021] Endoscopic Retrograde Cholangiopancreatography (ERCP) is a procedure that utilizes both endoscopic and fluoroscopic techniques to diagnose and treat problems occurring in the common bile and pancreatic ducts. Endoscopic and fluoroscopic visualization of these ducts requires access through the ampulla of Vater, and proper location of the papilla is important for successful cannulation. Because multiple cannulations of the pancreatic duct can lead to pancreatitis, it is desirable to limit or even prevent multiple cannulations of the pancreatic duct. In some cases, anatomical features of the papilla or periampullary diverticulum, inflammation, and adenomas may further complicate attempts to successfully cannulate the common bile duct without irritating the pancreatic duct.

[0022] FIG. 1 is a schematic diagram of a generalized anatomical structure 10. As shown, the anatomical structure 10 includes a portion of the duodenum 12. A common bile duct (CBD) 14 and a pancreatic duct (PD) 16 connect to the duodenum 12 at the ampulla of Vater 18. As shown, one or more gallstones 20 are located within the CBD 14. An endoscopic retrograde cholangiopancreatography (ERCP) can be performed to access the CBD 14 for the purpose of removing or breaking up the one or more gallstones 20. Performing an ERCP involves accessing the CBD 14 through the ampulla of Vater 18. As shown in FIG. 1, this can mean passing at a substantial angle relative to a location within the duodenum 12. This substantial angle can contribute to the difficulty of accessing the CBD 14 instead of accessing the PD 16. As mentioned, repeated cannulation of the PD 16 can lead to potential complications.

[0023] An endoscope 22 is shown positioned within the duodenum 12. A guidewire 24 is shown exiting the endoscope 22, passing through the ampulla of Vater 18, and entering the CBD 14. Figures 2-20 provide examples of cannulation devices that can be advanced through the endoscope 22 and used to help properly guide the guidewire 24 into the CBD 14 without repeated cannulation of the PD 16. Additionally, examples of the cannulation device in use are provided.

[0024] 2 is a schematic diagram of an exemplary cannulation device 26. The exemplary cannulation device 26 includes an elongate shaft 28 extending from a proximal portion 30 of the cannulation device 26 to a distal portion 32 of the cannulation device 26. In some cases, the cannulation device 26 includes a first guidewire lumen 34 extending through the elongate shaft 28 and terminating in a first diagonal guidewire port 36. A second guidewire lumen 38 extends through the elongate shaft 28 and terminates in a second diagonal guidewire port 40. The cannulation device 26 includes an atraumatic distal tip 42. In some cases, the first diagonal guidewire port 36 may be interpreted as being oblique, for example, because the first guidewire port 36 is neither parallel nor perpendicular to the first guidewire lumen 34. The second diagonal guidewire port 40 may be interpreted as being oblique because the second guidewire port 40 is neither parallel nor perpendicular to the second guidewire lumen 38. In some cases, the relative angle between first diagonal guidewire port 36 and second diagonal guidewire port 40 may be determined at least in part by the angle through which tapered outer surface 44 extends.

[0025] In some cases, the first diagonal guidewire port 36 and the second diagonal guidewire port 40 are both disposed within the atraumatic distal tip 42. The atraumatic distal tip 42 may be interpreted as having a tapered outer surface 44, with the first diagonal guidewire port 36 disposed on a first portion of the tapered outer surface 44 and the second diagonal guidewire port 40 disposed on a second portion of the tapered outer surface 44 that is circumferentially spaced from the first portion of the tapered outer surface 44. In some cases, at least a portion of the atraumatic distal tip 42 may be interpreted as having a frusto-conical or even conical shape.

[0026] A first guidewire 46 is shown extending through first guidewire lumen 34 and out first diagonal guidewire port 36, and a second guidewire 48 is shown extending through second guidewire lumen 38 and out second diagonal guidewire port 40. As shown, first guidewire 46 extends out of cannulation device 26 in a first direction indicated by arrow 50, while second guidewire 48 extends out of cannulation device 26 in a second direction indicated by arrow 52. It will be appreciated that depending on the particular direction cannulation device 26 is oriented within duodenum 12, one of first diagonal guidewire port 36 and second diagonal guidewire port 40 may be more closely aligned with CBD 14, while the other of first diagonal guidewire port 36 and second diagonal guidewire port 40 may be more closely aligned with PD 16.

[0027] In use, a physician or other professional would advance a guidewire through one of the guidewire lumens 34 and 38. As an example, assume the physician or other professional advances a first guidewire 46 through the first guidewire lumen 34 and out the first diagonal guidewire port 36. While observing under fluoroscopy, the physician or other professional could ascertain whether the first guidewire 46 has cannulated into the CBD 14 or the PD 16. Once it is determined that the first guidewire 46 has been successfully cannulated into the CBD 14, the second guidewire 48 is not used and the physician or other professional can continue with the ERCP procedure.

[0028] However, if the physician or other professional determines that the first guidewire 46 has cannulated the PD 16, the first guidewire 46 would be left in place while advancing the second guidewire 48 through the second guidewire lumen 38 and out the second diagonal guidewire port 40. Because the first guidewire 46 is positioned within the PD 16, it means that the second diagonal guidewire port 40 can be more closely aligned with the CBD 14. Furthermore, positioning the first guidewire 46 within the PD 16 means that it would be much more difficult to accidentally advance the second guidewire 48 into the PD 16 because the first guidewire 46 is already there. Therefore, advancing the second guidewire 48 through the second guidewire lumen 38 and out the second diagonal guidewire port 40 should successfully cannulate the CBD 14. Once the CBD 14 has been successfully cannulated, the first guidewire 48 can be withdrawn proximally from the PD 16, and the physician or other professional can continue with the ERCP procedure. In some cases, the cannulation device 26 may be formed from any of a variety of polymers, including, but not limited to, nylon, HDPE (high density polyethylene), PEBAX®, Arnitel®, Vestamid®, Grilamid®, or a combination of polymers. In some cases, the cannulation device 26 may be a cutting wire or cauterization wire 54. The wire component may include, for example, SS316LVM, nitinol, platinum, or titanium.

[0029] Figure 3 is a perspective view of a distal portion of an exemplary cannulation device 56, which may be construed as an embodiment of cannulation device 26. Figure 4 is a first end view of cannulation device 56 showing the proximal end of cannulation device 56, and Figure 5 is a second end view of cannulation device 56 showing the distal end of cannulation device 56. Cannulation device 56 includes an elongate shaft 58 extending to an atraumatic tip 60. Elongate shaft 58 includes a first guidewire lumen 62 and a second guidewire lumen 64. First guidewire lumen 62 terminates in a first diagonal guidewire port 66, and second guidewire lumen 64 terminates in a second diagonal guidewire port 68. In some cases, the first and second guidewire lumens 62, 64 may be considered parallel to one another as they extend through the elongate shaft 58, and the first and second guidewire lumens 62, 64 may be considered radially separated from one another within the atraumatic tip 60. In some cases, the atraumatic tip 60 may be considered to be located at the distal end of the cannulation device 56, with the elongate shaft 58 extending proximally therefrom. In some cases, the cannulation device 56 may be formed from any of a variety of polymers, including, but not limited to, nylon, HDPE (high density polyethylene), PEBAX®, Arnitel®, Vestamid®, Grilamid®, or combinations of polymers. The wire components may include, for example, SS316LVM, nitinol, platinum, or titanium.

[0030] In some cases, instead of being configured to accommodate two guidewires extending through two separate guidewire lumens, the cannulation device may instead employ an inflatable balloon to increase the likelihood that a single guidewire advanced through the cannulation device will successfully cannulate the CBD 14 rather than the PD 16. Figures 6 through 13 provide examples of cannulation devices employing inflatable balloons.

[0031] FIG. 6 is a schematic diagram of an exemplary cannulation device 70 shown positioned within the ampulla of Vater 18. The cannulation device 70 includes an inflatable balloon 72 (shown in an inflated configuration) positioned to block access to the PD 16. As a result, the CBD 14 can be easily cannulated with a guidewire 74 exiting the atraumatic tip 76. Avoiding cannulation of the PD 16, particularly multiple times while attempting to cannulate the CBD 14, provides improved results. In some cases, the cannulation device 70 may be formed from any of a variety of polymers, including, but not limited to, nylon, HDPE (high-density polyethylene), PEBAX®, Arnitel®, Vestamid®, Grilamid®, or combinations of polymers. The wire component may include, for example, SS316LVM, nitinol, platinum, or titanium.

[0032] FIG. 7 is a schematic diagram of an exemplary cannulation device 78 shown positioned within the ampulla of Vater 18. The cannulation device 78 includes an inflatable balloon 80 (shown in an inflated configuration) positioned to block access to the PD 16. The inflatable balloon 80 is adapted to simply block access to the PD 16, rather than extending into the PD 16 (as does the inflatable balloon 72). As a result, the guidewire 74 exiting the cannulation device 78 can easily cannulate the CBD 14. Avoiding cannulating the PD 16, particularly multiple times while attempting to cannulate the CBD 14, can provide improved results. In some cases, the cannulation device 78 may be formed from any of a variety of polymers, including, but not limited to, nylon, HDPE (high-density polyethylene), PEBAX®, Arnitel®, Vestamid®, Grilamid®, or a combination of polymers. The inflatable balloon 80 may be formed from any medical grade elastomer, including but not limited to silicone or thermoplastic elastomers, etc. The wire components may include, for example, SS316LVM, Nitinol, platinum, or titanium.

[0033] FIG. 8 is a schematic illustration of an exemplary cannulation device 82 having an inflatable balloon shown in a deflated configuration, while FIG. 9 is a schematic illustration of an exemplary cannulation device 82 with an inflatable balloon shown in an inflated configuration. Cannulation device 82 includes an elongate shaft 84 extending distally to an atraumatic distal tip 86. A guidewire lumen 88 extends through elongate shaft 84 and through the atraumatic distal tip. In some cases, a guidewire 90 may extend through guidewire lumen 88, as shown in FIG. 9. Cannulation device 82 includes an inflatable balloon 92 and an inflation lumen 94 extending through elongate shaft 84 and fluidly coupled to the interior of inflatable balloon 92.

[0034] In use, a physician or other professional would move cannulation device 82 into position and advance guidewire 90 through guidewire lumen 88. Using fluoroscopic observation, the physician or other professional would be able to determine whether guidewire 90 has cannulated into CBD 14 or PD 16. Once it is determined that guidewire 90 has been successfully cannulated into CBD 14, the physician or other professional may continue with the ERCP procedure.

[0035] However, if the physician or other professional determines that the PD 16 has instead been cannulated, the physician or other professional will withdraw the guidewire 90 and inflate the inflatable balloon 82. Because the inflatable balloon 82 (when inflated) blocks access to the PD 16, the physician or other professional can again advance the guidewire 90, which is then successfully cannulated into the CBD 14. In some cases, the physician or other professional may instead begin the procedure by inflating the inflatable balloon 92, thereby blocking access to the PD 16 and thus protecting it from cannulation. In some cases, the cannulation device 82 may be formed from any of a variety of polymers, including, but not limited to, nylon, polyurethane, HDPE (high-density polyethylene), PEBAX®, Arnitel®, Vestamid®, Grilamid®, or combinations of polymers. The inflatable balloon 82 may be formed from any medical-grade elastomer, including, but not limited to, silicone or a thermoplastic elastomer.

[0036] FIG. 10 is a side view of an exemplary cannulation device 96, which may be construed as an embodiment of cannulation device 82. The exemplary cannulation device 96 includes an elongate shaft 98 extending to an atraumatic distal tip 100. The atraumatic distal tip 100 includes an inflatable balloon 102. FIG. 10 shows the inflatable balloon 102 in a deflated configuration. FIG. 11 is a side view of the cannulation device 96, showing the inflatable balloon 102 in an inflated configuration. It will be appreciated that the inflatable balloon 102, when inflated, helps to block access to the PD 16. The inflatable balloon 102, when inflated, also helps to steer the guidewire port 104 away from the PD 16 and toward the CBD 14, particularly once the cannulation device 96 is properly positioned.

[0037] FIG. 12 is a schematic diagram of a cannulation device 96 positioned within the ampulla of Vater 18. As shown, the cannulation device 96 further includes an elongate member 106 extending proximally from the elongate shaft 98. In some cases, the elongate member 106 may be construed as an extension of the elongate shaft 98, for example. The elongate member 106 may be integrally formed with the elongate shaft 98. FIG. 13 shows the cannulation device 96 positioned within the ampulla of Vater 18, with the inflatable balloon 102 inflated. As a result, the PD 16 is blocked and a guidewire 108 extending through the cannulation device 96 can successfully reach the CBD 14. In some cases, the cannulation device 96 may be formed from any of a variety of polymers, including, but not limited to, nylon, polyurethane, HDPE (high density polyethylene), PEBAX®, Arnitel®, Vestamid®, Grilamid®, or a combination of polymers.

[0038] In some cases, the cannulation device may utilize an expandable element, including but not limited to an eversion-type soft robot, to increase the likelihood that a single guidewire advanced through the cannulation device will successfully cannulate the CBD 14 rather than the PD 16. Figures 14 through 19 provide examples of cannulation devices utilizing an expandable element.

[0039] 14 and 15 are schematic diagrams of an exemplary cannulation device 110. The exemplary cannulation device 110 includes an elongate shaft 112 that extends to an atraumatic distal tip 114. The cannulation device 110 includes a lumen 116 that extends through the elongate shaft 112 and the atraumatic distal tip 114. The lumen 116 is adapted to accommodate a guidewire (not shown). The lumen 116 is also adapted to accommodate an expandable element 118 that is positioned within the lumen 116. In some cases, the expandable element 118 is itself adapted to accommodate a guidewire that extends therethrough.

[0040] In some cases, the expandable element 118 may be fixed relative to the lumen 116 at point 120. The expandable element 118 may be movable between a retracted configuration, as seen in FIG. 14, for example, and an extended configuration, as partially shown in FIG. 15. In the retracted configuration, the expandable element 118 extends proximally from the attachment point 120 within the lumen 116. To move the expandable element 118 from its retracted configuration to its extended configuration, fluid may be advanced through the actuation lumen 122, causing the expandable element 118 to begin inverting, thereby extending itself. FIG. 16 shows the cannulation device 110 with the expandable element 118 in the extended configuration. As shown, the expandable element 118 defines a lumen 124 extending therethrough. The lumen 124 is adapted to accommodate a guidewire 126. In some cases, cannulation device 110 may be formed from any of a variety of polymers, including, but not limited to, nylon, polyurethane, HDPE (high density polyethylene), PEBAX®, Arnitel®, Vestamid®, Grilamid®, or a combination of polymers. Expandable element 118 may be formed from any medical grade elastomer, including, but not limited to, silicone or a thermoplastic elastomer, nylon, Pebax®, Grilamid®, or a suitable combination of polymers.

[0041] 17 is a perspective view of an exemplary cannulation device 128, which may be construed as an embodiment of cannulation device 110. Cannulation device 128 includes an elongate shaft 130 extending distally to an atraumatic distal tip 132. A lumen 134 extends through elongate shaft 130 and atraumatic distal tip 132 and is adapted to accommodate both a guidewire (not shown in FIG. 17 ) and an expandable element 136 disposed within lumen 134 (when expandable element 136 is in a contracted configuration).

[0042] 18 and 19 are schematic diagrams of the cannulation device 128 positioned within the ampulla of Vater 18. In FIG. 18, the expandable element 136 is shown in a retracted configuration. In FIG. 19, the expandable element 136 is shown in an extended configuration. In use, a physician or other professional would move the cannulation device 128 to a position (e.g., as shown in FIG. 18) and advance the guidewire 138 through the lumen 134. While viewing under fluoroscopy, the physician or other professional would be able to ascertain whether the guidewire 138 has cannulated into the CBD 14 or the PD 16. Once it is determined that the guidewire 138 has been successfully cannulated into the CBD 14, the physician or other professional may continue with the ERCP procedure.

[0043] However, if the physician or other professional determines that the PD 16 has instead been cannulated, the physician or other professional would withdraw the guidewire 138 and expand the expandable element 136 to its extended configuration, such as by adding inflation fluid, so that the expandable element 136 extends into the CBD 14 (as shown in FIG. 19 ). The physician or other professional would then extend the guidewire 138 through the cannulation device 128 and through the expandable element 136. Because the expandable element 136 now includes an extension portion 140 that extends directly into the CBD 14, there is no chance that the guidewire 138 will accidentally cannulate the PD 16 instead of the CBD 14. In some cases, the cannulation device 128 may be formed from any of a variety of polymers, including, but not limited to, nylon, polyurethane, HDPE (high density polyethylene), PEBAX®, Arnitel®, Vestamid®, Grilamid®, or a combination of polymers. The expandable element 136 may be formed from any medical grade elastomer, including but not limited to silicone or thermoplastic elastomers, nylon, Pebax®, Grilamid®, or any suitable combination of polymers.

[0044] Materials that can be used for the various components of cannulation devices may include materials commonly associated with medical devices. The various components of the cannulation devices described herein may be made from metals, metal alloys, polymers (some examples of which are disclosed below), metal-polymer composites, combinations thereof, etc., or any other suitable material. Some examples of suitable materials and metal alloys include stainless steels, such as 304V stainless steel, 304L stainless steel, 316LV stainless steel; mild steel; nickel-titanium alloys, such as linear-elastic nitinol and / or super-elastic nitinol; nickel-chromium-molybdenum alloys (e.g., UNS: N06625, such as INCONEL® 625; UNS: N06022, such as HASTELLOY® C-22®; H HASTELLOY® alloys (UNS:N10276, such as ASTELLOY® C276®, other HASTELLOY® alloys, etc.), nickel-copper alloys (UNS:N04400, such as MONEL® 400, NICKELVAC® 400, NICORROS® 400, etc.), nickel-cobalt-chromium-molybdenum alloys (UNS:R30035, such as MP35-N®), nickel-molybdenum alloys (UNS:N10276, such as ASTELLOY® C276®, other HASTELLOY® alloys, etc.), nickel-cobalt ...cobalt-chromium-molybdenum alloys (UNS:N10276, such as ASTELLOY® C276®, other HASTELLOY® alloys, etc.), nickel-cobalt alloys (UNS:N04400, such as MONEL® 400, NICKELVAC® 400, NICORROS® 400, etc Other nickel alloys, such as 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; cobalt-chromium alloys; cobalt-chromium-molybdenum alloys (e.g., UNS:R30003, such as ELGILOY®, PHYNOX®); platinum-enriched stainless steel; titanium; combinations thereof, etc.; or any other suitable material.

[0045] Within the family of commercially available nickel-titanium or nitinol alloys, such as those mentioned above, there is a category known as "linear elastic" or "non-superelastic," which may be chemically similar to traditional shape memory and superelastic varieties but may exhibit additional useful mechanical properties. Linear elastic and / or non-superelastic nitinol can be distinguished from superelastic nitinol in that its stress / strain curve does not exhibit the substantial "superelastic plateau" or "flag region" that superelastic nitinol exhibits. Instead, as recoverable strain increases in linear elastic and / or non-superelastic nitinol, stress continues to increase in a substantially linear relationship, or in a somewhat linear relationship, though not necessarily perfectly linear, until plastic deformation begins, or at least in a more linear relationship than the superelastic plateau and / or flag region that can be observed in superelastic nitinol. Thus, for purposes of this disclosure, linear elastic and / or non-superelastic nitinol may also be referred to as "substantially" linear elastic and / or non-superelastic nitinol.

[0046] Linear elastic and / or non-superelastic nitinol may also be distinguishable from superelastic nitinol in that in some cases, linear elastic and / or non-superelastic nitinol may tolerate a maximum strain of about 2-5% while remaining substantially elastic (e.g., before undergoing plastic deformation), whereas superelastic nitinol may tolerate a maximum strain of about 8% before undergoing plastic deformation. Both of these materials may be distinguished (or distinguished based on their composition) from other linear elastic materials, such as stainless steel, which can only tolerate a strain of about 0.2-0.44% before undergoing plastic deformation.

[0047] In some embodiments, a linear elastic and / or non-superelastic nickel-titanium alloy is an alloy that does not exhibit any martensite / austenite phase change detectable by DSC and DMTA analysis over a wide temperature range. For example, in some embodiments, a linear elastic and / or non-superelastic nickel-titanium alloy may not exhibit a martensite / austenite phase change detectable by DSC and DMTA analysis in the range of about -60°C to about 120°C. Thus, the mechanical bending properties of such a material may be generally inert to the effects of temperature over this very wide temperature range. In some embodiments, the mechanical bending properties of a linear elastic and / or non-superelastic nickel-titanium alloy at ambient or room temperature are substantially the same as those at body temperature, e.g., in that they do not exhibit a superelastic plateau and / or flag region. In other words, over a wide temperature range, a linear elastic and / or non-superelastic nickel-titanium alloy maintains its linear elastic and / or non-superelastic properties and / or characteristics and essentially has no yield point.

[0048] In some embodiments, the linear elastic and / or non-superelastic nickel-titanium alloy may be about 50 to about 60 weight percent nickel, with the remainder essentially titanium. In some embodiments, the composition is about 54 to about 57 weight percent nickel. One example of a suitable nickel-titanium alloy is FHP-NT alloy, available from Furukawa Techno Material Co., Ltd., Kanagawa Prefecture, Japan. Some examples of nickel-titanium alloys are disclosed in U.S. Pat. Nos. 5,238,004 and 6,508,803, which are incorporated herein by reference. Other suitable materials include ULTANIUM® (available from Neo-Metrics) and GUM METAL® (available from Toyota). In some other embodiments, superelastic alloys, such as superelastic nitinol, can be used to achieve desired properties.

[0049] In at least some embodiments, various components of the cannulation devices described herein comprise radiopaque materials, including those listed herein, or other suitable radiopaque materials.

[0050] In some embodiments, the cannulation devices described herein are provided with a degree of MRI compatibility. For example, to improve compatibility with magnetic resonance imaging (MRI) machines, it may be desirable to fabricate various components of the cannulation devices described herein in a manner that would provide a degree of MRI compatibility. For example, various components of the cannulation devices described herein, or portions thereof, may be fabricated from materials that do not significantly distort images or cause noticeable artifacts (artifacts are gaps in images). For example, certain ferromagnetic materials may not be suitable because they may produce artifacts in MRI images. Various components of the cannulation devices described herein, or portions thereof, may also be fabricated from materials that MRI machines can image. Some materials that exhibit these properties include, for example, tungsten, cobalt-chromium-molybdenum alloys (e.g., UNS:R30003 such as ELGILOY®, PHYNOX®), nickel-cobalt-chromium-molybdenum alloys (e.g., UNS:R30035 such as MP35-N®), and nitinol.

[0051] Some examples of suitable polymers that may be used to form the various components of the cannulation devices described herein include polytetrafluoroethylene (PTFE), ethylene tetrafluoroethylene (ETFE), fluorinated ethylene propylene (FEP), polyoxymethylene (POM, e.g., DELRIN® available from DuPont), polyether block esters, polyurethanes (e.g., polyurethane 85A), polypropylene (PP), polyvinyl chloride (PVC), polyetheresters (e.g., ARNITEL® available from DSM Engineering Plastics), ether- or ester-based copolymers (e.g., butylene / poly(alkylene ether) phthalates such as HYTREL® available from DuPont, and / or other polyester elastomers), polyamides (e.g., DURETHAN® available from Bayer or CRISTAMID® available from Elf Atochem), elastomeric polyamides, and the like. polyamide), polyamide-ether block copolymers (block polyamide / ethers), polyether block amide (PEBA, available, for example, under the trade name PEBAX®), ethylene vinyl acetate copolymer (EVA), silicone, polyethylene (PE), Marlex® high density polyethylene, Marlex® low density polyethylene, linear low density polyethylene (e.g., REXELL®), polyester, polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polytrimethylene terephthalate, polyethylene naphthalate (PEN), polyether ether ketone (PEEK), polyimide (PI), polyetherimide (PEI), polyphenylene sulfide (PPS), polyphenylene oxide (PPO), polyparaphenylene terephthalamide (e.g., KEVLAR®), polysulfone, nylon, nylon-12 (e.g., EMS American Grillon®).The sheath may include GRILAMID® (available from Grilon), perfluoro(propyl vinyl ether) (PFA), ethylene vinyl alcohol, polyolefin, polystyrene, epoxy, polyvinylidene chloride (PVdC), poly(styrene-b-isobutylene-b-styrene) (e.g., SIBS and / or SIBS 50A), polycarbonate, ionomer, biocompatible polymer, other suitable material, or mixtures, combinations, copolymers, polymer / metal composites, etc. In some embodiments, the sheath may be blended with a liquid crystal polymer (LCP). For example, the mixture may contain up to about 6% LCP.

[0052] In some embodiments, the exterior surface of the cannulation devices described herein may include, for example, a lubricious, hydrophilic, protective, or other type of coating. Hydrophobic coatings, such as fluoropolymers, provide dry lubricity, improving device maneuverability and exchangeability. Lubricious coatings improve steerability and lesion crossing performance. Suitable lubricious polymers may include polymers such as silicone, high-density polyethylene (HDPE), polytetrafluoroethylene (PTFE), polyarylene oxide, polyvinylpyrrolidone, polyvinyl alcohol, hydroxyalkyl celluloses, algins, sugars, caprolactones, and mixtures and combinations thereof. Hydrophilic polymers may be blended with each other or with a specified amount of a water-insoluble compound (including some polymers) to achieve a coating with suitable lubricity, binding, and solubility properties. Some other examples of such coatings, and the materials and methods used to make such coatings, can be found in U.S. Pat. Nos. 6,139,510 and 5,772,609, the entire disclosures of which are incorporated herein by reference.

[0053] It will be understood that this disclosure is in many respects merely illustrative, and changes may be made in details, particularly in matters of shape, size, and arrangement of steps, without exceeding the scope of the invention, which scope is, of course, defined in the language expressed in the appended claims.

Claims

1. 1. A cannulation device adapted to be advanced through an endoscope to a position adjacent to a patient's duodenum to access the patient's common bile duct, the cannulation device comprising: an elongate shaft extending to an atraumatic distal tip; a first guidewire lumen extending through the elongate shaft and terminating in a first diagonal guidewire port; a second guidewire lumen extending through the elongate shaft and terminating in a second diagonal guidewire port.

2. The cannulation device of claim 1 , wherein the first diagonal guidewire port is adapted to direct a guidewire extending through the first guidewire lumen in a first direction relative to the atraumatic tip.

3. 3. The cannulation device of claim 2, wherein the second diagonal guidewire port is adapted to guide a guidewire extending through the second guidewire lumen in a second direction relative to the atraumatic tip that is different from the first direction.

4. A cannulation device according to any one of claims 1 to 3, wherein the atraumatic distal tip includes a tapered outer surface, the first diagonal guidewire port is located on a first portion of the tapered outer surface, and the second diagonal guidewire port is located on a second portion of the tapered outer surface that is circumferentially spaced from the first portion of the tapered outer surface.

5. The cannulation device according to any one of claims 1 to 4, wherein the first guidewire lumen is parallel to the second guidewire lumen within a proximal portion of the cannulation device.

6. The cannulation device of claim 5 , wherein the first guidewire lumen is radially spaced from the second guidewire lumen within a distal portion of the cannulation device.

7. The cannulation device of any one of claims 1 to 6, further comprising a cutting wire extending through the elongate shaft.

8. 1. A cannulation device adapted to be advanced through an endoscope to a position adjacent to a patient's duodenum to access the patient's common bile duct, the cannulation device comprising: an elongate shaft extending to an atraumatic distal tip; a guidewire lumen extending through the elongate shaft, the guidewire lumen terminating in a guidewire port disposed within the atraumatic distal tip; and an inflatable balloon disposed against the atraumatic distal tip, the inflatable balloon being inflatable from a deflated configuration to an expanded configuration, the inflatable balloon adapted to occlude the patient's pancreatic duct; an inflation lumen extending through the elongate shaft and fluidly coupled to the inflatable balloon.

9. 9. The cannulation device of claim 8, wherein the inflatable balloon is further adapted, upon inflation, to push the atraumatic distal tip away from the patient's pancreatic duct and toward the patient's common bile duct, thereby assisting in aligning the guidewire port with the common bile duct.

10. The cannulation device of claim 8 or 9, wherein the inflatable balloon is positioned along a side of the atraumatic distal tip.

11. The cannulation device of any one of claims 8 to 10, wherein the inflatable balloon forms part of the atraumatic distal tip when the inflatable balloon is in a deflated configuration.

12. 1. A cannulation device adapted to be advanced through an endoscope to a position adjacent to a patient's duodenum to access the patient's common bile duct, the cannulation device comprising: an elongate shaft extending to an atraumatic distal tip; a guidewire lumen extending through the elongate shaft, the guidewire lumen terminating in a guidewire port disposed within the atraumatic distal tip; and an expandable element disposed within the guidewire lumen, the expandable element being expandable from a contracted configuration to an extended configuration, wherein in the contracted configuration the expandable element is disposed within the guidewire lumen and in the extended configuration a portion of the expandable element extends distally from the guidewire port, the expandable element being adapted to allow a guidewire to extend therethrough.

13. The cannulation device of claim 12 , wherein the expandable element is adapted to occlude the patient's pancreatic duct.

14. 14. The cannulation device of claim 12 or 13, wherein the cannulation device is adapted to access the patient's common bile duct from a location adjacent the patient's ampulla of Vater.

15. A cannulation device according to any one of claims 12 to 14, wherein an end of the expandable element is fixed relative to the distal end of the cannulation device.

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