Medical Device with Balloon and Removal Member - Patent application

Abstract

The medical device includes a tube, a sheath disposed around and coaxial with the tube, and an inflatable balloon disposed at the distal end of the sheath. The balloon is capable of receiving fluid from the sheath lumen and has a central opening along its longitudinal axis through which the tube extends, a proximal portion, a middle portion adjacent to and proximal to the proximal portion, and a distal portion adjacent to and proximal to the middle portion. When the balloon is inflated with fluid, the maximum diameter of the middle portion is smaller than the maximum diameter of the proximal portion and smaller than the maximum diameter of the distal portion. The medical device also includes an extraction member located at the distal end of the tube, distal to the balloon, and axially movable relative to the balloon.

Description

[Technical field]

[0001] The present invention relates to medical devices having balloons and removal members, and more particularly to medical devices and associated methods for removing material from a patient using dilatation balloons and removal members. [Background technology]

[0002] During endoscopic procedures to treat biliary lithiasis, such as biliary endoscopic sphincterotomy (ES) procedures, operators may encounter problems in removing material, such as stones, from the patient's bile duct. This requires the operator to use multiple types of devices during the procedure, especially if the material proves difficult to remove. For example, removing relatively large stones from the bile duct can be problematic if the size of the stone exceeds the size of the ampulla, which may impede removal or cause complications during removal. Biliary ES procedures may involve incision of the biliary sphincter and the intraduodenal area of ​​the patient's common bile duct, followed by intubation, by applying high-frequency electrical current with a special knife inserted into the papilla or sphincter. Thus, ES procedures may require multiple devices and multiple device exchanges throughout the ES procedure. Additionally, complications may arise during or as a result of the ES procedure, such as damage to the patient's sphincter mechanism. Summary of the Invention

[0003] The present invention relates to a medical device, and associated methods, for removing material from within a patient's body using an expansion balloon and an extraction member. Each embodiment disclosed herein may include one or more of the elements described in connection with any of the other disclosed embodiments.

[0004] According to one example, the medical device includes a tube, a sheath disposed about and coaxial with the tube, and an inflatable balloon disposed at a distal end of the sheath. The balloon is configured to receive fluid from a lumen of the sheath, the balloon having a central opening disposed along a longitudinal axis of the balloon through which the tube extends, a proximal portion, a middle portion adjacent to and distal to the proximal portion, and a distal portion adjacent to and distal to the middle portion. In response to inflation, a maximum diameter of the middle portion is equal to or less than a maximum diameter of the proximal portion and less than a maximum diameter of the distal portion. The medical device also includes an extraction member disposed at the distal end of the tube, i.e., distal to the balloon, and axially movable relative to the balloon.

[0005] Any of the medical devices described herein may include one or more of the following features: The distal end of the sheath may be disposed within the central opening of the balloon. The removal member has a central opening along a longitudinal axis of the removal member through which the tube may extend. The removal member is one of a balloon and a mesh configured to receive fluid from a lumen of the tube. The proximal portion of the balloon includes a proximal tapered portion. The proximal portion of the balloon includes a distal portion having a spherical shape and a proximal tapered portion. The distal portion of the balloon has a cylindrical shape with respect to the longitudinal axis of the balloon. The distal portion of the balloon has a spherical shape with respect to the longitudinal axis of the balloon. The maximum diameter of the proximal portion may be equal to the maximum diameter of the central portion of the balloon. The maximum diameter of the proximal portion may be less than the maximum diameter of the distal portion of the balloon. The length of the proximal portion of the balloon may be greater than each of the length of the distal portion of the balloon and the length of the central portion of the balloon with respect to the longitudinal axis of the balloon, and the length of the central portion may be less than or equal to the length of the distal portion. The tube includes a distal opening, and the lumen of the tube is configured to receive a guidewire that can extend beyond the distal opening of the tube. The distally facing surface of the distal portion of the balloon can be concave. The distally facing surface of the distal portion of the balloon can define a recess that extends radially inward and proximally toward a central portion of the balloon. The recess can extend proximally to a depth of no more than half the longitudinal length of the distal portion of the balloon.

[0006] According to another embodiment, the medical device includes a tube, a sheath disposed about and coaxial with the tube, and a balloon disposed at a distal end of the sheath. The balloon is configured to be inflated through a lumen of the sheath and has a concave surface facing in a distal direction. Upon inflation, the balloon has an hourglass shape. The medical device also includes a removal member disposed at the distal end of the tube, the removal member being distal to the balloon.

[0007] Any of the medical devices described herein may also include one or more of the following features: An hourglass shape is defined by a proximal bulbous portion, a central neck portion, and a distal bulbous portion. A distal surface of the distal bulbous portion of the balloon defines a recess extending radially inward and proximally toward the proximal bulbous portion of the balloon, the recess configured to accommodate a gallstone.

[0008] According to yet another embodiment, a method of removing material from a patient includes advancing an apparatus into a lumen of the patient, the apparatus including a tube, a sheath disposed around and coaxial with the tube, and a dilatation balloon disposed at a distal end of the apparatus. The dilatation balloon has a central opening disposed along a longitudinal axis for receiving the tube, a proximal portion, a central portion adjacent and distal to the proximal portion, and a distal portion adjacent and distal to the central portion. The apparatus also includes an extraction member disposed at a distal end of the tube, the extraction member distal to the dilatation balloon. The method further includes positioning the extraction member distal to the material, positioning the dilatation balloon proximal to the material, inflating the dilatation balloon such that a maximum diameter of the central portion of the dilatation balloon is equal to or less than a maximum diameter of the proximal portion of the dilatation balloon and equal to or less than a maximum diameter of the distal portion of the dilatation balloon, and pulling at least the extraction member proximally to pull the material proximally.

[0009] Any of the methods described herein may include one or more of the following features: The removal member includes a removal balloon. Additionally, the method may further include inflating the removal balloon before or after inflating the dilation balloon.

[0010] Both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate examples of the disclosure and, together with the description, serve to explain the principles of the disclosure. [Brief description of the drawings]

[0011] [Figure 1] 1 is a schematic diagram showing a portion of a medical device extending through the duodenum and into the patient's bile duct. [Diagram 2] 1 is a schematic diagram of a portion of a medical device according to the present invention, showing a portion of a medical instrument extending through the duodenum and into the bile duct of a patient. [Diagram 3] 1 is a schematic diagram showing a medical device according to the present invention. [Figure 4] 4 is a cross-sectional view of the tube and sheath of the medical device of FIG. 3 in accordance with the present invention. [Figure 5A] FIG. 2 is a perspective view of an expansion balloon according to one embodiment of the present invention. [Figure 5B] FIG. 2 is a side view of an expansion balloon according to one embodiment of the present invention. [Figure 5C] 1 is a cross-sectional view of an expansion balloon according to one embodiment of the present invention. [Figure 5D] 1 is an enlarged cross-sectional view of an expansion balloon according to one embodiment of the present invention. [Figure 6A] 13 is a side view of an expansion balloon according to another embodiment of the present invention. [Figure 6B] 13 is a cross-sectional view of an expansion balloon according to another embodiment of the present invention. [Figure 6C] 13 is an enlarged cross-sectional view of a dilatation balloon according to another embodiment of the present invention. [Figure 7A] 13 is a side view of an expansion balloon according to yet another embodiment of the present invention. [Figure 7B] 13 is a cross-sectional view of an expansion balloon according to yet another embodiment of the present invention. [Figure 7C] 13 is an enlarged cross-sectional view of an expansion balloon according to yet another embodiment of the present invention. [Figure 8] 1 illustrates a method of removing material from a patient's body in accordance with the present invention. [Figure 9] 13 is a side view of an expansion balloon according to yet another embodiment of the present invention. [Figure 10]1 is a side view of a medical device having an expansion balloon and a mesh according to another embodiment of the present invention. [Figure 11A] 13A-13C show a medical device having an expansion balloon with recesses in accordance with a further embodiment of the present invention. [Figure 11B] 13A-13C show a medical device having an expansion balloon with recesses in accordance with a further embodiment of the present invention. [Figure 11C] 13A-13C show a medical device having an expansion balloon with recesses in accordance with a further embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] The general description above and the detailed description below are exemplary and explanatory only and are not intended to limit the invention as claimed. As used herein, the terms "comprising," "including," "having," or any other variation thereof, including the following list of processes, methods, articles, or devices, are intended to cover a non-exclusive inclusion and may include other elements not expressly listed or inherent to such processes, methods, articles, or devices, and not only those elements. The term "exemplary" is used in the sense of "example" rather than "ideal." As used herein, the terms "proximal" or "proximally" mean in a direction closer to the operator and the terms "distal" or "distally" mean in a direction further from the operator. As used herein, the terms "about," "generally," and "approximately" indicate a range of values ​​within + / - 10% of the stated value. Although reference is made herein to endoscopes and endoscopic procedures, the references to endoscopes and endoscopic surgery should not be construed as limiting the possible uses of the disclosed medical instruments and other aspects, and the disclosed medical instruments and portions thereof may be used as part of other types of medical devices and in other types of medical procedures.

[0013] Instead of the ES procedure, an endoscopic papillary balloon dilation (EPBD) procedure can be performed. The endoscopic papillary balloon dilation (EPBD) procedure can minimize complications and preserve the sphincter mechanism. For example, as shown in FIG. 1, a material 10, such as a stone, can be removed in an EPBD procedure from within a patient's bile duct 12 using a medical instrument 14. During the procedure, the medical instrument 14 is advanced distally through a duodenoscope 16 (or other scope, catheter, sheath, or tube) placed in the patient's gastrointestinal tract. More specifically, the duodenoscope 16 is placed in the patient's duodenum 18 and has a distal opening 20 positioned to face the papilla, here the ampulla of Vater 22. An elevator (not shown) may be provided within the opening 20 to lift and direct the medical instrument to the side of the duodenoscope 16. The medical instrument 14 extends from the distal opening 20 through the ampulla of Vater 22 into the bile duct 12 and over a guidewire 24. The portion of the medical device 14 that extends into the bile duct 12 is the treatment section 26. The treatment section 26 includes a lumen 28 and a removal member 30. The removal member 30 is disposed toward the distal end of the treatment section 26. During endoscopic surgery, the removal member 30 is positioned distal to the material 10 and may be expanded or inflated with a fluid through an opening (not shown) in the lumen 28.

[0014] To remove the material 10 from the bile duct 12, the removal member 30 is pulled, or trawled, proximally through the bile duct 12. During this procedure, if the removal member 30 is a balloon, the force required to withdraw the material 10 from the bile duct 12 may cause the removal balloon 30 to rupture. Additionally, if the patient's bile duct 12 is an "S-shaped" bile duct, e.g., curved or crescent shaped, the medical instrument 14 may require torque by the operator performing the procedure, which requires additional strength and patience from the operator and can be irritating to the bile duct 12 and other lumens of the patient.

[0015] To reduce the force required to extract the material 10 from the bile duct 12 and reduce the risk of rupturing the removal balloon 30, the lumen proximal to the material 10 may be dilated. This may require additional equipment, including an additional lumen or sheath and a dilation balloon at its distal end. The dilation balloon is positioned proximal to the material 10 within the bile duct 12. The removal member 30 and the dilation balloon may be moved proximally simultaneously to remove the material 10 while preserving the sphincter mechanism.

[0016] However, problems can arise when multiple devices or instruments are required to trawl the bile duct 12 and dilate the ampulla of Vater 22. For example, the instruments can become entangled during insertion or exchange. Furthermore, as the instruments are exchanged or moved from one another, the guidewire 24 can become dislodged, resulting in the operator losing access to the bile duct 12 and needing to re-intubate. This process can result in further deterioration of the patient's ampulla of Vater. Furthermore, the use of multiple instruments not only increases the cost of the endoscopic procedure, but also increases the time required to complete the endoscopic procedure. Increasing the time required to complete the endoscopic procedure can increase the invasiveness of the procedure, irritation to the patient's gastrointestinal tract, and risk to the patient for infection or injury.

[0017] FIG. 2 is a schematic diagram of a portion of a medical device 32 according to one embodiment of the present invention. The medical device 32 is disposed within a duodenoscope 16 (or other scope, catheter, sheath, or tube) that is disposed within a patient's duodenum 18 during an endoscopic procedure. The medical device 32 extends through the duodenoscope 16, out a distal opening 20 of the duodenoscope 16, through the ampulla of Vater 22, and into the patient's bile duct 12. A treatment portion 38 of the medical device 32 extends into the bile duct 12 to a location around or near the material 10 to be removed from the bile duct 12. The treatment portion 38 includes a tube 40 (shown in FIG. 3) and a sheath 42 that extends coaxially about the tube 40 and is movable relative to the tube 40. The treatment portion 38 also includes an expansion balloon 44 and an extraction member 46, each of which is shown in an expanded state in FIG. 2. In the embodiment shown in FIGS. 1 and 2, the extraction member 46 is a balloon. However, the retrieval member 46 may be any suitable element for capturing and moving an object for retrieval, such as a net as shown in FIG. 10. Because the dilatation balloon 44 is attached to the sheath and the retrieval member 46 is attached to the tube 40, the dilatation balloon 44 and the retrieval member 46 may be expanded and moved independently of one another. The dilatation balloon 44 may be moved by moving the sheath 42 in a distal or proximal direction, while the retrieval member 46 may be moved by moving the tube 40 in a distal or proximal direction. Additionally, the dilatation balloon 44 and the retrieval member 46 may be expanded and moved simultaneously. As shown in FIG. 2, the dilatation balloon 44 is positioned proximal to the material 10 and the retrieval member 46 is positioned distal to the material 10. The treatment portion 38 is advanced over the guidewire 48 to reach the position shown in FIG. 2. Additionally, the distal tip 50 of the treatment portion 38 forms an atraumatic tip and includes a distal opening 51 through which the guidewire 48 may pass.

[0018] 3 is a schematic diagram of a medical device 32 according to one embodiment of the present invention. The tube 40, which is a tri-lumen extruded tube, is connected to a handle 54 at the proximal end 52 of the medical device 32. The handle 54 includes multiple ports, including a guidewire port 56, a contrast port 58, and a removal member expansion port 60. The guidewire port 56 receives the guidewire 48, the contrast port 58 receives a contrast material such as a dye from a contrast material source (not shown) or another desired fluid, and the removal member expansion port 60 receives a mechanism for expansion of the removal member 46. For example, if the removal member 46 is a balloon, the removal member expansion port 60 receives a fluid such as air or saline from a fluid source such as a pump or syringe (not shown). The handle 54 also provides for relative coaxial movement of the inflatable balloon 44 and the removal member 46.

[0019] Distal to the handle 54, a hypotube 61 and an adapter 62, such as a Tuohy Borst adapter, are provided around the outside of the tube 40, as shown in FIG. 3. The sheath 42 is connected to the adapter 62 and extends coaxially about the tube 40 from the adapter 62 toward the treatment portion 38 of the medical device 32. The adapter 62 includes a dilatation balloon inflation port 64. As shown in FIG. 3, the dilatation balloon inflation port 64 receives a fluid, such as air or saline, from a fluid source, such as a pump or syringe 66. The adapter 62 provides for coaxial movement of the handle 54 and hypotube 61 while preventing leakage of fluid back through the handle 54.

[0020] 3, the tube 40 and sheath 42 extend coaxially from the proximal end 52 to the distal tip 50 of the treatment portion 38 of the medical device 32. The sheath 42 extends through the proximal end 68 of the dilatation balloon 44, through a central opening 70 in the dilatation balloon 44, and terminates at or near the distal end 72 of the dilatation balloon 44. The sheath 42 has a circumferential opening 74 disposed between the proximal end 68 and the distal end 72 of the dilatation balloon 44.

[0021] The medical device 32 may have, for example, a length of about 220 cm from the proximal end 52 to the distal tip 50. However, the length of the medical device 32 is not limited to this value and may vary within a range of about 200 cm to 240 cm. The tube 40 of the medical device 32 may have a length of about 220 cm and a diameter of about 3.0 mm. However, the length and diameter of the tube 40 are not limited to these values ​​and may vary within a range of about 200 cm to 240 cm and a range of about 2.5 mm to 3.5 mm, respectively. The tube 40 may be formed of a material such as, for example, PEBAX®. However, the material forming the tube 40 is not limited to PEBAX®, but may be any one of low density polyethylene (LDPE), high density polyethylene (HDPE), polyetheretherketone (PEEK), nylon, Cristamid®, Grilamid®, polytetrafluoroethylene (PTFE), Zytel®, Rilsan®, or Vestamid®. Additionally, semi-compliant materials such as, for example, ethylene vinyl acetate, polyvinyl chloride (PVC), olefin copolymers or homopolymers, polyethylene, polyurethane, crosslinked low density polyethylene (PET), highly irradiated linear low density polyethylene (LDPE), acrylonitrile polymers and copolymers, acrylonitrile blends, and ionomer resins may be used. Examples of non-compliant materials include polyethylene terephthalate, polyacrylene sulfide, and copolyesters. Additionally, other example materials include poly(styrene-isobutylene-styrene) triblock polymers (SIBS), polyurethanes, elastomeric polymers, fabrics, multi-layer films of polymers, and combinations thereof.

[0022] The sheath 42 of the medical device 32 may have a length of about 165 cm and a diameter of about 3.0 mm. However, the length and diameter of the sheath 42 are not limited to these values ​​and may vary within the ranges of about 145 cm to 185 cm and about 2.5 mm to 3.5 mm, respectively. The sheath 42 may be formed of a material such as PEBAX®. However, the material forming the sheath 42 is not limited to PEBAX® and may be any one of low density polyethylene (LDPE), high density polyethylene (HDPE), polyetheretherketone (PEEK), nylon, Cristamid®, Grilamid®, polytetrafluoroethylene (PTFE), Zytel®, Rilsan®, or Vestamid®. In addition, semi-flexible materials may be used, such as, for example, ethylene vinyl acetate, polyvinyl chloride (PVC), olefin copolymers or homopolymers, polyethylene, polyurethane, crosslinked low density polyethylene (PET), highly irradiated linear low density polyethylene (LDPE), acrylonitrile polymers and copolymers, acrylonitrile blends, and ionomer resins. Examples of non-flexible materials include polyethylene terephthalate, polyacrylylene sulfide, and copolyesters. In addition, other examples of this material include poly(styrene-isobutylene-styrene) triblock polymers (SIBS), polyurethanes, elastomeric polymers, fabrics, multilayers of polymers, and combinations thereof.

[0023] In the embodiment shown in FIG. 3, the dilation balloon 44 has an hourglass shape, which allows for controlled dilation of the bile duct 12 and ampulla of Vater 22 during endoscopic surgery, as described below. In particular, from the proximal end 68 to the distal end 72, the dilation balloon 44 includes a proximal neck portion 76, a proximal portion 78, a central portion 80, a distal portion 82, and a distal neck portion 84. The dilation balloon 44 may have a wall thickness of, for example, about 0.050 mm, which may be constant throughout the proximal neck portion 76, the proximal portion 78, the central portion 80, the distal portion 82, and the distal neck portion 84. In the embodiment shown in FIG. 3, the shapes and diameters of the proximal neck portion 76, the proximal portion 78, the central portion 80, the distal portion 82, and the distal neck portion 84 vary. The various shapes and diameters of these portions of the dilation balloon 44 are described in more detail below with respect to FIGS. 5A-7C.

[0024] The distal portion 82 of the dilatation balloon has a distally facing surface 86 into which the material 10 may be transferred when the medical device 32 is in use. In the embodiment shown in FIG. 3, the distally facing surface 86 is shown as concave. The concave surface of the distally facing surface 86 forms a space in which the material 10 may be trapped or secured for removal, as described in more detail below. However, the distally facing surface 86 is not limited to being concave, and may be flat or convex or have a recess, as described below with respect to FIGS. 11A-11C. The central opening 70 of the dilatation balloon 44 extends the entire length of the dilatation balloon 44. Additionally, one or more marker bands may be provided on the dilatation balloon 44. In the embodiment shown in FIG. 3, two marker bands are provided, one marker band 88 disposed between the proximal portion 78 and the central portion 80 of the dilatation balloon 44, and the other marker band 90 disposed between the central portion 80 and the distal portion 82.

[0025] The expansion balloon 44 may be formed of, for example, nylon. However, the material forming the expansion balloon 44 is not limited to nylon and may be another material, such as polyethylene terephthalate (PET), PEBAX®, or other suitable material. As described above, the expansion balloon 44 may have various shapes and diameters among the proximal neck portion 76, the proximal portion 78, the central portion 80, the distal portion 82, and the distal neck portion 84, and may be formed using free forming. However, the expansion balloon 44 may be formed using other techniques, such as stretch blow molding, extrusion blow molding, etc. The expansion balloon 44 may be formed of a compliant or non-compliant material. Details of the various shapes and diameters of the expansion balloon 44 are described in more detail below with reference to FIGS. 5A-7C.

[0026] In FIG. 3, distal to the dilatation balloon 44, the tube 40 extends through a proximal end 92, through a central opening 94, and into a distal end 96 of the removal member 46, which terminates at the distal tip of the treatment portion 38 to form a tip 50 of the treatment portion 38. As shown in FIG. 3, when the removal member 46 is a balloon, the removal member 46 has a proximal neck portion 98, a central portion 100, and a distal neck portion 102. The tube 40 has a circumferential opening 104 disposed within the central portion 100 of the removal member 46. As shown in FIG. 3, when in an inflated state, the central portion 100 of the removal member 46 has an oval-shaped profile. The diameter D46 of the central portion of the removal member 46 is, for example, about 11 mm, and the length L46 of the removal balloon 46 is, for example, about 11 mm. However, the diameter D46 and length L46 of the extraction member 46 are not limited to these values ​​and may be within the ranges of approximately 5 mm to 13 mm and approximately 5 mm to 13 mm, respectively.

[0027] When the removal member 46 is a balloon, the removal member 46 may be formed of, for example, nylon. However, the material forming the removal member 46 is not limited to nylon and may be other materials, such as polyethylene terephthalate (PET), PEBAX®, or other suitable materials. As described above, the removal member 46 as a balloon has an ovoid shape and has specific diameters of the proximal neck portion 98, the central portion 100, and the distal neck portion 102, and may be formed using free forming. However, other techniques such as stretch blow molding, extrusion blow molding, etc. may be used to form the removal member 46. The removal member 46, such as a balloon, may be formed from a flexible or non-compliant material.

[0028] FIG. 4 shows a cross-sectional view of the tube 40 and the sheath 42 taken along section line 4-4 of FIG. 3. As shown in FIG. 4, the tube 40 has at least three lumens, including a guidewire lumen 106, a contrast lumen 108, and a removal member extension lumen 110. The guidewire lumen 106 receives a guidewire 48 that can extend from a guidewire port 56 of the handle 54 and extend through the distal tip 50 of the treatment portion 38 of the medical device 32. The contrast lumen 108 receives contrast material (or other desired fluid) from a contrast material source via the contrast port 58 of the handle 54. Additionally, if the removal member 46 is a balloon, the removal member extension lumen 110 receives fluid for inflation of the removal member 46 from a fluid source via the removal member extension port 60. That is, the removal member 46 expands when fluid is supplied through the removal member extension lumen 110 and the circumferential opening 104 of the tube 40. Further, the dilatation balloon inflation lumen 112 is formed between the outer peripheral surface of the tube 40 and the inner peripheral surface of the sheath 42, and is connected to the dilatation balloon inflation port 64. The dilatation balloon inflation lumen 112 receives fluid for inflating the dilatation balloon 44 from the syringe 66, as shown in FIG. 3. That is, when fluid is supplied through the dilatation balloon inflation lumen 112 and the circumferential opening 74 of the sheath 42, the dilatation balloon 44 is inflated.

[0029] 3, when the removal member 46 is a balloon, the proximal and distal neck portions 98, 102 of the removal member 46 fit snugly around the outside of the tube 40 to prevent fluid received from the removal member expansion lumen 100 from leaking out of the member expansion lumen 110. Similarly, the proximal and distal neck portions 76, 84 of the dilation balloon 44 fit snugly around the outside of the sheath 42 to prevent fluid received from the expansion balloon inflation lumen 112 from leaking out of the expansion balloon 44 when the sheath 42 terminates beyond the distal end 72 of the dilation balloon 44. When the sheath 42 terminates proximal to the distal end 72 of the dilation balloon 44, the distal neck portion 84 of the dilation balloon 44 fit snugly around the outside of the tube 40 to prevent fluid received from the expansion balloon inflation lumen 112 from leaking out of the expansion balloon 44. Additionally, the proximal neck portion 98 of the removal member 46 and the distal neck portion 84 of the dilation balloon 44 form a sturdy stop sleeve to prevent excessive retraction of the dilation member 46 into the dilation balloon 44 .

[0030] Figures 5A - 5D show further details of the expandable balloon 44 according to an embodiment of the present invention. Figure 5A shows a perspective view of the expandable balloon 44 having an hourglass shape defined by a proximal portion 78, a central portion 80, and a distal portion 82. The distal portion 82 is spherical or bulbous. Figure 5A also shows the surface 86 facing the distal side of the expandable balloon 44. Figure 5B is a side view of the expandable balloon 44, showing the respective lengths of the proximal neck portion 76, the proximal portion 78, the central portion 80, the distal portion 82, and the distal neck portion 84. That is, the proximal neck portion 76 has a length L76, the proximal portion 78 has a length L78, the central portion 80 has a length L80, the distal portion 82 has a length L82, and the distal neck portion 84 has a length L84. The relationship between the lengths of the proximal neck portion 76, the proximal portion 78, the central portion 80, the distal portion 82, and the distal neck portion 84 can be as follows: L76 < L84 < L80 = L82 < L78. However, the relationship between the lengths of the proximal neck portion 76, the proximal portion 78, the central portion 80, the distal portion 82, and the distal neck portion 84 is not limited to these relationships and may be different.

[0031] Figure 5C is a cross - sectional view of the expandable balloon 44 taken along line 5C - 5C of Figure 5B. In this embodiment, the proximal neck portion 76 and the distal neck portion 84 each have a substantially constant diameter D76 and D84, while the proximal portion 78, the central portion 80, and the distal portion 82 can have various diameters over their respective lengths. That is, the proximal portion 78 has a proximal portion maximum diameter D78_MAX of about 20 mm and a proximal portion minimum diameter D78_MIN of about 10 mm, the central portion 80 has a central portion maximum diameter D80_MAX of about 18 mm and a central portion minimum diameter D80_MIN of about 8 mm, and the distal portion 82 can have a distal portion maximum diameter D82_MAX of about 20 mm and a distal portion minimum diameter D82_MIN of about 10 mm. However, the respective diameters of the proximal neck portion 76, the proximal portion 78, the central portion 80, the distal portion 82, and the distal neck portion 84 of the expandable balloon 44 are not limited to these respective values and may be different.

[0032] As shown in FIG. 5C, the proximal portion 78 has a tapered shape having a proximal portion minimum diameter D78_MIN at a site that is the proximal end of the proximal portion 78 and is closest to the proximal neck portion 76, and a proximal portion maximum diameter D78_MAX at a site that is near the distal end of the proximal portion 78 and is closest to the central portion 80. The central portion 80 has a central portion minimum diameter D80_MIN at its center and has a central portion maximum diameter D80_MAX at each of its proximal and distal ends, and has a curved double convex outer shape that forms the neck of the expandable balloon 44. Further, the distal portion 82 has a spherical or bulbous-like shape and has a curved double convex shape, with the distal portion minimum diameter D82_MIN at the proximal end of the distal portion and the distal portion maximum diameter D82_MAX at the center of the distal portion. The outer peripheral surface of the expandable balloon 44 can be continuous and smooth over at least the proximal portion 78, the central portion 80, and the distal portion 82.

[0033] In the embodiment shown in FIG. 5C, the relationship between the diameters of the proximal neck portion 76, the proximal portion 78, the central portion 80, the distal portion 82, and the distal neck portion 84 can be as follows: D76 = D84 = D78_MIN < D80_MIN < D78_MAX = D80_MAX = D82_MIN < D82_MAX. That is, when the expandable balloon 44 is inflated, the maximum diameter D82_MAX of the distal portion is larger than the maximum diameter D80_MAX of the central portion, and the maximum diameter D80_MAX of the central portion is less than or equal to the maximum diameter D78_MAX of the proximal portion. However, the relationship between the diameters of the proximal neck portion 76, the proximal portion 78, the central portion 80, the distal portion 82, and the distal neck portion 84 is not limited to these relationships and can vary. When the maximum diameter D80_MAX of the central portion is smaller than the maximum diameter D82_MAX of the distal portion and the maximum diameter D78_MAX of the proximal portion, the central portion 80 of the expandable balloon 44 forms an anchor that reduces the possibility of the expandable balloon 44 entering and exiting the fatter expansion part during endoscopic surgery.

[0034] FIG. 5D is an enlarged view showing the surface 86 facing in the distal direction of the expansion balloon 44. In particular, FIG. 5D shows the angle θ between the distal surface 86 of the expansion balloon 44 and the distal neck portion 84. The angle θ is an acute angle and, more specifically, can be, for example, between about 80 degrees and 85 degrees. That is, in the embodiments shown in FIGS. 5A-5D, the distal surface 86 is concave with respect to the distal portion 82 of the expansion balloon 44. However, the distal surface 86 is not limited to being concave and may be flat, convex, or may include a concave portion, as will be described below with reference to FIGS. 11A-11C.

[0035] FIGS. 6A-6C show an expansion balloon 114 according to an alternative embodiment of the present invention. FIG. 6A is a side view showing the expansion balloon 114 including a proximal neck portion 116, a proximal portion 118, a central portion 120, a distal portion 122, and a distal neck portion 124. FIG. 6A also shows the respective lengths of the proximal neck portion 116, the proximal portion 118, the central portion 120, the distal portion 122, and the distal neck portion 124. That is, the proximal neck portion 116 has a length L116, the proximal portion 118 has a length L118, the central portion 120 has a length L120, the distal portion 122 has a length L122, and the distal neck portion 124 has a length L124. The relationship between the lengths of the proximal neck portion 116, the proximal portion 118, the central portion 120, the distal portion 122, and the distal neck portion 124 can be as follows: L116 < L124 < L118 = L120 = L122. However, the relationship between the diameters and lengths of the proximal neck portion 116, the proximal portion 118, the central portion 120, the distal portion 122, and the distal neck portion 124 is not limited to these relationships and may be different.

[0036] Figure 6B is a cross-sectional view showing the expansion balloon 114 taken along line 6B-6B of Figure 6A. In this embodiment, the proximal and distal neck portions 116 and 124 have constant diameters D116 and D124, respectively, while the proximal, central, and distal portions 118, 120, and 122 have varying diameters over their respective lengths. That is, the proximal portion 118 may have a proximal portion maximum diameter D118_MAX of about 20 mm, and a proximal portion minimum diameter D118_MIN of about 20 mm, the central portion 120 may have a central portion maximum diameter D120_MAX of about 18 mm, and a central portion minimum diameter D120_MIN of about 8 mm, and the distal portion 122 may have a distal portion maximum diameter D122_MAX of about 20 mm, and a distal portion minimum diameter D122_MIN of about 10 mm. However, the respective diameters of the proximal neck portion 116, the proximal portion 118, the central portion 120, the distal portion 122, and the distal neck portion 124 of the expansion balloon 114 are not limited to these respective values ​​and may vary.

[0037] 5A-5D, the proximal portion 118 of the expansion balloon 114 shown in Figures 6A-6C has a tapered shape with a proximal portion minimum diameter D118_MIN at the proximal end of the proximal portion 118 nearest the proximal neck portion 116 and a proximal portion maximum diameter D118_MAX near the distal end of the proximal portion nearest the central portion 120. The central portion 120 has a curved, biconcave profile that forms the neck of the expansion balloon 114, with a central portion minimum diameter D120_MIN at its center and a central portion maximum diameter D120_MAX at each of its proximal and distal ends.

[0038] As compared to the embodiments shown in FIGS. 5A - 5D, the distal portion 122 of the expandable balloon 114 shown in FIGS. 6A - 6C includes a hemispherical portion 126 having a curved contour at the proximal end of the distal portion 122 and a cylindrical portion 128 having a linear contour at the distal end of the distal portion 122. The minimum diameter D122_MIN of the distal portion is at the proximal end of the hemispherical portion 126 of the distal portion 122, and the maximum diameter D122_MAX of the distal portion is constant along the cylindrical portion 128 of the distal portion 122. The distal portion 122 also has a surface 130 facing in the distal direction, which is concave with respect to the distal portion 122 in this embodiment. The outer peripheral surface of the expandable balloon 114 can be continuous and smooth over at least the proximal portion 118, the central portion 120, and the distal portion 122.

[0039] In the embodiments shown in FIGS. 6A - 6C, the relationship between the diameters of the proximal neck portion 116, the proximal portion 118, the central portion 120, the distal portion 122, and the distal neck portion 124 is as follows: D116 = D124 = D118_MIN < D120_MIN < D118_MAX = D120_MAX = D122_MIN < D122_MAX. However, the relationship between the diameters of the proximal neck portion 116, the proximal portion 118, the central portion 120, the distal portion 122, and the distal neck portion 124 is not limited to these relationships and may be different.

[0040] FIG. 6C is an enlarged view showing the surface 130 facing in the distal direction of the expandable balloon 114. In particular, FIG. 6C shows the angle Δ between the distal surface 130 of the expandable balloon 114 and the distal neck portion 124. The angle Δ is an acute angle and more specifically can be, for example, an angle between about 80 degrees and 85 degrees. That is, in the embodiments shown in FIGS. 6A - 6C, the distal surface 130 is concave with respect to the distal portion 122 of the expandable balloon 114. However, the distal surface 130 is not limited to being concave and may be flat, convex, or may include recesses as will be described below with reference to FIGS. 11A - 11C.

[0041] Figures 7A-7C show an expandable balloon 132 according to yet another embodiment of the present invention. FIG. 7A is a side view showing the expandable balloon 132 including a proximal neck portion 134, a proximal tapered portion 136, a proximal bi-lobe portion 138, a central portion 140, a distal portion 142, and a distal neck portion 144. The proximal bi-lobe portion 138 is spherical or bulbous, and the central portion 140 forms a curved neck of the expandable balloon 132. Further, the distal portion 142 is spherical or bulbous. FIG. 7A also shows the respective lengths of the proximal neck portion 134, the proximal tapered portion 136, the proximal bi-lobe portion 138, the central portion 140, the distal portion 142, and the distal neck portion 144. That is, the proximal neck portion 134 has a length L134, the proximal tapered portion 136 has a length L136, the proximal bi-lobe portion 138 has a length L138, the central portion 140 has a length L140, the distal portion 142 has a length L142, and the distal neck portion 144 has a length L144. The relationship between the lengths of the proximal neck portion 134, the proximal tapered portion 136, the proximal bi-lobe portion 138, the central portion 140, the distal portion 142, and the distal neck portion 144 can be as follows: L134 < L140 < L144 < L136 < L142 < L138. However, the relationship between the lengths of the proximal neck portion 134, the proximal tapered portion 136, the proximal bi-lobe portion 138, the central portion 140, the distal portion 142, and the distal neck 144 is not limited to these relationships and may vary.

[0042] Figure 7B is a cross-sectional view taken along line 7B-7B of Figure 7A showing dilatation balloon 132. In this embodiment, proximal neck portion 134 and distal neck portion 144 have constant diameters D134 and D144, respectively, while proximal tapered portion 136, proximal biconvex portion 138, central portion 140, and distal portion 142 may have varying diameters along their respective lengths. That is, proximal tapered portion 136 has a proximal tapered portion maximum diameter D136_MAX of approximately 8 mm, and a proximal tapered portion minimum diameter D136_MIN of approximately 6 mm, proximal biconvex portion 138 has a proximal biconvex portion maximum diameter D138_MAX of approximately 20 mm, and a proximal biconvex portion minimum diameter D138_MIN of approximately 10 mm, central portion 140 has a central portion maximum diameter D140_MAX of approximately 18 mm, and a central portion minimum diameter D140_MIN of approximately 8 mm, and distal portion 142 has, for example, a distal portion maximum diameter D142_MAX of approximately 20 mm, and a distal portion minimum diameter D142_MIN of approximately 10 mm. However, the diameters of the proximal neck portion 134, the proximal tapered portion 136, the proximal biconvex portion 138, the central portion 140, the distal portion 142, and the distal neck portion 144 of the expansion balloon 132 are not limited to these respective values ​​and may vary.

[0043] 5A-5D and 6A-6C, the proximal tapered portion 136 of the expansion balloon 132 has a tapered profile with a proximal tapered portion 136 minimum diameter D136_MIN at the proximal end of the proximal tapered portion 136 closest to the proximal neck portion 134 and a proximal tapered portion maximum diameter D136_MAX near the distal end of the proximal tapered portion 136 closest to the proximal biconvex portion 138. However, in contrast to the expansion balloons 44 and 114 of the above embodiments, the expansion balloon 132 has a proximal biconvex portion 138 between the proximal tapered portion 136 and the central portion 140. The proximal biconvex portion 138 has a spherical shape with a biconvex profile. 7B, the proximal and distal ends of proximal biconvex portion 138 each have a proximal biconvex portion minimum diameter D138_MIN, and the center of proximal biconvex portion 138 has a proximal biconvex portion maximum diameter D138_MAX. Central portion 140 has a curved tapered profile with a central portion maximum diameter D140_MAX at its proximal end closest to proximal tapered portion 136, and a central portion minimum diameter D140_MIN at its distal end closest to distal portion 142.

[0044] 5A-5D, the distal portion 142 of the expansion balloon 132 has a curved, biconvex profile. As shown in FIG. 7B, the distal portion has a minimum diameter D142_MIN at each of its proximal and distal ends, and a maximum diameter D142_MAX at its center. The distal portion 142 also has a distally facing surface 146, which in this embodiment is flat. The outer circumferential surface of the expansion balloon 132 can be continuous and smooth over at least the proximal tapered portion 136, the proximal biconvex portion 138, the central portion 140, and the distal portion 142.

[0045] In the embodiment shown in FIG. 7B, the relationship between the diameters of the proximal neck portion 134, the proximal tapered portion 136, the proximal biconvex portion 138, the central portion 140, the distal portion 142, and the distal neck portion 144 is as follows: D134 = D144 = D136_MIN < D136_MAX = D138_MIN = D140_MIN = D142_MIN < D142_MAX < D138_MIN = D140_MAX < D138_MAX. That is, in contrast to the embodiments shown in FIGS. 5A-5D and FIGS. 6A-6C, the portion of the expanded balloon 132 having the largest diameter is not the distal portion 142, but the proximal biconvex portion 138. However, the relationship between the diameters of the proximal neck portion 134, the proximal tapered portion 136, the proximal biconvex portion 138, the central portion 140, the distal portion 142, and the distal neck portion 144 is not limited to these relationships and may be different.

[0046] FIG. 7C is an enlarged view showing the surface 146 facing the distal side of the expanded balloon 132. In particular, FIG. 7C shows the right angle formed between the distal surface 146 of the expanded balloon 132 and the distal neck portion 144. That is, in the embodiments shown in FIGS. 7A-7C, the surface 146 facing the distal side is perpendicular to the outer peripheral surface of the distal neck portion 144 of the expanded balloon 132. Although the surface 146 facing the distal direction is shown as a flat surface, the surface 146 facing the distal direction is not so limited and may be curved, concave, or convex, or may include recesses.

[0047] FIG. 8 shows a method 800 of using the medical device 32 during endoscopic surgery. In step 802, the medical device 32 is advanced into the lumen of the patient, such as the duodenum 18. In this step, the medical device 32 is advanced within the duodenoscope 16 disposed within the duodenum 18 of the patient's gastrointestinal tract. The distal opening 20 of the duodenoscope 16 can be arranged to face the inflated portion of the fartor inflated portion 22. The guide wire 48 is advanced through the medical device 32, the distal opening 20, and the fartor inflated portion 22 and into the bile duct 12. As shown in FIG. 2, the treatment portion 38 (contracted, shortened state) of the medical device 32 is advanced on the guide wire 48 and disposed within the bile duct 12.

[0048] Next, at step 804, the removal member 46, here a balloon, is positioned distally of the material 10, as shown in FIG. 2. At step 806, the dilation balloon 44 is positioned proximally of the material 10, as shown in FIG. 2. At step 808, the dilation balloon 44 is inflated. At step 810, the removal member 46 is pulled proximally (i.e., back toward the duodenum 18) to remove the material 10 from the bile duct 12. In this step, the material 10 is sandwiched between the removal member 46 and the distal-facing surface 86 of the dilation balloon 44. That is, while the removal member 46 is pulled proximally, the dilation balloon 44 is held stationary and the material 10 is pressed into the space formed by the concave distal-facing surface 86 until the material 10 is sandwiched and secured between the removal member 46 and the dilation balloon 44. The dilatation balloon 44 and the removal member 46 are movable separately from one another due to the dilatation balloon 44 being attached to the sheath 42 and the removal member 46 being attached to the tube 40, which is movable relative to the tube 40. Additionally, the dilatation balloon 44 and the removal member 46 are inflatable separately from one another due to circumferential openings 74 in the sheath 42, through which fluid can pass to inflate the dilatation balloon 44, and circumferential openings 104 in the tube 40, through which fluid can pass to inflate the removal member 46.

[0049] The treatment portion 38 (including the removal member 46 and dilation balloon 44) may then be withdrawn from the bile duct 12. In one embodiment, the duodenoscope 16 and instrument 32 may then both be removed from the patient's body. In another embodiment, all or a portion of the instrument 32 may be pulled back into the duodenoscope 16 through the distal opening 20, and the medical instrument 32, including the removed material 10, may then be removed from the patient's body.

[0050] Although method 800 is described as including steps 802 through 810, method 800 may include additional steps. For example, prior to performing step 804 of positioning a removal member 46 distal to object 10, method 800 may include cannulating bile duct 12, placing a guidewire 48 therein, advancing medical device 32 into duodenum 18 until distal tip 50 of medical device 32 is positioned against ampulla of Vater 22, and advancing treatment portion 38 over guidewire 48 into bile duct.

[0051] Moreover, if the removal member 46 is a balloon, the method 800 may also include the additional step of inflating the removal member 46. The step of inflating the removal member 46 may be performed after step 804, in which the removal member 46 is positioned beyond the distal side of the material, before, simultaneously with, or after step 808, in which the dilation balloon 44 is inflated. The method 800 may also include the step of withdrawing the material 10 sandwiched between the inflated removal member 46 and the inflated dilation balloon 44 from the bile duct 12 and into the duodenum 18. The method 800 may also include the step of deflating the removal member 46 and the dilation balloon 44 prior to withdrawing the material 10 into the duodenum 18.

[0052] Additionally, if the material 10 is particularly difficult to move using the steps of method 800 described above, in an alternative embodiment, method 800 may further include the steps of deflating the dilation balloon 44, moving the dilation balloon 44 proximally within the bile duct 12, and then re-inflating the dilation balloon 44. The removal member 46 may then be pulled proximally to move the material 10 toward the dilation balloon 44. These steps may be repeated until the material 10 is free to move or is removed from the bile duct 12.

[0053] In an alternative embodiment, the expansion balloon 44 and the removal member 46 may be expanded, or inflated, and moved simultaneously. In another alternative embodiment, the method 800 may include injecting a contrast agent into the bile duct 12 via the contrast port 58 and the contrast lumen 108 to form a fluoroscopic image of the material 10 and the size and complexity of the bile duct. In this alternative embodiment, the contrast agent may be injected before or after step 804, in which the removal member 46 is positioned distal to the material 10.

[0054] In yet another alternative embodiment, the method 800 may include using the marker bands 88 and 90 to confirm the location of the dilatation balloon 44 within the bile duct 12. That is, the marker bands 88, 90 may be used to confirm that at least the central portion 80 of the dilatation balloon 44 is disposed within the ampulla of Vater 22, and that at least the distal portion 82 of the dilatation balloon 44 is disposed within the interior of the bile duct 12. Confirming the location of at least the central portion 80 and the distal portion 82 of the dilatation balloon 44 may be performed prior to step 808 of inflating the dilatation balloon 44.

[0055] In yet another alternative embodiment, the method 800 may include an additional step of inflating the expansion balloon 148 to a second or subsequent expansion diameter D148_2 after inflating the expansion balloon 148 to a first or initial expansion diameter D148_1 in step 808, as shown in FIG. 9. In this alternative embodiment, if the material 10 is, for example, a large stone located in the bile duct, further expansion of the ampulla of Vater 22 is required to remove the stone from the bile duct 12. Thus, the expansion balloon 148 is inflated to a first expansion diameter D148_1 in step 808, and before the extraction balloon 46 is pulled proximally in step 810, the expansion balloon 148 may be further inflated to a second expansion diameter D148_2. The expansion balloon 148 in this embodiment may have the same structure as the expansion balloon 44 shown in FIGS. 5A-5D, the expansion balloon 114 shown in FIGS. 6A-6C, or the expansion balloon 132 shown in FIGS. 7A-7C. The expansion balloon 148 includes at least a distal portion 150 having a maximum diameter D150_MAX of the distal portion. The first inflated diameter D148_1 and the second inflated diameter D148_2 may be defined with respect to the maximum diameter D150_MAX of the distal portion of the expansion balloon 148, i.e., relative to the longitudinal axis AA of the expansion balloon 148, across the center of the distal portion 150, as shown in FIG.

[0056] Additionally, in another alternative embodiment, the retrieval member 46 may be a retrieval mesh 152, as shown in Figure 10. The medical device 32 may be the same as or similar to that shown in Figure 3. According to this alternative embodiment, the method 800 may further include deploying the retrieval mesh 152 after positioning the retrieval mesh 152 distal to the material 10.

[0057] In yet another alternative embodiment, the dilation balloon can be formed of a sponge material, i.e., an expansion sponge. In this alternative embodiment, the expansion sponge is housed within the sheath 40 until the medical device 32 is placed within the bile duct 12. The expansion sponge can then be deployed, i.e., extended outside the sheath 40, and cause the bile duct 12 to dilate and expand. The expansion sponge can function in a similar manner to the dilation balloon 44 described above, in that the expansion sponge dilates the bile duct 12 and the ampulla of Vater 22 during removal of material 10 from the bile duct 12.

[0058] Further, in another alternative embodiment, the dilatation balloon 154 may include a recess 156 in a distally facing surface 158 of the dilatation balloon 154, as shown in Figures 11A-11C. The recess 156 extends proximally within a distal portion 160 of the dilatation balloon 154 from the distally facing surface 158 to a depth D156 that is less than or equal to the length of the distal portion 160. More specifically, the recess may have a depth D156 that is less than or equal to half the length of the distal portion 160. In this alternative embodiment, the removal member 46 is a balloon that is positioned distal to the material 10 and inflated within the bile duct 12, and the dilatation balloon 154 is positioned proximally to the material 10 and inflated, as shown in Figure 11A. 11B, as the removal member 46 is pulled proximally in step 810, the dilation balloon 154 remains stationary and the removal member 46 displaces the material 10 within the bile duct 12 into the recess 156 of the inflated dilation balloon 154. Then, in a next step, the removal member 46 and the dilation balloon 154 may be deflated to trap or enclose the material 10 within the recess 156, as shown in FIG. 11C. The treatment portion 38 may then be withdrawn from the bile duct 12 to safely and securely remove the material 10 from the bile duct 12.

[0059] In a modification of the embodiment described with respect to FIGS. 11A-11C, the expansion balloon 154 has a fluid injection channel in addition to the recess 156. The fluid injection channel may be coupled to the fluid injection lumen of the tube 50. In this alternative embodiment, the method 800 may include a step of fracturing the material 10 after positioning the removal member 46 distal to the material 10 and prior to pulling the removal member 46 proximally, step 810. The step of fracturing the material 10 may include, for example, supplying a fluid (e.g., water) at high pressure to the fluid injection channel. As the water exits the water injection channel, the water is directed at the material to fracturize the material 10 into relatively small sized pieces. The expanded removal member 46 prevents the small pieces of the material 10 from migrating distally in the bile duct. The removal member 46 may then be pulled proximally, step 810, thereby moving the pieces of the material 10 into the recess 156 of the expansion balloon 154. In a next step, the removal member 46 and the expansion balloon 154 may be deflated, thereby trapping the material 10 within the recess 156. The treatment portion 38 may then be withdrawn from the bile duct 12 in order to safely and securely remove the material 10 from the bile duct 12.

[0060] Although the medical instrument 32 is described as being used during endoscopic surgery, the medical instrument 32 may be used in other medical procedures, such as, for example, a procedure to remove kidney stones. Thanks to the medical device 32 of the present invention, material 10 can be safely and reliably removed from a patient's bile duct 12 while preventing trauma to the wall of the bile duct 12. The removal member 46 and the dilatation balloon 44 function to trap the material 10 between them, preventing abrasion or laceration of the wall of the bile duct 12 by the material 10.

[0061] 5A-5C , the dilation balloon 44 enlarges the bile duct 12 just proximal to the material 10, reducing potential trauma to the bile duct 12 caused by the material 10 and improving maneuverability of the medical instrument 32. Additionally, the proximal tapered portion 78 of the dilation balloon 44 allows for gradual dilation of the ampulla of Vater 22 at the entrance to the duodenum 18 (i.e., the opening between the bile duct 12 and the duodenum 18). Additionally, as described above, the central portion 80 of the dilation balloon 44 acts as an "anchor" that reduces the likelihood of the dilation balloon moving in and out of the ampulla of Vater 22 during endoscopic surgery.

[0062] The dilation balloon 114 of the embodiment shown in FIGS. 6A-6C is similarly provided to dilate the bile duct 12 immediately proximal to the material 10, which reduces potential trauma to the bile duct 12 caused by the material 10 and improves maneuverability of the medical instrument 32. The shape of the distally facing surface 130, including its concave portion, provides a relatively more secure capture of the material 10 during the procedure. Similar to the proximal tapered portion 78 of the dilation balloon 44, the proximal tapered portion 118 of the dilation balloon 114 allows for gradual dilation of the ampulla of Vater 22 at its entrance to the duodenum 18. Additionally, similar to the central portion 80 of the dilation balloon 44, the central portion 120 of the dilation balloon 114 functions as an "anchor" that reduces the likelihood of the dilation balloon moving in and out of the ampulla of Vater 22 during the endoscopic procedure.

[0063] Furthermore, the expandable balloon 132 of the embodiment shown in FIGS. 7A-7C similarly expands the bile duct 12 immediately proximal to the substance 10 to reduce potential trauma to the bile duct caused by the substance 10 and to improve the operability of the medical instrument 32. Similar to the proximal tapered portion 78 of the expandable balloon 44, the proximal tapered portion 136 of the expandable balloon 132 allows for a gradual expansion of the fatter dilation portion 22 at the entrance to the duodenum. Furthermore, similar to the central portion 80 of the expandable balloon 44, the central portion 140 of the expandable balloon 132 functions as an "anchor" that reduces the possibility of the expandable balloon entering and exiting the fatter dilation portion 22 during the endoscopic procedure. The expandable balloon 132 of this embodiment, and in particular, the proximal biconvex portion 138 of the expandable balloon 132, accommodates variations in the biological structure that may require a relatively large portion of the expandable balloon 132 at the proximal end of the treatment portion 38, which is closest to the duodenum 18, during the endoscopic procedure.

[0064] Furthermore, as described herein, by positioning and inflating the expandable balloon 44 of the medical instrument 32, the lumen proximal to the substance 10 can be enlarged or expanded in a controlled manner, thereby reducing the force required to pull the substance 10 outside the bile duct 12 and reducing the risk of rupture of the retrieval member 46 when the retrieval member 46 is a balloon. The hourglass shape of the expandable balloon 44 allows for a smooth elongation of the bile duct 12 and / or the fatter dilation portion 22 during the endoscopic procedure, particularly during the withdrawal of the substance 10. Furthermore, if the patient's bile duct 12 is an "S-shaped" bile duct, for example, curved or crescent-shaped, the expandable balloon 44 expands the bile duct 12 and reduces the need for torque applied by the operator performing the procedure.

[0065] Additionally, by virtue of the medical instrument 32 and associated method 800 described herein, a single device is provided for use during endoscopic procedures such as EPBD. As a result, problems associated with using multiple devices, such as device entanglement during device insertion or exchange, loss of guidewire position, increased costs associated with the procedure, increased time required to complete the procedure, increased invasiveness and exacerbation of the patient's gastrointestinal tract, and increased risk to the patient of infection or injury, can be eliminated or reduced.

[0066] While the principles of the invention have been described herein with reference to illustrative examples of specific applications, it should be understood that the invention is not limited thereto. Those skilled in the art and with access to the teachings provided herein will recognize that additional modifications, applications, and equivalent substitutions are all within the scope of the embodiments described herein. Thus, the invention should not be considered as limited by the above description.

Claims

1. Tube and a sheath disposed around the tube and coaxial with the tube; an inflatable balloon at a distal end of the sheath and configured to receive fluid from the lumen of the sheath; a central opening along a longitudinal axis of the balloon, the central opening having the tube extending therethrough; A proximal portion; a central portion adjacent to and distal to the proximal portion; a distal portion adjacent to and distal to the central portion; the balloon, in response to inflation, having a maximum diameter of the central portion that is equal to or less than a maximum diameter of the proximal portion and less than a maximum diameter of the distal portion; a removal member provided at a distal end of the tube, the removal member being located distal to the balloon and axially movable relative to the balloon; A medical device wherein a distally facing surface of the distal portion of the balloon is concave.

2. The medical device of claim 1 , wherein the distal end of the sheath is disposed within the central opening of the balloon.

3. The medical instrument of claim 1 or 2, wherein the removal member has a central opening along a longitudinal axis, and the tube extends into the central opening.

4. The medical device of any one of claims 1 to 3, wherein the removal member is one of a balloon and a mesh configured to receive fluid from the lumen of the tube.

5. The medical device of any one of claims 1 to 4, wherein the proximal portion of the balloon comprises a proximal tapered portion.

6. The medical device of any one of claims 1 to 5, wherein the proximal portion of the balloon includes a distal portion having a spherical shape and a proximal tapered portion.

7. The medical device of any one of claims 1 to 6, wherein the distal portion of the balloon has a cylindrical shape relative to a longitudinal axis of the balloon.

8. The medical device of any one of claims 1 to 6, wherein the distal portion of the balloon has a spherical shape relative to a longitudinal axis of the balloon.

9. The medical device of any one of claims 1 to 8, wherein the maximum diameter of the proximal portion is equal to the maximum diameter of the central portion of the balloon.

10. The medical device of any one of claims 1 to 8, wherein the maximum diameter of the proximal portion is smaller than the maximum diameter of the distal portion of the balloon.

11. The medical device of any one of claims 1 to 10, wherein a length of the proximal portion of the balloon is longer than a length of the distal portion of the balloon and a length of the central portion of the balloon relative to a longitudinal axis of the balloon, and the length of the central portion is less than or equal to the length of the distal portion.

12. The medical device of any one of claims 1 to 11, wherein the tube includes a distal opening, and the lumen of the tube receives a guidewire that can extend beyond the distal opening of the tube.

13. 13. The medical device of any one of claims 1 to 12, wherein the distally facing surface of the distal portion of the balloon forms a recess extending radially inward and proximally toward the central portion of the balloon.

14. 14. The medical device of claim 13, wherein the recess extends proximally to a depth less than half the longitudinal length of the distal portion of the balloon.

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