WO2025071553A1

WO2025071553A1 - Implant delivery devices

Info

Publication number: WO2025071553A1
Application number: PCT/US2023/033798
Authority: WO
Inventors: Hiep Do; Chad Van Liere; Andrzej J. Chanduszko
Original assignee: ClearStream Technologies Ltd
Current assignee: ClearStream Technologies Ltd
Priority date: 2023-09-27
Filing date: 2023-09-27
Publication date: 2025-04-03
Anticipated expiration: 2026-03-27

Abstract

An implant delivery device (100) includes a catheter (102) and a balloon (104) mounted thereon. The catheter has an inflation lumen (112) and a material delivery lumen (114) for inflation of the balloon and for delivery of an implantable material. The catheter defines one or more material delivery ports (124) in fluid communication with the material delivery lumen. The balloon includes a balloon lumen in fluid communication with the inflation lumen, and that branches off of the inflation lumen. The inflated balloon extends to a position proximal and distal to the one or more material delivery ports, and provides a control barrier to delivery of the implantable material.

Description

IMPLANT DELIVERY DEVICES

TECHNICAL FIELD

[0001] The present specification generally relates to implant delivery devices and methods and, more specifically, implant delivery devices and methods for precision controlled delivery of an implantable material at a target location.

BACKGROUND

[0002] During radiation treatment of cancerous tissue, radiation may at times be reflected from treated tissue or otherwise inadvertently directed to non-targeted heathy tissue. For example, during radiation treatment of prostate cancer, radiation may be reflected or otherwise inadvertently directed away from the prostate toward the rectum. To protect healthy tissue from inadvertent radiation, a layer of temporary blocking implantable material (such as hydrogel) may be positioned between the target tissue (e.g., the prostate) and healthy tissue (e.g., the rectum).

[0003] However, during implantation when the hydrogel is initially in a liquid form, the implanted hydrogel can leak outside of a target area, and such leakage to adjacent organs and anatomical structures may cause pain or discomfort. Such leakage may also lead to non- uniform or insufficient thickness of the spacer as it cures, thereby resulting in non-optimal radiation protection.

[0004] Accordingly, a need exists for implant delivery devices and methods for implantation of a hydrogel or other curable material, which reduces leakage.

BRIEF SUMMARY

[0005] Embodiments of the present disclosure are directed to implant delivery devices and methods for precision controlled delivery of hydrogel or other implantable material, which results in reduced leakage, thereby reducing potential undesirable side effects and providing for improved radiation spacers.

[0006] In one embodiment, an implant delivery device includes a catheter and a balloon. The catheter has an inflation lumen and a material delivery lumen for delivery of an implantable material. The catheter defines one or more material delivery ports in fluid communication with the material delivery lumen. The balloon includes a balloon lumen and mounts to the catheter. The balloon lumen is in fluid communication with the inflation lumen. The balloon lumen branches off of the inflation lumen and extends to a position proximal and distal to the one or more material delivery ports.

[0007] Another embodiment of an implant delivery device includes a catheter, a first balloon, and a second balloon. The catheter has one or more inflation lumens and a material delivery lumen for delivery of an implantable material. The catheter defines one or more material delivery ports in fluid communication with the material delivery lumen. Each of the first balloon and the second balloon are mounted to the catheter and define a respective balloon lumen in fluid communication with an inflation lumen of the one or more inflation lumens, the respective balloon lumen branching off the one or more inflation lumens of the catheter and extending to a respective position proximal and distal to the one or more material delivery ports

[0008] In yet another aspect, a method of implanting an implantable material is disclosed. The method includes advancing an implant delivery device to a target location. The implant delivery device includes a catheter having an inflation lumen and a material delivery lumen for delivery of the implantable material, wherein the catheter defines one or more material delivery ports in fluid communication with the material delivery lumen, and a balloon including a balloon lumen and mounted to the catheter. The balloon lumen is in fluid communication with the inflation lumen, wherein balloon lumen branches off of the inflation lumen and extends to a position proximal and distal to the one or more material delivery ports. The method also includes inflating the balloon thereby defining an injection boundary along a contour of the target location, injecting the implantable material to the target location within a region defined by the injection boundary, curing the implantable material thereby providing a cured implantable material, deflating the balloon, and withdrawing the implant delivery device from the target location while leaving the cured implantable material at the target location.

[0009] These and additional features provided by the embodiments described herein will be more fully understood in view of the following detailed description, in conjunction with the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The embodiments set forth in the drawings are illustrative and exemplary in nature and not intended to limit the subject matter defined by the claims. The following detailed description of the illustrative embodiments can be understood when read in conjunction with the following drawings, where like structure is indicated with like reference numerals and in which:

[0011] FIG. 1 A schematically depicts implant delivery device for delivering an implantable material including a catheter and a balloon in a deflated configuration, according to one or more embodiments shown and described herein;

[0012] FIG. IB schematically depicts the control device of FIG. 1A with the balloon in an inflated configuration, according to one or more embodiments shown and described herein;

[0013] FIG. 1C schematically illustrates a longitudinal cross-section of the implant delivery device of FIG. IB, accordingly to one or more embodiments shown and described herein;

[0014] FIG. ID schematically illustrates a cross-section of the implant delivery device of FIG. 1C taken along line ID- ID, accordingly to one or more embodiments shown and described herein;

[0015] FIG. 2 illustrates a flowchart depicting a method of implanting an implantable material with a delivery device such as shown in FIGS. 1A-1D, according to one or more embodiments shown and described herein.

[0016] FIG. 3 A schematically illustrates a guidewire inserted into an incision, according to one or more embodiments shown and described herein;

[0017] FIG. 3B schematically illustrates an inserted and expanded implant delivery device of FIGS. 1A-1D over the guidewire of FIG. 3A, according to one or more embodiments shown and described herein;

[0018] FIG. 3C schematically illustrates delivery of implantable material via the implant delivery device into the target location of FIG. 3B, according to one or more embodiments shown and described herein; [0019] FIG. 3D schematically depicts a cross section along line 3D-3D of FIG. 3C, according to one or more embodiments shown and described herein;

[0020] FIG. 3E schematically depicts the cross section of FIG. 3D of remaining implantable material after removal of the control device of FIG. 3B, according to one or more embodiments shown and described herein;

[0021] FIG. 4A schematically depicts an implant delivery device including a catheter, a first balloon, and a second balloon in a deflated configuration, according to one or more embodiments shown and described herein;

[0022] FIG. 4B schematically depicts an embodiment of the implant delivery device of FIG. 4A an inflated configuration, according to one or more embodiments shown and described herein;

[0023] FIG. 4C schematically depicts a longitudinal cross section of the implant delivery device of FIG. 4B, according to one or more embodiments shown and described herein;

[0024] FIG. 4D schematically depicts a more detailed view of region 4D of FIG. 4C, according to one or more embodiments shown and described herein;

[0025] FIG. 5 illustrates a flowchart depicting a method of delivery implanting an implantable material, according to one or more embodiments shown and described herein.

[0026] FIG. 6A schematically illustrates a guidewire inserted into a target site, according to one or more embodiments shown and described herein;

[0027] FIG. 6B schematically illustrates an inserted and expanded implant delivery device of FIGS. 4A-4D into the incision of FIG. 6A, according to one or more embodiments shown and described herein;

[0028] FIG. 6C schematically illustrates delivery of implantable material via the implant delivery device into the target location of FIG. 6B, according to one or more embodiments shown and described herein; [0029] FIG. 6D schematically depicts a cross section of implant delivery device of implantable material of FIG. 6C taken along line 6D-6D, according to one or more embodiments shown and described herein; and

[0030] FIG. 6E schematically depicts the cross section of remaining implantable material after removal of the implant delivery device of FIG. 6D, according to one or more embodiments shown and described herein.

DETAILED DESCRIPTION

[0031] The present disclosure is directed to implant delivery devices and methods for delivery of implantable materials. For example, systems and methods as described herein may be used for precision controlled implantation of hydrogel materials for use as, for example, radiation spacers. Radiation spacers may be used to shield healthy tissue from radiation directed toward diseased or cancerous tissue. For example, radiation therapy for prostate cancer can take the form of placement of brachytherapy seeds into the prostate or external beam radiation therapy. Scatter radiation from these techniques, however, provides a significant risk to adjacent organs. As radiation therapy technology and administration techniques have improved, a significant limiting factor to dose administration is the risk of rectal toxicity from scatter radiation. Implant delivery devices and methods as described herein assist in the implantation and/or formation of radiation spacers to provide improved shielding to reduce the risk of radiation impacting non-targeted tissue.

[0032] In at least one embodiment, radiation spacers may be useful in the separation of healthy rectal tissue from treated prostate tissue, for example, during radiation treatment. Because radiation dose is inversely proportional to the distance squared, separating the prostate (for example) from the rectum with a radiation spacer can significantly lower the non-targeted tissue’s exposure to radiation. The radiation spacer thus may act as a radiation shield. In at least one embodiment, an implant delivery device includes a catheter for delivery of implantable material and a balloon (or plurality of balloons) that may be inflated. The catheter may have or include an inflation lumen and a material delivery lumen. The inflation lumen may be in fluid communication with the balloon allowing for inflation of the balloon. When inflated, the balloon may define an injection boundary for implantable material to be injected and may hold the implantable material in so as to reduce leakage of the implantable material from a target location. That is, the implant delivery device may provide a controlled zone for formation of a radiation spacer. These and additional embodiments and benefits will be described in greater detail below.

[0033] As used herein, the term “proximal” means closer to or in the direction of an origin of an element, such as a handle or other user-manipulated portion of a device. The term “distal” means further from the origin, such as toward a tip of the element. Objects or structures and point of reference can vary based on context, and it is to be appreciated that the terms are to be understood in the context of the discussion.

[0034] Turning to FIGS. 1A-1D, an embodiment of an implant delivery device 100 is generally depicted. As shown in FIG. 1 A, the implant delivery device 100 generally includes a catheter 102 and a balloon 104 mounted to the catheter 102. The implant delivery device 100 may further include a guidewire 106. Catheter 102 may define lumens as discussed herein. It is to be appreciated that in some embodiments, the implant delivery device 100 may further include a pump, syringe, or similar device (not shown) for delivery of implantable material. In various embodiments, a greater or fewer numbers of components may be included without departing from the scope of the present disclosure.

[0035] The catheter 102 may be an elongate, flexible tube that defines or contains one or more lumens therethrough. For example, and with reference to FIG. ID, in some embodiments, the catheter 102 may define a single main lumen 108 (best depicted in FIG. ID) sized to receive the one or more tubes (as described herein) or be formed to define one or more lumens (e.g., a guidewire lumen 110, an inflation lumen 112, and/or a material delivery lumen 114) as will be described in greater detail below. In other words, embodiments may include the catheter 102 itself to be formed so as to define discrete lumens such as including a guidewire lumen 110, an inflation lumen 112, and/or a material delivery lumen 114, or the discrete lumens may be provided by way of tubes, fitting within the single main lumen 108.

[0036] In the depicted embodiment, the catheter 102 includes a guidewire tube 110 defining a guidewire lumen, an inflation tube 112 defining an inflation lumen 112, and a material delivery tube 114 defining a material delivery lumen, each of which may be received within the single main lumen 108 of the catheter 102. Each tube, inclusive of catheter 102, may be formed of a flexible material such as, for example, pebax, nylon, polyurethane, polyethylene terephthalate (PET), any thermoplastic polymers, etc. In the interest of brevity, a tube and its respective lumen may be designated by the same name, and it is to be understood in the context of use whether a tube or its lumen is intended. In embodiments, a combination of separate tubes and the catheter lumen 108 may be used to provide the various inflation lumen 112, material delivery lumen 114, and guidewire lumen 110. For example, the lumen 108 of the catheter 102 may be used to providing the guidewire lumen 110, and a separate inflation tube and material delivery tube may be used for providing an inflation lumen 112 and material delivery lumen 114. Any combination is contemplated and possible.

[0037] Turning briefly to FIG. IB, it is to be appreciated that for illustrative purposes, the proximal portion 116 of the catheter 102 may define a centerline 120. As will be described in greater detail below, the balloon 104 may branch asymmetrically from the catheter 102 as shown and described.

[0038] Referring now to the balloon 104, in FIG. 1A the balloon 104 is illustrated in a deflated configuration. In the deflated configuration, the implant delivery device 100 may have a smaller or reduced radial profile to aid in insertion of the implant delivery device 100 to a desired location (such as between diseased and healthy tissue). FIG. IB and 1C illustrate the balloon 104 in an inflated configuration. In the inflated configuration, the implant delivery device 100 has a larger radial profile than in the deflated configuration. As will be described in greater detail below, once deployed in a desired region, the implant delivery device 100 (e.g., the balloon 104 and the catheter 102) may take on a curved configuration to enclose or substantially enclose a target location 122. For example, it is to be appreciated that as inflated and/or prior to inflation, but deployed within a desired location, the balloon 104 may circumscribe or most nearly circumscribe a target zone (or location) 122. In the embodiments described herein, it should be further appreciated that the balloon 104 may include a cross-section having a non-circular shape, such as an elliptical shape, a D-shape, a kidney-shape, a tear-drop shape, a triangular shape, or any other similar shape without departing from the scope of the present disclosure.

[0039] As best depicted in FIG. 1C, which depicts a longitudinal cross section through the implant delivery device 100, the catheter 102 defines one or more (such as a plurality of) material delivery ports 124 in fluid communication with the material delivery lumen 114. The plurality of material delivery ports 124 may be arranged in an array 126 opposite the balloon 104, such that the balloon 104 is positioned outer to the one or more material delivery ports 124. The plurality of material delivery ports 124 may include any number of ports such as two or more, three or more, four or more, five or more, six or more, etc. Each of the plurality of material delivery ports 124 may be the same size or may vary in size from one another. Moreover, the plurality of material delivery ports 124 may be equally spaced or unequally spaced from one another. As noted, the one or more material delivery ports 124 are in fluid communication with the material delivery lumen 114. For example, the material delivery lumen 114 may also define ports that align with the material delivery ports 124 of the catheter 102. Accordingly, the material delivery ports 124 may be used to deliver implantable material 128 (e.g., hydrogel material such as but not limited to Chitosan, alginate, gelatin, polyethylene glycol hydrogels, PLGA-PEG hydrogel, PLA-PEG hydrogel, PCL-PEG hydrogel, Poly(N-isopropylacrylacrylamide) (PolyNIPAm), etc.) from the material delivery lumen 114, which may be coupled to a reservoir, syringe, or the like (not shown), to the target location 122. The material delivery ports 124 may have any shape such as round, oval, rectangular, etc. Accordingly, material may flow substantially through the material delivery lumen 114 and out various ports 124, or portions thereof. In some embodiments, the size of each of the material delivery ports 124 of the array 126 may vary from one another. For example, the size of the material delivery ports 124 may be arranged along a gradient such as smaller to larger in a proximal to distal direction. Such arrangement may reduce resistance during material delivery and ensure more even diffusion of implantable material 128 to the target location 122.

[0040] At the distal end 118 of the catheter 102 may be a tip 130. The tip 130 may be rounded, such as to be atraumatic. In embodiments, the tip 130 may be tapered to aid in insertion of the tip 130 into a target location 122. In some embodiments, the tip 130 may be a cap affixed over the distal end 118 of the catheter 102. In some embodiments, the tip 130 may be configured to be pierceable by a guidewire 106, so as to enable the distal end 118 to follow a pre-inserted guidewire 106, for example.

[0041] The guidewire 106 may be sized to be received within the guidewire lumen 110. In various embodiments, the guidewire 106 may be formed of a memory shape material (e.g., Nitinol, etc.), zinc, copper, gold, and/or iron alloys, or any other similar material. For example, the guidewire 106 may be pre-shaped to fit within a desired treatment area. That is, the guidewire 106 may have a curved distal end 118. As the catheter 102 is advanced over the guidewire 106, the curved distal end 118 may cause the catheter 102 to curve and conform to the shape of the guidewire 106, as depicted, to provide a curved shape. Accordingly, the guidewire 106 may assist in bending the catheter 102 to a desired curved shape for delivery of implantable material 128.

[0042] In some embodiments, it is contemplated that instead of or in addition to the guidewire 106 providing a curvature, the catheter 102 and/or the balloon 104 may be biased to the curved shape. For example, the catheter 102 and/or the balloon 104 may include shape memory material (not shown) which bends the implant delivery device 100 into a desired configuration. For example, the catheter 102 and/or the balloon 104 may include a Nitinol support ribbon (not shown), or similar shape member material, to bend the implant delivery device 100 to the curved configuration. The balloon 104 may be coupled to the catheter 102 via any suitable coupling technique such as through adhesives, welds, etc. Turning particularly to FIG. 1C, the balloon 104 defines a balloon lumen 132, which is in fluid communication with the inflation lumen 112, such that an inflation fluid (e.g., water, saline, or the like) may be delivered to the balloon lumen 132 via the inflation lumen 112 to inflate the balloon 104, as depicted in FIG. 1C). It is to be appreciated that while a single opening 134 between the inflation lumen 112 and the balloon lumen 132 is portrayed, any desired predetermined number of openings may be defined between the balloon lumen 132 and the inflation lumen 112, and the openings may have any shape such as round, oval, rectangular, etc. In some embodiments, the size of each of the openings may vary from one another. For example, the size of the openings may be arranged along a gradient such as smaller to larger in a proximal to distal direction. Accordingly, the inflation lumen 112, which may be fluidically coupled to an inflation fluid source such as a syringe, reservoir, etc., may be selectively used to inflate the balloon 104. The balloon 104 may be fabricated from any suitable material such as polyurethane, PVC, Pebax, nylon, PET, thermoplastic polymers, or the like.

[0043] As illustrated, the one or more material delivery ports 124 may be positioned along the catheter 102 opposite to the balloon 104. In particular, and as shown, the balloon 104 and/or the balloon lumen 132 branches off of or away from the catheter 102 (e.g., the inflation lumen 112) and extends to a position proximal and distal to the one or more material delivery ports 124. In embodiments, the balloon 104 may be coupled to catheter 102 along a length 136 of the catheter 102 defined by or extending beyond the one or more material delivery ports 124. Accordingly, when in a curved shape as depicted, balloon 104 may act as a barrier at positions of the one or more material delivery ports 124, to maintain delivered implantable material 128 within the target location 122.

[0044] In embodiments, and to aid in removal of the implant delivery device 100, (an inner surface and/or an outer surface) of the implant delivery device 100 (such as the balloon 104 and the catheter 102) may be coated with one or more coatings to aid in removal of the implant delivery device 100 from cured implantable material. For example, the implant delivery device 100 may be coated with hydrophobic materials (e.g., PVDF-HFP), self-lubricated silicone, Acetal, or the like.

[0045] Turning to FIG. 2, a flow chart illustrating a method 200 of implanting an implantable material 128 using an implant delivery device such as described above is generally depicted. It is noted that while a number of steps are illustrated, a greater or fewer number of steps may be included in any order without departing from the scope of the present disclosure. It is noted the method may be best understood in conjunction with FIGS. 3A-3D, which will be referenced as well.

[0046] At block 202, the method includes advancing an implant delivery device, (for example, implant delivery device 100) to a target location 122. For example, and as noted above, a target location 122 may be any location in which a radiation spacer implant is desired, such as between a prostate and a rectum, or any diseased or cancerous tissue and adjacent healthy or non-targeted tissue. It is to be appreciated that prior to advancing an implant delivery device 100, preparation of the area to which radiation protection may be desired may be performed, including, creating an incision 304 (such as via hydrodissection) between the target tissue for radiation and the non-targeted tissue. In embodiments, a dilator (not shown) may be inserted into the incision 304 to dilate the target location 122. A delivery sheath (not shown), may be advanced to the target location 122 for delivery of the implant delivery device 100. As illustrated in FIG. 3 A, prior to advancing the catheter 102, the guidewire 106 may be advanced into the incision 304, such as through the delivery sheath (not shown). As noted above, in some embodiments, the guidewire 106 may be biased to a curved shape, such that the guidewire 106 curves around the target location 122 where the implantable material 128 will be delivered within the incision 304. Positioning of the guidewire 106 may be determined via ultrasound, x-ray, or the like. As disclosed above, guidewire 106 may be of a memory shape material and may be pre-shaped to fit within a treatment area. The catheter 102 may then be advanced over the guidewire 106 such as via the guidewire lumen 110 through tip 130 described above, such that the catheter 102 conforms to the curved shape of the guidewire 106 about the target location 122, as illustrated in FIG. 3B. Ultrasound, x-ray, or the like may be used to confirm the orientation of the one or more material delivery ports 124. For example, a user may twist the catheter 102 to adjust a position of the one or more material delivery ports 124 to be directed inward of the curved shape of the balloon 104 for injection of implantable material 128 into the target location 122 now circumscribed by the implant delivery device 100. In embodiments, an implant delivery device 100 may be shaped in the curved configuration to fit within a dimension of 3.5 mm by 5.2 mm incision, however other dimensions are contemplated and possible based on the particular incision site and implant delivery device 100 dimensions.

[0047] At block 204, the method 200 includes inflating the balloon 104 thereby defining an injection boundary along a contour of the target location 122, as illustrates in FIG. 3B and 3C. As noted above, inflation fluid may be delivered to the balloon 104 via an inflation lumen 112 from an inflation lumen reservoir (e.g., a syringe or the like; not shown). With the balloon 104 positioned to the outside of the one or more implant delivery ports 124, that balloon 104 acts as a barrier to assist in preventing implantable material 128 delivered within the injection boundary from leaking outside of the injection boundary, thereby providing an improved control mechanism for placement and containment of the implantable material 128.

[0048] At block 206, the method includes injecting implantable material 128, such as described above, to the target location 122 within a region defined by the injection boundary (e.g., within the injection boundary). As illustrated in FIG. 3C and 3D, implantable material 128 is delivered via the implant delivery ports 124 or array 126, thereby filling the incision 304 within the injection boundary defined by the balloon 104.

[0049] It is to be appreciated that material delivery lumen 114 may be comprised of a plurality of multiple lumens (not shown). A portion of the plurality of multiple lumens may be used for delivering implantable material 128, while a separate portion of the plurality of multiple lumens may be used to deliver a release fluid such a saline, water or the like, to aid in lubricating and releasing the implant delivery device 100 (or 400 as disclosed herein) from the implanted material. In some embodiments, the release fluid may be pushed through the same lumen of the implantable material 128 after the implantable material 128 cures. In some embodiments, the multiple lumens may have different sizes, for example, one larger lumen may be for delivering of implantable material 128 and a smaller lumen may be for delivering of lubricating fluid. Separate lumens may also be used for maintaining separation of components of particular implantable materials (such as for example, implantable materials that cure in the presence of other implantable materials upon delivery to a target site 122). Such may prevent gelling or curing of the combined implantable materials within the material delivery lumen 114.

[0050] Referring again to FIG. 2, the implantable material 128 may then be allowed to cure in place at block 208, thereby providing a cured implantable material (or radiation spacer), such as for example cured implantable material 138 depicted in FIG. 3E. The delivery implant device 100 may remain in place throughout curing and may be is removed after curing thereby preventing disturbance during the curing phase which may otherwise lead to inconsistent thickness or positioning.

[0051] Once cured, at block 208, the method 200 may include deflating the balloon 104. It is to be appreciated that inflation of the balloon 104 may anchor the implant delivery device 100 within the target location 122 by engaging and applying force to the tissue surrounding the target location 122. With deflating the balloon 104, the force holding the implant delivery device 100 in place may be released, which may allow at block 210 for the implant delivery device 100 to be withdrawn from the target location 122 while leaving the cured implantable material 138 at the target location 122. In such embodiments, the guidewire 106 may also be withdrawn. It is to be appreciated that withdrawal of the guidewire 106 may occur earlier in embodiments as disclosed above in which bias curvature may be maintained by for example a Nitinol strip attached to a balloon 104 or catheter 102. It is noted that implantable materials 128 such as hydrogels may be inherently slippery even when cured, and accordingly, the implant delivery device 100 may be withdrawn as illustrated in FIG. 3E. After withdrawal of the delivery device, it is contemplated that the surrounding tissue may move into fill the void left by the implant delivery device 100.

[0052] Turning to FIGS. 4A-4C, an embodiment of an implant delivery device 400 is generally depicted. As shown in FIG. 4A, the implant delivery device 400 generally includes a catheter 402 that features an interlock shaft 404, a first balloon 406 and a second balloon 408 each mounted to the catheter 402. Catheter 402 may define or house a plurality of lumens as discussed herein. It is to be appreciated that in some embodiments, the implant delivery device 400 may further include a pump, syringe, or similar device (not shown) for delivery of implantable material 128. In various embodiments, a greater or fewer numbers of components may be included without departing from the scope of the present disclosure.

[0053] As in the embodiment described above, the catheter 402 may be an elongate, flexible tube that defines or contains one or more lumens therethrough. For example, in some embodiments, the catheter 402 may define a single main lumen 108 sized to receive the one or more tubes (as described herein) or be formed to define one or more lumens (e.g., a guidewire lumen 110, an inflation lumen 112, and/or a material delivery lumen 114) as will be described in greater detail below. In other words, embodiments may include the catheter 402 itself to be formed so as to define discrete lumens such as including a guidewire lumen 110, an inflation lumen 112, and/or a material delivery lumen 114, or the discrete lumens may be provided by way of tubes, fitting within the single main lumen 108.

[0054] In the depicted embodiment, the catheter 402 includes an inflation tube 112 defining an inflation lumen and a material delivery tube 114 defining a material delivery lumen, each of which may be received within the single main lumen 108 of the catheter 402. Each tube, inclusive of the catheter 402 may be formed of a flexible material such as, for example, pebax, nylon, polyurethane, polyethylene terephthalate (PET), any thermoplastic polymers, etc. In the interest of brevity, a tube and its respective lumen may be designated by the same name, and it is to be understood in the context of use whether a tube or its lumen is intended. In embodiments, a combination of separate tubes and the catheter lumen 108 may be used to provide the various inflation lumen 112, and material delivery lumen 114. For example, the lumen of the catheter 108 may be used to providing an inflation lumen 112, and a separate material delivery tube may be used for providing a material delivery lumen 114. Any combination is contemplated and possible.

[0055] In the depicted embodiment, the inflation tube 112 is positioned concentrically within the single main lumen 108 of the catheter 402. The material delivery tube 114 is positioned concentrically within the inflation tube 112 and extends distally to an end of the inflation tube. Positioned concentrically within the material delivery tube 114, is the interlock shaft 404. In embodiments, positioning of the material delivery tube 114 and/or the inflation tube may be fixed relative to the catheter 402.

[0056] As illustrated in FIGS. 4A and 4B, the catheter 402 may define a centerline 120 or central axis extending through a centroid of the catheter 402. As will be described in greater detail below, the first balloon 406 and the second balloon 408 may branch asymmetrically from the catheter 402 radially away from the centerline 120, as shown. That is, each of the first balloon 406 and the second balloon 408 may branch from the catheter 402 such to be spaced from the centerline 120 of the catheter 402.

[0057] Still referring to FIGS. 4A-4D and as noted above, positioned within the catheter 402 may be the interlock shaft 404. The interlock shaft 404 may extend distally from the catheter 402, so that at least a portion of the interlock shaft 404 extends past an end of the catheter 402. In embodiments, the interlock shaft 404 may be a rod, wire, tube, or the like. The interlock shaft 404 may be slidable relative to the catheter 402 and/or rotatable relative to the catheter 402. For example, the interlock shaft 404 may slide or rotate within the material delivery tube 114 or other portions of the catheter 402. The distal end 118 of the interlock shaft 404 may be atraumatic and/or tapered to aid in insertion of the tip 130 into a desired region.

[0058] Referring specifically to FIG. 4A, the first balloon 406 and the second balloon 408 are illustrated in a deflated configuration. The first balloon 406 and the second balloon 408 may be substantially similar to the balloon described in the embodiment above except as otherwise noted or apparent. Accordingly, like description applies and is not repeated for brevity. As in the embodiment above, in the deflated configuration, the implant delivery device 400 may have a smaller or reduced radial profile to aid in insertion of the implant delivery device 400 to a desired location (such as between diseased and healthy tissue). FIGS. 4B and 4C illustrate the first balloon 406 and the second balloon 408 in an inflated configuration. In the inflated configuration, the implant delivery device 400 has a larger radial profile than in the deflated configuration. It is to be appreciated that in the inflated configuration and/or prior to inflation, the first balloon 406 and a second balloon 408 may curve outward so as to enclose or substantially enclose (e.g., such as circumscribe or most nearly circumscribe) a target zone (or location) 122. [0059] As best depicted in FIG. 4C, which depicts a longitudinal cross section through the implant delivery device 400, the catheter 402 defines one or more (such as a plurality of) material delivery ports 124 in fluid communication with the material delivery lumen 114. The plurality of material delivery ports 124 may be arranged in an array 410 along the catheter 402 between the first balloon 406 and a second balloon 408. The plurality of material delivery ports 124 may include any number of ports such as two or more, three or more, four or more, five or more, six or more, etc., as may be pre-determined. Each of the plurality of material delivery ports 124 may be the same size or may vary in size from one another. Moreover, the plurality of material delivery ports 124 may be equally spaced or unequally spaced from one another. As noted, the one or more material delivery ports 124 are in fluid communication with the material delivery lumen 114. Accordingly, the material delivery ports 124 may be used to deliver implantable material 128, as described above to the target location 122. The ports 124 may have any shape such as round, oval, rectangular, etc. Accordingly, material may flow substantially evenly through the material delivery lumen 114 and out various material delivery ports 124, or portions thereof. In some embodiments, the size of each of the ports 124 of the array 126 may vary from one another. For example, the size of the ports 124 may be arranged along a gradient such as smaller to larger in a proximal to distal direction. Such arrangement may reduce resistance during material delivery and ensure more even diffusion of implantable material 128.

[0060] As depicted and upon inflation, the first balloon 406 and a second balloon 408 may be biased to the curved shape. For example, the first balloon 406 and a second balloon 408 may include shape memory material (not shown) which bends the first balloon 406 and the second balloon 408 into the desired, curved shape. For example, the first balloon 406 and a second balloon 408 may include a Nitinol support ribbon (not shown), or similar shape member material, to bend the first balloon 406 and the second balloon 408 to the curved configuration. In some embodiments, the c-shape, curved portions may be provided via how the balloons 406, 408 are mounted to various components of the implant delivery device 400. For example, proximal portions of first balloon 406 and second balloon 408 may be attached e.g., adhered, welded, or the like) to a distal end 118 of catheter 402 as depicted. Distal portions of the first balloon 406 and the second balloon 408 may be removably coupled to the interlock shaft 404 in a first configuration. In embodiments, the distal portions of the balloons 406, 408 may include mounting structures 409 (e.g., hooks, loops, or the like), that engage with the interlock shaft 404, such that the interlock shaft 404 extends through the mounting structures 409 (though other interlocks are contemplated and possible). In embodiments, the interlock shaft 404 may be pulled or pushed relative to the catheter 402 to adjust a curvature of the balloons 406, 408. However, in other embodiments, pushing or pulling the interlock shaft 404 may not adjust the curvature of the balloons 406, 408. In embodiments, and as will be described in greater detail herein, the interlock shaft 404 may be used to separate the balloons 406, 408 from the distal end 118 of the implant delivery device 400 in a second configuration.

[0061] As noted above, the first balloon 406 and a second balloon 408 may be coupled to the catheter 402 via any suitable fabrication technique such as through adhesives, welds, etc. Turning briefly to FIG. 4B, the first balloon 406 and a second balloon 408 defines respective balloon lumens 132, which are in fluid communication with the inflation lumen 112, such that an inflation fluid (e.g., water, saline, or the like) may be delivered to the respective balloon lumens 132 via the inflation lumen 112 to inflate the first balloon 406 and a second balloon 408, as depicted in FIG. 4C). It is to be appreciated that while a single opening 134 is portrayed providing fluidic communication between the inflation lumen 112 and the balloon lumens 132, any desired number of openings may be defined between the respective balloon lumens 132 and the inflation lumen 112, and the openings may have any shape such as round, oval, rectangular, etc. In some embodiments, the size of each of the openings may vary from one another. For example, the size of the openings may be arranged along a gradient such as smaller to larger in a proximal to distal direction. Accordingly, the inflation lumen 112, which may be fluidically coupled to an inflation fluid source such as a syringe, reservoir, etc., selectively may be used to inflate the balloons 406, 408. The first balloon 406 and a second balloon 408 may be fabricated from any suitable material such as polyurethane, PVC, Pebax, nylon, PET, thermoplastic polymers, or the like.

[0062] As illustrated, the one or more material delivery ports 124 may be positioned along the catheter 402 within the target location 122 created by the first balloon 406 and a second balloon 408. In particular, and as shown, the first balloon 406 and a second balloon 408 and/or the respective balloon lumens 132 branches off of or away from the catheter 402 (e.g., the inflation lumen 112) and extends to a position proximal and distal to the one or more material delivery ports 124. Accordingly, when expanded, the balloons 406, 408 act as a barrier at positions of the one or more material delivery ports 124, to maintain delivered implantable material within the target location 122. In embodiments and as shown, such as where there are a plurality of material delivery ports 124, ports 124 may be arranged so as to face the first balloon 406 and the second balloon 408. In the particular embodiment shown, the first balloon 406 and a second balloon 408 may be de-coupled from the catheter 402 along a length 412 of the catheter 402 including the one or more material delivery ports 124 or array 410.

[0063] In embodiments, and to aid in removal of the implant delivery device 400, (an inner surface and/or an outer surface) of the implant delivery device 400 may be coated with one or more coatings to aid in removal of the implant delivery device 400 from the cured implantable material 138. For example, the implant delivery device 400 may be coated with hydrophobic materials (e.g., PVDF-HFP), self-lubricated silicone, Acetal, or the like.

[0064] To also aid in removal, the interlock shaft 404 may be actuated to allow decoupling of the balloons 406, 408 from the interlock shaft 404. For example, the interlock shaft 404 may be withdrawn from the mounting structures 409 described above. Alternatively, the interlock shaft 404 may be threadingly couple to mounting structures 409 of the balloons 406, 408 and may be unscrewed to be uncoupled from the balloons 408, 408. In some embodiments, the balloons 406, 408 may be mounted to the interlock shaft 404 via breakable connections (e.g., tabs), which break under shear such that rotation of the interlock shaft 404, breaks the connection and allows for withdrawal of the interlock shaft 404 from the balloons 406, 408. Other interlocks are contemplated and possible. In embodiments, removal of the interlock shaft 404 allows distal ends of the first balloon 406 and the second balloon 408 to separate from one another.

[0065] Turning to FIG. 5, a flow chart illustrating a method 500 of implanting an implantable material 128 using the implant delivery device 400 such as described above is generally depicted. It is noted that while a number of steps are illustrated, a greater or fewer number of steps may be included in any order without departing from the scope of the present disclosure. It is noted the method 500 may be best understood in conjunction with FIGS. 4A- 4C as well as FIGS. 6A-6D that will be referenced as well.

[0066] At block 502, the method includes advancing an implant delivery device, (for example, implant delivery device 400) to a target location (for example, a target location 122). For example, and as noted above, a target location may be any location in which a radiation spacer implant is desired, such as between a prostate and a rectum, or any diseased or cancerous tissue and adjacent healthy or non-targeted tissue. It is to be appreciated that prior to advancing the implant delivery device 400, preparation of the area to which radiation protection may be desired may be performed, including, creating an incision 304 (such as via hydrodissection) between the target tissue for radiation and the non-targeted tissue. In embodiments, a dilator (not shown) may be inserted into the incision 304 to dilate the target location 122. A delivery sheath (not shown), may be advanced to the target location 122 for delivery of the implant delivery device 400. As illustrated in FIG. 6A, prior to advancing a catheter 402, a guidewire 106 may be advanced into a body region 302 to a target location 122, such as through the delivery sheath (not shown). Positioning of the guidewire 106 may be determined via ultrasound, x-ray, or the like. Insertion of the guidewire 106 may mark the depth of incision 304 and subsequent depth for insertion of the catheter 402, as illustrated in FIG. 6B. Ultrasound, x-ray, or the like may be used to confirm the position of catheter 402. It is to be appreciated that guidewire 106 may be removed prior to insertion of implant delivery device 400, and may serve to provide location and depth of insertion, rather than remain in a catheter lumen 108. As shown in FIG. 6B, guidewire 106 has been removed prior to insertion of implant delivery device 400, with implant delivery device 400 placed to the location and depth of the prior guidewire insertion. In some embodiments, it is contemplated that the interlock shaft 404 may include a guidewire lumen, such that the implant delivery device 400 may be delivered over the guidewire 106. In some embodiments, it is contemplated that the guidewire 106 may be the interlock shaft 404.

[0067] At block 504, the method 500 includes inflating as for example first balloon 406 and second balloon 408 thereby defining an injection boundary along a contour of the target location 122. As noted above, inflation fluid may be delivered to the first balloon 406 and second balloon 408 via inflation lumen 112 from an inflation lumen reservoir (e.g., a syringe or the like; not shown). With the first balloon 406 and second balloon 408 positioned to the outside of the one or more implant delivery ports 124, the first balloon 406 and second balloon 408 act as a barrier to assist in preventing implantable material 128 delivered within the injection boundary from leaking outside of the injection boundary, thereby providing an improved control mechanism for placement and containment of implantable material 128.

[0068] It is to be appreciated interlock shaft 404 may provide for various adjustments, for example, rotation and translation of the connecting points for first balloon 406 and second balloon 408. Orientation may be accomplished by a number of methods, including manipulation (including translation, rotation or a combination of translation and rotation) of interlock shaft 404 and/or catheter 402. Manipulation of interlock shaft 404 and/or the catheter 402 may thus form and control the curved shape of the asymmetric first balloon 406 and second balloon 408 for injection of implantable material 128. In embodiments, an implant delivery device 400 may be shaped in the curved configuration to fit within a dimension of 3.5 mm by 5.2 mm incision, however other dimensions are contemplated and possible based on the particular incision site and implant delivery device 400 dimensions. It is to be appreciated that FIG. 6B shows the implant delivery device 400 after insertion (insertion would be in a deflated state, as discussed herein), with the balloons 406 and 408 inflated and oriented such that the each offset balloon face of balloons 406 and 408 face outward.

[0069] At block 506, the method includes injecting implantable material 128, described above, to the target location 122 within a region defined by the injection boundary (e.g., within the injection boundary). As illustrated in FIGS. 6C and 6D, implantable material 128 is delivered via the implant material delivery port(s) 124 or array 410.

[0070] FIG. 6D illustrates a section view of FIG. 6C, with a section of the implant delivery device 400 illustrating catheter 402, balloons 406 and 408 (with their respective balloon lumens 132), and an implantable material 128. It is to be appreciated that the implantable material 128 upon initial delivery will be fluid, and that the balloons 406 and 408 provides a retaining feature to control placement.

[0071] The implantable material 128 may then be allowed to cure in place at block 508, thereby providing a cured implantable material (or radiation spacer), such as for example cured implantable material 138, depicted in FIG. 6E.

[0072] Once cured, at block 508, the method 500 includes deflating the balloons (such as, for example first balloon 406 and second balloon 408). It is to be appreciated that inflation of the first balloon 406 and second balloon 408 may anchor the implant delivery device 400 within the target location 122 by engaging and applying force to the tissue surrounding the target location 122. With deflating the first balloon 406 and second balloon 408, the force holding the implant delivery device 400 in place may be released, which may allow at block 210 for the implant delivery device 400 to be withdrawn from the target location 122 while leaving the cured implantable material 138 at the target location 122, as illustrated in FIG. 6E. To aid in removal of the implant delivery device 400, the interlock shaft 404 may be actuated to decouple from the first balloon 406 and the second balloon 408 as described above. One decoupled, the first and second balloons 406, 408 may slide around the cured implantable material 138. It is noted that implantable materials 128 such as hydrogels may be inherently slippery even when cured, and accordingly, the implant delivery device 400 may be withdrawn as illustrated in FIG. 6E. After withdrawal of the delivery device, it is contemplated that the surrounding tissue may move into fill the void left by the implant delivery device 400.

[0073] It should now be understood that embodiments of the present disclosure and directed to a delivery device for the delivery of implantable material. For example, embodiments as provided herein may be useful for implantation of hydrogel materials for use as, for example, radiation spacers. In embodiments, implantable material may be allowed to cure within a controlled zone and then after sufficient curing, the implant delivery device may be withdrawn from the cured implantable material. Accordingly, implantable material may be maintained in position during curing, thereby leading to reduced leakage of implantable material from the target delivery space. Efficiencies by way of reduced waste and mess are gained from reduced leakage. Better-controlled placement of the implantable material leads to reduced stray radiation affecting non-target tissue.

[0074] Embodiments of the present disclosure may be further described with respect to the following numbered clauses:

[0075] 1. An implant delivery device comprising a catheter defining a centerline and having an inflation lumen and a material delivery lumen for delivery of an implantable material, wherein the catheter defines one or more material delivery ports in fluid communication with the material delivery lumen; and a balloon comprising a balloon lumen and mounted to the catheter, the balloon lumen in fluid communication with the inflation lumen, wherein balloon lumen branches off of the inflation lumen and extends to a position proximal and distal to the one or more material delivery ports.

[0076] 2. The implant delivery device of clause 1, wherein the catheter and the balloon are biased to a curved shape. [0077] 3. The implant delivery device of any preceding clause, wherein the balloon is coupled to the catheter along a length defined by the one or more material delivery ports.

[0078] 4. The implant delivery device of any preceding clause, wherein the one or more material delivery ports comprise an array of material delivery ports.

[0079] 5. The implant delivery device of any preceding clause, further comprising a guidewire, wherein: the catheter includes a guidewire lumen; and the guidewire comprises a shape memory material and is biased to a curved shape.

[0080] 6. The implant delivery device of any preceding clause, wherein the balloon comprises a material that biases the balloon into a curved shape.

[0081] 7. The implant delivery device of any preceding clause, wherein the catheter comprises a material that biases the balloon into a curved shape.

[0082] 8. An implant delivery device comprising a catheter defining a centerline and having one or more inflation lumens and a material delivery lumen for delivery of an implantable material, wherein the catheter defines one or more material delivery ports in fluid communication with the material delivery lumen; and a first balloon and a second balloon, each of the first balloon and the second balloon mounted to the catheter and defining a respective balloon lumen in fluid communication with an inflation lumen of the one or more inflation lumens, the respective balloon lumens branching off the inflation lumen of the catheter and extending to a position proximal and distal to the one or more material delivery ports.

[0083] 9. The implant delivery device of clause 8, further comprising an interlock shaft extending through the catheter, wherein a distal end of the first balloon and the second balloon are coupled to the interlock shaft in a first configuration.

[0084] 10. The implant delivery device of clause 9, wherein the first balloon and the second balloon are uncoupled from the interlock shaft in a second configuration.

[0085] 11. The implant delivery device of clause 9 or 10, wherein the interlock shaft is slidable relative to the catheter. [0086] 12. The implant delivery device of any one of clauses 9 to 11, wherein the interlock shaft is rotatably relative to the catheter.

[0087] 13. The implant delivery device of any one of clauses 8 to 12, wherein the one or more material delivery ports comprise an array of material delivery ports.

[0088] 14. The implant delivery device of any one of clauses 8 to 13, wherein the first balloon and the second balloon are unattached to the catheter along a length of the catheter defined by the one or more material delivery ports.

[0089] 15. The implant delivery device of any one of clauses 8 to 14, wherein the first balloon and the second balloon when inflated extend from the catheter opposite one another across the catheter.

[0090] 16. A method of implanting an implantable material, the method comprising: advancing an implant delivery device to a target location, the implant delivery device comprising: a catheter defining a centerline and having an inflation lumen and a material delivery lumen for delivery of the implantable material, wherein the catheter defines one or more material delivery ports in fluid communication with the material delivery lumen; and a balloon comprising a balloon lumen and mounted to the catheter, the balloon lumen in fluid communication with the inflation lumen, wherein balloon lumen branches off of the inflation lumen and extends to a position proximal and distal to the one or more material delivery ports; inflating the balloon thereby defining an injection boundary along a contour of the target location; injecting the implantable material to the target location within a region defined by the injection boundary; curing the implantable material thereby providing a cured implantable material; deflating the balloon; and withdrawing the implant delivery device from the target location while leaving the cured implantable material at the target location.

[0091] 17. The method of clause 16, further comprising: advancing a guidewire to the target location, wherein the guidewire is biased to a curved shape; advancing the catheter over the guidewire, wherein the catheter conforms to the curved shape of the guidewire within the target location; and directing the one or more material delivery ports inward of the curved shape for injection of the implantable material. [0092] 18. The method of clause 16 or 17, wherein: the balloon is a first balloon and the implant delivery device comprises a second balloon mounted to the catheter and in fluid communication with the inflation lumen, the second balloon branching off the inflation lumen, of the catheter and extending to a position proximal and distal to the one or more material delivery ports; the method further comprising : inflating the first balloon and the second balloon prior to injecting the implantable material; and deflating the first balloon and the second balloon after curing the implantable material.

[0093] 19. The method of any one of clauses 16 to 18, wherein the target location is a space between a rectum and a prostate.

[0094] 20. The method of clause 19, further comprising forming the target location between the rectum and the prostate.

[0095] While particular embodiments have been illustrated and described herein, it should be understood that various other changes and modifications may be made without departing from the spirit and scope of the claimed subject matter. Moreover, although various aspects of the claimed subject matter have been described herein, such aspects need not be utilized in combination. It is therefore intended that the appended claims cover all such changes and modifications that are within the scope of the claimed subject matter.

Claims

1. An implant delivery device comprising: a catheter having an inflation lumen and a material delivery lumen for delivery of an implantable material, wherein the catheter defines one or more material delivery ports in fluid communication with the material delivery lumen; and a balloon comprising a balloon lumen and mounted to the catheter, the balloon lumen in fluid communication with the inflation lumen, wherein balloon lumen branches off of the inflation lumen and extends to a position proximal and distal to the one or more material delivery ports.

2. The implant delivery device of claim 1, wherein the catheter and the balloon are biased to a curved shape.

3. The implant delivery device of claim 1, wherein the balloon is coupled to the catheter along a length defined by the one or more material delivery ports.

4. The implant delivery device of claim 1, wherein the one or more material delivery ports comprise an array of material delivery ports.

5. The implant delivery device of claim 1, further comprising a guidewire, wherein: the catheter includes a guidewire lumen; and the guidewire comprises a shape memory material and is biased to a curved shape.

6. The implant delivery device of claim 1, wherein the balloon comprises a material that biases the balloon into a curved shape.

7. The implant delivery device of claim 1, wherein the catheter comprises a material that biases the balloon into a curved shape.

8. An implant delivery device comprising: a catheter having one or more inflation lumens and a material delivery lumen for delivery of an implantable material, wherein the catheter defines one or more material delivery ports in fluid communication with the material delivery lumen; and a first balloon and a second balloon, each of the first balloon and the second balloon mounted to the catheter and defining a respective balloon lumen in fluid communication with an inflation lumen of the one or more inflation lumens, the respective balloon lumen branching off the one or more inflation lumens of the catheter and extending to a respective position proximal and distal to the one or more material delivery ports.

9. The implant delivery device of claim 8, further comprising an interlock shaft extending through the catheter, wherein a distal end of the first balloon and the second balloon are coupled to the interlock shaft in a first configuration.

10. The implant delivery device of claim 9, wherein the first balloon and the second balloon are uncoupled from the interlock shaft in a second configuration.

11. The implant delivery device of claim 9, wherein the interlock shaft is slidable relative to the catheter.

12. The implant delivery device of claim 9, wherein the interlock shaft is rotatably relative to the catheter.

13. The implant delivery device of claim 8, wherein the one or more material delivery ports comprise an array of material delivery ports.

14. The implant delivery device of claim 8, wherein the first balloon and the second balloon are unattached to the catheter along a length of the catheter defined by the one or more material delivery ports.

15. The implant delivery device of claim 8, wherein the first balloon and the second balloon when inflated extend from the catheter opposite one another across the catheter.

16. A method of implanting an implantable material, the method comprising: advancing an implant delivery device to a target location, the implant delivery device comprising: a catheter having an inflation lumen and a material delivery lumen for delivery of the implantable material, wherein the catheter defines one or more material delivery ports in fluid communication with the material delivery lumen; and a balloon comprising a balloon lumen and mounted to the catheter, the balloon lumen in fluid communication with the inflation lumen, wherein balloon lumen branches off of the inflation lumen and extends to a position proximal and distal to the one or more material delivery ports; inflating the balloon thereby defining an injection boundary along a contour of the target location; injecting the implantable material to the target location within a region defined by the injection boundary; curing the implantable material thereby providing a cured implantable material; deflating the balloon; and withdrawing the implant delivery device from the target location while leaving the cured implantable material at the target location.

17. The method of claim 16, further comprising: advancing a guidewire to the target location, wherein the guidewire is biased to a curved shape; advancing the catheter over the guidewire, wherein the catheter conforms to the curved shape of the guidewire within the target location; and directing the one or more material delivery ports inward of the curved shape for injection of the implantable material.

18. The method of claim 16, wherein: the balloon is a first balloon and the implant delivery device comprises a second balloon mounted to the catheter and in fluid communication with the inflation lumen, the second balloon branching off the inflation lumen of the catheter and extending to a second position proximal and distal to the one or more material delivery ports; the method further comprising: inflating the first balloon and the second balloon prior to injecting the implantable material; and deflating the first balloon and the second balloon after curing the implantable material.

19. The method of claim 16, wherein the target location is between a rectum and a prostate.

20. The method of claim 19, further comprising forming the target location between the rectum and the prostate.