Release-limiting sleeve to enable staged release by product section

Description

TECHNICAL FIELD

[0001] This disclosure relates generally to medical devices, and more specifically, to medical devices for connecting tissue layers to create an anastomosis, implantable devices for occluding inhibiting or preventing material movement through tissue apertures, sealing, and allowing healing of defects in tissues, and deployment of the medical devices discussed herein.BACKGROUND

[0002] An anastomosis is a cross-connection between two tissue structures, such as blood vessels or intestines. For example, in the context of coronary artery bypass graft surgery, a graft vessel is anastomosed to a native coronary artery so that blood can flow through the graft vessel.

[0003] Anastomoses can be created in various manners including, but not limited to: end-to-end, end-to-side, and side-to-side anastomoses. Often, suturing is used to create such anastomoses.

[0004] US2015313595 is directed to implantable medical devices for connecting tissue layers, such as for connecting a gallbladder and a portion of a gastrointestinal tract to create an anastomosis, include a tubular structure having a plurality of apposition portions, a central region, and a covering material. The methods of using the devices include endoscopic deployment, and the devices may include self-expanding frameworks that facilitate a secure connection between the tissue structures.SUMMARY

[0005] A medical device system according to the invention is defined in claim 1. Further embodiments of the invention are recited in the dependent claims.

[0006] Various aspects of the present disclosure are directed toward medical device systems. The medical device systems may include an expandable medical device having a first end portion, a second end portion, and an intermediate portion between the first end portion and the second end portion. The intermediate portion of the expandable medical device may include a radially expansive force greater than a radially expansive force of at least one of the first end portion and the second end portion. In addition, the expandable medical device may include a first constraining mechanism configured to releasably constrain the expandable medical device, and a second constraining mechanism arranged between the expandable medical device and the first constraining mechanism and configured to lessen expansion of the intermediate portion of the expandable medical device in response to release of the first constraining mechanism.

[0007] Various aspects of the present disclosure are also directed toward systems for deploying a medical device having a first flange, a second flange, and an intermediate portion therebetween and a delivery configuration and a deployed configuration. The systems include a first constraining mechanism configured to constrain the expandable medical device to the delivery configuration and deploy the first flange and the second flange to the deployed configuration in response to release thereof, and a second constraining mechanism arranged between the expandable medical device and the first constraining mechanism and configured to maintain the intermediate portion of the expandable medical device in an intermediate configuration in response to release of the first constraining mechanism.

[0008] Aspects of the disclosure are also directed toward methods of deploying an expandable medical device having a delivery configuration and a deployed configuration. The methods include positioning the expandable medical device at the target location (with expandable medical device including a first end portion, a second end portion, and an intermediate portion having a radially expansive force greater than a radially expansive force of the first end portion). The methods also include releasing a first constraining mechanism to deploy the first end portion and the second end portion to the deployed configuration and deploy the intermediate portion to an intermediate configuration. Further, the methods include releasing a second constraining mechanism to deploy the intermediate portion to the deployed configuration.BRIEF DESCRIPTION OF THE DRAWINGS

[0009] FIG. 1 shows a cutaway perspective view of an exemplary expandable medical device implanted within a patient, according to various aspects of the present disclosure. FIG. 2 shows a delivery system for an expandable medical device, according to various aspects of the present disclosure. DETAILED DESCRIPTION

[0010] Persons skilled in the art will readily appreciate that various aspects of the present disclosure can be realized by any number of methods and apparatus configured to perform the intended functions. It should also be noted that the accompanying figures referred to herein are not necessarily drawn to scale, but may be exaggerated to illustrate various aspects of the present disclosure, and in that regard, the figures should not be construed as limiting.

[0011] Various aspects of the present disclosure are directed to medical devices for connecting tissue layers, for example, to circumvent a conduit or organ blockage, such as by creating a direct passage between tissue structures to create an anastomosis that facilitates material flow therebetween. The expandable medical devices may be endoscopically deployable or deliverable via a catheter and may be self-expanding to facilitate a secure connection between the tissue structures. The present disclosure discusses one or more constraining mechanisms that facilitate deployment of the expandable medical devices that facilitate delivery thereof and lessen misdeployment.

[0012] FIG. 1 is a cutaway perspective view of an exemplary expandable medical device 100 implanted within a patient, according to various aspects of the present disclosure. The expandable medical device 100 is configured to be implanted in a patient to create a fluidic connection between spaces, tissue structures, conduits, organs, and the like, and combinations thereof. As shown in FIG. 1, for example, the expandable medical device 100 may be used to connect a gallbladder 102 (that defines an internal gallbladder space 104) with an intestine 106 (that defines an internal intestinal space 108). As a result, the expandable medical device 100 acts as a fluidic shunt device between the internal gallbladder space 104 and the internal intestinal space 108.

[0013] Such an implementation may provide a beneficial treatment to the patient when, for example, a flow blockage exists in the native anatomical conduits connecting the internal gallbladder space 104 and the internal intestinal space 108. In certain instances the patient may have one or more gallstones that cause a blockage of the patient's cystic duct 110 and / or common bile duct 112. In such a case, the expandable medical device 100 may provide a fluidic passageway such that bile from the gallbladder 102 may flow into the intestine 106.

[0014] The expandable medical device 100 may include a first end portion 114, a second end portion 116, and an intermediate portion 118 therebetween. The intermediate portion 118 defines a lumen 120 that extends longitudinally from the first end portion 114 to the second end portion 116. The lumen 120 may act as a connection (e.g., a shunt passageway) between the two spaces (e.g., tissue structures, conduits, organs) that the expandable medical device 100 connects. In the example shown in FIG. 1, the lumen 120 acts as a connection between the internal gallbladder space 104 and the internal intestinal space 108, such that the internal gallbladder space 104 is in fluid communication with the internal intestinal space 108 via the expandable medical device 100.

[0015] Although FIG. 1 shows the expandable medical device 100 connecting the gallbladder 102 and the intestine 106 of a patient, the expandable medical device 100 may be used in conjunction with various body tissue structures and organs such as, but not limited to, stomachs, colons, small intestines, pancreases, blood vessels, bladders, kidneys, and conduits.

[0016] FIG. 2 shows a delivery system 200 for an expandable medical device, according to various aspects of the present disclosure. The delivery system 200 may include a catheter body 202 upon which the expandable medical device (not shown) may be arranged. The delivery system 200 also includes a first constraining mechanism 204 configured to constrain the expandable medical device to a delivery or constrain configuration. The first constraining mechanism 204 may be used in connection with a second constraining mechanism (as shown and discussed in further detail below with reference to FIGS. 3-6).

[0017] To deploy the expandable medical device arranged with the delivery system 200, tension may be applied to a deployment line 206 coupled to the first constraining mechanism 204. The deployment line 206 is accessible to a user such as a physician and may be arranged through a port 208 in the catheter body 202. In response to tension applied to the deployment line 206, the primary constraining mechanism 204 may open, withdraw or evert from an end of the delivery system 200, such as a distal tip 210, toward the port 208. In some embodiments, the first constraining mechanism 204 may have multiple layers constraining the expandable medical device and as such may move from one end of the delivery zone to the other end multiple times during deployment. In certain instances, the delivery system 200 may also include a skirt 212 that is arranged about the first constraining mechanism 204 prior to the delivery system 200 being traversed to a target location within a patient.

[0018] In some embodiments (not shown) a first constraining mechanism is configured to constrain the expandable medical device to the delivery configuration. The first constraining mechanism extends between a proximal end of the expandable medical device to a distal end of the expandable medical device. In addition, the expandable medical device may be arranged on a delivery catheter or delivery system. The delivery catheter or delivery system, in certain instances, is routed within a patient to a target location for delivery of the expandable medical device.

[0019] To deploy the expandable medical device, tension may be applied to a deployment line coupled to the first constraining mechanism, which is accessible to a user such as a physician. In response, the first constraining mechanism may open, withdraw or evert from the proximal end towards the distal end and then continue back toward the proximal end of the expandable medical device. Releasing the first constraining mechanism in this manner may deploy the distal end of the expandable medical device prior to deploying the remaining portions of the expandable medical device.

[0020] In some embodiments (not shown), the expandable medical device may include a first flange arranged at the distal end. The first flange may be deployed after the first constraining mechanism is withdrawn past the first flange. The user may continue to apply tension to the deployment line of the first constraining mechanism to continue deployment of the expandable medical device.

[0021] In some embodiments (not shown), the expandable medical device may include a second flange arranged at the proximal end. The first constraining mechanism has been released past the proximal end of the expandable medical device, and released and uncoupled from the expandable medical device. Thus, the first constraining mechanism is configured to release and deploy the first flange and the second flange to a fully-deployed configuration in response to release thereof. An intermediate portion of the expandable medical device, however, remains in an intermediate configuration.

[0022] A second constraining mechanism, arranged between the expandable medical device and the first constraining mechanism in the delivery configuration shown in FIG. 2, is configured to maintain the intermediate portion of the expandable medical device in the intermediate configuration after the release of the first constraining mechanism. The intermediate portion of the expandable medical device may have a radially expansive force greater than a radially expansive force of one or both of the first flange and the second flange when they are constrained by the first constraining mechanism. The expandable medical device may include a plurality of elongate elements. The plurality of elongate elements may have a greater density and / or winding pattern in the intermediate portion of the expandable medical device than in one or both of the first flange and the second flange. In addition and as a result, the intermediate portion of the expandable medical device has a greater resistance to compressive force (a greater radial strength) than one or both of the first flange and the second flange.

[0023] In certain instances, the intermediate portion is approximately cylindrical whereas the first flange and the second flange deploy approximately perpendicular to the intermediate portion such that the expandable medical device includes an hourglass shape having a lumen therethrough in an intermediate configuration (not shown). The second constraining mechanism is coupled to the expandable medical device and is secured to the intermediate portion. The second constraining mechanism is arranged about a circumference of the intermediate portion 318 of the expandable medical device.

[0024] To facilitate staged deployment of the expandable medical device, the second constraining mechanism may be configured to mitigate against premature expansion of the intermediate portion. The expandable medical device, in certain instances, is self-expanding and therefore is biased to deploy to the full-deployed configuration from the delivery configuration. In certain instances, the intermediate portion and the first flange and / or the second flange having different radial forces may result in forces from the intermediate portion, desiring to be in the deployed configuration, to force the first constraining mechanism from the expandable medical device. The second constraining mechanism 304 is configured to lessen expansion of the intermediate portion by deploying the intermediate portion to the intermediate configuration as opposed to directly to the deployed configuration.

[0025] The second constraining mechanism is configured to release in response to a force applied thereto. In certain instances, the force is applied from within the intermediate portion of the expandable medical device to break, fracture, or distend the second constraining mechanism. In certain instances, the second constraining mechanism remains coupled to the intermediate portion of the expandable medical device after release thereof. The intermediate portion of the expandable medical device may deploy to the fully-deployed configuration, after release of the second constraining mechanism.

[0026] An expandable medical device and constraining mechanism, according to various aspects of the present disclosure, in an intermediate configuration(not shown) may include a first end portion having a flange shape, a second end portion having a flange shape, and an intermediate portion extending therebetween.

[0027] In addition, the first end portion, the second end portion, and the intermediate portion are formed by a framework of elongate elements. The elongate elements in the intermediate portion include a greater density than the first end portion and the second end portion. The expandable medical device may include a covering material (which may also be referred to herein as a "covering"). In certain instances, the covering material is disposed on some or all of the first end portion, the second end portion, and the intermediate portion. The elongate elements in the intermediate portion include a greater concentration or greater windings than the first end portion and the second end portion. Thus, the intermediate portion has a greater resistance to radial forces than the first end portion and the second end portion. In certain instances, the difference in density of the elongate elements in the intermediate portion and the first end portion and the second end portion 606 causes the first end portion and the second end portion results in the intermediate portion having a greater radial expansive force than the first end portion and the second end portion.

[0028] In addition and in certain instances, the intermediate portion includes a radially expansive force greater than a radially expansive force than one or both of the first end portion and the second end portion in the delivery (constrained) configuration. The expandable medical device is deployed by releasing a first constraining mechanism. A second constraining mechanism may be configured to lessen expansion of the intermediate portion of the expandable medical device in response to release of the first constraining mechanism. In certain instances, the second constraining mechanism may be arranged to extend across the intermediate portion of the expandable medical device. In addition, the second constraining mechanism is configured to deploy the intermediate portion of the expandable medical device to an intermediate configuration, between the delivery configuration (shown in FIG. 2) and a fully-deployed configuration (not shown), in response to release of the first constraining mechanism.

[0029] In addition to deploying the intermediate portion of the expandable medical device to the intermediate configuration, the first end portion and the second end portion are deployed to the deployed configuration after release of the first constraining mechanism .

[0030] In the intermediate configuration, the intermediate portion of the expandable medical device may include a diameter less than a diameter of the intermediate portion of the expandable medical device in the deployed configuration. The diameter of the intermediate portion in the intermediate configuration may be approximately between 40% to 80% less than a diameter of the intermediate portion in the deployed configuration. The second constraining mechanism may constrain the intermediate portion in the intermediate configuration until the second constraining mechanism is released. For example, the second constraining mechanism is configured to release and deploy the intermediate portion of the expandable medical device to the fully deployed configuration. The second constraining mechanism is released in response to a force applied thereto. In certain instances, the force may be a radial force applied within the intermediate portion 608 of the expandable medical device. In addition, the force may be applied by an inflatable balloon or other force applied from within the intermediate portion of the expandable medical device.

[0031] The second constraining mechanism may release, rupture, distend, or otherwise break in response to the force. Further, the second constraining mechanism may be configured to remain coupled to the expandable medical device subsequent to the force being applied thereto with the first constraining mechanism being configured to deploy the expandable medical device and uncouple from the expandable medical device in response thereto. The second constraining mechanism may surround or enclose a circumference of the intermediate portion 608 of the expandable medical device. In addition, the second constraining mechanism may be a flexible film (formed from, for example, polytetrafluoroethylene (ePTFE)) and attached (and remain attached to after release of the first constraining mechanism) to one or more portions of the intermediate portion of the expandable medical device via a medical adhesive (e.g., fluorinated ethylene propylene (FEP), a polymer of tetrafluoroethylene, hexafluoropropylene and vinylidene fluoride (THV), and other biocompatible adhesives).

[0032] As noted above, the intermediate portion includes a radially expansive force that is greater than a radially expansive force than one or both of the first end portion and the second end portion in the constrained (delivery) configuration. Thus, the second constraining mechanism may be configured to mitigate against premature deployment of the expandable medical device. The intermediate portion 608 has a radially expansive force greater than one or both of the first end portion and the second end portion that may force the first constraining mechanism (not shown) to be removed / released from the expandable medical device without a user applying tension to remove the first constraining mechanism. The second constraining mechanism may be configured to lessen expansion of the intermediate portion, thereby mitigating against the potential for the intermediate portion to force the first constraining mechanism from the expandable medical device without the user removing the first constraining mechanism.

[0033] In addition, the second constraining mechanism may be arranged between the first constraining mechanism (prior to release thereof) and the intermediate portion of the expandable medical device. Further, the second constraining mechanism may be arranged within the bounds of the intermediate portion of the expandable medical device. The expandable medical device may include a first inflection area between the first end portion and the intermediate portion, and a second inflection area between the second end portion and the intermediate portion. The first inflection area and the second inflection area may transition the substantially cylindrical shape of the intermediate portion to, respectively, the first end portion and the second end portion 606. Further, the second constraining mechanism may be arranged to extend between the first inflection area and the second inflection area. The second constraining mechanism extending between but not covering the first inflection area and the second inflection area may facilitate deployment of the first end portion and the second end portion by not interfering or encroaching on the first end portion and the second end portion while maintaining the staged deployment of each portion of the expandable medical device.

[0034] In certain instances, the intermediate portion of the expandable medical device is constructed to have a tailored radial strength by, for example, varying sine wave amplitude, angle, number of apices per row, number of rows, and / or wire diameter of the elongate elements (or other similar constructions). In addition, the intermediate portion of the expandable medical device includes a radial strength to resist circumferential loading from the surrounding tissue. In certain instances, the radial strength of the intermediate portion of the expandable medical device facilitates remodeling of the tissue external to the intermediate portion to become approximate in size to the outer diameter of the intermediate portion. When the expandable medical device (and the other expandable medical devices discussed herein) is implanted to form an anastomosis, the radial strength of the intermediate portion may provide resistance to the hoop force applied by the surrounding tissue. Thus, the expandable medical device substantially maintains an open lumen at a desired dimension.

[0035] In a full deployed configuration (not shown), the intermediate portion of the expandable medical device is no longer constrained by the second constraining mechanism. Thus, the intermediate portion is in the fully-deployed configuration. Comparing an intermediate configuration and a fully deployed configuration, the intermediate portion expands to a greater diameter from the intermediate configuration. The second constraining mechanism, in certain instances, remains coupled to the intermediate portion of the expandable medical device after release of the constraining force.

[0036] The expandable medical devices, as discussed herein, may form a connection between two areas. The connection may also be referred to herein as a "shunt," "passageway," "shunt passageway," or "tunnel". In certain instances, the expandable medical devices discussed herein are configured to be removable after implantation. For example, the expandable medical devices may be implanted and remain in place until the gallbladder and / or its associated ducts are cleared of blockages, after which the device is removed. In another example, the expandable medical devices may remain implanted until the body grows a tissue-anastomosis around the device, and then the device is removed. In other instances, tissue ingrowth into and / or around the device permanently implants the expandable medical device, and the expandable medical device is not removed. The expandable medical devices discussed herein may provide an alternative treatment for patients who are not suitable candidates for other types of treatments (e.g., gallbladder removal surgery) and / or to avoid known complications of other types of treatments (e.g., external biliary drainage).

[0037] In certain instances, the elongate elements or framework of the expandable medical devices may be treated in various ways to increase the radiopacity of the expandable medical devices for enhanced radiographic visualization. In some embodiments, the expandable medical devices are at least partially a drawn-filled type of NiTi containing a different material at the core, such as a material with enhanced radiopacity. In some embodiments, the devices include a radiopaque cladding or plating on at least portions of the expandable medical devices. In certain instances, one or more radiopaque markers are attached to the expandable medical devices. In certain instances, the elongate elements and / or other portions of the expandable medical devices provided herein are also visible via ultrasound, and may include portions with enhanced echogenicity.

[0038] In addition, the covering material arranged on the expandable medical devices may be generally fluid impermeable. For example, the covering material may be made of a material that inhibits or reduces passage of blood, bile and / or other bodily fluids and materials through the covering material. In certain instances, the covering material has a material composition and configuration that inhibits or prevents tissue ingrowth and / or endothelialization or epithelialization into the covering material. In addition, the covering material may be configured to inhibit or prevent tissue ingrowth and / or endothelialization such that the expandable medical devices may be more readily removed from the patient at a future date. In certain instances, the covering material, or portions thereof, may include a microporous structure that provides a tissue ingrowth scaffold for durable sealing and / or supplemental anchoring strength of the expandable medical devices.

[0039] The covering material and the constraining mechanisms may include a fluoropolymer membrane, such as an expanded polytetrafluoroethylene (ePTFE) polymer, polyvinylidene fluoride (PVDF), or polyvinylidene acetate (PVDA). In other instances, the covering material comprises a polyester, a silicone, a urethane, biocompatible polymer(s), polyethylene terephthalate (e.g., Dacron ®< ), bioabsorbable materials, copolymers, or combinations thereof. In addition, the covering material may include a bioabsorbable web. Expanded polytetrafluoroethylene (ePTFE) membranes prepared in accordance with the methods described in U.S. Patent No. 7,306,729 to Bacino et al., U.S. Patent No. 3,953,566 to Gore, U.S. Patent No. 5,476,589 to Bacino, or U.S. Patent No. 5,183,545 to Branca et al. may be used as the covering material herein. Additionally, expanded modified PTFE and expanded copolymers of PTFE, such as described in U.S. Patent No. 5,708,044 to Branca; U.S. Patent No. 6,541,589 to Baillie; U.S. Patent No. 7,531,611 to Sabol et al.; U.S. Patent No. 8,637,144 to Ford; and U.S. Patent No. 9,139,669 to Xu et al. may be used herein. In other embodiments, the bioabsorbable material may also provide an anti-migration feature by promoting attachment between the expandable medical devices and tissue until the bioabsorbable material is absorbed.

[0040] The covering material (or portions thereof) may also be modified by one or more chemical or physical processes that enhance one or more properties of the coating. For example, a hydrophilic coating may be applied to the covering material to improve the wettability and echo translucency of the covering. In certain instances, the covering material, or portions thereof, may be modified with chemical moieties that facilitate one or more of endothelial cell attachment, endothelial cell migration, endothelial cell proliferation, and resistance to or promotion of thrombosis. In certain instances, the covering material, or portions thereof, may be modified to resist biofouling. In addition, the covering material, or portions thereof, may be modified with one or more covalently attached drug substances (e.g., heparin, antibiotics, and the like) or impregnated with the one or more drug substances. The drug substances can be released in situ to promote healing, reduce tissue inflammation, reduce or inhibit infections, and to promote various other therapeutic treatments and outcomes. In some embodiments, the drug substance may be, but is not limited to a corticosteroid, a human growth factor, an anti-mitotic agent, an antithrombotic agent, a stem cell material, or dexamethasone sodium phosphate. In addition, a pharmacological agent may be delivered separately from the covering material to the target site to promote tissue healing or tissue growth.

[0041] Persons skilled in the art will readily appreciate that various aspects of the present disclosure can be realized by any number of methods and apparatus configured to perform the intended functions. It should also be noted that the accompanying figures referred to herein are not necessarily drawn to scale, but may be exaggerated to illustrate various aspects of the present disclosure, and in that regard, the figures should not be construed as limiting.

Claims

1. A medical device system comprising: an expandable medical device (100, 200) including a first end portion (114), a second end portion (116), and an intermediate portion (118) therebetween, the intermediate portion (118) defining a lumen (120) that extends longitudinally from the first end portion (114) to the second end portion (116), the first end portion (114) transitioning to the intermediate portion (118) at a first inflection area and the second end portion (116) transitioning to the intermediate portion (118) at a second inflection area; the intermediate portion having a radially expansive force greater than a radially expansive force of at least one of the first end portion and the second end portion; a first constraining mechanism (204) extending from a proximal end of the expandable medical device (100, 200) to a distal end of the expandable medical device and back toward a proximal end of the expandable medical device (100, 200) configured to releasably constrain the expandable medical device (100, 200) to a substantially cylindrical delivery configuration; and a second constraining mechanism configured to constrain the intermediate portion (118) between the first inflection area and the second inflection area, the second constraining mechanism arranged between the expandable medical device (100, 200) and the first constraining mechanism (204), and configured to lessen expansion of the intermediate portion (118) of the expandable medical device (100, 200) in response to release of the first constraining mechanism; wherein the second constraining mechanism extends to but does not cover the first and second inflection areas.

2. The system of claim 1, wherein the first constraining mechanism (204) and the second constraining mechanism are configured to deploy the intermediate portion (118) of the expandable medical device (100, 200) to an intermediate configuration and deploy the first end portion (114) and the second end portion (116) of the expandable medical device (100, 200) to a deployed configuration in response to release of the first constraining mechanism (204).

3. The system of claim 2, wherein the second constraining mechanism is configured to release and deploy the intermediate portion (118) of the expandable medical device (100, 200) to the deployed configuration.

4. The system of claim 3, wherein the second constraining mechanism is configured to release in response to a force applied thereto.

5. The system of claim 4, wherein the force is a radial force applied within the intermediate portion (118) of the expandable medical device (100, 200), and the second constraining mechanism is configured to remain coupled to the expandable medical device (100, 200) subsequent to the force being applied thereto.

6. The system of claim 1, wherein the first end portion (114) comprises a first flange, the second end portion (116) comprises a second flange, and the intermediate portion (118) comprises a substantially cylindrical shape.

7. The system of claim 6, wherein the expandable medical device (100, 200) comprises a first inflection area between the first flange and the intermediate portion (118), a second inflection area between the second flange and the intermediate portion (118), and the second constraining mechanism is arranged between the first inflection area and the second inflection area.

8. The system of claim 1, wherein the second constraining mechanism is coupled to the expandable medical device (100, 200), and the first constraining mechanism (204) is configured to deploy the expandable medical device (100, 200) and uncouple from the expandable medical device (100, 200) in response to tension applied to the first constraining mechanism.