PERICARDIAL IMPLANTS
CROSS-REFERENCE TO RELATED APPLICATION^ )
[0001] This application claims the benefit of U.S. Provisional Application No. 63/612,983, filed December 20, 2023, the disclosure of which is hereby incorporated by reference in its entirety.
BACKGROUND
[0002] The present disclosure relates to implantable devices, and in particular, to catheter-delivered cardiac implantable devices.
[0003] Pericardial restraint is a condition which causes the right heart chambers to run out of space when filling, thereby squeezing and over pressurizing the left heart chambers during physical activity in patients with preserved ejection fraction (HFpEF). The increased pressure backs up into the lungs and causes exertional dyspnea, a common cause for hospital admission. Existing methods for relieving pericardial restraint include the catheter-based incision of the pericardium. Less traumatic methods for providing increased pericardial space are desirable.
SUMMARY
[0004] An implantable device for stretching pericardial tissue of a heart includes a first wire configured to be disposed within a pericardial cavity of the heart and forming at least one complete evolution around the heart. The first wire includes a metallic core and a non-metallic sheath encasing the metallic core.
[0005] An implantable device for stretching pericardial tissue of a heart includes a first wire configured to be disposed externally to and in contact with the pericardial tissue. The first wire includes a metallic core and a non-metallic sheath encasing the metallic core. The first wire is attached to the pericardial tissue with at least one anchoring device.
[0006] An implantable device for stretching pericardial tissue of a heart includes at least one bladder configured to be disposed within the pericardial cavity, a reservoir in fluid communication with the at least one bladder, and a valve for selectively controlling a flow of fluid between the at least one bladder and the reservoir. [0007] A method of stretching pericardial tissue of a heart includes delivering, via a catheter, an implantable wire into a pericardial cavity, the wire forming at least one full loop around the heart. An outward force is exerted, via the wire, against the pericardial tissue such that the pericardial tissue moves away from the heart.
[0008] A method of stretching pericardial tissue of a heart includes disposing at least one implantable wire along the pericardial tissue and anchoring the at least one wire to the pericardial tissue. The pericardial tissue is pulled, via the at least one wire, away from the heart.
[0009] A method of stretching pericardial tissue of a heart includes delivering at least one bladder into a pericardial cavity, the at least one bladder being in fluid communication with a reservoir. The at least one bladder is selectively filled with a fluid to exert an outward force on the pericardial tissue such that the pericardial tissue moves away from the heart.
BRIEF DESCRIPTION OF THE DRAWINGS
100101 FIG. 1 is an isometric view of a human heart showing a pericardium partially torn away over the left ventricle.
[0011 ] FIG. 2 is a schematic cross-sectional view of a heart with a pericardium.
[0012] FIGS. 3A, 3B, 3C, and 3D are schematic views showing a first example of a pericardial implant being implanted in the pericardial cavity of the heart.
[0013] FIGS. 4A, 4B, 4C, 4D, 4E, and 4F are schematic views of alternative atraumatic wire tips.
[0014] FIGS. 5A and 5B are schematic cross-sectional views of alternate wires.
[0015] FIGS. 6A and 6B are schematic cross-sectional views of the heart with the first example of the pericardial implant implanted in the pericardial cavity in deployed and expanded states, respectively.
[0016] FIG. 7 is a schematic side view of a second example of a pericardial implant having a wire with a barbed exterior.
[0017] FIG. 8 is a schematic view of a third example of a pericardial implant mounted on a delivery catheter.
[0018] FIG. 9 is a schematic view of the third example of the pericardial implant of FIG. 8 implanted within the pericardial cavity of the heart.
[0019] FIG. 10 is a schematic view of a fourth example of a pericardial implant implanted within the pericardial cavity. [0020] FIGS. 11 A, 1 IB, and 11C are schematic views of different examples of adjustable hoop- shaped wires.
[0021] FIG. 12 is a schematic view of a fifth example of a pericardial implant disposed externally to the pericardium.
[0022] FIG. 13 is a schematic view of a sixth example of a pericardial implant.
[0023] FIG. 14 is a schematic view of a seventh example of a pericardial implant.
[0024] FIG. 15 is a schematic view of an eight example of a pericardial implant.
[0025] FIG. 16 is a schematic view of a suction device used to implant the rods of FIG. 15 into the pericardium.
[0026] FIG. 17 is a schematic view of a ninth example of a pericardial implant implanted in the pericardial cavity.
[0027] FIGS. 18A and 18B are schematic cross-sectional views of the ninth example of the pericardial implant of FIG. 17 in a first, unfilled state and a second, filled state, respectively.
DETAILED DESCRIPTION
[0028] FIG. 1 is an isometric view of human heart 10 showing pericardium 12 partially torn away over the left ventricle. FIG. 2 is a schematic cross-sectional view of heart 10 with pericardium 12. FIGS. 1-2 are discussed together. FIGS. 1-2 shows heart 10, pericardium 12, epicardium 14, and pericardial cavity 22. FIG. 1 further shows right atrial appendage 16 and apex 18. FIG. 2 further shows myocardium 20, parietal layer 24, and fibrous pericardium 26.
[0029] Heart 10 is encompassed by pericardium 12, which is a fibrous fluid- filled sac that encloses heart 10. The outer layers of pericardium 12 are shown partially removed in FIG. 1 to reveal epicardium 14. Heart 10 further includes right atrial appendage 16 and apex 18, either of which can serve as an introduction point for a pericardial implant, as is discussed in greater detail below.
[0030] Pericardium 12 includes, as its innermost layer, epicardium 14. Epicardium 14 is also the external surface of heart 10, surrounding myocardium 20. Pericardium 12 further includes pericardial cavity 22, parietal layer 24, and fibrous pericardium 26. Pericardial cavity 22 is a fluid- filled space separating epicardium 14 from parietal layer 24 and fibrous pericardium 26. Fibrous pericardium 26 forms the outer layer of pericardium 12. Transcatheter alleviation of pericardial restraint (TAPR) is a catheter- based therapy that can reduce pericardial restraint by incising or opening pericardium 12 with the intention of improving exercise tolerance and reducing heart failure-related hospitalizations due to breathing difficulties among obese patients with HFpEF. In order to pursue atraumatic means of treating pericardial restraint, the present disclosure proposes various implantable devices which can stretch pericardium 12, thereby increasing the volume of pericardial cavity 22.
[0031] FIGS. 3 A- l lC disclose examples of pericardial implants that are implanted within a pericardia] cavity of the heart. In some cases, it can be desirable to dispose a pericardial implant within a pericardial cavity of the heart. Such implants can be configured to radially expand to press on the exterior of and expand the pericardial cavity.
[0032] FIGS. 3A, 3B, 3C, and 3D are schematic views showing a first example of pericardial implant 28 being implanted in pericardial cavity 22 of heart 10. FIGS. 3A- 3D are discussed together. FIGS. 3A-3D show heart 10, pericardium 12, right atrial appendage 16, apex 18, pericardial implant 28, wire 30, and atraumatic tip 34. FIGS. 3A- 3C also show catheter 32. FIG. 3D also shows sutures 36.
|0033 | FIGS. 3A-3D shows progressive stages of the implantation of pericardial implant 28 within pericardial cavity 22 of heart 10. Pericardial implant 28 includes wire 30, which can be advanced into pericardial cavity 22 by catheter 32. In each of FIGS. 3A-3D, at least a portion of wire 30 is shown in dashed lines to represent transparency where it is covered by the outer layers of pericardium 12. Atraumatic tip 34 is disposed on the distal end of wire 30 and is shaped to prevent damage to pericardium 12 and heart 10 as wire 30 is advanced into pericardial cavity 22. Wire 30 can be metallic with a biocompatible coating, as is discussed in greater detail below.
[0034] The point of insertion of wire 30 into pericardial cavity 22 can be proximate right atrial appendage 16, as shown in FIG. 3 A, although other locations are contemplated herein. Wire 30 can then be advanced through pericardial cavity 22, as shown in FIG. 3B. Wire 30 can be advanced such that it fully circumscribes heart 10 at least once (as shown in FIG. 3C), and preferably, such that it circumscribes heart 10 several times (as shown in FIG. 3C). The orientation of wire 30 about heart 10 can be random, that is, wire 30 can cross over itself and/or face different directions with each evolution, for example, with atraumatic tip 34 facing downward, toward apex 18 in FIG. 3C, and then facing upward in FIG. 3D. Wire 30 can be a predetermined length based on such factors as the circumference of heart 10 and the desired minimum number of evolutions by wire 30. When fully released from catheter 32, one or more sutures 36 (shown in FIG. 3D) can be used to secure the now freed proximal end of wire 30 in place. Sutures 36 may be anchored in the tissue of myocardium 20. Wire 30 can otherwise be held in place by its outwardly expanding force, as is discussed in greater detail below.
[0035] Wire 30 is stiff to allow wire 30 to push outwards on pericardium 12. As wire 30 is inserted into pericardial cavity 22, wire 30 will form a minimum bend radius and start to push away from epicardium 14. This will stretch pericardium 12 and expand pericardial cavity 22. FIGS. 4A, 4B, 4C, 4D, 4E, and 4F are schematic views of alternative atraumatic wire tips. FIG. 4A is a schematic side view of atraumatic tip 34A. FIG. 4B is a schematic end view of atraumatic tip 34A. FIGS. 4A-4B show atraumatic tip 34A having distal end 38 A. FIG. 4C is a schematic side view of atraumatic tip 34B. FIG. 4D is a schematic end view of atraumatic tip 34B. FIGS. 4C-4D show atraumatic tip 34B having distal end 38B. FIG. 4E is a schematic side view of atraumatic tip 34C. FIG. 4F is a schematic end view of atraumatic tip 34C. FIGS. 4E-4F show atraumatic tip 34C having distal end 38C. FIGS. 4A-4F are discussed together.
[0036] Atraumatic tip 34A, atraumatic tip 34B, and atraumatic tip 34C can be used at the distal end of wire 30 discussed with respect to FIGS. 3A-3D. The profiles of atraumatic tip 34 A, atraumatic tip 34B, and atraumatic tip 34C are designed to avoid perforation of pericardium 12 while wire 30 is advanced through pericardial cavity 22. As shown in FIGS. 4A-4B, distal end 38A of atraumatic tip 34A has an oval-shaped profile. As shown in FIGS. 4C-4D, distal end 38B of atraumatic tip 34B has a circular profile. As shown in FIGS. 4E-4F, distal end 38C of atraumatic tip 34C has a semicircular profile. Each of atraumatic tip 34A, atraumatic tip 34B, and atraumatic tip 34C can be formed from or coated with a biocompatible polymer or elastomeric material.
[0037] FIGS. 5A and 5B are schematic cross-sectional views of alternative wires. FIG. 5A is a schematic cross-sectional view of wire 30A having an oval cross- sectional profile. FIG. 5A shows wire 30A having center wire 40A and sheath 42A. FIG. 5B is a schematic cross-sectional view of wire 30B having a circular cross-sectional profile. FIG. 5B shows wire 30B having center wire 40B and sheath 42B. FIGS. 5A-5B are discussed together.
[0038] Wire 30A, shown in FIG. 5A, includes metallic center wire 40A with a circular cross-sectional geometry. Center wire 40A can be formed from a biocompatible shape-set memory alloy, such as a nickel titanium alloy. Center wire 40A is encased in sheath 42A, which gives wire 30A an oval, or ribbonlike, cross-sectional profile. The oval cross-sectional profile of wire 30A is atraumatic to pericardium 12. Sheath 42A can be formed from a biocompatible cloth or silicone.
[0039] Wire 30B, shown in FIG. 5B, includes metallic center wire 40B with a circular cross-sectional geometry. Center wire 40B can be formed from a biocompatible shape-set memory alloy, such as a nickel titanium alloy. Center wire 40B is encased by sheath 42B, which unlike sheath 42A, has a circular cross-sectional profile. The circular cross-sectional profile of wire 30B is atraumatic to pericardium 12. Sheath 42B can be formed from silicone. In one example, sheath 42B is a silicone coating formed on center wire 40B.
[0040] Wire 30 of pericardial implant 28 shown in FIGS. 3A-3D can have the oval cross-sectional profile of wire 30A shown in FIG. 5A or the circular cross-sectional profile of wire 30B shown in FIG. 5B.
[0041] FIGS. 6A and 6B are schematic cross-sectional views of heart 10 with pericardial implant 28 implanted in pericardial cavity 22 in deployed and expanded states, respectively. FIGS. 6A-6B are discussed together. FIGS. 6A-6B show heart 10, pericardium 12, epicardium 14, myocardium 20, pericardial cavity 22, parietal layer 24, fibrous pericardium 26, pericardial implant 28, wire 30, first side SI, and second side S2. FIG. 6A shows first distance DI. FIG. 6B shows second distance D2.
[0042] Pericardial implant 28 includes wire 30 having an oval cross-sectional profile similar to wire 30A of FIG. 5A. Wire 30 can have any suitable cross-sectional profile in alternate examples, including for example a circular cross-sectional profile as shown in FIG. 5B.
[0043] FIG. 6A shows wire 30 in a first, deployed (i.e., implanted) state, having been advanced from catheter 32 (shown in FIGS. 3A-3C) into pericardial cavity 22. In this deployed state, the distance between epicardium 14 and parietal layer 24 (i.e., the “thickness” of pericardial cavity 22) is first distance DI. First side SI of wire 30 faces and contacts parietal layer 24 (the pericardium-facing side), and second side S2 of wire 30 at least faces, and in the first deployed state, can also contact epicardium 14 (the epicardiumfacing side). The shape set memory alloy within wire 30 exerts an outward force, relative to epicardium 14, and is biased toward parietal layer 24.
[0044] FIG. 6B shows wire 30 in a second, expanded state. As wire 30 is inserted fully into pericardial cavity 22, it will form a minimum bend radius and reach an expanded state where wire 30 forces parietal layer 24 further away from epicardium 14. In the expanded state, the distance between epicardium 14 and parietal layer 24 expands to second distance D2, which is greater than first distance DI. The force exerted by wire 30 stretches, or remodels, pericardium 12 to help alleviate pericardial restraint.
[0045] FIG. 7 is a schematic side view of pericardial implant 128 having wire 130 with a barbed exterior. FIG. 7 shows pericardial implant 128, wire 130, barbs 144, and outer surface 146.
[0046] Pericardial implant 128 can be substantially similar to pericardial implant 28 discussed in reference to FIGS. 3A-6B, except that wire 130 of pericardial implant 128 includes directional barbs 144 on its outer surface 146. For wires having circular profiles (e.g., wire 30B shown in FIG. 5B), barbs 144 may circumscribe outer surface 146. For wires having oval profiles (e.g., wire 30A shown in FIG. 5A), barbs 144 may circumscribe outer surface 146 or may be disposed along one side (for example, first side SI as shown in FIG. 5A). Barbs 144 penetrate surrounding tissue (e.g., parietal layer 24) helping to anchor wire 130 to the tissue to prevent significant movement of pericardial implant 128 in the deployed and subsequent expanded states. Other anchoring means, such as sutures (e.g., sutures 36 shown in FIG. 3D) can additionally be used. Barbs 144 can be oriented opposite the direction of advancement into the pericardial cavity so that they do not catch on tissue during deployment of pericardial implant 128.
[0047] FIG. 8 is a schematic view of pericardial implant 228 mounted on delivery catheter 232. FIG. 9 is a schematic view of pericardial implant 228 implanted within the pericardial cavity of heart 10. FIGS. 8 and 9 are discussed together. FIGS. 8-9 show pericardial implant 228, helical wire 230, and catheter 232, which includes inner sheath 232A and outer sheath 232B. FIG. 9 further shows heart 10, pericardium 12, and pericardial cavity 22.
[0048] Pericardial implant 228 can be substantially similar to pericardial implant 28 discussed in reference to FIGS. 3A-6B, having helical wire 230 (similar to wire 30 shown in FIGS. 3A-6B) and an atraumatic tip (not shown). Helical wire 230 can have any suitable atraumatic tip, including atraumatic tip 34A shown in FIGS. 4A-4B, atraumatic tip 34B shown in FIGS. 4C-4D, or atraumatic tip 34C shown in FIGS. 4E-4F. Helical wire 230 can include a metallic center wire similar to wires 40A or 40B as shown in FIGS. 5A- 5B, and a polymer sheath/coating similar to sheath 42A or 42B as shown in FIGS. 5A-5B. Helical wire 230 can have any suitable cross-sectional profile, including an oval cross- sectional profile as shown in FIG. 5A or a circular cross-sectional profile as shown in FIG. 5B. [0049] Helical wire 230 can be crimped onto catheter 232 for delivery. Catheter 232 includes inner sheath 232A extending through outer sheath 232B, which is shown in a retracted position in FIG. 8. A guide wire can be wrapped around heart 10 using a separate guidewire delivery catheter. The guidewire delivery catheter can be removed while the guidewire remains wrapped around the heart. Catheter 232 can then be advanced into heart 10 over the guidewire, and helical wire 230 can be released from catheter 232. The guidewire can then be removed. Helical wire 230 is released in the pericardial cavity in such a manner that it loops several times around heart 10 forming a helical coil. Helical wire 230 can transition to an expanded state substantially similar to helical wire 30 as shown in FIG. 6B. Helical wire 230 can optionally be anchored via sutures and/or barbs, for example barbs 144 as shown in FIG. 7.
[0050] FIG. 10 is a schematic view of pericardial implant 328 implanted within pericardial cavity 22. FIG. 10 shows heart 10, pericardium 12, pericardial cavity 22, pericardial implant 328, wires 330, and hoops 348.
[0051] Pericardial implant 328 includes three wires 330 in the example shown in FIG. 10. Each wire 330 is configured as hoop 348 circumscribing heart 10. Although three hoops 348 are shown in FIG. 10, one, two, or more than three hoops 348 can be deployed in other examples. Each wire 330 can include a metallic center wire similar to wires 40A or 40B as shown in FIGS. 5 A-5B, and a polymer sheath/coating similar to sheath 42A or 42B as shown in FIGS. 5A-5B. Each wire 330 can have any suitable cross-sectional profile, including an oval cross-sectional profile as shown in FIG. 5A or a circular cross- sectional profile as shown in FIG. 5B. Each wire 330 can be delivered to the pericardial cavity via a catheter and anchored via sutures and/or barbs, for example barbs 144 as shown in FIG. 7.
[0052] Each wire 330 has a spring force to stretch the pericardial tissue and push parietal layer 24 (shown in FIG. 2) away from epicardium 14 (shown in FIG. 2). However, wires 330 can be stretched over time. FIGS. 11 A-l 1C disclose mechanisms for further expanding wires 330.
[0053] FIGS. 11 A, 1 IB, and 11C are schematic views of different examples of adjustable hoop-shaped wires 330A, 330B, and 330C, respectively. FIGS. 11A-11C are discussed together. FIG. 11A shows wire 330A and ratcheting mechanism 350A. FIG. 11B shows wire 330B, magnetically driver gear 350B, and external magnet 352B. FIG. 11C shows wire 330C and bioabsorbable layer 350C. [0054] Pericardial implant 328 shown in FIG. 10 can include any of wire 330A, wire 33OB, or wire 330C, which are examples of hoop-shaped wires. Wire 330A, wire 330B, or wire 330C are configured to expand radially outwards after implantation into the pericardial cavity of the heart.
[0055] Wire 330A shown in FIG. 11A includes one or more ratcheting mechanisms 35OA which can be turned to incrementally expand wire 330A. Wire 33OA includes two ratcheting mechanisms 350 A in the example shown in FIG. 11 A. Wire 330 A can include one or three or more ratcheting mechanisms 350A in alternate examples. Ratcheting mechanisms 350 A can be any suitable ratcheting mechanism. Ratcheting mechanisms 35OA can be ratcheted to adjust the stress in wire 330A and further expand wire 330 A to expand pericardium 12.
[0056] Wire 330B shown in FIG. 1 IB includes magnetically driven gear 35OB to incrementally expand wire 33OB when exposed to external magnet 352B. In alternate examples, wire 330B can include two or more magnetically driven gears 350B. When magnetically driven gears 350B are exposed to the external magnet 352B, the size of wire 330B can be expanded to further expand pericardium 12.
[0057] Wire 330C shown in FIG. 11C includes bioabsorbable layer 35OC encasing wire 330C. Over time, and as the material of bioabsorbable layer 35OC is absorbed into a patient’s body, wire 330C expands as it is no longer constrained by bioabsorbable layer 350C. In this regard, wire 330C is self-expanding, requiring no further intervention post deployment, whereas wire 330A and wire 330B require adjustment by a medical provider.
[0058] FIGS. 12-16 disclose examples of pericardial implants that are implanted external to the pericardium. In some cases, it can be desirable to dispose a pericardial implant external to the pericardium. Such implants can, for example, be more easily accessed for adjustment.
[0059] FIG. 12 is a schematic view of pericardial implant 428 disposed externally to pericardium 12. FIG. 12 shows heart 10, pericardium 12, pericardial cavity 22, pericardial implant 428, wires 430, hoops 448, and ratcheting mechanisms 450.
[0060] Pericardial implant 428 is substantially similar to pericardial implant 328 described with respect to FIG. 10. Pericardial implant 428 includes wires 430 arranged as individual hoops 448. Each wire 430 can further include means for adjustment, which as shown are ratcheting mechanisms 450. Other adjustment means, such as magnetically driven gears (for example, magnetically driven gears 350B shown in FIG. 1 IB) or bioabsorbable layers (for example, bioabsorbable layer 350C shown in FIG. 11C) are contemplated herein. Each wire 430 can be anchored by sutures 436.
[0061] Externally disposed pericardial implants operate to pull pericardial tissue (i.e., parietal layer 24 and fibrous pericardium 26 shown in FIG. 2) away from epicardium 14 (shown in FIG. 2), stretching the pericardial tissue and increasing the volume of pericardial cavity 22. Once pericardial implant 428 is implanted and each wire 430 is anchored to heart 10, the means for adjustment can be adjusted to radially expand each wire 430. For example, in the example shown in FIG. 12, ratcheting mechanisms 450 can be ratcheted to expand each wire 430 and stretch the pericardial tissue radially away from heart 10 to increase the volume of pericardial cavity 22.
[0062] FIG. 13 is a schematic view of pericardial implant 528. FIG. 13 shows pericardial implant 528, wires 530, and central node 552.
[0063] Pericardial implant 528 has a basketlike configuration formed by individual wires 530 projecting from central node 552. Central node 552 is configured to be positioned at apex 18 of heart 10 (shown in FIG. 1) so that wires 530 expand upwards around pericardium 12 of heart 10 (shown in FIG. 1). Wires 530 can be different lengths, for example, with the relatively shorter wires 530 disposed posteriorly to heart 10 when deployed. This may be necessary to avoid contact between wires 530 and the coronary sinus. Pericardial implant 528 can include any suitable number of wires 530, but preferably includes at least three wires 530.
[0064] FIG. 14 is a schematic view of pericardial implant 628. FIG. 14 shows heart 10, pericardium 12, apex 18, pericardial implant 628, wires 630, hoops 648, and central node 652.
[0065] Pericardial implant 628 is substantially similar to pericardial implant 528 described in reference to FIG. 13, but includes hoops 648. Pericardial implant 628 has wires 630 projecting from central node 652. Pericardial implant 628 further includes additional wires 630 configured as hoops 648 encircling heart 10. As shown in FIG. 14, central node 652 is positioned at apex 18 of heart 10.
[0066] Discussing both FIGS. 13 and 14, pericardial implants 528 and 628 may be implanted via a subxiphoid approach or an apical approach. Pericardial implants 528 and 628 can further be anchored to pericardium 12 by sutures (not shown in FIGS. 13 and 14). Wires 530 and wires 630 of pericardial implant 528 and pericardial implant 628, respectively, can have a spring force that force wires 530 and wires 630 outward to stretch pericardium 12. [0067] Wires 530 and 630 of pericardial implants 528 and 628, respectively, can include a metallic center wire similar to wires 40A or 40B as shown in FIGS. 5A-5B, and a polymer sheath/coating similar to sheath 42A or 42B as shown in FIGS. 5A-5B. Wires 530 and 630 can have any suitable cross-sectional profile, including an oval cross- sectional profile as shown in FIG. 5A or a circular cross-sectional profile as shown in FIG. 5B.
[0068] FIG. 15 is a schematic view of pericardial implant 728. FIG. 15 shows heart 10, pericardium 12, pericardia] implant 728, rods 730, and spring clips 754.
[0069] Pericardial implant 728 can include a number of rods 730 arranged in rows along pericardium 12. Each rod 730 can be implanted such that it stitched through pericardium 12 such that portions of each rod 730 are external to pericardium 12. Spring clips 754 can interconnect adjacent rods 730. Rods 730 and spring clips 754 can be formed from a metallic material covered with a polymer sheath or coating, similar to the various wires discussed above. Rods 730 and spring clips 754 pull pericardium 12 away from epicardium 14.
|0070| FIG. 16 is a schematic view of suction device 756 used to implant rods 730 into pericardium 12. FIG. 16 shows pericardium 12, rod 730, suction device 756, and internal volume 758.
[0071] Suction device 756 is used to implant rods 730 in pericardium 12. Suction device 756 includes a head with internal volume (recess) 758. Suction device 756 can be positioned over rod 730 and activated to suck an amount of pericardial tissue into internal volume 758. When the pericardial tissue is sucked into internal volume 758, rod 730 can be inserted through the pericardial tissue. This process can be repeated until each rod 730 is embedded to the extent desired.
[0072] FIGS. 17-18B disclose an example of a pericardial implant having a bladder disposed in the pericardial cavity.
[0073] FIG. 17 is a schematic view of pericardial implant 828 implanted in the pericardial cavity. FIGS. 18A and 18B are schematic cross-sectional views of pericardial implant 828 in a first, unfilled state and a second, filled state, respectively. FIGS. 17-19 are discussed together. FIGS. 17-18B show heart 10, pericardium 12, pericardial cavity 22, pericardial implant 828, bladders 860, and reservoir 862. FIG. 17 further shows control valve 864 and pressure sensor 866. FIGS. 18A-18B further show myocardium 20, epicardium 14, parietal layer 24, and fibrous pericardium 26. [0074] Pericardial implant 828 includes one or more bladders 860 disposed within pericardial cavity 22. Each bladder 860 can be in fluid communication with reservoir 862, which is disposed externally to pericardial cavity 22. Control valve 864 and pressure sensor 866 (shown in FIG. 17) are collocated and can help regulate the flow of fluid from reservoir 862 to bladder(s) 860, and vice versa. Bladder(s) 860 can be formed from a biocompatible elastomer. The fluid used within pericardial implant 828 can be a gas in one example, and a liquid, such as saline, in another example. In operation, pericardial implant 828 can be programmed to operate at certain times of day. For example, during the daytime when a patient is active, fluid can remain in reservoir 862 such that bladder 860 contains little or no fluid, as is shown in FIG. 18 A. At night, fluid can be released from reservoir 862 into bladder 860 by control valve 864, as is shown in FIG. 18B. The fluid- filled bladder pushes parietal layer 24 away from epicardium 14, temporarily increasing the volume of pericardial cavity 22 and, over time, stretching pericardium 12.
[0075] Any of the various systems, devices, apparatuses, etc. in this disclosure can be sterilized (e.g., with heat, radiation, ethylene oxide, hydrogen peroxide, etc.) to ensure they are safe for use with patients, and the methods herein can comprise sterilization of the associated system, device, apparatus, etc. (e.g., with heat, radiation, ethylene oxide, hydrogen peroxide, etc.).
[0076] The treatment techniques, methods, steps, etc. described or suggested herein or in references incorporated herein can be performed on a living animal or on a non-living simulation, such as on a cadaver, cadaver heart, anthropomorphic ghost, simulator (e.g., with the body parts, tissue, etc. being simulated), etc.
[0077] Discussion of Possible Examples
[0078] The following are non-exclusive descriptions of possible examples of the present invention.
[0079] An implantable device for stretching pericardial tissue of a heart includes a first wire configured to be disposed within a pericardial cavity of the heart and forming at least one complete evolution around the heart. The first wire includes a metallic core and a non-metallic sheath encasing the metallic core.
[0080] The implantable device of the preceding paragraph can optionally include, additionally and/or alternatively, any one or more of the following features, configurations, and/or additional components:
[0081] Wherein the first wire has an oval cross-sectional shape having a pericardium-facing side and an epicardium-facing side. [0082] Wherein the first wire comprises directional barbs on an outer surface of the non-metallic sheath.
[0083] Wherein the metallic core comprises a shape set memory alloy.
[0084] Wherein the shape set memory alloy is a nickel titanium alloy.
[0085] Wherein the non-metallic sheath comprises a biocompatible silicone.
[0086] Wherein the non-metallic sheath comprises a biocompatible cloth.
[0087] Wherein the first wire further comprises an atraumatic tip.
[0088] Wherein a distal end of the atraumatic tip has one of an oval, circular, and semicircular profile.
[0089] Wherein the first wire configured to make at least two complete evolutions around the heart.
[0090] Wherein an orientation of the first wire is random.
[0091 ] Wherein an orientation of the first wire forms a helical coil.
[0092] Wherein the first wire has a circular cross-sectional shape.
[0093] The implantable device further includes a suture anchoring the first wire to the heart.
[0094] The implantable device further includes a second wire configured to be disposed within a pericardial cavity of the heart and forming at least one complete evolution around the heart. The second wire includes a metallic core and a non-metallic sheath encasing the metallic core.
[0095] Wherein each of the first wire and the second wire is configured as a hoop.
[0096] Wherein each of each of the first wire and the second wire has one of an oval or a circular cross-sectional shape.
[0097] Wherein the metallic core of each of the first wire and the second wire comprises a shape set memory alloy.
[0098] Wherein the shape set memory alloy is a nickel titanium alloy.
[0099] Wherein the non-metallic sheath of each of the first wire and the second wire comprises a biocompatible silicone.
[0100] Wherein the non-metallic sheath of each of the first wire and the second wire comprises a biocompatible cloth.
[0101] Wherein each of the first wire and the second wire further comprises a ratcheting mechanism for expanding the first wire and the second wire. [0102] Wherein each of the first wire and the second wire further comprises a magnetically driven gear for expanding the first wire and the second wire.
[0103] Wherein each of the first wire and the second wire further comprises a first bioabsorbable layer surrounding the first wire and a second bioabsorbable layer surrounding the second wire for expanding the first wire and the second wire.
[0104] Wherein the first wire is configured to be delivered via a catheter.
[0105] An implantable device for stretching pericardial tissue of a heart includes a first wire configured to be disposed externally to and in contact with the pericardial tissue. The first wire includes a metallic core and a non-metallic sheath encasing the metallic core. The first wire is attached to the pericardial tissue with at least one anchoring device.
[0106] The implantable device of the preceding paragraph can optionally include, additionally and/or alternatively, any one or more of the following features, configurations, and/or additional components:
[0107] Wherein the at least one anchoring device comprises a suture.
|0108| Wherein the first wire is configured as a hoop.
[0109] Wherein the metallic core comprises a shape set memory alloy.
[0110] Wherein the shape set memory alloy is a nickel titanium alloy.
[0111] Wherein the non-metallic sheath comprises a biocompatible silicone.
[0112] Wherein the non-metallic sheath comprises a biocompatible cloth.
[0113] Wherein the first wire further comprises a ratcheting mechanism for expanding the first wire.
[0114] Wherein the first wire further comprises a magnetically driven gear for expanding the first wire.
[0115] Wherein the first wire further comprises a bioabsorbable layer surrounding the first wire for expanding the first wire.
[0116] The implantable device further includes a second wire configured to be disposed externally to and in contact with the pericardial tissue. The second wire includes a metallic core and a non-metallic sheath encasing the metallic core.
[0117] Wherein each of the first wire and the second wire are configured as hoops.
[0118] Wherein the metallic core of each of the first wire and the second wire comprises a shape set memory alloy.
[0119] Wherein the shape set memory alloy is a nickel titanium alloy. [0120] Wherein the non-metallic sheath of each of the first wire and the second wire comprises a biocompatible silicone.
[0121] Wherein the non-metallic sheath of each of the first wire and the second wire comprises a biocompatible cloth.
[0122] The implantable device further includes a third wire configured to be disposed externally to and in contact with the pericardial tissue. The third wire includes a metallic core and a non-metallic sheath encasing the metallic core.
[0123] Wherein each of the first wire, the second wire, and the third wire are attached to and extend from a node.
[0124] Wherein the node is configured to be positioned at an apex of the heart.
[0125] Wherein the first wire is longer than the third wire.
[0126] Wherein the third wire is configured to be disposed along a posterior of the heart.
[0127] Wherein the metallic core of each of the first wire, the second wire, and the third wire comprises a shape set memory alloy.
|0128| Wherein the shape set memory alloy is a nickel titanium alloy.
[0129] Wherein the non-metallic sheath of each of the first wire, the second wire, and the third wire comprises a biocompatible silicone.
[0130] Wherein the non-metallic sheath of each of the first wire, the second wire, and the third wire comprises a biocompatible cloth.
[0131] Wherein each of the first wire, the second wire, and the third wire are stitched through the pericardial tissue.
[0132] The implantable device further includes a plurality of spring clips interconnecting each of the first wire, the second wire, and the third wire.
[0133] Wherein the metallic core of each of the first wire, the second wire, and the third wire comprises a shape set memory alloy.
[0134] Wherein the shape set memory alloy is a nickel titanium alloy.
[0135] Wherein the non-metallic sheath of each of the first wire, the second wire, and the third wire comprises a biocompatible silicone.
[0136] Wherein the non-metallic sheath of each of the first wire, the second wire, and the third wire comprises a biocompatible cloth.
[0137] An implantable device for stretching pericardial tissue of a heart includes at least one bladder configured to be disposed within a pericardial cavity, a reservoir in fluid communication with the at least one bladder, and a valve for selectively controlling a flow of fluid between the at least one bladder and the reservoir.
[0138] The implantable device of the preceding paragraph can optionally include, additionally and/or alternatively, any one or more of the following features, configurations, and/or additional components:
[0139] Wherein the reservoir is configured to be located externally to the pericardial cavity.
[0140] Wherein the valve selectively controls the flow of fluid between the at least one bladder and the reservoir.
[0141] The implantable device further includes a pressure sensor collocated with the valve.
[0142] Wherein the fluid is a gas.
[0143] Wherein the fluid is a liquid.
[0144] Wherein the liquid is saline.
[0145] Wherein the at least one bladder is formed from an elastomeric material.
|0146| Wherein the at least one bladder comprises a first bladder and a second bladder.
[0147] A method of stretching pericardial tissue of a heart includes delivering, via a catheter, a wire into a pericardial cavity. The wire forms at least one full loop around the heart. The method further includes exerting, via the wire, an outward force against the pericardial tissue such that the pericardial tissue moves away from the heart.
[0148] The method of the preceding paragraph can optionally include, additionally and/or alternatively, any one or more of the following features, configurations, and/or additional components:
[0149] Wherein the wire is delivered via a subxiphoid approach.
[0150] Wherein the wire is delivered via a right atrial appendage.
[0151] Wherein the wire forms at least two evolutions around the heart in a random orientation.
[0152] Wherein the wire is helically crimped on the catheter.
[0153] The method further includes adjusting the wire to expand the wire.
[0154] Wherein adjusting the wire comprises turning a ratcheting mechanism.
[0155] Wherein adjusting the wire comprises actuating a magnetically driven gear.
[0156] The method further includes securing the wire to the heart. [0157] A method of stretching pericardial tissue of a heart includes disposing at least one wire along the pericardial tissue, anchoring the at least one wire to the pericardial tissue, and pulling, via the at least one wire, the pericardial tissue away from the heart.
[0158] The method of the preceding paragraph can optionally include, additionally and/or alternatively, any one or more of the following features, configurations, and/or additional components:
[0159] Wherein the at least one wire makes one complete evolution around the heart.
[0160] The method further includes securing the at least one wire to the heart.
[0161] The method further includes stitching the at least one wire through the pericardial tissue using a suction device.
[0162] Wherein the at least one wire comprises a first wire and a second wire.
[0163] A method of stretching pericardial tissue of a heart includes delivering at least one bladder into a pericardial cavity, the at least one bladder being in fluid communication with a reservoir. The method further includes selectively filling the at least one bladder with a fluid to exert an outward force on the pericardial tissue such that the pericardial tissue moves away from the heart.
[0164] While the invention has been described with reference to an exemplary embodiment(s), it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, the invention is not limited to the particular embodiments disclosed, but that the invention will include all embodiments described herein.