IP Library › Granted Patent US 12,303,376
Granted Patent B2
US 12,303,376 · App. 17/282,564 · Granted May 20, 2025

Bypass graft

Inventors: Jason N. MacTaggart (Omaha, NE); Alexey Kamenskiy (Omaha, NE); Kaspars Maleckis (Omaha, NE)
Assignee: Board of Regents of the University of Nebraska
A61F2/064A61L31/06B29C53/56B29C53/80A61F2210/0057A61F2220/0008A61F2220/0075A61F2230/0091A61F2240/001B29K2071/00B29L2031/7532
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Quick Facts
Patent No.
US 12,303,376
App. No.
17/282,564
Granted
May 20, 2025
Kind
B2
Abstract

Elastomeric bypass grafts (EBG) described herein can be pre-stretched and are able to accommodate limb flexion-induced or organ-induced deformations without producing excessive tortuosity or stresses. In comparison to known grafts, EBGs demonstrate significantly less tortuosity when used for lower extremity repair during limb flexion, and improved flow patterns within the grafts. Longitudinally pre-stretched EBGs described herein improve hemodynamics and may produce better healing responses in the harsh mechanical environment of the lower limbs, compared to known grafts.

Claims (32)

1. A vascular bypass graft, comprising:

an elongate tubular graft made of an elastomeric material that comprises a network of nanofibers arranged to cause the tubular graft to exhibit non-linear elastic compliance in response to increasing longitudinal tensile loads;

a first pre-stretch regulator coupled to a first end portion of the tubular graft and a second pre-stretch regulator coupled to a second end portion of the tubular graft; and

one or more wings extending laterally from the tubular graft.

2. The vascular bypass graft of claim 1 , wherein the elastomeric material comprises nanofibrillar elastomeric material.

3. The vascular bypass graft of claim 1 , wherein the network of nanofibers is arranged to cause the tubular graft to exhibit anisotropic properties.

4. The vascular bypass graft of claim 3 , wherein the anisotropic properties include a greater longitudinal compliance than radial compliance.

5. The vascular bypass graft of claim 1 , further comprising one or more reinforcing elements disposed between an inner layer of the elastomeric material and an outer layer of the elastomeric material.

6. The vascular bypass graft of claim 5 , wherein the one or more reinforcing elements comprises an undulating wire spirally wrapped between the inner and outer layers of the elastomeric material.

7. The vascular bypass graft of claim 5 , wherein the one or more reinforcing elements comprises an elongate element spirally wrapped between the inner and outer layers of the elastomeric material.

8. The vascular bypass graft of claim 5 , wherein the one or more reinforcing elements comprises an elongate polyethylene terephthalate element spirally wrapped between the inner and outer layers of the elastomeric material.

9. The vascular bypass graft of claim 1 , wherein the first and second pre-stretch regulators comprise tethers.

10. A method of implanting a blood vessel bypass graft, the method comprising:

creating a first anastomosis between a vascular bypass graft and a native blood vessel; and

creating a second anastomosis between the vascular bypass graft and the native blood vessel,

longitudinally pre-stretching the vascular bypass graft so that the vascular bypass graft is in tension between the first and second anastomoses,

wherein the vascular bypass graft comprises an elastomeric material made of a network of nanofibers arranged to cause the vascular bypass graft to exhibit non-linear elastic compliance in response to increasing longitudinal tensile loads.

11. The method of claim 10 , further comprising:

attaching to the native blood vessel a first pre-stretch regulator that is coupled to a first end portion of the vascular bypass graft; and

attaching to the native blood vessel a second pre-stretch regulator that is coupled to a second end portion of the vascular bypass graft.

12. The method of claim 10 , further comprising:

attaching to the native blood vessel one or more wings that extend laterally from the vascular bypass graft.

13. The method of claim 10 , wherein: creating the first anastomosis between the vascular bypass graft and the native blood vessel comprises creating the first anastomosis between the vascular bypass graft and a femoropopliteal artery; and

creating the second anastomosis between the vascular bypass graft and the native blood vessel comprises creating the second anastomosis between the vascular bypass graft and the femoropopliteal artery.

14. A method of making a prosthetic blood vessel bypass graft, the method comprising:

depositing a first layer of elastomeric material onto a rotating mandrel, wherein the elastomeric material comprises polyether-based urethane;

positioning one or more reinforcing framework members on the first layer; and

depositing a second layer of the elastomeric material onto the first layer and the one or more reinforcing framework members while the mandrel is rotating,

wherein the blood vessel bypass graft is configured to be longitudinally pre-stretched so that the blood vessel bypass graft is in tension between a first anastomosis and second anastomosis following implantation of the blood vessel bypass graft.

15. The method of claim 14 , wherein the method results in the prosthetic blood vessel bypass graft exhibiting non-linear elastic compliance in response to increasing longitudinal tensile loads.

16. The method of claim 14 , wherein at least one of the depositing the first layer of the elastomeric material or the depositing the second layer of the elastomeric material comprises electrospinning, and wherein the method further comprises controlling fiber undulation of the elastomeric material to attain a desired level of non-linear elastic compliance.

17. The method of claim 14 , wherein the method results in the prosthetic blood vessel bypass graft exhibiting anisotropic properties comprising a greater longitudinal compliance than radial compliance.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Apr 7, 2021
From: MACTAGGART, JASON; KAMENSKIY, ALEXEY; MALECKIS, KASPARS
To: BOARD OF REGENTS OF THE UNIVERSITY OF NEBRASKA
Reel/Frame 055855/0587 →
Continuity (2)
Provisional Application 62741828 · Oct 5, 2018
Related Publication 20210338412A1 · Nov 4, 2021
References Cited (116)
US 4552707A · How · 1985 [cited by applicant]
US 6939372B2 · Dong · 2005 [cited by applicant]
US 7993391B2 · Stinson · 2011 [cited by applicant]
US 8057537B2 · Zilla et al. · 2011 [cited by applicant]
US 8715340B2 · Rudakov et al. · 2014 [cited by applicant]
US 9132003B2 · Bar et al. · 2015 [cited by applicant]
US 9237945B2 · El-Kurdl · 2016 [cited by examiner]
US 9603729B2 · Soletti · 2017 [cited by examiner]
US 10076427B2 · Soletti · 2018 [cited by examiner]
US 10149750B2 · Wagner · 2018 [cited by examiner]
US 10335519B2 · Kaplan · 2019 [cited by examiner]
US 20040092976A1 · Mowry · 2004 [cited by examiner]
US 20060085063A1 · Shastri · 2006 [cited by examiner]
US 20090306770A1 · Kassab · 2009 [cited by applicant]
US 20110124951A1 · Walsh · 2011 [cited by applicant]
US 20110196475A1 · Kitaoka et al. · 2011 [cited by applicant]
US 20130131780A1 · Armstrong et al. · 2013 [cited by applicant]
US 20140284827A1 · Pokorny et al. · 2014 [cited by applicant]
US 20150112419A1 · Ahn et al. · 2015 [cited by applicant]
US 20150359619A1 · Lelkes et al. · 2015 [cited by applicant]
US 20170216062A1 · Armstrong et al. · 2017 [cited by applicant]
US 20170312102A1 · Mangiardi · 2017 [cited by applicant]
US 20190365953A1 · Turng · 2019 [cited by examiner]
US 20200237494A1 · El-Kurdi · 2020 [cited by examiner]
US 20210236260A1 · MacTaggart · 2021 [cited by examiner]
US 20210338412A1 · MacTaggart · 2021 [cited by examiner]
US 20220047783A1 · Hall · 2022 [cited by examiner]
US 20230310002A1 · Woods · 2023 [cited by examiner]
KR 20090113318 · 2009 [cited by applicant]
WO WO2005084730 · 2005 [cited by applicant]
WO WO2014143866 · 2014 [cited by applicant]
WO WO2015126768 · 2015 [cited by applicant]
WO WO2018200972 · 2018 [cited by applicant]
WO WO2019213161 · 2019 [cited by applicant]
Adam et al., “Bypass versus angioplasty in severe ischaemia of the leg (BASIL): multicentre, randomised controlled trial,” Lancet., Dec. 2005, 366(9501):1925-34, 10 pages. [cited by applicant]
Albertini et al., “Long-term results of arterial allograft below-knee bypass grafts for limb salvage: A retrospective multicenter study,” J Vasc Surg., Mar. 2000, 31(3):426-435. [cited by applicant]
Andrews et al., “Placement of a flexible endovascular stent across the femoral joint: An in vivo study in the swine model,” J Vasc Interv Radiol., Oct. 1999, 10(9):1219-1228. [cited by applicant]
Ansari et al., “Design considerations for studies of the biomechanical environment of the femoropopliteal arteries,” J Vasc Surg., Sep. 2013, 58(3):804-813. [cited by applicant]
Bergmeister et al., “Biodegradable, thermoplastic polyurethane grafts for small diameter vascular replacements,” Acta Biomater., Jan. 2015, 11:104-113. [cited by applicant]
Biemans et al., “Beware the kinking bypass—A hidden cause of graft reocclusion,” EJVES Extra., May 2002, 3(5):88-90. [cited by applicant]
Bisdas et al., “Results of peripheral bypass surgery in patients with critical limb ischemia (CRITISCH registry),” Gefasschirurgie, 2016, 21(Suppl 2):S71-79. [cited by applicant]
Carter et al., “Morphologic characteristics of lesion formation and time course of smooth muscle cell proliferation in a porcine proliferative restenosis model,” J Am Coll Cardiol., Nov. 1994, 24(5):1398-1405. [cited by applicant]
Chakfe et al., “The impact of knee joint flexion on infrainguinal vascular grafts: an angiographic study,” Eur J Vasc Endovasc Surg., Jan. 1997, 13(1):23-30. [cited by applicant]
Charanpreet et al., “Medical Textiles as Vascular Implants and Their Success to Mimic Natural Arteries,” Journal of Functional Biomaterials, Jun. 2015, 6:500-525. [cited by applicant]
Chatzizisis et al., “Role of endothelial shear stress in the natural history of coronary atherosclerosis and vascular remodeling: molecular, cellular, and vascular behavior,” J Am Coll Cardiol., Jun. 2007, 49(25):2379-2… [cited by applicant]
Chesnutt and Han, “Effect of Red Blood Cells on Platelet Activation and Thrombus Formation in Tortuous Arterioles,” Front Bioeng Biotechnol., Dec. 2013, 1(18): 12 pages. [cited by applicant]
Chew et al., “Bypass in the absence of ipsilateral greater saphenous vein: Safety and superiority of the contralateral greater saphenous vein,” J Vasc Surg., 2002, 35:1085-1091, 14 pages. [cited by applicant]
Conte et al., “Results of Prevent III: a multicenter, randomized trial of edifoligide for the prevention of vein graft failure in lower extremity bypass surgery,” J Vasc Surg., Apr. 2006, 43(4):742-751. [cited by applicant]
Courtney et al., “Design and analysis of tissue engineering scaffolds that mimic soft tissue mechanical anisotropy,” Biomaterials, Jul. 2006, 27(19):3631-3638. [cited by applicant]
Desyatova et al., “Constitutive modeling of human femoropopliteal artery biaxial stiffening due to aging and diabetes,” Acta Biomater., Dec. 2017, 64:50-58, 9 pages. [cited by applicant]
Desyatova et al., “Effect of aging on mechanical stresses, deformations, and hemodynamics in human femoropopliteal artery due to limb flexion,” Biomech Model Mechanobiol., 2017, 17(1):181-189, 9 pages. [cited by applicant]
Desyatova et al., “Limb flexion-induced twist and associated intramural stresses in the human femoropopliteal artery,” J R Soc Interface., Mar. 2017, 14(128):20170025, 11 pages. [cited by applicant]
Desyatova et al., “The choice of a constitutive formulation for modeling limb flexion-induced deformations and stresses in the human femoropopliteal arteries of different ages,” Biomech Model Mechanobiol., Jun. 2017, 16… [cited by applicant]
Desyatova, “Cross-sectional pinching in human femoropopliteal arteries due to limb flexion, and stent design optimization for maximum cross-sectional opening and minimum intramural stresses,” J R Soc Interface., 2018, 1… [cited by applicant]
Edelman and Rogers, “Pathobiologic responses to stenting,” Am J Cardiol., Apr. 1998, 81(7A):4E-6E. [cited by applicant]
EP Extended European Search Report in European Appln. No. 19796029.7, dated May 18, 2021, 7 pages. [cited by applicant]
EPO Communication Pursuant to Rule 114(2) EPC in European Appln. No. 19796029.7, dated Feb. 15, 2022, 4 pages. [cited by applicant]
Favreau et al., “Acute reductions in mechanical wall strain precede the formation of intimal hyperplasia in a murine model of arterial occlusive disease,” J Vasc Surg., Nov. 2014, 60(5):1340-1347. [cited by applicant]
Feng et al., “Numerical Simulation of Thrombotic Occlusion in Tortuous Arterioles,” J Cardiol Cardiovasc Med., Dec. 2017, 2(1):95-111. [cited by applicant]
Filipe et al., “Rapid Endothelialization of Off-the-Shelf Small Diameter Silk Vascular Grafts,” JACC Basic Transl Sci., Feb. 2018, 3(1):38-53. [cited by applicant]
Fisher et al., “Below-knee PTFE bypass graft fatigue,” Eur J Vasc Endovasc Surg., Sep. 1999, 18(3):266-267. [cited by applicant]
Guan et al., “Compliance Study of Endovascular Stent Grafts Incorporated with Polyester and Polyurethane Graft Materials in both Stented and Unstented Zones,” Materials (Basel), Aug. 2016, 9(8):658, 15 pages. [cited by applicant]
Gupta et al., “Prospective, randomized comparison of ringed and nonringed polytetrafluoroethylene femoropopliteal bypass grafts: a preliminary report,” J Vasc Surg., 1991, 13:163-72. [cited by applicant]
Hasan et al., “Electrospun Scaffolds for Tissue Engineering of Vascular Grafts—Review,” Acta Biomater., Jan. 2014, 10(1)11-25. [cited by applicant]
Hollier et al., “Femoral anastomotic aneurysms,” Ann Surg., Jun. 1980, 191(6):715-719. [cited by applicant]
Horný et al., “A comparison of age-related changes in axial prestretch in human carotid arteries and in human abdominal aorta,” Biomech Model Mechanobiol., May 2016, 16(1):375-383, 9 pages. [cited by applicant]
Humphrey et al., “Fundamental role of axial stress in compensatory adaptations by arteries,” J Biomech., Jan. 2009, 42:1-8. [cited by applicant]
International Preliminary Report on Patentability in International Appln. No. PCT/US2019/030041, dated Nov. 12, 2020, 7 pages. [cited by applicant]
International Preliminary Report on Patentability in International Appln. No. PCT/US2019/054401, dated Apr. 15, 2021, 8 pages. [cited by applicant]
International Search Report and Written Opinion in International Appln. No. PCT/US2019/030041, dated Jul. 2, 2019, 7 pages. [cited by applicant]
International Search Report and Written Opinion in International Appln. No. PCT/US2019/054401, dated Feb. 6, 2020, 11 pages. [cited by applicant]
Jackson et al., “Partial off-loading of longitudinal tension induces arterial tortuosity,” Arterioscler Thromb Vasc Biol., 2005, 25:957-62. [cited by applicant]
Jackson et al., “Wall Tissue Remodeling Regulates Longitudinal Tension in Arteries,” Circ Res., May 2002, 90(8):918-925, 9 pages. [cited by applicant]
Kamenskiy et al., “A mathematical evaluation of hemodynamic parameters after carotid eversion and conventional patch angioplasty,” Am J Physiol Heart Circ Physiol., Sep. 2013, 305(5):H716-24. [cited by applicant]
Kamenskiy et al., “Age and disease-related geometric and structural remodeling of the carotid artery,” J Vasc Surg., Dec. 2015, 62(6):1521-8. [cited by applicant]
Kamenskiy et al., “Comparative Analysis of the Biaxial Mechanical Behavior of Carotid Wall Tissue and Biological and Synthetic Materials Used for Carotid Patch Angioplasty,” J Biomech Eng., Nov. 2011, 133(11):111008, 11… [cited by applicant]
Kamenskiy et al., “Constitutive description of human femoropopliteal artery aging,” Biomech Model Mechanobiol., 2017, 16(2):681-692. [cited by applicant]
Kamenskiy et al., “Effects of age on the physiological and mechanical characteristics of human femoropopliteal arteries,” Acta Biomater., Nov. 2015:304-13. [cited by applicant]
Kamenskiy et al., “Hemodynamically Motivated Choice Of Patch Angioplasty For The Performance Of Carotid Endarterectomy,” Ann Biomed Eng., Aug. 2012, 41(2):263-278, 16 pages. [cited by applicant]
Kamenskiy et al., “In situ longitudinal pre-stretch in the human femoropopliteal artery,” Acta Biomater., Mar. 2016, 32:231-237. [cited by applicant]
Kamenskiy et al., “Passive biaxial mechanical properties and in vivo axial pre-stretch of the diseased human femoropopliteal and tibial arteries,” Acta Biomater., Mar. 2014, 10(3):1301-1313. [cited by applicant]
Kamenskiy et al., “Patient demographics and cardiovascular risk factors differentially influence geometric remodeling of the aorta compared with the peripheral arteries,” Surgery, 2015, 158(6):1617-1627, 11 pages. [cited by applicant]
Kamenskiy et al., “Prevalence of Calcification in Human Femoropopliteal Arteries and its Association with Demographics, Risk Factors, and Arterial Stiffness,” Arterioscler Thromb Vasc Biol., Apr. 2018, 38(4):e48-e57, 9 … [cited by applicant]
Kapadia et al., “Modified prosthetic vascular conduits,” Circulation, Apr. 2008, 117(14):1873-1882, 11 pages. [cited by applicant]
Kissin et al., “Vein interposition cuffs decrease the intimal hyperplastic response of polytetrafluoroethylene bypass grafts,” J Vasc Surg., Jan. 2000, 31:69-83. [cited by applicant]
Lowe et al., “The Porcine Coronary Model of In-Stent Restenosis: Current Status in the Era of Drug-Eluting Stents,” Catheter Cardiovasc Interv., Dec. 2003, 60(4):515-523. [cited by applicant]
Lundgren et al., “External support of a polytetrafluoroethylene graft improves patency for bypass to below-knee arteries,” Ann Vasc Surg., Nov. 2013, 27(8):1124-1133. [cited by applicant]
MacTaggart et al., “Accepted Manuscript: Three-dimensional bending, torsion and axial compression of the femoropopliteal artery during limb flexion,” J Biomech., Jul. 2014, 47(10):2249-2256, 27 pages. [cited by applicant]
MacTaggart et al., “Morphometric roadmaps to improve accurate device delivery for fluoroscopy-free resuscitative endovascular balloon occlusion of the aorta,” J Trauma Acute Care Surg., Jun. 2016, 80(6):941-6. [cited by applicant]
MacTaggart et al., “Stent Design Affects Femoropopliteal Artery Deformation,” Ann Surg., 2019, 270(1):180-187, 8 pages. [cited by applicant]
Mahoney et al., “One-year costs in patients with a history of or at risk for atherothrombosis in the United States,” Circ Cardiovasc Qual Outcomes., Sep. 2008, 1(1):38-45, 10 pages. [cited by applicant]
Mahoney et al., “Vascular hospitalization rates and costs in patients with peripheral artery disease in the United States,” Circ Cardiovasc Qual Outcomes., Nov. 2010, 3(6):642-51, 12 pages. [cited by applicant]
Maleckis et al., “Comparison of Femoropopliteal Artery Stents Under Axial and Radial Compression, Axial Tension, Bending, and Torsion Deformations,” J Mech Behav Biomed Mater., Nov. 2017, 75:160-168. [cited by applicant]
Maleckis et al., “Nitinol Stents in the Femoropopliteal Artery: A Mechanical Perspective on Material, Design, and Performance,” Ann Biomed Eng., May 2018, 46(5):684-704, 21 pages. [cited by applicant]
Maleckis, “Towards Precision Nanomanufacturing for Mechanical Design: From Individual Nanofibers to Mechanically Biomimetic Nanofibrillary Vascular Grafts,” Thesis for the degree of Doctor of Philosophy, University of N… [cited by applicant]
Malek et al., “Hemodynamic Shear Stress and Its Role in Atherosclerosis,” JAMA, Dec. 1999, 282(21):2035-2042. [cited by applicant]
Mellander et al., “Healing of PTFE grafts in a pig model recruit neointimal cells from different sources and do not endothelialize,” Eur J Vasc Endovasc Surg., Jul. 2005, 30(1):63-70. [cited by applicant]
Mithieux and Weiss, “Elastin,” Adv Protein Chem., 2005, 70:437-61. [cited by applicant]
Morishima et al., “Prolonged sitting-induced leg endothelial dysfunction is prevented by fidgeting,” Am J Physiol—Hear Circ Physiol., Jul. 2016, 311(1):H177-H182. [cited by applicant]
Pennel et al., “Accepted Manuscript: Transmural capillary ingrowth is essential for confluent vascular graft healing,” Acta Biomater., Jan. 2018, 65:237-247, 38 pages. [cited by applicant]
Poulson et al., “Limb flexion-induced axial compression and bending in human femoropopliteal artery segments,” J Vasc Surg., Feb. 2018, 67(2):607-613, 7 pages. [cited by applicant]
Restaino et al., “Endothelial dysfunction following prolonged sitting is mediated by a reduction in shear stress,” Am J Physiol Heart Circ Physiol., Mar. 2016, 310(5):H648-H653. [cited by applicant]
Schillinger et al., “Balloon angioplasty versus implantation of nitinol stents in the superficial femoral artery,” N Engl J Med., May 2006, 354(18):1879-1888. [cited by applicant]
Schillinger et al., “Sustained benefit at 2 years of primary femoropopliteal stenting compared with balloon angioplasty with optional stenting,” Circulation, May 2007, 115(21):2745-9. [cited by applicant]
Sheriff et al., “High-shear stress sensitizes platelets to subsequent low-shear conditions,” Ann Biomed Eng., Apr. 2010, 38(4):1442-1450. [cited by applicant]
Singh et al., “Importance of stent-graft design for aortic arch aneurysm repair,” Bioengineering, Feb. 2017, 4(1):133-150. [cited by applicant]
Singh et al., “Medical textiles as vascular implants and their success to mimic natural arteries,” Biomaterials, Jun. 2015, 6(3):500-525. [cited by applicant]
Suwandi et al., “Inducing tissue specific tolerance in autoimmune disease with tolerogenic dendritic cells,” Clin Exp Rheumatol., 2015, 33:S97-S103. [cited by applicant]
Taylor et al., “Acute disruption of polytetrafluoroethylene grafts adjacent to axillary anastomoses: a complication of axillofemoral grafting,” J Vasc Surg., Oct. 1994, 20:520-528. [cited by applicant]
Taylor et al., “Autogenous reversed vein bypass for lower extremity ischemia in patients with absent or inadequate greater saphenous vein,” Am J Surg., May 1987, 153(5):505-510. [cited by applicant]
Thosar et al., “Effect of prolonged sitting and breaks in sitting time on endothelial function,” Med Sci Sports Exerc., Apr. 2015, 47(4):843-849. [cited by applicant]
Vasita and Katti, “Nanofibers and their applications in tissue engineering,” Int J Nanomedicine, 2006, 1(1):15-30. [cited by applicant]
Vriens et al., “Superior two-year results of externally unsupported polyester compared to supported grafts in above-knee bypass grafting: A multicenter randomised trial,” Eur J Vasc Endovasc Surg., 2013, 45(3):275-281. [cited by applicant]
Walsh et al., “Prolonged leg bending impairs endothelial function in the popliteal artery,” Physiol Rep., Nov. 2017, 5(20):e13478, 8 pages. [cited by applicant]
Wang et al., “Biomimetic electrospun nanofibrous structures for tissue engineering,” Mater Today, Jun. 2013, 16(6):229-241. [cited by applicant]
Watt, “Origin of femoro-popliteal occlusions,” Br Med J., Dec. 1965, 2(5476):1455-1459. [cited by applicant]