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Abstract
One of the most crucial requirements since the inception of the artificial heart program has been the need to develop biomaterials specific to chronic implantation. Major problems include the propensity for thrombus formation at the blood-materials interface, long-term flexing reliability, and the tendency of the body to reject foreign objects.
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Kameneva MV, Repko BM, Krasik EF, Perricelli BC, Borovetz HS. Polyethylene Glycol Additives Reduce Hemolysis in Red Blood Cell Suspensions Exposed to Mechanical Stress. ASAIO J 2003; 49:537-42. [PMID: 14524560 DOI: 10.1097/01.mat.0000084176.30221.cf] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Mechanical damage to blood cells is of considerable concern in the development and use of circulatory assist devices and other blood contacting systems. Furthermore, hemodilution with saline, dextran, and other plasma expanders applied during extracorporeal circulation and dialysis increases red blood cell (RBC) susceptibility to the high shear stresses associated with these procedures. In this paper, we present polyethylene glycol (PEG) as a potential erythrocyte protective agent against mechanically induced cellular trauma. Bovine RBCs were subjected to mechanical stress induced by rolling stainless steel shots through RBC suspensions for a constant exposure time. The suspensions were prepared at a hematocrit of 30% in various media: PEG (20,000 molecular weight), autologous bovine plasma, Dextran 40 solution, and phosphate buffered saline (PBS). RBC suspensions in Dextran 40 were prepared at a viscosity similar to the PEG suspensions. We found the hemolysis level of RBCs suspended in plasma and in PEG solutions to be several times lower (p < 0.001) than in the Dextran and PBS solutions. No statistically significant difference was found between the hemolysis that occurred in suspensions of RBCs in autologous plasma and in 2.0% PEG solutions. Even PEG concentration as low as 0.1% reduced hemolysis by more than 40% compared with PBS or the same concentration of Dextran in suspension medium. Our data demonstrate the efficacy of PEG molecules in reducing mechanical trauma to erythrocytes and suggest the potential for using PEG in assisted circulation, dialysis, and other procedures where RBCs are subjected to extensive mechanical stress.
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Affiliation(s)
- Marina V Kameneva
- McGowan Institute for Regenerative Medicine, Department of Surgery, University of Pittsburgh, 3025 East Carson St., Pittsburgh, PA 15203, USA
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3
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Abstract
In the 1960s, when LVADs and TAHs were introduced into clinical use, researchers estimated that, with this technology, the problem of heart failure could be solved within 20 years. Unfortunately, the evolution of these devices has taken much longer than anticipated. Nevertheless, significant advances have been achieved in both cardiac assistance and replacement, and today's cardiac surgeons have a wide range of devices from which to choose (Table 4). This progress has largely been due to the support of the NHLBI, especially the Devices and Technology Division headed by John Watson, and of the devoted commitment of the investigators. Because of the long-term commitment required for both basic and clinical research, commercial medical technology companies are unable to assume this burden. Advances in mechanical circulatory support and replacement have benefited numerous patients worldwide who would otherwise have died of heart failure, and devices now exist for use as bridges to recovery, bridges to transplant, and destination therapy. The current challenge is to refine what we have and to apply these technologies to broader patient populations with maximal safety and at a reasonable cost.
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Affiliation(s)
- O H Frazier
- Texas Heart Institute at St. Luke's Episcopal Hospital, P.O. Box 20345, Houston, TX 77225-0345, USA.
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4
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Coumbe A, Graham TR. The pathology of artificial hearts and ventricular assist devices. CURRENT TOPICS IN PATHOLOGY. ERGEBNISSE DER PATHOLOGIE 1994; 86:161-97. [PMID: 8162710 DOI: 10.1007/978-3-642-76846-0_5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- A Coumbe
- Department of Morbid Anatomy, Royal London Hospital, Whitechapel, UK
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5
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Bernhard WF. A fibrillar blood-prosthetic interface for both temporary and permanent ventricular assist devices: experimental and clinical observations. Artif Organs 1989; 13:255-71. [PMID: 2669695 DOI: 10.1111/j.1525-1594.1989.tb02873.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- W F Bernhard
- Cardiovascular Surgical Research Laboratory, Children's Hospital, Massachusetts 02115
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Bernhard WF, Clay W, Gernes D, Hougen T, Sherman C, Burke D, Schoen FJ, Poirier VL. Temporary and permanent left ventricular bypass: laboratory and clinical observations. World J Surg 1985; 9:54-64. [PMID: 3984371 DOI: 10.1007/bf01656256] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Bernhard WF, Gernes DG, Clay WC, Schoen FJ, Burgeson R, Valeri RC, Melaragno AJ, Poirier VL. Investigations with an implantable, electrically actuated ventricular assist device. J Thorac Cardiovasc Surg 1984. [DOI: 10.1016/s0022-5223(19)38382-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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9
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Levy RJ, Zenker JA, Bernhard WF. Porcine bioprosthetic valve calcification in bovine left ventricle-aorta shunts: studies of the deposition of vitamin K-dependent proteins. Ann Thorac Surg 1983; 36:187-92. [PMID: 6603825 DOI: 10.1016/s0003-4975(10)60454-7] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Calcification of glutaraldehyde-preserved bioprosthetic cardiac valves represents a serious clinical problem. Previous work from this laboratory has established the presence in clinical bioprosthetic valve calcifications of vitamin K-dependent calcium-binding proteins, which contain the calcium-binding amino acid gamma-carboxyglutamic acid; no proteins containing gamma-carboxyglutamic acid are present in nonmineralized valves. The purpose of the present study was to examine a series of bovine circulatory bioprosthetic valve explants for calcification and proteins containing gamma-carboxyglutamic acid. Biochemical analyses of explanted bioprosthetic valves from calves demonstrated proteins with gamma-carboxyglutamic acid accumulating in calcified valves during both the onset and progression of valve calcification; calcium levels in the explanted calf bioprostheses were in the same range as those noted in clinical material. Accumulation of calcium and protein with gamma-carboxyglutamic acid occurred simultaneously and progressively, beginning 2 months after implantation. Small amounts of osteocalcin, the bone-derived protein containing gamma-carboxyglutamic acid, were present in both human and bovine bioprosthetic valve calcifications at comparable levels. No osteocalcin was detectable in non-mineralized valve tissue. Warfarin anticoagulant therapy did not prevent calcification or accumulation of protein with gamma-carboxyglutamic acid. It is concluded that proteins containing gamma-carboxyglutamic acid are involved in both the onset and progression of bioprosthetic valve calcification, and that conventional means of vitamin K antagonism do not alter this association or the course of bioprosthetic valve mineralization.
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Fuqua JM, Igo SR, Wayne Hibbs C, Poirier VL, Chambers JA, Clay WC, McGee MG, Turner SA, Norman JC. Development and evaluation of electrically actuated abdominal left ventricular assist systems for long-term use. J Thorac Cardiovasc Surg 1981. [DOI: 10.1016/s0022-5223(19)39452-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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11
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McCormick JR, Berger RL, Davis Z, Dobnik DB, Bernhard WF. Infection in remnant of left ventricular assist device after successful separation from assisted circulation. J Thorac Cardiovasc Surg 1981. [DOI: 10.1016/s0022-5223(19)39453-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Bernhard WF, Colo NA, Szycher M, Wesolowski JS, Haudenschild CC, Franzblau CC, Parkman R, Liss RH. Development of a nonthrombogenic collagenous blood-prosthetic interface. Ann Surg 1980; 192:369-81. [PMID: 6448027 PMCID: PMC1344921 DOI: 10.1097/00000658-198009000-00013] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Investigations to develop an implantable assist pump for prolonged circulatory support have been impeded by accumulation of friable thrombus on the prosthetic interface, with subsequent embolization. To circumvent this problem, the textured, fibril surface of a polyurethane pump chamber (mat thickness 430 microns) was inoculated with cultured bovine fetal fibroblasts (labelled with thymidine-14C) prior to animal implantation. The pneumatically actuated device (stroke volume 75 ml), maintained a pulsatile blood flow throughout each study. In 20 calf experiments, extending up to 335 days, 30 X 10(6) fibroblasts (in 50 ml media) derived from a single Holstein fetus were distributed on the urethane surface (360 +/- 50 cells/mm2) by rotation of a sealed device for three hours (12 revolutions/hour). Following connection to the circulation, cell washout was minimal. Resultant biologic linings, examined after animal sacrifice, were densely adherent to the underlying polymer matrix, and varied in thickness from 250 micron-1.5 mm. Microscopically, fibroblasts were identified from the surface to base, accompanied by numerous collagen bundles and abundant ground substance. Amino acid analysis in 10/20 pumps implanted for 31--335 days, revealed 50 +/- 5 Hydroxyproline residues/1000 residues (50% collagen) and scant elastin. Donor fibroblasts were identified by radioautography and karyotyping. Lack of immunologic response in 12 Hereford pump recipients as confirmed by serial fibroblast cytotoxicity assays. In conclusion, an induced collagenous-blood interface permitted prolonged mechanical circulatory support in animals without thromboembolic complications.
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Abstract
From June, 1977, to December, 1978, 14 children had intraaortic balloon support after open-heart operation. There were 6 long-term survivors. Four of 5 children more than 10 years old and 2 of 5 children between 5 and 10 years old survived. All 4 children less than 5 years old died. In the youngest group, it was difficult to use the balloon successfully because of their very low cardiac output coming off bypass and their greater aortic elasticity. The smallest sizes of balloon available were found to be too long, extending well below the diaphragm in younger patients. In 7 out of 10 patients 5 years old or more, augmentation was obtained.
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Pierce WS, Donachy JH, Rosenberg G, Baier RE. Calcification inside artificial hearts: inhibition by warfarin-sodium. Science 1980; 208:601-3. [PMID: 7367883 DOI: 10.1126/science.7367883] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Intracavitary calcium phosphate deposits were observed in smooth, elastomeric blood pump sacs implanted in male calves for periods of 115 to 166 days. These deposits occurred predominantly on the flexing surface of the sacs. In contrast, similar pump sacs remained generally free of mineral deposits for up to 150 days in calves treated with the anticoagulant warfarin-sodium. These results implicate a vitamin K-dependent process in calcium phosphate deposition on elastomeric sacs.
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Bernhard WF, Colo NA, Wesolowski JS, Szycher M, Fishbein MC, Parkman R, Franzblau CC, Haudenschild CC. Development of collagenous linings on impermeable prosthetic surfaces. J Thorac Cardiovasc Surg 1980. [DOI: 10.1016/s0022-5223(19)37920-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Golding LR, Groves LK, Peter M, Jacobs G, Sukalac R, Nosé Y, Loop FD. Initial clinical experience with a new temporary left ventricular assist device. Ann Thorac Surg 1980; 29:66-9. [PMID: 6965444 DOI: 10.1016/s0003-4975(10)61630-x] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
A new, simple left ventricular assist system has been developed and its use in experimental animals has been evaluated. The system achieves ventricular drainage by a transaortic valve cannula and utilizes a new centrifugal pump; the blood access is unique in requiring only a simple end-to-side synthetic graft anastomosis to the ascending aorta. Adequate pulsatility is obtained by concomitant use of an intraaortic balloon pump. This case report documents our initial clinical experience with this system in a postoperative patient with profound left ventricular failure unresponsive to all usual treatment. There was temporary recovery of left ventricular function upon decannulation after five and a half days of assist pumping. Despite the eventual death of the patient, the system functioned adequately, suggesting that it has good potential for use in a small, selected group of patients.
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Berger RL, Merin G, Carr J, Sossman HA, Bernhard WF. Successful use of a left ventricular assist device in cardiogenic shock from massive postoperative myocardial infarction. J Thorac Cardiovasc Surg 1979. [DOI: 10.1016/s0022-5223(19)38094-8] [Citation(s) in RCA: 33] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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19
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Trono R, Brewer MA, Edmonds CH, Fuqua JM, Hibbs CW, Holub DA, Igo SR, Norman JC. Molecular, microscopic, microstructural and mechanical methods of analyzing pseudoneointimal linings within partial artificial hearts in man and the calf. Artif Organs 1978; 2:173-82. [PMID: 687175 DOI: 10.1111/j.1525-1594.1978.tb03448.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Ex vivo molecular, microscopic (cellular), microstructural and mechanical methods have been utilized to evaluate biologic, blood-interfacing linings (pseudoneointimal) formed on textured, fibril-flocked pumping surfaces within abdominal left ventricular assist devices (ALVADs) on partial artificial hearts. Thus far, seventeen human and twenty bovine pseudoneointimal linings (1--28 day pumping durations) have been evaluated by these methods. The results indicate that pseudoneointima begins developing within 24 hours after contact of the pumping surface with blood and is well developed at five days. The linings exhibit surface immunofluorescent fibrinogen activity, viable surface macrophages and histiocytes and scattered erythrocytes at ALVAD removal. Structurally similar linings (20 micrometer to 500 micrometer in thickness) develop in calves and in man. Mechanically, pseudoneointima is a stable, adherent, highly compliant, isotropic structural material. It is linearly elastic and strain-rate independent, with small viscous energy losses under physiologic strains. The methods employed for the evaluation of pseudoneointima provide useful information to determine the suitability of textured or rough surfaces for blood interfacing. The cumulative results indicate that the textured surface approach is useful for intermediate-term clinical ALVAD utilization.
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