돼지 대동맥 판막과 폐동맥 판막의 고정 방법에 따른 양방향 압력-신장도의 비교분석

Biaxial Strain Analysis of Various Fixation Models in Porcine Aortic and Pulmonary Valves

  • 조성규 (서울대학교 의과대학 흉부외과학교실) ;
  • 김용진 (서울대학교 의과대학 흉부외과학교실) ;
  • 김수환 (서울대학교병원 임상의학 연구소, 바이오 이종장기개발사업단) ;
  • 최승화 (서울대학교병원 임상의학 연구소, 바이오 이종장기개발사업단)
  • Cho, Sung-Kyu (Department of Thoracic and Cardiovascular Surgery, Seoul National University Hospital, Seoul National University College of Medicine) ;
  • Kim, Yong-Jin (Department of Thoracic and Cardiovascular Surgery, Seoul National University Hospital, Seoul National University College of Medicine) ;
  • Kim, Soo-Hwan (Seoul National University Hospital Clinical Research Institute, Xenotransplantation Research Center) ;
  • Choi, Seung-Hwa (Seoul National University Hospital Clinical Research Institute, Xenotransplantation Research Center)
  • 발행 : 2009.10.05

초록

배경: 심장 판막의 기능은 대부분 판엽의 성질에 의해 결정된다. 단방향성 압력 장력 검사로 광범위하게 연구 되었으나, 단방향성 압력 장력 검사는 자연 상태에서의 압력 부하를 측정할 수 없다. 이번 연구는 더 나은 이종 이식 판막의 개발을 위하여 돼지의 대동맥 판막과, 폐동맥 판막을 고정액에 따라 자연적인 상태에서의 물리적 변화 즉 앙방향성 압력-팽창성 변화를 알아 보고자 하였다. 대상 및 방법: 돼지의 대동맥 판막과 폐동맥 판막을 아무것도 처리하지 않은 신선한 판막과 글루타알데하이드(glutaraldehyde, GA)로 고정한 군, GA에 에탄올과 같은 용매로 고정한 군으로 나누어 판막의 방사방향과 원주 방향의 양방향성 압력-신장도 변화를 조사 비교하였다. 결과: 신선한, GA고정 후의, 그리고 GA+ 용매 고정 후의 대동맥 판막(p=.00), 폐동맥 판막(p=.00) 모두에서 방사방향이 원주방향보다 압력 증가에 따라 더 잘 늘어 났다. GA 고정 후와 GA+용매 고정후의 대동맥 판막이 폐동맥 판막보다 각각 원주 방향과, 방사방향 비교했을 때 폐동맥 판막이 같은 압력에 대해 더 많이 늘어 났다(p=.00). 돼지의 신선한 대동맥 판막을 GA 고정 후에 원주 방향과 방사 방향에서 모두 신장도가 유의하게 감소 하였다(p=.00). GA+용매 고정 시에 방사 방향에서는 신장도가 유의하게 감소 하였으나(p=.00), 원주 방향에서는 그렇지 않았다(p=0.785). 그리고 GA 고정 그룹과 GA+용매 그룹간의 비교에서 원주 방향(p=0.785), 방사방향(p=0.137), 신장도가 유의한 차이는 얼었다. 폐동맥 판막에서도 GA 고정 그룹과 GA+용매 그룹간의 비교에서 원주 방향(p=0.718), 방사방향(p=0.910), 신장도가 유의한 차이는 없었다. 걸론: 돼지의 대동맥 판막과 폐동맥 판막의 GA 고정 시, 용매의 첨가는 물리적 손실은 가져 오지 않으나 신장도는 더 나아지지 않았다. 돼지의 대동맥 판막과 폐동맥 판막은 고정방법에 관계 없이 방사방향 신장도가 원주 방향보다 더 낫다.

Background: The function of a bioprosthetic heart valve is determined largely by the material properties of the valve cusps. The uniaxial tensile test has been studied extensively. This type of testing, however, does not replicate the natural biaxial loading condition. The objective of the present study was to investigate the regional variability of the biaxial strain versus pressure relationship based on the types of fixation liquid models. Material and Method: Porcine aortic valves and pulmonary valves were assigned to three groups: the untreated fresh group, the fixed with glutaraldehyde (GA) group, and the glutaraldehyde with solvent (e.g., ethanol) group. For each group we measured the radial and circumferential stretch characteristics of the valve as a function of pressure change. Result: Radial direction elasticity of porcine aortic and pulmonary valves were better than circumferential direction elasticity in fresh, GA fixed and GA+solvent fixed groups (p=0.00). Radial and circumferential direction elasticity of pulmonary valves were better than aortic valves in GA fixed, and GA+solvent fixed groups (p=0.00). Radial and circumferential direction elasticity of aortic valves were decreased after GA and GA+solvent fixation(p=0.00), except for circumferential elasticity of GA+solvent fixed valves (p=0.785). The radial (p=0.137) and circumferential (p=0.785) direction of elasticity of aortic valves were not significantly different between GA fixed. and GA+solvent fixed groups. Radial (p=0.910) and circumferential (p=0.718) direction of elasticity of pulmonary valve also showed no significant difference between GA fixed and GA+solvent fixed groups. Conclusion: When fixing porcine valves with GA, adding a solvent does not cause a loss of mechanical properties, but, does not improve elasticity either. Radial direction elasticity of porcine aortic and pulmonary valves was better than circumferential direction elasticity.

키워드

참고문헌

  1. Opie JC, Larrieu AJ, Cornell IS. Pericardial substitutes: delayedexploration and findings. Ann Thorac Surg 1987;43: 383-5 https://doi.org/10.1016/S0003-4975(10)62808-1
  2. Carpentier A, Nashef A, Carpentier S, Ahmed A, Goussef N. Technique for prevention of calcification of valvular bioprosthesis. Circulation 1984;70(Suppl I):I165-8
  3. Neethling WM, Hodge AJ, Clode P, Glancy R. A multi-step approach in anti-calcification of glutaraldehyde-preserved bovine pericardium. J Cardiovasc Surg (Torino) 2006;47: 711-8
  4. Garcia Paez JM, Jorge-Herrero E, Carrera A, et al. Chemical treatment and tissue selection: factors that influence the mechanical behaviour of porcine pericardium. Biomaterials 2001;22:2759-67 https://doi.org/10.1016/S0142-9612(01)00019-9
  5. Sung HW, Hsu CS, Lee YS, Lin DS. Crosslinking characteristics of an epoxy-fixed porcine tendon: Effects of pH, temperature, and fixative concentration. J Biomed Mater Res 1998;31:511-8 https://doi.org/10.1002/(SICI)1097-4636(199608)31:4<511::AID-JBM11>3.0.CO;2-J
  6. Zilla P, Weissenstein C, Human P, Dower T, Oppell UO. High glutaraldehyde concentrations mitigate bioprosthetic root calcification in the sheep model. Ann Thorac Surg 2000;70: 2091-5 https://doi.org/10.1016/S0003-4975(00)02011-7
  7. Nimni ME. The cross-linking and structure modification of the collagen matrix in the design of cardiovascular prosthesis. J Card Surg 1988;3:523-33 https://doi.org/10.1111/j.1540-8191.1988.tb00446.x
  8. Mayne AS, Christie GW, Smaill BH, Hunter PJ, Barratt- Boyes BG. An assessment of the mechanical properties of leaflets from four second-generation porcine bioprostheses with biaxial testing techniques. J Thorac Cardiovasc Surg 1989;98:170-80
  9. Grant WC, Barratt-Boyes BG. Mechanical properties of porcine pulmonary valve leaflet: how do they differ from aortic leaflets? Ann Thorac Surg 1995;60:S195-9 https://doi.org/10.1016/0003-4975(95)00279-T
  10. David L, Ivan V. Biaxial strain analysis of the porcine aortic valve. ATS 1995;60:S374-8 https://doi.org/10.1016/0003-4975(95)00249-K
  11. Gratzer PF, Pereira CA, Lee JM. Solvent environment modulates effects of glutaraldehyde crosslinking on tissue- derived biomaterials. J Biomed Mater Res 1996;31:533-43 https://doi.org/10.1002/(SICI)1097-4636(199608)31:4<533::AID-JBM14>3.0.CO;2-H
  12. Pathak CP, Adams AK, Simpson T, Phillips RE, Moore MA. Treatment of bioprosthetic heart valve tissue with long chain alcohol solution to lower calcification potential. J Biomed Mater Res 2004;69:140-4 https://doi.org/10.1002/jbm.a.20129
  13. Webb CL, Benedict JJ, Schoen FJ, Linden LA, Levy RJ. Inhibition of bioprosthetic heart valve calcification with aminodiphosphonate covalently bound to residual aldehyde groups. Ann Thorac Surg 1988;46:309-16 https://doi.org/10.1016/S0003-4975(10)65932-2
  14. Stein PD, Riddle JM, Kemp SP, et al. Effect of warfarin on calcification of spontaneously degenerated porcine bioprosthetic valves. J Thorac Cardiovasc Surg 1985;90:119-25
  15. Golomb G, Ezra V. Prevention of bioprosthetic heart valve tissue calcification by charge modification: effects of protamine binding by formaldehyde. J Biomed Mater Res 1991; 25:85-98 https://doi.org/10.1002/jbm.820250107
  16. Christie GW. Anatomy of aortic heart valve leaflets: the influence of glutaraldehyde fixation on function. Eur J Cardiothorac Surg 1992;6(Suppl)1:S25-32 https://doi.org/10.1016/1010-7940(92)90018-S
  17. Broom ND, Christie GW. The structure/fuction relationship of fresh and glutaraldehyde-fixed leaflets. In: Cohn LH, Gallucci V. Cardiac bioprotheses. New York: Yorke Medical Books 1982;476-91
  18. Humana P, Benzuidenhouta D, Torriannib M, Hendriksc M, Zilla P. Optinization of diamine bridges in glutaraldehyde treated bioprosthetic aortic wall tissue. Biometrerials 2002; 23:2099-103 https://doi.org/10.1016/S0142-9612(01)00302-7
  19. Zilla P, Fullard L, Trescony P, et al. Gulutaraldehyde detoxification of aortic wall tissue: a promising perspective for emerging bioprosthesis valve concepts. J Heart Valve Dis 1997;6:510-20
  20. Korossis SA, Booth C, Wilcox HE, et al. Tissue engineering of cardiac valve prostheses II: biomechanical characterization of decellularized porcine aortic heart valves. J Heart Valve Dis 2002;11:463-71