Maintained geometry, elasticity and contractility of human saphenous vein segments stored in a complex tissue culture medium.
OBJECTIVE
Improved maintenance of endothelial function and higher viability of saphenous vein grafts stored in a complex tissue culture medium (TCM) have been demonstrated. This article studies the biomechanical properties of saphenous vein segments.


METHODS
Biomechanical properties of 72 saphenous vein segments remaining from coronary bypass grafting of 32 patients have been studied after different storage procedures.


METHODS
The materials studied included fresh segments, segments stored in a cooled conventional physiological salt solution (normal Krebs-Ringer (nKR)) for 1-2 weeks, segments stored in a cooled chemically defined TCM (X-Vivo) for 1,2,3 and 4 weeks and segments cryopreserved for a few weeks.


METHODS
Specimens were cannulated at both ends and pressure-diameter curves were recorded in the 0-85-mmHg range in nKR with 10 microM norepinephrine added to induce maximum smooth muscle contraction, as well as in Ca(2+)-free medium to induce full relaxation. Tensile strength was checked at 300 mmHg. Distensibility, elastic modulus and active strain were computed.


RESULTS
Segments stored in nKR dilated morphologically, their distensibility decreased and they lost their ability to contract (1.5+/-0.7% from 10.1+/-1.5% of control) in 1 week. The TCM-stored segments preserved their contractility until 1 week, and this parameter only slowly decreased afterwards (first week, 11.5+/-7.3%; fourth week, 3.9+/-0.6%). There was a slight decrease in wall thickness but the lumen diameter was not affected. The elastic parameters of these segments were practically identical to those of fresh segments. Cryopreserved segments narrowed morphologically, their wall thickened and contractility diminished.


CONCLUSIONS
Storage in TCM helps preserve the passive and active biomechanical properties of human saphenous vein segments. Such properties can be expected to improve graft tissue viability.
Molnár
G F
GF
Department of Cardiovascular Surgery, Semmelweis University, Budapest, Hungary.
Nemes
A
A
Kékesi
V
V
Monos
E
E
Nádasy
G L
GL
D001696:Biomechanical Phenomena; D002118:Calcium / Q000378:metabolism; D015925:Cryopreservation; D003470:Culture Media / Q000494:pharmacology*; D004548:Elasticity; D006801:Humans; D009638:Norepinephrine / Q000494:pharmacology; D019188:Organ Preservation Solutions / Q000494:pharmacology*; D011312:Pressure; D012501:Saphenous Vein / Q000033:anatomy & histology / Q000187:drug effects* / Q000502:physiology; D013718:Tensile Strength; D013997:Time Factors; D014021:Tissue Preservation / Q000379:methods*; D014022:Tissue Survival / Q000187:drug effects; D014661:Vasoconstriction / Q000187:drug effects*; D014662:Vasoconstrictor Agents / Q000494:pharmacology; D014664:Vasodilation / Q000187:drug effects*
D003470:Culture Media; D019188:Organ Preservation Solutions; D014662:Vasoconstrictor Agents; D002118:Calcium; D009638:Norepinephrine