INFLUENCE OF PERIOPERATIVE CATHETER INJURY ON THE LONG-TERM VEIN GRAFT FUNCTION AND MORPHOLOGY

Background: It has been shown that suboptimal preparation of a vein gr aft prior to its insertion results in immediate morphological and func tional damage to both endothelial cells and underlying smooth muscle c ells. This study examines the influence of perioperative balloon cathe ter injury on the subsequent development of intimal hyperplasia and va somotor function in experimental vein grafts, Methods: Twenty New Zeal and White rabbits had a carotid vein bypass graft performed: 10 were c ontrols and 10 had a balloon catheter passed through their lumen which resulted in deendothelialization and intramural injury (4Fr Fogarty c atheter, 0.6-0.75 mi H2O inflation, three passes), All grafts were har vested after 28 days for either morphology (n = 6) or functional studi es (n = 4; four 5-mm rings/graft). Results: Perioperative balloon inju ry of the vein graft resulted in a 23% increase in the intimal thickne ss (102 +/- 7 mu m vs 83 +/- 2 mu m, deendothelialized vs control; mea n +/- SEM, P < 0.01) and a 67% increase in medial thickness (144 +/- 1 9 mu m vs 86 +/- 8 mu m; mean +/- SEM, P < 0.01) of the vein grafts, B oth the sensitivity and maximal contraction of the responses elicited by norepinephrine, serotonin, and bradykinin were increased in the dee ndothelialized group compared to controls. Conclusion: Perioperative d enuding balloon injury of the vein graft results in the increased deve lopment of intimal hyperplasia with an overall enhanced contractility, This study demonstrates the long-term structural and functional effec ts of perioperative balloon catheter injury on vein grafts that may co ntribute to decreased graft patency. (C) 1996 Academic Press