Effect of peroperative hypertension on 125I-albumin uptake by vein graft media.
Aortocoronary bypass, in use for over 20 years, is followed by lesions in 80% of vein grafts after 10 years. In 8 patients (mean age 60, SD = 7.8) before cardiopulmonary bypass, segments of saphenous vein were harvested, and following hydraulic distension (760 mmHg x 10 min), stripped of adventitia, de-endothelialized, cannulated, immersed in oxygenated Krebs solution pH 7.4 37 deg C, and pressurized (100 mmHg) with 4% 125I-albumin-Evans blue for two hours. The samples were then frozen, and serially sectioned in the plane of the lumenal surface. The radioactivity of the 20 microns-thick sections was then determined, and expressed as a tissue: labelled solution concentration ratio (cpm unit volume wet tissue/cpm unit volume labelled solution). Distended portions had a higher mean transmural concentration ratio, as compared with the undistended portion; the ratio distended/undistended was 1.23, SD = 0.17, n = 8, p less than 0.01 (paired t test). This suggests alteration in the transport properties of vein interstitium by hypertension. Random histologic examination of native veins revealed no structural damage apart from age-related dystrophy of elastic fibres and intimal and medial fibrosis in grossly normal veins. These results suggest that the quality of the vein used, combined with hypertension during its preparation, may be factors in the genesis of postoperative graft failure.
Kennedy
J H
JH
Cardiovascular Surgery Service, Hôpital Lariboisiere, Paris, France.
Tedgui
A
A
Juan
L
L
Lavergne
A
A
Piwnica
A
A
D000368:Aged; D000418:Albumins / Q000493:pharmacokinetics*; D001026:Coronary Artery Bypass; D006801:Humans; D006973:Hypertension / Q000503:physiopathology*; D066298:In Vitro Techniques; D007457:Iodine Radioisotopes; D008875:Middle Aged; D008955:Models, Cardiovascular; D012501:Saphenous Vein / Q000378:metabolism* / Q000473:pathology / Q000637:transplantation
D000418:Albumins; D007457:Iodine Radioisotopes