Influence of several solutions used in bypass surgery on the permeability of the endothelium of carotid arteries in New Zealand rabbits

Abstract

Background: Alteration of endothelial permeability by perfusion solutions used may influence the outcome of bypass grafts.

Method: Carotid arteries of New Zealand rabbits were locally perfused in situ for 20 or 60 min with various solutions used in bypass surgery. After restoring normal circulation, horseradish peroxidase was injected in the ear vein. Endothelial permeability was measured by electronmicroscopy as the peroxidase accumulation in the subendothelial space during 6min circulation.

Results: The density indices (mean standard deviation) as a parameter for permeability in comparison to the control vessels were significantly greater than 100% for all solutions: for physiological saline 254+/-22% and 358+/-15%, for Ringer's lactate 206+/-26% and 302+/-17%, for St. Thomas' Hospital solution 163+/-15 % and 252+/-29%, and for Bretschneider's HTK solution 130+/-15% (p=0.003) and 169+/-26%, after 20 and 60 min perfusion. Addition of heparin (50IU/ml) caused a significant increase in endothelial permeability (p<0.05).

Conclusions: Bretschneider's is the most suitable of the solutions studied as a graft storage medium in bypass and cardiothoracic surgery, but a solution causing even less damage is desireable.