Influence of transmural hydrostatic pressure during preparation and intraoperative storage of saphenous vein grafts on endothelial preservation

Objectives: The aim of the present study was to investigate the influence of transmural pressure on intimal structure of saphenous vein grafts (SVG) during preparation and intraoperative storage.

Methods: Alcian blue staining of subendothelial areas at pH<3, digital microphotographic image acquisition and subsequent computer-aided planimetry of the pictures allowed for the first time to perform rapid serial assessment of the degree of de-endothelialization in SVG. The viability of the residual endothelial cells was assessed in tissue culture after their proteolytic detachment and isolation.

Results: In saline more than 50% of the endothelium in SVG-remnants detached already at low transmural pressures (0–100mmHg, 45min at room temperature, n=10). Rising the pressure up to 500mmHg caused increasing and finally complete de-endothelialization (n=10). In contrast, grafts incubated in a customized plasma derivative (Biseko®) tolerated pressures of up to 500mmHg (often reached during conventional rinsing and sealing) with no significant endothelial loss (n=20). Even after exposure to 1,000mmHg more than 70% of the endothelium were intact and vital (n=5). An specially developed and easily manageable pressure adjusted rinsing system (PARS) prevented destructive transmural pressures.

Conclusions: These findings imply strongly that the quality of aortocoronary SVG can be improved substantially by the use of Biseko® for intraoperative sealing and preservation and by monitoring and controlling the transmural pressures by the application of PARS.