Differences between arterial and venous occlusion in microvascular surgery.

Between November 1985 and November 1988 11 patients developed arterial occlusion after microvascular anastomoses, 10 patients venous occlusions and five combined arterial and venous occlusions. We undertook a retrospective study to see whether colour, capillary refill, thermometry, or laser Doppler measurements could distinguish arterial and venous occlusions. Neither skin thermometry nor total backscattered light intensity change and flow band width (laser Doppler measurements) were significantly different (p > 0.05) between arterial and venous occlusions, but there were significant differences in colour (p = 0.006), capillary refill (p = 0.007), and laser Doppler flow (p = 0.02). The values obtained from cases with combined arterial and venous occlusions were like those of a venous occlusion or of an arterial occlusion or somewhere in between. Although none of the variables was diagnostic, we advise that the suspect vascular anastomosis should first be checked during reoperation. If an occluded anastomosis is found, one should also check the other anastomosis because occlusion of both artery and vein cannot be reliably detected.