Histopathologic findings in a human arterial anastomosis after free flap transfer.

During the removal of subcutaneous fat 4 months after free groin flap transfer in a 25-year-old male, the anastomosed artery was also removed for histologic examination. The removal of the artery did not impair flap viability. The considerable narrowing of the arterial lumen caused by extensive hyperplasia of the intima suggested a restriction of arterial function. In addition, the internal elastic membrane had disappeared or was partially intact, doubled, and fragmented. Where sutures were tight, necrosis of the media was found, with heavy scar formation. If the sutures were loose, the media remained intact. The tissue of the flap artery was more heavily altered than the tissue of the recipient artery. This was evidently the result of trauma incurred during preparation of the flap vessels. Functional restriction of the anastomosed artery and secondary flap revascularization apparently occurred in a temporally favorable relationship in this case.