Microvascular anastomosis timing in digital replantations

The proper sequence of vascular anastomosis in digital microsurgical replantation is still controversial.1 To evaluate whether the sequence of arterial and venous repair and clamp removal affects the success rate in digit replantation, we studied retrospectively 74 cases of digit replantation, with different amputation levels and mechanisms of trauma. In the avulsion and crush injuries, the artery was repaired first, to permit assessment of the integrity of circulation within the replanted digit and to check the presence of the “no reflow phenomenon.” In guillotine-type amputations, venous anastomosis was generally performed first. The rule for the timing of anastomosis in the clinical setting is difficult to appraise, because the outcome of digit replantation is influenced above all by the mechanism of injury. The arterial repair restores blood flow to the digit and reduces ischemia, thereby permitting the evaluation of effective circulation and the choice of the proper vein. On the other hand, re-establishing the venous continuity first allows one to avoid venous stasis, and the bloodless field reduces the technical time spent positioning the suture.2 Presently, we make our decision based on the nature of the trauma and the condition of the amputated stump. The arterial repair is performed first in avulsion and crush traumas, when there is a long ischemia time and an inadequately preserved stump. With guillotine or saw lesions, we prefer to suture the veins first, to reduce the operative time and simplify the surgery.