PERIOPERATIVE ANTICOAGULANT EFFECTS OF HEPARINIZATION FOR CAROTID ENDARTERECTOMY

The question of whether or not to reverse heparin following carotid en darterectomy is a topic of debate. The potential reduction of the risk of thrombosis at the endarterectomy site with non-reversal has to be measured against a potential increase in the risk of wound haematoma. This study prospectively followed activated clotting time (ACT) of 42 consecutive patients undergoing carotid endarterectomy. A standard hep arin dose of 100 units/kg was used, and heparin reversal was employed only if the wound appeared excessively haemorrhagic at the procedure's completion. Heparin was reversed in 11 patients. Following heparin ad ministration, ACT increased to a mean 2.72 +/- 0.09 times baseline (ra nge 1.84-4.07), and fell with time, until at 3 h after heparin adminis tration mean ACT in the non-reversed patients was 1.48 +/- 0.03 times baseline (range 1.1-2.03). There was one postoperative neurological ev ent (2%), a contralateral hemisphere stroke. No patient developed a fr ank wound haematoma requiring evacuation, although three patients (7% of the total study group, 9% of patients not receiving heparin reversa l) developed neck swelling and symptoms of airway compromise, and were intubated. Measurements of ACT suggest that a heparin dose of 100 uni ts/kg achieves an adequate anticoagulant level in the operative and ea rly postoperative phase, when thrombosis is most likely to occur, and is not associated with an increased risk of wound haematoma. If hepari n is to be selectively reversed in patients felt to be at high risk of postoperative haematoma, the decision should be based on an objective measurement such as ACT, and not the surgeon's impression of wound ha emostasis.