USE OF ANTITHROMBIN-III CONCENTRATES TO CORRECT ANTITHROMBIN-III DEFICIENCY DURING VASCULAR-SURGERY

Congenital deficiency of antithrombin III (AT III) is the only inherit ed hypercoagulable disorder for which a concentrate of purified protei n is available for replacement therapy during periods of increased thr ombotic risk. This report describes how such concentrates have been us ed in a patient with congenital AT-III deficiency undergoing venous su rgery. A 40-year-old woman with AT III deficiency was evaluated for bi lateral grade 3 chronic venous insufficiency. Noninvasive venous asses sment and ascending venography revealed incompetence of the lower leg perforators, a patent deep venous system, and competent greater and le sser saphenous veins. Staged subfascial ligations were performed. Past eurized AT LII was administered 1 hour before surgery and at 30 hours at a dose calculated to increase AT-III activity to at least 120%. Per ioperative AT III activity levels were measured. Subcutaneous heparin and oral warfarin were initiated the evening of surgery. An infusion o f AT III increased plasma AT III from the baseline activity of 51% to 180%; it was 87% 13 hours later. Two measurements of the initial half- life of AT III were 7 and 14 hours. No perioperative thrombotic compli cations occurred. The ulcers healed, and the patient remains symptom f ree. Pasteurized AT III concentrates are now commercially available, e asily administered, and provide a useful adjunct to the anticoagulatio n regimen of patients with AT III deficiency undergoing vascular surge ry.