Anticoagulation with enoxaparin versus intravenous unfractionated heparin in postoperative vascular surgery patients

AbstractBackground: The use of postoperative anticoagulation is not uncommon for patients undergoing vascular procedures, whether for adjunctive therapy to the surgical procedure or for resumption of preoperative anticoagulation. We investigated whether low-molecular-weight heparin, specifically enoxaparin, was an effective replacement for intravenous heparin during the postoperative period until achievement of a therapeutic international normalized ratio, together with the impact on postoperative length of stay. Methods: We retrospectively examined 330 patients who received either traditional intravenous unfractionated heparin with adjusted-dose warfarin daily (n = 169) or subcutaneous low-molecular-weight heparin, specifically enoxaparin 1 mg/kg every 12 hours, with adjusted-dose warfarin daily (n = 161). Safety was defined as incidence of bleeding, hematoma, stroke, expiration, thrombocytopenia, return to surgery for graft thrombosis or hematoma, and readmission within 30 days for hematoma or thrombosis. Results: For all procedures, regardless of type of anticoagulation treatment, there was no difference in the incidence of postoperative complications, except for the increased incidence of return to surgery for graft thrombosis (P = .02), failing graft (P = .0004), and debridement (P = .01) in patients who received unfractionated heparin. For all procedures combined, the average postoperative length of stay was shortened by 2 days with use of low-molecular-weight heparin (P = .0001). Conclusions: In this series, use of enoxaparin appears to be safe and effective for vascular postoperative anticoagulation. At the same time, its use can significantly reduce the average postoperative length of stay for patients undergoing vascular procedures. Further prospective data are needed before this protocol can be accepted as an alternative for postoperative anticoagulation in this set of patients. (J Vasc Surg 2002;36:341-5.