INTRODUCTION: Systemic heparin is used to decrease the failure rate of finger replantation after severe hand crush injuries; however, risks include bleeding, difficulty in controlling dosage, and possible ineffectiveness. Low molecular weight heparin (enoxaparin) is a possible safer alternate.  This study tested local and systemic enoxaparin in vascular crush injuries.

MATERIALS & METHOD: Four groups of 10 SD male rats, 250-300g each, were anesthetized; a 4-cm segment of tail artery was exposed, and a 1-cm segment was crushed by two needle holders and clamped for 60 minutes. The clamp was then released and the skin closed. Group 1. Control (C): These rats received no further treatment. Group 2. Local Enoxaparin (LE):  3 hours after crush, 0.3 ml of enoxaparin (0.5mg/100g weight, 5mg/ml solution) was subcutaneously injected in the tail; a second injection was given at 24 hours. Group 3. Local Heparin (LH):  3 hours after crush, 0.25 ml of heparin (15 units/100g weight, 200 units/ml solution,) was subcutaneously injected in the tail; a second injection was given at 24 hours. Group 4. Systemic Enoxaparin (SE): 3 hours after crush, 0.6 ml of enoxaparin (1mg/100g weight, 5mg/ml solution) was injected intraperitoneally; a second injection was given at 24 hours.  At 48 hours, all rats were re-anesthetized for evaluation of vascular patency.  Patency evaluation was performed by vascular appearance, arterial milk test, bleeding at the cut distal end of the artery, and measurement of artery diameter.  Histological studies (H&E) were performed on the arterial segments, and lumen diameter was measured by computer imaging system. PTT (partial thromboplastin time) was taken before surgery and at 48 hours. Statistical analysis was performed.

RESULTS: