Popliteal artery trauma. Systemic anticoagulation and intraoperative thrombolysis improves limb salvage

This study was conducted to evaluate those factors associated with popliteal artery injury that influence amputation, with emphasis placed on those that the surgeon can control.

Generally accepted factors impacting amputation after popliteal artery injury include blunt trauma, prolonged ischemic times, musculoskeletal injuries, and venous disruption. Amputation ultimately results from microvascular thrombosis and subsequent tissue necrosis, predisposed by the paucity of collaterals around the knee.

Patients with popliteal artery injuries over the 10-year period ending November 1995 were identified from the trauma registry. Preoperative (demographics, mechanism and severity of injury, vascular examination, ischemic times) and operative (methods of arterial repair, venous repair-ligation, anticoagulation-thrombolytic therapy, fasciotomy) variables were studied. Severity of extremity injury was quantitated by the Mangled Extremity Severity Score (MESS). Amputations were classified as primary (no attempt at vascular repair) or secondary (after vascular repair). After univariate analysis, logistic regression analysis was performed to identify the independent risk factors for limb loss.

One hundred two patients were identified; 88 (86%) were males and 14 (14%) were females. Forty injuries resulted from blunt and 62 from penetrating trauma. There were 25 amputations (25%; 11 primary and 14 secondary). Patients with totally ischemic extremities (no palpable or Doppler pulse) more likely were to be amputated (31% vs. 13%; p < 0.04). All requiring primary amputations had severe soft tissue injury and three had posterior tibial nerve transection; the average MESS was 7.6. Logistic regression analysis identified independent factors associated with secondary amputation: blunt injury (p = 0.06), vein injury (p = 0.06), MESS (p = 0.0001), heparin-urokinase therapy (p = 0.05). There were no complications with either heparin or urokinase.

Minimizing ischemia is an important factor in maximizing limb salvage. Severity of limb injury, as measured by the MESS, is highly predictive of amputation. Intraoperative use of systemic heparin or local urokinase or both was the only directly controllable factor associated with limb salvage. The authors recommend the use of these agents to maximize limb salvage in association with repair of popliteal artery injuries.