Characterizing bleeding risk of extracorporeal limb salvage with concomitant vascular injury

Abstract

BACKGROUND: Acute limb ischemia following trauma is a time-critical surgical emergency in which warm ischemia duration strongly determines limb salvage. Delays to revascularization are common in both civilian and military settings, prompting interest in extracorporeal limb perfusion strategies such as Lower Extremity Extracorporeal Distal Revascularization (LEEDR). However, concern exists that extracorporeal perfusion could exacerbate hemorrhage in the presence of uncontrolled vascular injury. METHODS: A porcine model of standardized groin hemorrhage was used to evaluate hemorrhage risk during LEEDR. Yorkshire swine were assigned to femoral arterial injury (FAI) or combined femoral arterial and venous injury (FAVI). Percutaneous vascular access was obtained in the contralateral femoral and ipsilateral saphenous vein. After controlled free bleeding of 300 mL via a 5 mm incision to the applicable vasculature and hemostasis with combat gauze, LEEDR was initiated using contralateral femoral arterial inflow and distal saphenous artery outflow. Pump speed was increased in 1,000 RPM increments every 10 minutes to a programmed maximum of 8,000 RPM or until system limits were reached. Hemorrhage during LEEDR was quantified, and injured vessels underwent histologic analysis at study completion. RESULTS: Twelve animals (FAI n=6, FAVI n=6) successfully underwent LEEDR. Maximal achieved RPM did not differ significantly between groups (6,708±990 vs. 6,442±1,107 RPM; p=0.67). No additional hemorrhage occurred in the FAI group. One FAVI animal experienced additional bleeding at high RPM, but overall post-LEEDR blood loss did not differ between groups (0±0 vs. 175±428.7 mL; P=0.34). Histology demonstrated intact early thrombus in arterial and venous injuries without evidence of washout. CONCLUSIONS: In this porcine model, LEEDR did not meaningfully exacerbate hemorrhage despite progressively increasing extracorporeal perfusion. Distal arterial resistance and favorable shear conditions may preserve thrombus integrity. These findings suggest vascular injury may represent a relative, rather than absolute, contraindication to LEEDR, supporting further feasibility evaluation. (J Trauma Acute Care Surg. 2026;00: 00-00. Copyright © 2026 Wolters Kluwer Health, Inc. All rights reserved.). LEVEL OF EVIDENCE: Level V evidence.