Duplex Ultrasound May Predict the Best Level of Lower Limb Amputation in Patients with Chronic Limb-Threatening Ischemia: A Retrospective Observational Cohort Study

Abstract

Despite improved revascularization options, many patients with chronic limb-threatening ischemia (CLI) require lower limb amputation. Duplex ultrasound (DUS) is recommended as first-choice imaging technique in CLI. However, the prognostic utility of DUS for planning lower limb amputations has never been described before. This study aims to evaluate if DUS and findings from physical examination could be used to help predict the best level of lower limb amputation in patients with CLI. A retrospective cohort of 124 patients with CLI and a lower limb amputation was analyzed. Outcome measurements were reoperation, revision, and conversion rates, which were related to findings from physical examination and DUS examinations. Thirty-nine reoperations were performed, of which 17 stump revisions and 22 conversions were from below- to above-knee amputation. There was a discrepancy in findings of physical examination and DUS of 25% and 64% of femoral and popliteal pulsations respectively. Conversion rates increased with a more proximal occlusion on DUS. All patients with a vascular occlusion in the aortoiliac trajectory or deep femoral artery required a higher amputation level. Physical examination seems to be unreliable, and therefore should not be used to assess the optimal level of lower extremity amputation. Performing a primary above-knee amputation in patients with vascular occlusion in the aortoiliac trajectory or deep femoral artery could significantly reduce reoperation rates.