Early ABI Testing May Decrease Risk of Amputation for Patients With Lower Extremity Ulcers

Abstract

Background: Patients with lower extremity wounds from diabetes mellitus or peripheral artery disease (PAD) have a risk of amputation as high as 25%. In patients with arterial disease, revascularization decreases the risk of amputation. We aimed to determine if the early assessment of arterial perfusion correlates with the risk of amputation.

Methods: We retrospectively reviewed patients referred to the vascular clinic over 18 months with Rutherford Grade 5 and 6 chronic limb-threatening ischemia to determine if patients had a pulse exam done at the time the wound was identified and when ankle brachial index (ABI) testing to evaluate perfusion was performed. Kaplan Meier analysis was used to determine if the timing of ABI testing affected the time to revascularization, wound healing, and risk of amputation.

Results: Ninety-three patients with lower extremity wounds were identified. Of these, 59 patients (63%) did not have a pulse exam performed by their primary care provider when the wound was identified. Patients were classified by when they underwent ankle brachial index testing to assess arterial perfusion. Twenty-four had early ABI (<30 days) testing, with the remaining 69 patients having late ABI testing. Patients in the early ABI group were more likely to have a pulse exam done by their PCP than those in the late group, 12 (50%) vs. 22 (32%), P = 0.03. Early ABI patients had a quicker time to vascular referral (13 days vs. 91 days, P < 0.001). Early ABI patients also had quicker times to wound healing than those in the late group (117 days vs. 287 days, P < 0.001). Finally, patients that underwent early ABI were less likely to require amputation (Fig. 1), although this did not reach statistical significance (P = 0.07).

Conclusions: Early ABI testing expedites specialty referral and time to revascularization. It can decrease the time to wound healing. Larger cohort studies are needed to determine the overall effect of early ABI testing to decrease amputation rates.

Keywords: ABI; Ankle brachial index; CLI; CLTI; PAD; Peripheral artery disease; chronic limb-threatening ischemia; critical limb ischemia.