Clinical Features of Acute on Chronic Lower Limb Ischemia and the Importance of Underlying Arterial Disease for Revascularization.

Background: Acute lower extremity limb ischemia (ALI) is a common vascular surgery emergency, primarily caused by embolism or atherosclerotic in situ thrombosis-acute on chronic limb ischemia (AoCLI). This study aimed to examine the clinical features and treatment challenges of AoCLI.

Methods And Results: Between January 2014 and December 2022, 73 patients with AoCLI (n=35) or embolic ALI (n=38) were analyzed. The time from ALI onset was significantly longer (P<0.01), and the rate of contralateral diseases was higher in AoCLI than embolic ALI (P<0.01). Treatment and intraoperative findings showed higher rates of failed thrombectomy (P=0.027), difficulty in crossing lesions (P<0.01), defined as failure of Fogarty catheter crossing despite guidewire navigation and requirement of the balloon angioplasty for the lesions, additional revascularization (P<0.01), and multi-segment treatment (P<0.01) in AoCLI. In multivariate analysis, unfavorable factors for endovascular therapy (EVT) were >2.5 days from ALI onset (odds ratio [OR] 1.4; 95% confidence interval [CI] 1.0-2.0), non-atrial fibrillation (OR 4.2; 95% CI 1.0-16.7), and collateral development (OR 9.0; 95% CI 1.0-81.5). Rates of failed EVT were 0% for no factors, 18% for 1 factor, 43% for 2 factors, and 90% for 3 factors.

Conclusions: AoCLI had more complex and multi-segment arterial lesions, making limb perfusion restoration difficult. The unfavorable factors for EVT could help stratify the optimal treatment of ALI in emergency settings.