Predictors of poor outcomes after lower extremity revascularization for acute limb ischemia.

Objectives: Acute lower extremity ischemia is one of the most common emergencies in vascular surgery and is a cause of considerable morbidity and mortality. The goal of this study was to evaluate outcomes of revascularization for acute lower extremity ischemia and to determine factors associated with perioperative morbidity and mortality.

Methods: A total of 354 patients underwent urgent revascularization for acute lower extremity ischemia at an academic medical center between 2014 and 2019. A retrospective review of patients' demographics, comorbidities, etiology and severity of limb ischemia, and procedural characteristics was recorded. Outcomes, including postoperative complications, perioperative limb loss, and mortality, were analyzed.

Results: The mean patient age was 69 ± 17 years, and 52% were females. 50% of patients presented with Rutherford Class IIb ischemia. Arterial embolization was the most common cause of limb ischemia, seen in 33% of cases. Open surgical revascularization was performed in 241 (68%) patients, while endovascular and hybrid approaches were utilized in 53 (15%) and 60 (17%) cases, respectively. Postoperative adverse events occurred in 44% of patients, including wound complications (11%), cardiac (5%) and pulmonary (16%) complications, strokes (4%), UTIs (10%), renal failure (14%), bleeding (5%), and compartment syndrome (3%). The rate of unplanned return to the operating room was 21%. Major adverse cardiovascular events were seen in 103 (29%) patients and major adverse limb events were seen in 57 (16%) patients. The median length of stay was 10 days (IQR = 4); 49% patients were discharged to skilled nursing facility and 19% were readmitted within 30 days.The rate of amputation during index admission was 10%, and perioperative mortality was 20%. Gender, tibial runoff, and etiology of limb ischemia were independent predictors of limb loss. Women had lower risk of limb loss than men (OR, 0.11; 95% CI, 0.023, 0.38). Poor tibial runoff (one-vessel or absence of flow below the knee) was a significant predictor of limb loss as compared to three-vessel runoff (OR, 14.92; 95% CI, 1.92, 115.88). Aneurysmal disease (OR, 38.35; 95% CI, 3.54, 42.45) and traumatic injuries (OR, 108.08; 95% CI, 8.21, 159.06) were the strongest predictors of amputation as compared to other etiologies of limb ischemia. Multivariate model identified ESRD (OR, 9.2; 95% CI, 1.8-46.3), degree of ischemia (class IIb or higher vs class IIa; OR, 3.5; 95% CI, 1.2-10.6), and age (OR, 1.5; 95% CI 1.1-2.0 for every 10 years) as independent predictors of perioperative mortality.

Conclusions: Urgent revascularization for management of acute limb ischemia is associated with high morbidity and mortality. Elderly patients with ESRD presenting with severely threatened limbs have especially high risk of perioperative mortality and may not be ideal candidates for limb salvage.