Single-center experience with Indigo aspiration thrombectomy for acute lower limb ischemia

Objective: Acute lower limb ischemia (ALLI) is a challenging vascular emergency with notable morbidity. Aspiration mechanical thrombectomy (AMT) devices are an alternative approach to remove thrombus in the peripheral arterial system and to restore limb perfusion, but data are limited. We evaluated the outcomes of AMT for the treatment of ALLI at our institution. Methods: We performed a single-center retrospective review of patients with ALLI treated with Indigo (Penumbra Inc, Alameda, Calif) AMT device from 2014 to 2017. The primary outcome was technical success (restoration of blood flow with <50% residual thrombus without need for catheter-directed thrombolysis [CDT] or open surgery) as main treatment or adjunctive treatment (after failure of another modality). Indications, anatomic segments treated, outcomes, and complications were reviewed. Results: There were 41 patients (68% male, 32% female; mean age, 67 years; range, 27-90 years) who underwent 43 procedures. The cause of ALLI was embolism (18), native vessel thrombosis (13), bypass thrombosis (7), intraluminal thrombus due to pseudoaneurysm (1), stent thrombosis (1), intraprocedural embolization (1), recurrent thrombosis of native vessel (1), and chronic thrombosis (1). AMT was the main treatment in 29 cases and adjunctive in 14. Technical success was 52% (15/29) as main treatment and 50% (7/14) as adjunctive treatment. Thrombolysis was avoided in 53% of patients (23/43). There were six thrombotic recurrences, one after successful isolated AMT. The other five required multiple modalities after AMT failure. There were no 30-day deaths. Five patients required amputations, but only one after successful AMT. Complications included intraoperative distal embolization (two), access site hematoma (one), pseudoaneurysm (one), acute kidney injury (one), and spontaneous calf hematoma (one). There were no blood transfusions required or severe bleeding complications. Conclusions: With an overall success rate of 51% in selected patients, the Indigo AMT device avoided the need for CDT or open surgery in about half of patients with ALLI. The device has a favorable safety profile, particularly in high-risk cases. Given its moderate effectiveness, the role of Indigo AMT in the management of ALLI will further be defined by the description of optimal technique, the determination of treatment indications, and a direct comparison with CDT.