INDIAN Trial Supports Thrombo-Aspiration in Acute Lower Limb Ischemia

April 7, 2021—Gianmarco de Donato, MD, et al published findings from the INDIAN trial, which evaluated the short-term safety and effectiveness of the Indigo aspiration thrombectomy system (Penumbra Inc.) in patients with acute lower limb ischemia. The study is available online ahead of print in the European Journal of Vascular and Endovascular Surgery (EJVES).

As part of the INDIAN trial on the assessment of vacuum-assisted thrombo-aspiration systems in patients with acute lower limb ischemia, de Donato et al proposed the TIPI (Thrombo-aspiration In Peripheral Ischemia) classification to assess vessel patency.

As noted by the investigators, TIPI is a modification of the Thrombolysis in Myocardial Infarction (TIMI) classification. In this study, TIPI flow was assessed at presentation, immediately after treatment with the study device, and after all adjuvant procedures.

The INDIAN trial enrolled 150 patients with a mean age of 72.4 years, with 73.3% being men. On enrollment, 16% of patients were Rutherford grade I; 40.7% were IIa, and 43.3% were IIb with a mean ankle-brachial index of 0.19.

The primary outcome in INDIAN was the technical success of thrombo-aspiration with the investigative Indigo system, defined as near-complete or complete revascularization TIPI 2–3. This was achieved in 88.7% of patients. Adjunctive procedures were performed in 91 cases including angioplasty/stenting of chronic atherosclerotic lesions (n = 39), thrombolysis (n = 31), covered stenting (n = 15), and supplementary Fogarty embolectomy (n = 6). After accounting for all interventions, TIPI flow was assessed with TIPI 3 in 76%, TIPI 2 in 19.3%, TIPI 1 in 3.3%, and TIPI 0 in 1.3% of patients. Additionally, 95.3% assisted primary technical success (TIPI 2-3) was reported. No systemic bleeding complications or device-related serious adverse events were reported.

Safety and clinical success rate were collected at 1 month. At 1 month, one death and one below-the-knee amputation were reported. Primary patency at 1 month was 92%. Reintervention occurred in 11 (7.33%); eight with complete occlusion and three with > 50% restenosis. As such, the assisted primary and secondary patency rates of 94% and 99.33%, respectively, were reported.

The authors concluded that these data from the INDIAN registry suggest that mechanical thrombectomy using the Indigo system as a primary therapy for revascularization of acute lower limb ischemia is safe and effective.

Commenting on the findings to Endovascular Today, Dr. de Donato said, “The most recent European Society for Vascular Surgery guidelines for the management of acute lower limb ischemia suggest that endovascular thrombectomy should be considered (recommendation 25, class IIa, level C) in all patients with recent onset of ischemia.”

Also, Dr. de Donato advised that the registry is still recruiting patients in a different phase of the investigation. “Continuing the enrollment of patients in a further phase of the registry (INDIAN UP) will allow an improved definition of the optimal technique and the ideal candidates for this technology.”