Aspiration thrombectomy with off-label distal access catheters in the distal intracranial vasculature

Background: As neurointerventionalists aim to treat occlusions in the ever more distal vasculature, off-label catheters (OLCs) have been adapted for aspiration thrombectomy. This may not be without its attendant risks. Recently issued, a letter from the FDA cautioned providers against using OLCs as substitutes for FDA-cleared aspiration thrombectomy catheters, especially in the distal vasculature. In light of this, we evaluated the efficacy and safety of OLCs used for aspiration thrombectomy in the distal vasculature at our institution. Methods: We retrospectively queried all patients who underwent thrombectomy at our institution between January 1, 2016 and March 1, 2017. Patients were screened for: (1) occlusion location in the distal vasculature (M2 or more distal) and (2) direct thrombus aspiration attempt with an OLC. Demographic, clinical, and procedural data were recorded. Results: Eight patients were included for analysis (Table 1). The median admission NIHSS was 17 (IQR 13–23.3). Occlusion locations included left M2 (6/8), right M2 (1/8), and left M3 (1/8). The OLCs employed included the Stryker Catalyst 6 (5/8), Penumbra Velocity (2/8), and the MicroVention Sofia Plus (1/8). Direct thrombus aspiration was successful in 50% (4/8) of cases, though final TICI 2b-3 was achieved in all patients. There were no instances of symptomatic intracranial hemorrhage. Median NIHSS at discharge was 5 (IQR 0.8, 15). Conclusions: Aspiration thrombectomy with OLCs may be safe and effective in the distal vasculature. In light of the recent FDA warning regarding their use, further evaluation of OLCs in this capacity is warranted.