Penumbra, Inc. (NYSE: PEN) announced results from the THUNDER study, an Investigational Device Exemption trial evaluating its THUNDERBOLT computer assisted vacuum thrombectomy (CAVT) system in stroke patients with emergent large vessel occlusion (ELVO). The data were presented at the Society of NeuroInterventional Surgery 23rd Annual Meeting.

The study met its predefined performance goal, with 87.5% of cases achieving successful reperfusion, defined as mTICI 2b-3, following treatment with THUNDERBOLT. Post-procedure, mTICI 2c-3 was achieved in 70.4% of cases. Additional results included a first-pass mTICI 2b-3 rate of 64.8%, a median time-to-revascularization of 20 minutes, and a complete clot ingestion rate of 83%.

Device or procedure-related serious adverse events occurred in 2.8% of cases, symptomatic intracranial hemorrhage in 0.9%, and all-cause mortality at 90 days was 11.7%.

THUNDER was a single-arm, prospective, multicenter study enrolling 216 patients across 29 U.S. centers.

"The THUNDER study demonstrated a high rate of complete clot ingestion with THUNDERBOLT, along with a low rate of complications," said Donald Frei, M.D., co-principal investigator and neurointerventional radiologist at Swedish Medical Center in Denver.

David Fiorella, M.D., Ph.D., co-principal investigator and director of the Cerebrovascular Center at Stony Brook University Hospital, said modulated aspiration facilitated consistent and complete clot removal when used with standard-sized aspiration thrombectomy catheters.

THUNDERBOLT has received U.S. FDA clearance and CE Mark. The device uses modulated aspiration technology designed to detect, fatigue, and ingest clot at the site of occlusion.

Penumbra also noted in its press release that a pending acquisition by Boston Scientific Corporation is subject to regulatory approvals and may not be completed in the expected timeframe.