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Latest THUNDER Data Support Safety and Effectiveness of THUNDERBOLT for Stroke Care

September 6, 2026
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Results from the THUNDER Investigational Device Exemption (IDE) study highlight the effectiveness of THUNDERBOLT™, Penumbra’s novel computer assisted vacuum thrombectomy (CAVT™) system, and could represent a significant advancement in stroke care for patients with emergent large vessel occlusion (ELVO).

The data were presented by David Fiorella, MD, PhD, co-principal investigator of THUNDER and director of the Cerebrovascular Center at Stony Brook University Hospital, Stony Brook, NY on September 3rd at the European Society of Minimally Invasive Neurological Therapy (ESMINT) in Marseille, France.

“In the THUNDER study, we observed that modulated aspiration facilitated consistent and complete clot removal when used in conjunction with standard-sized aspiration thrombectomy catheters,” said Dr. Fiorella. “Through this study, our early experience with THUNDERBOLT suggests that this technology could significantly advance treatment for stroke patients.”

THUNDER met its predefined performance goal, with 87.5% of cases achieving successful reperfusion, defined as mTICI 2b-3, after treatment with THUNDERBOLT. Notably, post-THUNDERBOLT, mTICI 2c-3 was achieved 70.4% of the time, which is associated with significantly better functional recovery and lower complication rates. Additionally:

  • First-pass mTICI 2b-3 was 64.8%.
  • Median time-to-revascularization was 20 min.
  • Complete clot ingestion rate was 83%, demonstrating that the THUNDERBOLT system reliably facilitates the removal of clot.
  • Device/procedure-related serious adverse events occurred in 2.8%, sICH in 0.9%, and the rate of all-cause mortality at 90 days was 11.7%, which is comparatively low to other thrombectomy therapies.

Mechanical thrombectomy is considered frontline treatment for stroke; however, current technologies may not fatigue and completely ingest the clot quickly or effectively at the site of the occlusion. The THUNDER study demonstrated a high rate of complete clot ingestion with THUNDERBOLT, along with a low rate of complications.

THUNDER is a single-arm, prospective, multicenter study with core-lab adjudication to evaluate the safety and effectiveness of THUNDERBOLT, which features Penumbra’s CAVT technology, in stroke patients with ELVO. The study enrolled 216 patients across 29 U.S. centers.

“The THUNDER study provides robust clinical evidence supporting the safety and effectiveness of THUNDERBOLT for revascularization in ELVO stroke,” said James F. Benenati, MD, FSIR, chief medical officer at Penumbra. “These findings reinforce modulated aspiration as a significant advancement in mechanical thrombectomy and suggest it could expand physicians’ treatment options to achieve rapid, effective revascularization in stroke, which is critical for patient outcomes.”

Acute ischemic stroke (AIS) remains a major global health challenge, accounting for approximately 87% of all strokes and affecting an estimated 68 million people worldwide.i Approximately 20% to 42% of AIS cases are due to ELVO.ii

THUNDERBOLT recently received CE Mark and FDA clearance. It introduces modulated aspiration to Penumbra’s neuro thrombectomy portfolio, offering advanced CAVT technology designed to detect, fatigue, and completely ingest clot at the site of the occlusion.

Important Safety Information

Additional information about Penumbra’s products can be located on Penumbra’s website at https://www.penumbrainc.com/eu/products/neuro-thrombectomy/. Caution: Federal (USA) law restricts these devices to sale by or on the order of a physician. Prior to use, please refer to the Instructions for Use (IFU) for complete product indications, contraindications, warnings, precautions, potential adverse events, and detailed instructions for use. Please visit www.peninc.info/risk for the complete IFU Risk Summary Statements.

i Tsao CW, Aday AW, Almarzooq ZI, et al. Heart Disease and Stroke Statistics-2023 Update: A Report From the American Heart Association. Circulation. Feb 21 2023;147(8):e93-e621. doi:10.1161/cir.0000000000001123.
ii Rennert RC, Wali AR, Steinberg JA, et al. Epidemiology, Natural History, and Clinical Presentation of Large Vessel Ischemic Stroke. Neurosurgery. Jul 1 2019;85(suppl_1):S4-s8. doi:10.1093/neuros/nyz042.

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