Introduction Modulated aspiration is a new technology for endovascular thrombectomy for the treatment of acute ischemic stroke (AIS) secondary to large vessel occlusion (LVO). The primary objective of the THUNDER study (NCT05437055) is to demonstrate the safety and efficacy of a novel modulated aspiration thrombectomy system (Penumbra System® including Thunderbolt™ Aspiration Tubing [Thunderbolt]) in a patient population with AIS secondary to LVO.

Methods THUNDER is a multicenter prospective single-arm study involving a clinical events committee and core laboratory for the independent assessment of safety and imaging outcomes, respectively. Adults aged 18 to 80 years with AIS secondary to LVO, pre-stroke modified Rankin Scale (mRS) 0-2, and planned frontline treatment with the Penumbra System including Thunderbolt within 8 hours of symptom onset are eligible for enrollment. Up to 160 participants at up to 25 sites in the United States will be enrolled. Thunderbolt is the aspiration tubing component of the Penumbra System and can modulate the pressure delivered to the aspiration catheter by alternating between connecting the aspiration catheter to the continuous vacuum aspiration pump and ambient pressure saline in a predetermined modulated aspiration sequence. The primary efficacy endpoint is angiographic revascularization (mTICI ≥2b) of the occluded target vessel at immediate post-procedure and the primary safety endpoint is incidence of device related and/or procedure related serious adverse events within 24 hours post-procedure. Secondary efficacy endpoints include first pass angiographic revascularization to mTICI ≥2b, immediate post-procedure angiographic revascularization to mTICI ≥2c, time to revascularization, and mRS 0-2 at 90 days as determined by blinded assessors. Secondary safety endpoints include all-cause mortality at 90 days and occurrence of symptomatic intracranial hemorrhage at 24 hours.

Results The first patient was enrolled August 11, 2022, and as of March 2023 there are 58 patients enrolled. The estimated date for enrollment completion is December 2023.

Conclusion We report the design of THUNDER—a multicenter prospective study that examines the use of a novel modulated aspiration thrombectomy system in patients with AIS secondary to LVO.

Disclosures D. Fiorella: 1; C; Cerenovus, Medtronic, Siemens, Stryker, Microvention, Penumbra. 2; C; Balt, Marblehead, Medtronic, Stryker, Microvention, Penumbra, Cerenovus. K. Woodward: 2; C; Coviden. E. Levy: None. C. Matouk: 2; C; Silk Road Medical, Penumbra, MicroVention-TERUMO, Medtronic, Stryker. 3; C; Silk Road Medical, Penumbra. I. Kaminsky: 3; C; Penumbra. K. Reuland: None. M. Stiefel: None. A. Kansagra: 1; C; Penumbra. 2; C; Penumbra, Microvention, Medtronic. D. Frei: 1; C; Penumbra. 2; C; Penumbra, Stryker. 3; C; Penumbra, Stryker. 4; C; Penumbra.