Angioplasty and/or stenting following successful mechanical thrombectomy for intracranial atherosclerosis-related emergent large vessel occlusive stroke (ASSET): protocol of a multicentre randomised trial.

Rationale: The management of residual stenosis after mechanical thrombectomy in patients with intracranial atherosclerotic stenosis-related emerge large vessel occlusive (ICAS-LVO) stroke is still unclear question in clinical practice.

Aim: To demonstrate the design of a clinical trial on emergency balloon angioplasty and/or stenting (BAS) combined with standard medical treatment (SMT) for residual stenosis of ICAS-LVO stroke patients with successful recanalisation.

Design: ASSET is a multicentre, prospective, randomised, open-label, blinded end-point, controlled clinical trial designed (PROBE) by investigators. This trial evaluates the effectiveness and the safety of emergency BAS in combination with SMT compared with SMT alone in ICAS-LVO stroke patients with successful recanalisation (defined as expanded treatment in cerebral ischaemia grade of 2b50-3 and maintained for more than 20 min) and residual stenosis (defined as ≥50%) up to 24 hours after the onset of symptoms or the last known well.

Outcome: The primary outcome assessed at 90 (±7) days after randomisation is the incidence of ischaemic stroke in the responsible vessel. Symptomatic intracranial haemorrhage within 24 (±3) hours is the primary safety outcome.

Discussion: The ASSET trial is designed to provide strong evidence on the effectiveness and safety of emergency BAS to treat residual stenosis after successful recanalisation in patients with ICAS-LVO stroke.

Trial registration number: ChiCTR2300079069.