The Thrombolysis in Cerebral Infarction Grading Scheme: Historical Development, Evolution, and Current Status

Abstract

Background: The Thrombolysis in Cerebral Infarction (TICI) grading scheme is the principal angiographic language used to describe reperfusion after endovascular treatment of acute ischemic stroke. It was introduced to standardize reporting in intra-arterial cerebral thrombolysis and was subsequently adapted to modern endovascular thrombectomy, where the therapeutic endpoint is restoration of downstream tissue perfusion rather than proximal arterial opening alone.

Objectives: To review the historical development, evolution, clinical validation, limitations, and current role of TICI, modified TICI (mTICI), TICI 2c, expanded TICI (eTICI), quantitative TICI (qTICI), and automated TICI assessment.

Methods: A narrative review was performed using seminal reporting standards, consensus statements, peerreviewed angiographic grading studies, thrombectomy outcome analyses, meta-analyses, and current stroke qualitymeasure specifications. No formal systematic-review protocol or quantitative synthesis was undertaken.

Results: The original TICI scheme was proposed in 2003 and later became variably applied across studies, particularly at the boundary between partial and successful reperfusion. The 2013 consensus recommendations promoted mTICI as the standard reperfusion scale and helped establish mTICI 2b-3 as the conventional definition of successful reperfusion. With improving thrombectomy performance, the broad 2b category became insufficiently granular, leading to adoption of TICI 2c and eTICI. Outcome studies show a graded relationship between reperfusion quality and functional outcome, with TICI 2c/3 or eTICI 2c/3 frequently associated with better outcomes than TICI 2b alone. However, subgroup data in large-core and mild-symptom populations suggest that additional attempts to convert a satisfactory 2b result to complete reperfusion should be individualized.

Current Status: As of 2026, mTICI ≥2b remains the dominant operational benchmark for technical success and is embedded in contemporary stroke quality measures. More granular reporting with eTICI or mTICI 2c/3 is increasingly favored for clinical trials, core-lab adjudication, device evaluation, and procedural quality improvement.

Conclusions: TICI has evolved from a thrombolysis-era angiographic reporting tool into a central endpoint of endovascular stroke therapy. Current best practice is to document the full reperfusion grade, specify the scale used, and interpret the result alongside time to reperfusion, number of passes, first-pass effect, procedural complications, and patient-specific tissue context.

Keywords: Thrombolysis in Cerebral Infarction; TICI; modified TICI; expanded TICI; cerebral infarction; ischemic stroke; endovascular thrombectomy; reperfusion; recanalization