Improving mTICI2b reperfusion to mTICI2c/3 reperfusions: A retrospective observational study assessing technical feasibility, safety and clinical efficacy.

Background: Recent studies suggested that modified Thrombolysis in Cerebral Infarction grade (mTICI) 3 reperfusions are associated with superior outcome to mTICI2b reperfusions, questioning if neurointerventionalists should generally strive to achieve mTICI3.

Methods: Retrospective analysis of successfully reperfused MCA occlusions (n=246) with available angiography runs between every manoeuvre was performed. Final reperfusion success and those between all single manoeuvres were evaluated applying the modified version of the TICI score (including TICI2c). Final TICI2c/3 reperfusions were dichotomized as 'direct' (reperfusion before final manoeuvre ≤mTICI2a) or 'secondary improved' (mTICI2b was achieved).

Results: Patients with mTICI2c reperfusion had similar outcome to patients with mTICI3 rather than mTICI2b reperfusions. Compared with mTICI2c/3-patients, mTICI2b-patients had lower rates of neurological improvement (33.3% vs. 61.2%, p<0.001) and good functional outcome (28.7% vs. 46.5%, p=0.008). In 28 patients, mTICI2b reperfusion was improved to mTICI2c/3 without complications. Outcome of patients with 'direct' or 'secondary improved' mTICI2c/3 did not differ (p>0.5).

Conclusion: Improving mTICI2b reperfusions to mTICI2c/3 reperfusions is sometimes technically feasible and safe, and associated with clinical benefit comparable to 'direct' mTICI2c/3 reperfusions. If confirmed, a more aggressive treatment approach in cases of already achieved mTICI2b may be justified, although proper patient selection is needed.

Key Points: • Patients with mTICI2c or 3 reperfusions have a comparable clinical course. • mTICI2c/3 are associated with a larger therapeutic benefit than are mTICI2b reperfusions. • Improving reperfusion from mTICI2b to mTICI2c/3 is sometimes feasible and reasonably safe. • Outcome of patients with 'secondary improved' and 'direct' mTICI2c/3 is not different.