Microcatheter contrast injections during intra-arterial thrombolysis increase intracranial hemorrhage risk

Background and purpose Combined analysis of the Interventional Management of Stroke I and II trials demonstrated a significant association between microcatheter contrast injections and both intracranial hemorrhage (ICH) and contrast extravasation following combined intravenous (IV) and intra-arterial (IA) thrombolysis. The reliability of these observations was tested in our local registry of IA cases. Design/methods Treatment angiograms and post-procedure CTs of patients treated with combined IV/IA or IA only recombinant tissue plasminogen activator for ICA-T, M1 or M2 occlusions (n=77) were reviewed. The number of microcatheter injections (MCIs) within/distal to the target occlusion was assigned for every case. The association of MCIs to total ICH, total parenchymal hematoma (PH1+PH2) and PH2 after adjusting for significant covariates was tested. Results MCIs were used in 21 (27%) cases (range MCI 0-6). Any ICH occurred in 38 (49%) cases, including eight (10%) PH1s and eight (10%) PH2s. The use of MCIs was associated with increased PH (p=0.04), PH2 (p-0.07) and total ICH (p-0.03). MCIs were associated with increased contrast extravasation (CEx) (p=0.02). ICH was observed in all CEx cases (n=5, 100% vs 46% non-CEx; p=0.03), and four (80%) CEx cases developed PH2s (p<0.01). MCIs remained associated with total ICH after adjustment for significant covariates of Thromolysis in Cerebral Infarction score, glucose level and presence of atrial fibrillation (OR 3.60; 95% CI 1.12 to 11.49, p=0.03). MCI use was the only significantly associated covariate for total PHs. Conclusions MCI use was associated with ICH and with clinically significant PHs in this cohort, providing further evidence that MCIs be reduced during IA thrombolysis.