Absent Filling Of The Superficial Middle Cerebral Vein Is Associated With Reperfusion But Not Parenchymal Hematoma In Stroke Patients Undergoing Thrombectomy: An Observational Study

Background: Parenchymal hematoma (PH) is the most feared complication of reperfusion therapy after stroke. The opacification of the superficial middle cerebral vein (SMCV) on computed tomography perfusion (CTP) has been associated with poor functional outcomes after stroke, while its association with PH has not been verified for acute stroke patients undergoing thrombectomy.Methods: Consecutive patients with acute anterior large artery occlusion (LAO) who received thrombectomy were retrospectively enrolled between May 2018 and May 2019. Absent filing of the SMCV (SMCV-) on CTP-derived CT angiography was defined as no contrast filling of the SMCV across the whole venous phase in the ischemic hemisphere, while SMCV+ was defined as the presence of contrast filling of the SMCV at any time point of the venous phase.Results: A total of 52 patients were enrolled in the study, and 15 patients (28.8%) developed a PH within 48 hours after thrombectomy. SMCV- was not associated with PH in both the univariate and multivariate logistic regression analyses (all P>0.05), but was an independent risk factor for reperfusion [modified thrombolysis in cerebral infarction score of 2b-3; odds ratio (OR) =0.172, 95% confidence interval (CI): 0.031-0.960, P=0.045]. Reperfusion was associated with a reduced risk of PH (OR = 0.110, 95% CI: 0.013-0.913, P=0.041). However, in a subgroup analysis of patients who had reperfusion, the SMCV- group had a higher rate of PH than the SMCV+ group (40.0% vs. 13.8%, P=0.049).Conclusions: In patients who received thrombectomy, SMCV- did not predict PH, but was a risk factor for reperfusion. Although reperfusion was a protective factor for PH, the SMCV- group was still at a higher risk of PH compared with the SMCV+ group when reperfusion was successfully achieved.