Risk factors of difficult cases of deliberate postoperative hypotension after endovascular embolization in patients with brain arteriovenous malformation

Background: Endovascular embolization was successfully used in treatment of brain arteriovenous malformations (bAVM), respectively or in combination with surgical resection. Deliberate employment of post-operative hypotension was widely recommended by neurosurgeons. Researches on predictors of difficulties in deliberate postoperative hypotension remain scarce. This study aimed to analyze the potential risk factors of difficult cases of deliberate post-operative hypotension. Methods: We retrospectively reviewed all patients who received bAVM embolization between January 2010 and December 2015. Demographic features, clinical presentation, AVM characteristics, peri-operative medication, hemodynamic features, treatment-related information and outcome-related data were recorded. Univariate analysis and logistic regression were performed to find out associated risk factors. Results: Difficulty in deliberate postoperative hypotension was observed in 75 patients the first postoperative day. Logistic regression indicated that higher Sptzler-Martin (S-M) grade was an independent risk factor of difficult deliberate postoperative hypotension following embolization (OR=2.058; 95% CI, 1.364-3.105; P=0.001). While infra-operative dexmedetomidinc administration was a potential independent protective factor (OR=0.356; 95% CI, 0.133-0.956; P=0.040). Conclusions: Higher S-M grade was an independent risk factor of difficult cases of deliberate postoperative hypotension after endovascular embolization, while intra-operative dexmedetomidine administration was potential protective predictor.