Risk factors of cerebral vasospasm associated with ruptured arterio-venous malformation: A systematic review and meta-analysis

Objective: Cerebral vasospasm (CVS) could be an undetected reason for worsening condition in ruptured arteriovenous malformation (AVM) patients during the course. It is important to investigate the risk factors associated with vasospasm in order to establish preventive and therapeutic treatments in a timely manner. This study aimed to describe the risk factors of CVS associated with ruptured AVM. Methods: We systematically searched electronic databases (PubMed, Science Direct, Cochrane Library, and SSRN) for studies assessing risk factors of CVS associated with spontaneous ruptured AVM. Risk factors assessed include demographic conditions, comorbidities, substance use, lab and vital parameters, and also the severity of bleeding. Meta-analysis was performed using data extracted from each study then Review Manager was used to analyze the risk ratio (RR) with 95% confidence intervals (95% CI). Results: There were a total of 14 studies included. Chronic renal disease (RR=0.5 [95% CI 0.46-0.67]) and hyperlipidemia (RR=0.78 [95% CI 0.73-0.84]) as comorbid conditions both were found as protective factors. Then the use of substances, including smoking and stimulants, was found to tend to increase the incidence of CVS (RR=1.31 [95% CI 1.11-1.54] and RR=1.31 95% CI 1.11-1.51]) respectively. In the lab and vital parameters section, 8 of them showed results as risk factors for CVS, including leukocytosis (RR=1.58 [95% CI 1.35-1.84]), hyperglycemia (RR=1.17 [95% CI 1.07-1.29]), hyponatremia (RR=1.45 [95% CI 1.23-1.71]), hypokalemia (RR=1.28 [95% CI 1.20-1.36]), fever (RR=1.38 [95% CI 1.23-1.54]), hypovolemia (RR=1.39 [95% CI 1.15-1.67]), acute hypotension (RR=1.4 [95% CI 1.26-1.55]), and electrocardiogram (ECG) abnormality (RR=1.74 [95% CI 1.34-2.26]). Conclusions: Chronic renal disease and hyperlipidemia were found as protective factors. Meanwhile, smoking, stimulant use, leukocytosis, hyperglycemia, hyponatremia, hypokalemia, fever, hypovolemia, acute hypotension, and ECG abnormalities are risk factors for CVS in patients with AVM rupture.