Spontaneous Cystic Arteriovenous Malformation-A Novel Treatment Alternative.

BACKGROUND: Brain arteriovenous malformation (BAVM) is a life-threatening vascular congenital malformation due to the risk of intracerebral hemorrhage. The formation of a spontaneous cyst within a BAVM, without history of hemorrhage or gamma knife surgery, is rare and has an unknown pathophysiology. We suggest a novel theory of spontaneous cystic BAVM formation, subsequently treated with endovascular embolization followed by surgery with a favorable long-term outcome. METHODS: Review of the literature using PUBMED database and comparison between clinical presentation, diagnostic imaging studies, and treatment options. RESULTS: The high flow causing a shear stress over the drainage vein may be responsible for venous ectasia and thus incrementing hydrostatic intranidal pressure causing a serous effusion that develops into a pseudocyst. We hypothesize that hemodynamic factors may be responsible for both origin and growth of such cystic lesions. CONCLUSIONS: Endovascular treatment allowed us to achieve cyst volume reduction by managing its unique flow characteristics. To our knowledge, this is the first case report of combined treatment with endovascular and surgical approach of a cystic BAVM.

Risk of intracranial haemorrhage and ischaemic stroke after convexity subarachnoid haemorrhage in cerebral amyloid angiopathy: international individual patient data pooled analysis.

OBJECTIVE: To investigate the frequency, time-course and predictors of intracerebral haemorrhage (ICH), recurrent convexity subarachnoid haemorrhage (cSAH), and ischemic stroke after cSAH associated with cerebral amyloid angiopathy (CAA). METHODS: We performed a systematic review and international individual patient-data pooled analysis in patients with cSAH associated with probable or possible CAA diagnosed on baseline MRI using the modified Boston criteria. We used Cox proportional hazards models with a frailty term to account for between-cohort differences. RESULTS: We included 190 patients (mean age 74.5 years; 45.3% female) from 13 centers with 385 patient-years of follow-up (median 1.4 years). The risks of each outcome (per patient-year) were: ICH 13.2% (95% CI 9.9-17.4); recurrent cSAH 11.1% (95% CI 7.9-15.2); combined ICH, cSAH, or both 21.4% (95% CI 16.7-26.9), ischemic stroke 5.1% (95% CI 3.1-8) and death 8.3% (95% CI 5.6-11.8). In multivariable models, there is evidence that patients with probable CAA (compared to possible CAA) had a higher risk of ICH (HR 8.45, 95% CI 1.13-75.5, p = 0.02) and cSAH (HR 3.66, 95% CI 0.84-15.9, p = 0.08) but not ischemic stroke (HR 0.56, 95% CI 0.17-1.82, p = 0.33) or mortality (HR 0.54, 95% CI 0.16-1.78, p = 0.31). CONCLUSIONS: Patients with cSAH associated with probable or possible CAA have high risk of future ICH and recurrent cSAH. Convexity SAH associated with probable (vs possible) CAA is associated with increased risk of ICH, and cSAH but not ischemic stroke. Our data provide precise risk estimates for key vascular events after cSAH associated with CAA which can inform management decisions.