Location-based clinical and angiographic profile of brain arteriovenous malformations - a single-center observational study.

BACKGROUND: The location of brain arteriovenous malformations (bAVM) is one of the most relevant prognostic factors included in surgical, endovascular and radiosurgical scores. However, their characteristics according to location are seldom described. The goal of this study was to describe the clinical and angiographic characteristics of bAVM classified according to their location. METHODS: This retrospective observational study included patients diagnosed with bAVM and attending a national referral hospital during the period 2010-2020. Data regarding clinical and angiographic variables were extracted, including characteristics on nidus, arterial afferents, venous drainage and associated aneurysms. BAVM were classified in 8 groups according to their location: frontal, temporal, parieto-occipital, periventricular, deep, cerebellar, brainstem and mixed. Data distribution for each group was determined and between-group differences were assessed. RESULTS: A total of 269 bAVM (in 258 patients) were included. The most frequent location was parieto-occipital; and the least frequent, brainstem. Statistically significant differences were observed between groups for most studied variables, including: clinical presentation, functional status at admission; nidus size and density, classification according to the Spetzler-Martin, Buffalo and modified Pollock-Flickinger scales; number, diameter, origin and type of afferents; number, diameter, type and direction of venous drainage, retrograde venous flow; and presence and size of flow-related aneurysms. CONCLUSION: The clinical and angiographic differences observed between brain AVM groups allow the formulation of profiles according to their location.

Multiple brain arteriovenous malformations: systematic review and individual patient data meta-analysis.

Multiple brain arteriovenous malformations (bAVM) are rare neurovascular lesions usually related to genetic syndromes. Its management is not well established given its rarity. The objective of this study was to describe the clinical and angiographic features of published cases and to explore their associations with treatment outcomes. We performed a literature search of published cases in Medline and the Regional Index Medici. Additional cases were searched in our single-center registry. Data on the proportions of patients and clinical and angiographic characteristics were extracted. The study outcomes were nidal instability in patients who underwent staged treatment and radiological cure in patients who underwent treatment using any treatment modality. Logistic regression models for the study outcomes were analyzed. Data on the proportions of multiple bAVM patients were summarized with meta-analyses of proportions. We included 118 patients (reported in 68 studies) from the literature and 6 cases identified in our registry. A total of 124 patients harboring 339 bAVM nidi were included in the analyses. Differences between syndromic and non-syndromic cases were observed. The logistic regression analyses showed that angiographically occult untreated bAVM was associated (OR 14.37; 95% CI 2.17 to 95.4) with nidal instability after staged treatment, and deep (OR 5.11; 95% CI 1.51 to 17.27) and eloquent (OR 3.91; 95% CI 1.22 to 12.52) locations were associated with residual disease after treatment. Inconsistent reporting of relevant data throughout the included studies undermined the planned analyses. Some prognostic factors were found to be related to the study outcomes. Study Registration: The protocol of the systematic review was registered in PROSPERO as CRD42021245814.