Predictors of Functional Outcome After Microsurgical Resection of Brain Arteriovenous Malformations: A Retrospective...

Background/Objectives: Brain arteriovenous malformations (AVMs) are rare but clinically significant lesions associated with hemorrhage, seizures, and neurological deficits. Microsurgical resection remains the gold standard for low- and intermediate-grade AVMs, though treatment of unruptured AVMs is still debated. To present functional outcomes of microsurgical treatment for intracranial AVMs in a high-volume neurosurgical center. Methods: We retrospectively analyzed 111 patients who underwent microsurgical AVM resection between 2010 and 2022 at the Clinical Center of Serbia. Demographic, clinical, radiological, and surgical data were collected. Functional outcomes were assessed using the modified Rankin Scale (mRS) at discharge and after nine months. Results: The mean patient age was 36 years (range 8-75); 54 (48.6%) were male. AVMs were most often supratentorial (91.9%), located in the frontal (26.1%) and temporal lobes (19.8%). Hemorrhage was the presenting symptom in 53.2% of patients. Postoperative complications included hematoma (10.8%), meningitis (13.5%), and wound infection (8.1%). The mean mRS at discharge was 2.10, improving significantly to 1.15 at nine months (p < 0.001). Favorable outcome (mRS ≤ 2) was achieved in 64.0% at discharge and 81.1% at nine months. Prognostic factors for poor outcome included AVM size larger than 6 cm, higher supplementary Spetzler-Martin grade, and combined venous drainage. Conclusions: Microsurgical resection provides an important component of multidisciplinary AVM management, especially in low- and selected intermediate-grade lesions, achieving favorable functional outcomes in the majority of patients. Careful patient selection, AVM grading, and venous drainage analysis remain essential for prognosis and treatment planning.