Preservation of Non-nidal Medial Veins During Microsurgical Resection of Cerebral Arteriovenous Malformations: Technical Considerations and Early Clinical Outcomes.

Background The surgical management of cerebral arteriovenous malformations (AVMs) requires a meticulous balance between complete nidus eradication and the preservation of adjacent normal physiological structures. While the elimination of true malformed, nidal-draining veins is mandatory to avoid intraoperative rupture, sacrificing adjacent, non-malformed, medial cortical, and deep venous channels can cause localized venous congestion, tissue infarction, and poor functional outcomes. Objective This study analyzed the clinical, radiological, and functional outcomes of a deliberate microsurgical strategy focused on preserving critical medial venous pathways during AVM resection in an early patient series. Materials and methods A retrospective study was conducted on a consecutive series of 16 adult patients (aged >18 years) who underwent micro-neurosurgical resection of cerebral AVMs (Spetzler-Martin grades I-IV) at a single private academic institution between 2018 and 2025. Preoperative baseline features, clinical presentation (hemorrhage, seizures, focal deficits), and structural profiles were documented. Microsurgical dissection emphasized circumferential nidal isolation with strict preservation of non-nidal medial veins. Long-term functional assessment was evaluated using the Patient-Reported Outcomes Measurement Information System (PROMIS) score and the modified Rankin Scale (mRS) at a minimum of six months postoperatively. Results A total of 16 patients were included in the study, of whom 10 were male (62.5%) and six were female (37.5%). Primary clinical presentations included intracranial hemorrhage in 10 patients (62.5%), seizures in eight patients (50.0%), and focal deficits in nine patients (56.3%). Complete angiographic eradication of the AVM nidus was achieved in all 16 patients. No perioperative mortality was observed. Postoperative outcome assessment demonstrated improvements or stabilization in functional capacity. Favorable neurological recovery, defined as mRS 0-2, was documented in 14 patients (87.5%), supported by increases in PROMIS physical and mental health T-scores. No delayed venous infarction or hemorrhagic transformation occurred in any patient. Conclusions In this early clinical series, prioritizing the integrity of non-malformed medial veins during cerebral AVM surgery was a safe, effective, and anatomically sound strategy. Preserving healthy venous pathways surrounding the malformation limits the incidence of secondary venous hypertension, leading to exceptional functional preservation and minimal morbidity across a range of Spetzler-Martin grades.