Surgical outcomes after intracranial nidal arteriovenous malformation resection in children: the Hospital for Sick Children experience.

OBJECTIVE: Recurrence after angiographically confirmed microsurgical obliteration of brain arteriovenous malformations (bAVMs) is considered rare but occurs more frequently in children than in adults. Reported recurrence rates vary widely. The authors aimed to determine recurrence rates at a high-volume pediatric referral center and identify clinical and radiographic predictors of recurrence. METHODS: The authors retrospectively analyzed 129 children with bAVMs who presented to the Hospital for Sick Children between 1998 and 2023 and underwent complete resection. These cases were partitioned into recurrence and no recurrence groups with subsequent univariate and multivariable Cox proportional hazards regression. Given the relatively small number of recurrences (n = 14), a parsimonious model with key predictors (arteriovenous malformation [AVM] size, venous drainage) was constructed, and Firth's penalized Cox regression was applied to reduce bias from sparse events. Hazard ratios (HRs) with 95% confidence intervals (CIs) are reported. RESULTS: The recurrence rate after surgical cure was 10.9% (14/129), with a mean time to recurrence of 30.4 ± 21.6 months; the most delayed recurrence occurred at 11.6 years. On univariate Cox analysis, deep venous drainage (HR 9.7, 95% CI 2.8-33.1; p = 0.0005) and AVM size (HR 1.4 per cm, 95% CI 1.1-1.6; p = 0.0007) were significantly associated with recurrence. Eloquence approached significance (HR 2.2, 95% CI 0.7-6.6; p = 0.1). In multivariable and Firth-penalized models, deep venous drainage remained an independent predictor of recurrence, with AVM size demonstrating a trend toward increased recurrence risk. Age, sex, hemorrhagic presentation, AVM location, and embolization were not associated with recurrence. CONCLUSIONS: Children and adolescents develop recurrent AVMs at a higher rate than adult patients despite angiographic cure after initial resection. On multivariable analysis, deep venous drainage was independently associated with recurrence. Further work can help elucidate clinical and radiographic predictors of disease recurrence.