Selection of Patients for Treatment of Brain Arteriovenous Malformations by the Transvenous Approach: Relationship with Venous Anatomy and Risk of Hemorrhagic Complications

BACKGROUND AND PURPOSE:Intracranial hemorrhage represents a severe complication of brain arteriovenous malformation treatment. The aim of this cohort was to report the rate of hemorrhagic complications after transvenous endovascular embolization and analyze the potential angioarchitectural risk factors as well as clinical outcomes.MATERIALS AND METHODS:During an 11-year period, 57 patients underwent transvenous endovascular embolization. All cases of hemorrhagic complications were identified. We analyzed the following variables: sex, age, hemorrhagic presentation, Spetzler-Martin grade, size of the AVM before the transvenous treatment, number of venous collectors, pattern of drainage, presence of dilated veins, and technical aspects. Univariate and multivariate multiple regression analyses were performed to evaluate the potential risk factors for procedure-related hemorrhagic complications.RESULTS:Hemorrhagic complications (either intraprocedural or periprocedural) unrelated to a perforation due to micronavigation occurred in 8 (14.0%) procedures. Significant (mRS > 2) and persistent neurologic deficits were present in 2 (3.5%) patients at 6-month control. Larger nidi, especially >3 cm (P = .03), and a larger number of venous collectors have shown a statistically significant correlation with hemorrhagic complications. Only the number of venous collectors was identified as an independent predictor of hemorrhagic complications in the multivariate analysis (OR, 8.7; 95% confidence interval, 2.2–58.2) (P = .006).CONCLUSIONS:Larger nidus sizes and an increased number of venous collectors may increase the risk of hemorrhagic complications when implementing transvenous endovascular treatment of AVMs. The technique is effective and promising, especially with small nidi and single venous collectors.

Endovascular treatment for brain arteriovenous malformations (bAVMs) was traditionally focused on targeting the nidus through an intra-arterial approach, whether as a means of curative treatment or targeted embolization as an adjunctive or emergency treatment. In an attempt to target parts of the nidus that lie in the deep brain areas or that are supplied by very thin or perforating arterial branches, transvenous endovascular embolization (TVE) has emerged and is becoming a new tool to target otherwise incurable brain AVMs.^1-3Even though TVE has several advantages, including a very high rate of angiographic cure up to 92.6%³ and a means of curing otherwise incurable bAVMs,^4,5 it still needs to be used very selectively, to reduce hemorrhagic complications (HC).Nevertheless, the technique is not exempt from intraprocedural or periprocedural complications. Hemorrhagic complications represent the most important and challenging procedure-related issues with this technique, which may lead to poor clinical outcomes.^6-9A greater understanding of the frequency and risk factors for HC may optimize patient selection for TVE. The aim of this study was to estimate the rates of intraprocedural and periprocedural hemorrhage after TVE for bAVMs, to assess the morbidity and mortality associated with bleeding, and to analyze the angioarchitectural risk factors linked with such complications.