Transvenous Embolization of Brain Arteriovenous Malformations: Up-to-Date Meta-Analysis.

AIM: To conduct an up-to-date meta-analysis to assess the success and complication rates of transvenous embolization (TVE) of brain arteriovenous malformations (BAVMs), and to determine its efficacy and safety. MATERIAL AND METHODS: Relevant and potentially relevant studies from 1982 to February 2021 were searched; after which those that satisfied our eligibility criteria and reported the main outcomes (endovascular occlusion and complication rates) were included. RESULTS: Ultimately seven studies were selected. In total, 154 patients were comprehensively reviewed for BAVMs characteristics and endovascular TVE techniques. The weighted mean rate of immediate endovascular total occlusion, overall technical complication, and overall good functional outcome (mRs < 2) were 93% (95% confidence intervals (CI), 89.1%?96.9%, I2 = 0%, p=0.487), 10.5% (95% CI, 4.3%?16.6%, I2 = 30.8%, p=0.193), and 90.9% (95% CI, 85.3%?96.6%, I2 = 26.6%, p=0.241), respectively. CONCLUSION: TVE for BAVMs was found to be generally safe and effective in certain selected patients. However, the complementary role of TAE to TVE as a definitive endovascular treatment for BAVMs cannot be separated. More studies regarding this role need to be conducted.

Transarterial Embolization of Intracranial Arteriovenous Fistulas with Large Venous Pouches in the Form of Venous Outlet Ectasia and Large Venous Varix or Aneurysm : Two Centers Experience.

OBJECTIVE: There are different types of cerebral vascular malformations. Pial arteriovenous fistulas (PAVFs) and dural arteriovenous fistulas (DAVFs) are two entities; they consist of one or more arterial connections to a single venous outlet without a true intervening nidus. The high turbulent flow of PAVFs and aggressive DAVFs with cortical venous reflux can result in venous outflow varix and aneurysmal dilatation. They pose a significant challenge to transvenous embolization (TVE), stereotactic radiosurgery, and surgical treatment. We aim to share our centers' experience with the transarterial embolization (TAE) for arteriovenous fistulas (AVFs) with large venous pouches and to report the outcome. METHODS: The authors' two institutions' databases were retrospectively reviewed from February 2017 to February 2021. All patients with intracranial high flow PAVFs and aggressive DAVFs with venous outlet ectasia and large venous varix and were treated by TAE were included. RESULTS: Fifteen patients harboring 11 DAVFs and four PAVFs met our inclusion criteria. All patients underwent TAE in 17 sessions. Complete angiographic obliteration was achieved after 14 sessions in 12 patients (80%). Four patients (25%) had residual after one TAE session. Technical failure was documented in one patient (6.7%). Fourteen patients (93.3%) had favorable functional outcome (modified Rankin score 0-2). CONCLUSIONS: TAE for high flow or aggressive intracranial AVFs is a safe and considerable treatment option, especially for those associated with large venous pouches that are challenging and relatively high-risk for TVE.