Endovascular approach as first-line therapy for congenital arteriovenous malformations – a case series

Abstract

INTRODUCTION: Congenital vascular malformations are entities with a broad spectrum of presentations and variable prognosis. They typically present at a young age and are historically associated with extensive resection surgeries and with high morbidity. This study aims to evaluate the results of arteriovenous malformations (AVMs) embolization as a first-line approach in lesions which are not suitable for surgical resection. METHODS: A retrospective analysis of the clinical records of patients with infiltrative arteriovenous malformations who underwent embolization at our center between 2019 and 2021 was performed. The Schobinger Classification was applied to categorize the clinical stage. Angiographic findings were reported according to the Yakes classification. The decrease in the Schöbinger grade after treatment, the need for reintervention and the associated complications were the main outcomes. A descriptive statistical analysis was performed. RESULTS: Nine patients undergoing embolization of infiltrative arteriovenous malformations were evaluated, accounting for a total of seventeen interventions. There was a preponderance of females (n=6; 66.7%) and the mean age of referral to the Vascular Surgery consultation and the first treatment was 16.8 (±12.9) and 20.9 (± 14.5) years, respectively. All patients were in stage II (n=4; 44.4%) or III (n=5; 55.6%) of Schöbinger. The angiographic pattern of the AVMs was classified according to the Yakes Classification, which guided the approach. Yakes type IIa was found most frequently (n=6; 55.6%), followed by type IV (n=2; 22.2%) and type IIb (n=1; 1.1%). Patients underwent AVM embolization via transarterial, transvenous or direct nidus puncture with sclerosing agents, liquid embolizers, microparticles and microcoils, separately or in combination. The median number of interventions per patient was 1 (1 – 5) and Yakes type IV appears to be associated with a higher rate of reintervention. Reduction of the Schöbinger stage was achieved in 7 (77.8%) patients with clinical resolution in 3 (33.3%). Tissue necrosis was the only complication reported in this series (n=2; 11,8%). CONCLUSION: The endovascular approach of arteriovenous malformations through nidus and/or afferent/ efferent embolization requires a detailed angiographic characterization but seems to be an effective strategy with a low risk of complications. The Yakes classification, can be useful both in guiding the approach and inpredicting the need for reintervention.

Keywords

• Arteriovenous malformation
• vascular anomalies
• embolization
• endovascular
• Yakes Classification