EP25* A retrospective case series of tectal arteriovenous malformations: clinical characteristics, angioarchitecture description and therapeutic management

Introduction Tectal arteriovenous malformations (TAVMs) are rare lesions deeply located close to eloquent structures making them challenging to treat. Aim of Study To present clinical revealing conditions, angiographic features and treatment strategies of TAVMs through a single center retrospective case series. Methods TAVMs were defined as a nidus located in the parenchyma or on the pia mater of the posterior midbrain. Records of consecutive patients admitted with TAVMs over a 21-years‘ period were retrospectively analyzed. Results Thirteen patients (1.63% of the complete cohort; 10 males), mean age 48 years, were included. All patients presented with intracranial hemorrhage. Two patients (15%) died after an early recurrent bleeding. Mean size of the TAVMs was 10.1±5 mm. Multiple arterial feeders was noted in every cases. Eleven patients underwent an exclusion treatment; 8 via embolization (6 via arterial access and 2 via venous access) and 4 via stereotactic radiosurgery (SRS) (1 patient received both). Overall success treatment rate was 7/11 patients (64% overall; 63% in the embolization group, 25% in the SRS group). Two hemorrhagic events lead to a worsened outcome, one during embolization and one several years after SRS. All other patients remained clinically stable or improved. Conclusion TAVMs are rare but stereotypic lesions found in a hemorrhagic context. Multiple arterial feeders are always present. Endovascular therapy seems to be an effective technic with relatively low morbidity; SRS had a low success rate but was only use in a limited number of patients. References Chaynes P. Microsurgical anatomy of the venous drainage of the mesencephalodiencephalic junction. Neurosurgery 2004;54:678–85; discussion 685–686. Thines L, et al. Challenges in the management of ruptured and unruptured brainstem arteriovenous malformations: outcome after conservative, single-modality, or multimodality treatments. Neurosurgery 2012;70:155–61; discussion 161. Cohen-Inbar O, et al. Stereotactic radiosurgery for brainstem arteriovenous malformations: a multicenter study. Neurosurgery 2017;81:910–20. Madhugiri VS, et al. Brainstem arteriovenous malformations: lesion characteristics and treatment outcomes. J Neurosurg 2018;128:126–36. Han SJ, et al. Brainstem arteriovenous malformations: anatomical subtypes, assessment of ‘occlusion in situ’ technique, and microsurgical results. J Neurosurg 2015;122:107–17. Disclosure Nothing to disclose