Purpose

Tectum mesencephali arteriovenous malformations (TM-AVMs) are rare lesions deeply located close to eloquent structures making them challenging to treat. We aimed to present clinical presentation, angiographic features and treatment strategies of TM-AVMs through a single center retrospective case series.

Methods

A TM-AVMs is defined as a nidus located in the parenchyma or on the pia mater of the posterior midbrain. Records of consecutive patients admitted with TM-AVMs over a 21-year period were retrospectively analyzed. Vascular anatomy of the region is also reviewed.

Results

In this study 13 patients (1.63% of the complete cohort; 10 males), mean age 48 years, were included. All patients presented with intracranial hemorrhage and two patients (15%) died after an early recurrent bleeding. Mean size of the TM-AVMs was 10.1 ± 5 mm. Multiple arterial feeders were noted in every cases. Of the patients 11 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 led to a worsened outcome, one during embolization and one several years after SRS. All other patients remained clinically stable or improved.

Conclusion

The TM-AVMs are rare but stereotypic lesions found in a hemorrhagic context. Multiple arterial feeders are always present. Endovascular treatment seems to be an effective technique with relatively low morbidity; SRS had a low success rate but was only use in a limited number of patients.

中文翻译：

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中脑顶盖动静脉畸形的临床特征、血管结构和治疗

目的

中脑顶盖动静脉畸形 (TM-AVMs) 是一种罕见的病变，其位置靠近功能强大的结构，使其难以治疗。我们旨在通过单中心回顾性病例系列介绍 TM-AVM 的临床表现、血管造影特征和治疗策略。

方法

TM-AVMs 定义为位于脑实质或中脑后部软脑膜上的病灶。回顾性分析了 21 年期间连续入院 TM-AVM 患者的记录。还回顾了该区域的血管解剖。

结果

在这项研究中，包括 13 名患者（占整个队列的 1.63%；10 名男性），平均年龄 48 岁。所有患者均出现颅内出血，两名患者（15%）在早期复发性出血后死亡。TM-AVM 的平均尺寸为 10.1 ± 5 mm。在每种情况下都注意到多个动脉供血器。11 名患者接受了排除治疗，8 名通过栓塞（6 名通过动脉通路，2 名通过静脉通路）和 4 名通过立体定向放射外科（SRS）（1 名患者同时接受）。总体治疗成功率为 7/11 患者（总体为 64%；栓塞组为 63%，SRS 组为 25%）。两次出血事件导致结果恶化，一次在栓塞期间，一次在 SRS 后数年。所有其他患者保持临床稳定或改善。

结论

TM-AVM 是一种罕见但在出血环境中发现的定型病变。始终存在多个动脉供血器。血管内治疗似乎是一种发病率相对较低的有效技术。SRS 的成功率较低，但仅用于有限数量的患者。