Long-term outcome in a cohort of 36 patients with sacral dural arteriovenous fistulae after endovascular embolisation or microsurgery.

Objective: Sacral dural arteriovenous fistula (SDAVF) is a rare spinal vascular malformation and often misdiagnosed or even mistreated. This study delved into the clinical characteristics, vascular architecture and treatment results of SDAVF, with the goal of enhancing upcoming diagnostic and therapeutic methodologies.

Methods: From March 2014 to March 2022, consecutive patients with SDAVF were retrospectively analysed. The data on demographics, symptom resolution, angioarchitectural features and postoperative course were studied. Spinal cord function was evaluated by modified Aminoff-Logue scale.

Results: A total of 36 patients with 36 SDAVFs were enrolled, 12 of whom were misdiagnosed on their initial visit. The SDAVFs were located at S1 in 24 (66.7%), S2 in 10 (27.8%) and S3 in 2 (5.6%) cases, respectively. The primary feeding arteries included lateral sacral artery (LSA) of internal iliac artery (31/36, 86.1%), the branches of external iliac artery (2/36, 5.6%) and median artery (3/36, 8.3%), most of which are straight. Venae terminalisis is the sole drainage vein, flowing back into perimedullary venous network. Endovascular embolisation is the main therapy method for 30 cases, while the other 6 cases were treated with microsurgical fistulectomy. MRI tests showed that the abnormal vascular signals around the medulla disappeared, and the spinal cord oedema was alleviated in the majority of cases (32/36, 88.9%). Six patients, who all were treated by endovascular embolisation at first time, had residual or recurrent and two of them were performed by microsurgical fistulectomy again. All patients by microsurgical fistulectomy had no residual or recurrent during follow-up. According to the spinal cord functional assessment, the Aminoff-Logue score was significantly decreased (Z=-3.449, p=0.001) postoperatively.

Conclusion: The misdiagnosis rate of SDAVF is very high. The most feeding artery of SDAVF came from the LSA, which was thicker and more straight, making it easier for microcatheters to reach the fistula site. So, endovascular embolism has become the first choice of treatment with minimal invasion, and safe and effective results.