Multimodality treatment maximizing outcome in spinal dural arteriovenous fistulae

Background

Spinal dural arteriovenous fistula (sDAVF) is a rare cause of myelopathy and progressive paraplegia. sDAVFs are the most frequent type of spinal vascular malformation and comprise 70 % of all vascular spinal malformations. Despite the availability and published efficacy of both microsurgical resection and endovascular embolization, the optimal treatment for sDAVFs remains to be determined. We aimed to assess the efficacy of a multimodal treatment approach to sDAVFs at our institution.

Methods

A retrospective review of all sDAVFs treated between 1998 and 2021 at Stanford Hospital and Clinics was conducted. The medical records were inspected and data, including presenting symptoms, duration, angiographic features, and treatment modality, were extracted. Cure was defined as the absence of an arteriovenous fistulous connection on digital subtraction angiography and radiologic improvement on follow-up MRI. Functional outcomes were assessed at presentation and at last follow-up using the Aminoff-Logue Scale (ALS).

Results

47 patients underwent treatment of sDAVFs between August 1998 to May 2021. As an initial treatment, 32 patients underwent microsurgical excision, and 15 had endovascular embolization. Radiological cure was achieved in 84.4 % of patients during the first treatment and in 97.9 % of patients at the final treatment time point. At initial treatment, surgery cured the sDAVF in 84.4 % of patients, with endovascular embolization curing in 86.7 % of patients. When assessed as an additional treatment for failed prior treatment, surgery achieved cure in 80 % of patients and endovascular embolization in 100 % of patients. At all time points, high cure rates were observed, with success rates achieving 96.9 % and 100 % for surgery and endovascular embolization, respectively. A significant improvement in ALS Gait score was noted after treatment, with a mean reduction of 0.6 from baseline (p = 0.0003). A similar improvement trend was observed in the ALS Micturition score with a mean decrease of 0.3 points (p = 0.057).

Conclusions

Our study demonstrates high efficacy for cure and improved functional outcomes in both surgical and endovascular treatments, assuming good patient selection. This series also highlights the importance of a multimodality treatment approach in managing spinal dural arteriovenous fistulae. Further delineation is required to determine the radiological and patient factors that might recommend specific initial treatment modalities.