Surgical treatment of marginal sinus dural arteriovenous fistula: a narrative review

Background

Dural arteriovenous fistulas of the marginal sinus (DAVFms) are uncommon and complex, with varied symptoms. Their complexity is heightened by the region's dense anastomotic network, posing risks for endovascular treatment. Surgical intervention can be effective, but this depends on thorough pre-operative understanding and optimal intra-operative visualization of the fistula.

Objective

To review the relevant anatomy, presentation patterns of DAVFms, and provide insights for surgical treatment.

Methods

Recent literature on DAVFms was reviewed, and three surgical cases are discussed to highlight treatment principles.

Results

The symptoms of a DAVFms vary depending on its venous drainage pattern. Drainage may be either ascending towards the cranial compartment or descending towards the spinal canal. Patients suffering from DAVFms may experience hemorrhage, particularly when venous drainage is directed upwards. Congestive symptoms of the spinal cord or brainstem can occur in cases of downward venous drainage. Compared to the endovascular approach, open surgery has a higher success rate in obliterating the fistula and yields better outcomes in cases of perimedullary venous drainage. Achieving surgical success necessitates thorough preoperative evaluation and adequate surgical exposure. Brainstem hyperintensity observed on T2-weighted MRI scans is linked to a poorer prognosis for recovery.

Conclusion

Treating complex DAVFms often requires surgery, as endovascular methods may not be feasible. Successful surgery hinges on a precise understanding of the fistula's venous architecture and its spatial relationships, assessed using digital substraction angiography (DSA), angio-MRI, and angio-CT. Optimal intraoperative exposure is crucial for effective surgery.