Intraoperative microdoppler monitoring for spinal dural arteriovenous fistulae

One of the most important goals in the surgical treatment of spinal dural arteriovenous fistulae is complete interruption of the flow in the fistula. To confirm complete interruption, we use intraoperative microdoppler monitoring.

Three patients with spinal dural arteriovenous fistulae with perimedullary venous drainage underwent surgical treatment using microdoppler monitoring. All of them suffered from congestive myelopathy before treatment. Microdoppler monitoring was performed on the perimedullary draining vein to detect the arterial spectrum before and after the interruption of the arteriovenous shunt.

In all patients, an arterial spectrum was detected on the dorsal perimedullary vein. Sequential monitoring demonstrated the effects of each surgical procedure, which included epidural coagulation of the fistulae or intradural ligation of the retrogradely draining radiculomedullary veins. After complete interruption of the fistula, the arterial spectrum disappeared completely. In a patient with duplicated dural arteriovenous fistulae, the direction of the flow of the second arteriovenous shunt could be demonstrated by microdoppler monitoring combined with temporary clipping. This is especially useful in a complex case with duplicated fistulae. In all patients, postoperative angiography demonstrated complete disappearance of the arteriovenous fistulae. The patients all showed remarkable improvement with no therapeutic morbidity.

Intraoperative microdoppler monitoring is an easily available and useful technique to safely confirm complete obliteration of spinal dural arteriovenous fistulae.