gms | German Medical Science

Objective: Perimedullar cervical fistulas are rare and present with a complex vascular architecture. Surgical elimination of the pathology, often located in the cervical spine, must include preservation of nutritive vessels under all circumstances in order to avoid severe functional deficits. To identify the pathological blood flow and to distinguish it from nutritive vessels is known to be the major difficulty in this challenging diagnosis.

Methods: We report on a 44-year-old patient suffering from spinal ataxia due to a cervical perimedullar fistula. Microscope-assisted surgery was chosen to eliminate the fistula because endovascular treatment did not seem to be promising. Preoperative angiography revealed two feeding arteries, originating from the left vertebral artery and a branch of the thyrocervical trunk at the level of C4/5. Therefore, surgery was thought to be sufficient if these two feeders were eliminated. Following laminectomy of C4 and C5, intraoperative micro-doppler ultrasound showed a bundle of perimedullar vessels confirming a high-flow (mean flow 220 cm/s) pathology. The feeders were identified by microscopic inspection and blood flow interrupted by temporary clipping of the feeders. Surprisingly, repeated intraoperative ICG- (indocyanine-green) angiography before and after clipping of the first two feeders showed another feeder, which had not been diagnosed preoperatively. Even on re-evaluation of the angiography, this additional feeder could not be detected. All three feeders were coagulated and the fistula was successfully isolated from its blood supply. ICG and micro-doppler-sonography performed at the end of the procedure showed no remaining pathological flow.

Results: Our case is only an exemplary case, but it nicely illustrates the potential benefits of intraoperative ICG-angiography influencing the surgical strategy and facilitating the successful treatment of spinal vascular malformations. In addition to miscellaneous intraoperative techniques, a fourth, time-related dimension offers insight into the hemodynamic changes following surgical manipulations on the vessels where changes of shunt volume can reliably be identified by ICG-angiography as well.

Conclusions: Intraoperative ICG-angiography serves as a very useful tool in spinal vascular malformations, especially in those pathologies in which a complex angioarchitecture prevents an adequate understanding of an arterio-venous malformation supplied by multiple feeders.