Neuroradiology(1991) 33:195-199 Neuro-- radiology 9 Springer-Verlag 1991 Percutaneous reposition of dislodged coils in the treatment of a vertebral arteriovenous fistula- with CT follow-up M. M. H. Teng 1, T. Chang 2, C.I. Huang 3, D. H. C. Pan 3, H. H. Hu 4, Y. O. Luk 4, C. C. Chen 2, W.Y. Guo 2, and L. S. Lee 3 1 Department of Radiology, Veterans General Hospital-Taipei, National Defense Medical Center, and National Yang Ming Medical College. Taiwan, Republic of China. Departments of 2 Radiology, 3 Neurosurgery and 4 Neurology, Veterans General Hospital-Taipei, and National Yang Ming Medical College Taiwan, Republic of China Received: 19 July i990 Summary. We report a case of vertebral arteriovenous fis- tula, in which embolization was complicated by migration of two coils and a partially inflated balloon. In order to re- lieve compression to the spinal cord, the displaced balloon was punctured percutaneously. For both relieving com- pression to the spinal cord and obliterating the residual fistula, the dislodged coils in the partially thrombosed epidural venous sinus were removed percutaneously and placed in the fistula, and more coils were implanted in the fistula percutaneously through the needle. CT follow-up half a year later showed complete resolution of compres- sion of the spinal cord and complete recovery from myelo- pathy was clinically apparent. Key words: Vertebral arteriovenous fistula - Emboliza- tion - Endovascular occlusion - Detachable balloon - CT Vertebral arteriovenous fistula (AVF) may form after trauma or occur spontaneously [1]. In the former, it may result from knife wounds, gunshot injuries [2], be iatro- genic [3-5], or follow blunt injury [6]; in the latter, the causes may be fibromuscular dysplasia [7, 8], neurofibro- matosis [9], or congenital [10]. We report a case of traumatic vertebral AVF of Kon- doh's type 2 [11]. During embolization, two Gianturco steel coils and one balloon were accidentally dislodged to the venous side of the fistula - the intraspinal longitudinal venous sinus, because of the strong pulsation and large flow toward the fistula. A small residual fistula from a seg- mental branch of the right vertebral artery was also noted after the first embolization. Percutaneous puncture of the displaced balloon, percutaneous reposition of the dis- lodged coils, and percutaneous obliteration of persistent fistula by implantation of coils were performed later. Di- rect puncture of the fistula to implant coils or other emboli for embolization has been reported before in a case of ca- rotid cavernous fistula and in a case of persistent vertebral arteriovenous fistula [12, 13]. We would like to report this case, believing that percutaneous reposition of displaced coils has not been mentioned before. Case report Clinical history A 29-year-old male was referred to us for embolization because a vertebral angiogram showed a vertebral AVF (Fig. i a). He had developed gradual weakness and muscle atrophy of extremities since a stab injury to the left poste- rior neck half a year before. He had been chairbound for about one month. On physical examination, bruits could be heard in the neck. There was muscle atrophy in all four extremities, more severe over the left side. Lower extremities could not move against gravity. There was no sensory abnor- malities except numbness over the left upper extremity. Radiologic diagnosis Repeat left vertebral angiogram with 5 frames per second confirmed the AVF of the left vertebral artery at the level of C6-7 (Fig. lb). An aneurysm on the anterolateral as- pect of the left vertebral artery at the level of AVF was also noted (Fig. 1 c). The right vertebral angiogram showed retrograde opacification of the distal left vertebral artery and the fistula. Contrast enhanced CT of the spine showed changes compatible with vertebral AVF and confirmed the presence of an aneurysm anteromedial to the left ver- tebral artery (Fig. i d). Embolization Embolization was performed from a femoral approach. Preservation of the blood flow in the left vertebral artery was attempted initially. A Debrun's type detachable bal- loon (Ingenor, Paris, France) was firstly detached into the aneurysm. Then we tried to obliterate the fistula. Because the flow in the fistula was large and the pulsation in the vertebral artery was strong, one partially inflated balloon was accidentally detached and migrated to the venous side