Emergent Vertebral Artery Embolization during C12 Screw Fixation for Rheumatoid Arthritis

Abstract

The subaxial screw fixation technique is commonly used for fixation in a wide range of cervical diseases, including traumatic, degenerative, and neoplastic diseases, rheumatoid arthritis (RA), and spondyloarthropathy. Although it is regarded as a relatively safe procedure, several complications may be encountered during surgery, such as vertebral artery (VA) and nerve root injuries, facet violation, and mass fracture. We report a case of endovascular embolization after VA injury during a high cervical spinal surgery. A 48-year-old woman was scheduled for C-1-2-3 posterior fixation. Plain radiography of the cervical spine revealed a severely unstable state. During dissection around the C1 lateral mass on the right side, sudden brisk arterial bleeding was observed. On vertebral angiography, flow voiding was noted above the right V3 portion. After checking patent collateral flow from the contralateral VA, routine coil embolization was performed to pack the V3 segment. Iatrogenic vascular injuries due to spinal surgery are rare but serious complications. For patients with RA, we recommend careful preoperative evaluation before a high cervical surgical procedure to avoid iatrogenic VA injury and endovascular interventions that are safe and effective in the diagnosis and treatment of such vascular injuries.

INTRODUCTION

Subaxial screw fixation technique is commonly used for fixation of wide range of cervical diseases including traumatic, degenerative, neoplastic, rheumatoid arthritis (RA), and spondyloarthropathy since introduced by Roy-Camille et al.²,⁷⁾ Regraded as relatively safe procedure, several complications may be encountered during operation, such as vertebral arteries and nerve roots injuries, facet violation, and mass fracture.⁶⁾ The incidence of vertebral artery (VA) injury during posterior C1-2 screw fixation is reported as approximately 3% and may remain asymptomatic or causing arteriovenous fistulae, occlusion, narrowing, or dissection, and lead to transient ischemic attacks, stroke, or death.¹⁶⁾ In our case, sudden massive bleeding in the operative field, emergent intraoperative embolization using multiple coils was done and good hemostasis was acquired. At the time of discharge, the patient showed no significant neurologic deficit or mental problem. We report a case of iatrogenic VA injury that was successfully treated using emergent coil embolization. Through this case, we want to discuss promising good strategies for iatrogenic VA injury.

CASE REPORT

A 48-year-old woman presented with right side pelvic pain and quadriparesis after slip down accident. The patient was planned for C1-2-3 posterior fixation previously. The X-ray findings showed pelvic bone fracture. In emergency room, in-hospital care by department of Orthopedic surgery was recommended. She had history of total knee replacement and total hip replacement 14 years ago and medical care for RA for 30 years. The plain x ray finding for cervical spine showed severe unstable state. The Ranawat index was 7.09 mm and the Redlund-Johnell index was 21.8 mm. The computed tomography findings revealed atlanto-dens interval and posterior atlando-dens interval index were 70.5 mm and 10.97 mm respectively (FIGURE 1). For proper surgical management for upper cervical pathology, we decided to perform Subaxial fixation. During dissection around the C1 lateral mass, on the left side, sudden brisk arterial bleeding was encountered. Immediate packing with surgical was done and acceptable hemostasis achieved. Emergent intraoperative vertebral angiography was performed and flow occlusion was noted above left V3 portion by intra-op gauze packing compression (FIGURE 2). The flow of VA was confirmed only up to V3 segements, and no other extravasation was noticed in transfemoral cerebral angiography. After checking right posterior inferior cerebellar artery and collateral flow from contralateral VA, we decided to trap the right VA. First. After guiding the microcatheter to the proximal of the suspected rupture point, coil packing was performed. Second, using the opposite VA, the microcatheter was moved to the right VA, and coil packing was performed on the distal area of the suspected rupture point. Total occlusion was noted from the involved area (FIGURE 3), It was confirmed that there was no bleeding after removal of the gauze packing on the surgical field of view. C1-2-3 screw fixation was done without further bleeding event. At discharge, the patient had no specific neurological symptoms other than pain at the surgical site, and the modified Rankin Scale was 0.

FIGURE 1. CT images. (A) sagittal view, (B) axial view. CT shows wide atlanto-dens interval and posterior atlando-dens interval index.

CT: computed tomography.

FIGURE 2. Pre-operative transfemoral cerebral angiography images, (A) left vertebral artery, (B) right vertebral artery. Left vertebral artery angiography shows right vertebral collateral (arrow) via basilar artery. Right vertebral angiography shows V4 segment occlusion (arrow) by op site packing.

FIGURE 3. Post-operative transfemoral cerebral angiography images, (A) right vertebral angiography, (B) left vertebral angiography. Right vertebral angiography shows occlusion by coils (arrow). Left vertebral angiography shows right vertebral distal portion occlusion by coils (arrow).

DISCUSSION

Iatrogenic vascular injuries after spine operation is uncommon though serious, life-threatening complications with high mortality and morbidity rates.⁵⁾ VA injury during posterior C1-2 transarticular screw fixation may remain asymptomatic or result in arteriovenous fistulae, occlusion, narrowing, or dissection. The incidence of VA injury during cervical spine surgery was reported as 0.3%–0.5% and most cases occur during corpectomy procedures.¹⁷⁾ The overall incidence of iatrogenic VA injury during cervical spine surgery in our country from 21 multicenter studies was reported as 0.08% and iatrogenic VA injury during C1-2 screw fixation occurred in 1.35% of the surgeries, which was the most common cause of this study.¹¹⁾ Three common causes of VA injury during cervical spine were analyzed by Smith et al.¹⁷⁾: 1) off of the midline use of a power burr, 2) excessive width of bone and disc removal, and 3) abnormal softening of the lateral bone resulting from a tumor or infection. Also, the presence of VA anomalies may increase the risk of injury. Gantwerker et al. presented a unique case unilateral VA injury during anterior cervical discectomy in a patient with bilateral VA anomalies. The authors concluded that careful preoperative evaluation of the course of the VA is critical to avoid iatrogenic VA injury.³⁾ Many authors recommend endovascular management, such as coil embolization, stent-assist coil embolization, and the use of stent grafts or covered stents for VA injury.¹,⁵,⁸,⁹,¹⁰,¹²,¹⁵⁾ We report a case of iatrogenic VA injury case during C1-2-3 screw fixation, who has a long history of RA. The synovitis of RA injures structures in the cervical spine, allowing atlantoaxial subluxation, atlantoaxial impaction, and subaxial subluxation. Spinal cord and VA injury can ensue. Subluxations are common, but neurologic abnormalities are less so.¹³⁾ Miyata et al.¹⁴⁾ reported 3-dimention analysis of the C2 pedicle screw trajectory in 2008. Their results strongly suggest that closer attention should be paid to the bone architecture of the axis in patients with RA. In C2 pedicle screw placement, the course of the VA through the axis can limit the space available for placement of the screw through the pedicle of the axis. It should be kept in mind that C-2 pedicle screw placement in patients with RA entails more risk than in patients without RA. Gillick et al.⁴⁾ reported that considering the course of the VA is important for the surgeon prior to C1-2 fusion. If the VA has an aberrant course, it may be unacceptably unsafe to place either C2 pedicle or C1-2 transarticular screws due to potential injury to the artery or violation of the foramen transversarium. C2 translaminar screws provide a safe alternative for fixation. In this patient, it is difficult to accurately determine because there is no preoperative angiography image, but it is presumed that the VA was damaged during dissection because the distance between C1 and the VA was closer than that of the general patient.

We recommend careful preoperative evaluation for RA patient before high cervical operation procedure for fear of iatrogenic VA injury. Since the VA is mostly on both sides, even if one side is sacrificed when the blood vessel is damaged, there may be no special neurological symptoms because of the collateral by the opposite vessel. Therefore, using it in case of iatrogenic VA injury can select a much more diverse rescue strategy. As with general dissection, the primary goal is to maintain parent artery patency, and if that is impossible, sacrifice would be a good option if it can save the posterior inferior cerebellar artery. Therefore, it should be recognized that a detailed examination of preoperative vertebral angiography can be of great help in such treatment. After this patient, we performed VA CT angiography as a routine for all cervical fracture patients

CONCLUSION

A detailed preoperative evaluation is necessary to prepare for various complications that may occur during high cervical spinal operation in RA patients. Also, for iatrogenic vascular injuries due to spinal surgeries are rare but serious complications that occurs during cervical fusion surgery, endovascular intervention that is safe and effective in the diagnosis and treatment immediately after the occurrence.