PR_208: Intravascular Injection of Contrast During Lumbar Diskography: A Previously Unreported Complication

Abstract

Setting: Case report from an academic university spine center. Patient: A 40-year-old woman with L5-S1 degenerative disk disease and persistent low back pain. Case Description: The patient failed to respond to multiple conservative treatments. Magnetic resonance imaging of the lumbosacral spine demonstrated disk desiccation with a paracentral bulge at L4-5. In consideration of surgical treatment, diskography was requested. Assessment/Results: A 22-gauge, 15.2-cm (6-in) needle was inserted to the central nucleus by a left posterolateral approach. Diskography was performed at L4-5 and L5-S1. Testing was performed with pressure manometry, beginning with the L4-5 disk as a control. The pressure increased with contrast injection, which is indicative of a normal disk. At 45psi, there was a drop to 20psi. Lateral views obtained during contrast injection demonstrated cephalad flow from a central nucleogram through the posterior annulus into the anterior epidural space. Images obtained with live fluoroscopy demonstrated a vascular flow pattern, confirmed with lateral and anteroposterior views. The needle tip was repositioned anterior-superiorly. Repeat injection resulted in an identical vascular pattern. From the time the pressure dropped, contrast flowed in the vascular pattern without propagation of the nucelogram or increase in intradiskal pressure. The patient was asymptomatic throughout the injection at L4-5. Injection at L5-S1 demonstrated a severely degenerative nucleogram and reproduced the patient’s usual low back pain. Discussion: Lumbar diskography is often used to direct surgical intervention for refractory diskogenic pain. Complications of diskography include diskitis, nerve injury, and dural puncture. However, hematoma formation following cervical diskography has been reported. The lumbar disk is an avascular structure, so vascular complications are rare. While superficial lamellae of the annulus fibrosis contain capillaries, blood vessels are not normally found within healthy lumbar disks. Conclusions: Vascular uptake of contrast can occur during lumbar diskography, even when the needle tip is ideally located.