Brandon goenawan, BS
MS4
University of California, San Francisco
Bakersfield, California, United States
Conor O'Neill, MD
Professor Physical Medicine and Rehabilitation Spine
University of California, San Francisco
San Francisco, California, United States
Patricia Zheng, MD
Associate Orthopaedics Clinical Professor and Physical Medicine and Rehabilitation Specialist
University of California, San Francisco
San Francisco, California, United States
Peter I-Kung Wu, MD, PhD, MPH
Associate Professor
UCSF
San Francisco, California, United States
Lyndly Tamura, MD
Assistant Professor /Health sciences Assistant Clinical Professor/ PM&R spine
UCSF
San Rafael, California, United States
Injury to the vertebral artery during cervical transforaminal epidural steroid injections (CTFESIs) can lead to catastrophic complications. However, the incidence and significance of “vertebral artery sheath filling,” defined as persistent, extravascular, vertical contrast flow that outlines the vertebral artery but does not clear during these injections, are poorly understood. We aim to characterize the incidence of “vertebral artery sheath filling” during CTFESIs.
We performed a retrospective chart review of consecutive CTFESIs performed by a single provider according to Spine Intervention Society protocol. Saved fluoroscopy images were reviewed by two independent physicians to look for filling of the “vertebral sheath” as described by Bogduk and colleagues, along with the targeted epidural flow. The incidence of such filling was calculated.
37 CTFESIs on 36 patients were reviewed. These injections occurred between C3-4 and C7-T1; 18 of these injections were right-sided, 18 were left-sided and 1 was bilateral. Six (16%) demonstrated “vertebral artery sheath filling.” Three of these were at C5-6, one was at C4-5, one was at C6-7, and one was a two-level procedure at both C5-6 and C6-7. Five sheath fillings occurred on the right, and one on the left.
“Vertebral artery sheath filling” is underrecognized, but relatively common, and this study demonstrated an incidence of 16% in 37 CTFESIs. This study supports the prior work done by Levin et al., which showed an even higher incidence of 49% in 100 patients undergoing CTFESI. Although vertebral artery sheath filling outlines the shape of the vertebral artery, the persistent outline indicates that it is not truly intravascular. More studies need to be done reviewing the correlation of vertebral artery sheath filling regarding safety and efficacy of CTFEIs. However, to our knowledge, there have been no reported adverse events associated with injection into the vertebral artery sheath.
