Anomalous Vertebral Artery Injured During Anterior Cervical Discectomy A Case Report

Study Design. Case report. Objective. To describe treatment and injury prevention from discectomy with a newly described vertebral artery anomaly. Summary of Background Data. Cervical segment vertebral artery (VA) anomalies of various types are described with the least common type involving erosion into the vertebral body medial to the uncinate process. The morphology of these includes return to the lateral position at the disc level where they have been immune to anterior cervical discectomy surgery. This case report demonstrates the first published account of a medial vertebral artery adjacent to a disc and injured by discectomy alone. VA injury is a serious complication with a significant percentage of neurological injury and death. The lesion was missed by a neuroradiologist reading the thin slice preoperative magnetic resonance imaging (MRI) study. Subsequently, 6 additional specialists blinded to the study all missed the diagnosis. The difficulty of diagnosis is similar to another study where 6 neuroradiologists missed 100% of diagnosis of similar lesions on 49 MRI studies. Methods. A 55-year-old female with left-sided weakness in the neck and shoulder and C5-C6 stenosis underwent anterior cervical microdiskectomy. When a fine-tipped drill bit was used to smoothen a slight convexity on the C6 endplate, high pressure and volume hemorrhage started. After tamponade, the patient was brought directly to angiography and CT scanning. Several days later, the patient underwent endovascular evaluation and stenting for a pseudoaneurysm. Results. No neurological deficits occurred from the complication. Cervical discomfort and headache symptoms partially improved. Conclusion. A previously undescribed medial vertebral artery anomaly involving the cervical disc level is documented with near disastrous hemorrhage from simple anterior discectomy. The rate of preoperative diagnosis from MRI scans is dismal. Preoperative studies should be scrutinized with suspicion and any questionable area studied further regardless of a negative diagnosis.