Surgical Decompression of Traumatic Cervical Spinal Cord Injury: A Pilot Study Comparing Real-Time Intraoperative Ultrasound After Laminectomy With Postoperative MRI and CT Myelography

Abstract

BACKGROUND: Decompression of the injured spinal cord confers neuroprotection. Compared with timing of surgery, verification of surgical decompression is understudied. OBJECTIVE: To compare the judgment of cervical spinal cord decompression using real-time intraoperative ultrasound (IOUS) following laminectomy with postoperative MRI and CT myelography. METHODS: Fifty-one patients were retrospectively reviewed. Completeness of decompression was evaluated by real-time IOUS and compared with postoperative MRI (47 cases) and CT myelography (4 cases). RESULTS: Five cases (9.8%) underwent additional laminectomy after initial IOUS evaluation to yield a final judgment of adequate decompression using IOUS in all 51 cases (100%). Postoperative MRI/CT myelography showed adequate decompression in 43 cases (84.31%). Six cases had insufficient bony decompression, of which 3 (50%) had cerebrospinal fluid effacement at >1 level. Two cases had severe circumferential intradural swelling despite adequate bony decompression. Between groups with and without adequate decompression on postoperative MRI/CT myelography, there were significant differences for American Spinal Injury Association motor score, American Spinal Injury Association Impairment Scale grade, AO Spine injury morphology, and intramedullary lesion length (IMLL). Multivariate analysis using stepwise variable selection and logistic regression showed that preoperative IMLL was the most significant predictor of inadequate decompression on postoperative imaging (P = .024). CONCLUSION: Patients with severe clinical injury and large IMLL were more likely to have inadequate decompression on postoperative MRI/CT myelography. IOUS can serve as a supplement to postoperative MRI/CT myelography for the assessment of spinal cord decompression. However, further investigation, additional surgeon experience, and anticipation of prolonged swelling after surgery are required.