Immediate postoperative MRI findings after lumbar decompression surgery: Correlation of imaging features with clinical outcome. (July 2021)

• Record Type: Journal Article
• Authors: Yeo, Joon Bum; Lee, Eugene; Lee, Joon Woo; Kim, Bo Ram; Kang, Yusuhn; Ahn, Joong Mo; Park, Sang-Min; Kang, Heung Sik
• Is Part Of: Journal of clinical neuroscience. Volume 89(2021)
• Page Start: 365
• Page End: 374
• Publication Date: 2021-07
• Subjects: Lumbar spinal stenosis -- Epidural hematoma -- Facet joint effusion -- Laminectomy -- Magnetic resonance imaging -- Postoperative complications -- Subdural fluid collection; Brain -- Surgery -- Periodicals; Neurosciences -- Periodicals; Nervous system -- Surgery -- Periodicals; Brain -- surgery -- Periodicals; Neurosurgical Procedures -- Periodicals; Neurosciences -- Periodicals; Electronic journals; 616.8
• DOI: 10.1016/j.jocn.2021.05.045
• Languages: English
• ISSNs: 0967-5868

Abstract

Highlights: Worsened canal stenosis at adjacent segments is common after lumbar decompression, showing no statistically significant correlation with the immediate postoperative outcome. Postoperative fluid collections at the laminectomy site is the commonest finding. Higher hemorrhagic fluid rates are observed in two-level decompression. More severe canal compromise occurs in two-level decompression. Abstract: An understanding of the common MRI findings observed after decompression surgery is important. However, to date, no study addressing this has been published. The aim of this study was to analyze and describe the immediate postoperative MRI findings after lumbar decompression surgery. We retrospectively analyzed the immediate postoperative MRIs of 121 consecutive patients who underwent lumbar decompression surgery between July 2017 and June 2018. Changes in stenosis at the decompressed and adjacent levels, epidural fat edema, epidural and subdural fluid collections, nerve root swelling, facet joint effusions, intervertebral disc signal, and paravertebral muscle edema were correlated with clinical characteristics. Both groups had reduced central canal stenosis postoperatively (p < 0.001) but worsened stenosis at adjacent segments. Fluid collection, hemorrhagic or non-hemorrhagic, at the laminectomy site was the commonest finding (one-level: 73.8%, two-level: 88.5%), with a higher percentage of severe central canal compromise in the two-level decompression group (p = 0.003). Other postoperative MRI findings, such as epidural fat edema, nerve root swelling, subdural fluid collection, and facet joint effusion, were noted without statistical significance. In conclusion, even with successful decompression for lumbar canal stenosis, increased central canal stenosis at adjacent segments is common on immediate postoperative MRI scans, showing no statistically significant correlation with the immediate postoperative outcome. Postoperative fluid collection at the laminectomy site is the commonest imaging finding, and higher rates of hemorrhagic fluid and more severe central canal compromise occur in two-level decompression, but rarely cause clinical problems.