Charles A. Bruno DO, Presenter: Nothing to Disclose

David Taylor MD, Abstract Co-Author: Nothing to Disclose

Khuram Shahzad Kazmi MD, Abstract Co-Author: Nothing to Disclose

Spinal subdural fluid collections are a poorly understood complication of lumbar laminectomies. These fluid collections are important to recognize as they may be a source of postoperative pain and may be associated with other postoperative complications including CSF leak and infection. Given the frequency with which lumbar laminectomies are performed, understanding potential morbidities associated with this procedure may help to improve patient outcomes. Therefore, the purpose of this study is to describe the MRI findings, estimate the frequency and analyze the potential clinical significance of spinal subdural collections following lumbar laminectomy.  

We performed a single center, retrospective cohort study of 32 consecutive patients who had undergone lumbar laminectomy over a 3-year period. The patients’ postoperative lumbar spine MRI’s were reviewed by two radiologists at our institution. MRI studies were deemed positive for subdural fluid collections if they demonstrated intradural collections with signal intensity similar to cerebrospinal fluid with displacement of the cauda equina nerve roots. The Fisher Exact test was used to evaluate the relationship between subdural fluid collections, CSF leak and infection.  

32 patients were included in the study. 8 patients (25%) were found to have subdural fluid collections. Of the 8 patients with subdural fluid collections, 3 (37.5%) had a CSF leak. Of the patients without subdural collections (n=24), none (0%) had a CSF leak. The likelihood of having a CSF leak was 9.3 times greater in those patients with a subdural fluid collection versus those without subdural collection (p=0.002). Of those patients with subdural fluid collections, 50% (n=4) had postoperative infection. By contrast, 20.8% (n=5) of those without subdural fluid collections had postoperative infection. Although there was a trend towards increased postoperative infection in those with subdural collections, the results were not statistically significant.  

Subdural fluid collections after lumbar laminectomy are an important postoperative finding. Our preliminary data suggests an association with CSF leaks as well as a trend towards an association with infection. This warrants further investigation.

Subdural collections may be associated with infection.

Bruno, C, Taylor, D, Kazmi, K, MRI Evaluation of Spinal Subdural Fluid Collections after Lumbar Laminectomy  .  Radiological Society of North America 2010 Scientific Assembly and Annual Meeting, November 28 - December 3, 2010 ,Chicago IL. http://archive.rsna.org/2010/9004463.html