Lumbar decompression surgery for cauda equina syndrome: A meta-analysis and systematic review of the safety of operating out of hours.

Objectives: We conduct a systematic review and meta-analysis of the published literature regarding the impact of performing lumbar decompression for cauda equina syndrome (CES) out of hours compared to regular operating hours.

Methods: A search of databases including Medline, EMBASE and Cochrane Library was performed with two independent reviewers per the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A senior author arbitrated in event of disagreement. MeSH terms [((cauda equina) OR (CES)) AND ((hours) OR OOH)] were used. Filters including date range (from January 01, 1990 to November 01, 2022) and the English language were applied. Inclusion criteria consisted of retrospective or prospective cohort studies, English or full translation available, surgical complication as primary or secondary outcome and out of hours surgery as an independent variable. Case reports and studies without complication frequency were excluded. There were no additional studies identified through a snowballing secondary search through references of identified articles. Operative metrics were compiled into ad-hoc tables. Statistical analysis was performed using RevMan 5.4. A difference in complication rates with a P value of < .05 was deemed statistically significant. Heterogeneity was reported using I². Study quality was assessed using the Newcastle Ottawa Score (NOS).

Results: The search strategy yielded 363 articles. After duplicate removal and application of inclusion/exclusion criteria, 15 studies were sought for retrieval and full text review. Of these, 5 studies were included for qualitative synthesis. Of these, 4 studies underwent quantitative analysis with 581 datasets. Meta-analysis was undertaken on 3 studies comprising 495 datasets. A dichotomous outcome was modelled using the Mantel-Haenszel statistical method with fixed effect which demonstrated an odds ratio (OR) of 2.38 (95 % CI 1.39-4.07) for sustaining an adverse event from out of hours surgery compared to routine operative hours. I² = 12 %, suggesting homogeneity between studies analysed.

Conclusions: This study provides clinical evidence that out of hours surgery for lumbar decompression for CES is associated with a higher rate of surgical complications. The spinal surgeon should appropriately counsel the patient with CES that while it is important to do the surgery as soon as possible, operating out of hours carries a higher risk of surgical complications.