Spinal Surgery for Degenerative Lumbar Spine Disease: Predictors of Outcome

Introduction: Although its exact incidence is unknown, lumbar stenosis is estimated to affect between three and 12 patients per 100,000 inhabitants per year in the elderly population of Brazil. Major complications in these patients are reoperations due to complications from the first surgery, such as cerebrospinal fluid (CSF) leakage and surgical site infection (SSI) (spinal surgeries have a reported SSI rate of 2% to 15%). The occurrence of dural tearing (DT) is related to the high complication rate and less-than-ideal results for these patients.

Objectives: Identify predictors of outcomes for results in Degenerative Lumbar Spine Disease (DLSD).

Patients and Methods: A retrospective analysis of 164 patients who underwent surgery for DLSD was performed. The study duration was 24 months (January 2013-December 2014). The patients were first evaluated and were assessed for their results regarding the extent of surgery in four groups: patients undergoing surgery for treatment of one segment, two segments, three segments, and four or more segments of DLS. Posteriorly, the same group of patients was divided based on the presence or absence of Dural Tear (DT) during surgery. In addition, the relationship between elderlies and the incidence of surgical site infection (SSI) and reoperation was also analyzed.

Results: A total of 193 surgeries were performed on 164 patients (74 males/90 females), with a mean age of 53.18 years old (53.18 ± 17.54). SSI occurred in 7.31% of cases and re-operations due to SSI or because of complications resulting from the first procedure occurred in 11,58% of cases. Results statistically significant were found regarding the incidence of SSI (P = 0.05) and the rate of re-operation (p = 0.003) in surgeries involving more than three segments. DT is directly related to the rate of re-operation (p = 0.0172) and SSI (p = 0.0002). Elderly patients were not a predictor of poor outcome, neither to incidence of SSI (p = 0.2), nor chance of re-operation (p = 0.36).

Conclusion: Surgeries involving more than three segments are directly related to SSI, incidence of accidental DT and chance of re-operation. The presence of DT during the procedure is presented as a predictor of postoperative SSI and an increase in re-operation rate. Furthermore, elderly patients are not related to a higher risk for SSI and re-operations.