CSF Leak Predicts Delayed Revision After Posterior Lumbar Interbody Fusion

Introduction: Posterior lumbar fusion, through techniques such as transforaminal lumbar interbody fusion (TLIF) and posterior lumbar interbody fusion (PLIF) is a safe and well tolerated procedure. Post-operative cerebrospinal fluid (CSF) leak is a known complication associated with short-term complications such as infection and delayed postoperative recovery. However, it is not known if CSF leak, even if appropriately treated, is associated with pseudoarthrosis and revision surgery. This study aims to evaluate the risk of delayed revision surgery in cases of CSF leak during posterior lumbar fusions (TLIF/PLIF).

Methods: PearlDiver (Colorado Springs, CO), a private analytics database of both commercial and Medicaid claims data, was utilized to search for patients between the age of 18-85 who underwent posterior instrumented lumbar fusion between 2015 and 2020. Gender, Age, BMI class, pre-operative tobacco and opioid use were compared with t-test (gender) and Chi-squared tests. A p < 0.01 (Bonferonni correction) was considered statistically significant. A generalized linear model was developed using these variables.

Results: A total of 80904 patients who underwent posterior lumbar fusions from between 2015 and 2020 were included in the study. There were 261 diagnosed CSF leaks within 60 days after the index fusion, and 2863 revision fusions after 90 days from the index surgeries. In a generalized linear model accounting for BMI, tobacco and opioid use, CSF leak, the odds of revision surgery were 1.79 times higher in those that had CSF leaks, when compared to those that did not (97.5%CI 1.05, 2.84). Increased odds of ultimately undergoing delayed revision were also seen in those with recorded pre-operative tobacco use (OR 1.42, 97.5%CI 1.31, 1.54) and opioid use (OR 1.49, 97.5%CI 1.38, 1.61), as well as those who were underweight (OR 2.41, 97.5%CI 1.48, 3.73), and in the overweight (OR 1.49, 97.5%CI 1.31, 1.71) and obese (OR 1.58, 97.5%CI1.46, 1.71).

Conclusion : This study demonstrates that post operative CSF leak, though rare, greatly increases the risk of delayed revision surgery. Notably, this effect was greater than that of smoking opioid use and being of high BMI class.