From Research to Clinical Practice: Long-Term Impact of Randomized Clinical Trial of Lumbar Drains on Cerebrospinal Fluid Leak Rates in Skull Base Surgery

Introduction: High-flow intraoperative cerebrospinal fluid (CSF) leaks are associated with an increased risk of postoperative CSF leaks despite multilayered reconstruction with vascularized tissue. A recent randomized controlled trial (RCT) on the use of perioperative lumbar drains (LD) in high-risk skull base defects found significant reduction in postoperative CSF leak rates (21.2 vs. 8.2%; p = 0.017). Clinical application of these results outside the controlled setting of a RCT integrates subjective elements to the decision making, such as disease severity, patient comorbidities and prior surgery. This study was conducted to assess the effectiveness of a new reconstructive algorithm, one that incorporates the selective use of CSF diversion, for patients with high flow CSF leaks in endoscopic endonasal surgery (EES) of the skull base.

Method: Outcomes from consecutive patients of a pre-RCT cohort (January 2009 to January 2011) and post-RCT cohort (July 2016 to July 2018) were analyzed and compared. Included patients underwent EES with reconstruction of high-flow CSF leak of the anterior or posterior cranial fossa. Cohorts were compared for patient age, body mass index (BMI), rate of revision surgery, tumor histology, CSF diversion and nasoseptal flap (NSF) reconstruction. The primary outcome was postoperative CSF leak. Chi-square test and Students-T test were performed for categorical and numerical data analysis, respectively.

Results: Pre-RCT cohort included 85 patients and post-RCT cohort included 89 patients with high flow CSF leaks of the anterior or posterior cranial fossa. There was no difference in patient age (p = 0.69), BMI (p = 0.14), revision surgery (p = 0.91), malignant versus benign pathology (p = 0.21), or NSF reconstruction (p = 0.71) between cohorts. Postoperative CSF leak rate was reduced in the post-RCT cohort from 24.7% to 10.1% (p = 0.011). The use of CSF diversion was significantly higher in the post-RCT cohort (p = 0.0013).

Conclusion: This study demonstrates how implementing knowledge acquired from a randomized controlled trial (level I evidence) improves patient outcomes outside the setting of a research trial. The addition of selective CSF diversion to the reconstructive algorithm improved postoperative CSF leak rates in patients with anterior and posterior cranial fossa defects.