Contribution of watertight dural closure to prevention of postoperative cerebrospinal fluid leakage in endoscopic transnasal surgery for intradural lesions

OBJECTIVE The goal of this study was to evaluate the efficacy of watertight dural closure (WTDC) in preventing postoperative CSF leakage during extended endoscopic transnasal surgery (ETS) for skull base tumors, while preserving sinonasal quality by omitting the routine use of a nasoseptal flap. METHODS This retrospective study included 28 patients who underwent ETS and experienced Esposito grade 3 CSF leakage at a single institution between June 2022 and June 2024. WTDC was performed using fascia lata grafts and various suturing techniques. Surgical videos and electronic medical records were reviewed to assess suturing times and postoperative outcomes. The efficacy of WTDC in preventing CSF leakage was evaluated, and the technical aspects of the procedure were analyzed. RESULTS Among the 28 patients (14 female, 14 male), WTDC was successfully achieved in 14 cases, with near-watertight closure in the remaining 14. The average suturing time decreased with experience, showing a trend of improved efficiency. No postoperative CSF leaks were observed, and 1 case of postoperative meningitis resolved without sequelae. Despite significant risk factors for CSF leakage, WTDC was effective in all patients without the routine use of lumbar drainage. CONCLUSIONS WTDC in ETS is a reliable method for preventing postoperative CSF leakage, particularly in complex skull base surgeries with high-risk factors. This technique avoids the complications associated with nasoseptal flap use, preserves sinonasal quality, and reduces the need for lumbar drainage, making it a valuable option for skull base reconstruction.