Factors influencing timing of cerebrospinal fluid leak after endoscopic skull base surgery: a multicenter study

Considerable work has been done to delineate risk factors for cerebrospinal fluid (CSF) leak after endoscopic skull base surgery (ESBS). Little work has been done to evaluate factors that influence the timing of CSF leaks after ESBS. The timing of when CSF leaks occur may have important implications on postoperative precautions and managing the underlying etiology. The aim of this multi-institutional study was to evaluate postoperative CSF leaks after ESBS to determine timing of occurrence and factors that influence when leaks occur.

Data were collected retrospectively on patients diagnosed with CSF leak after ESBS at 5 institutions from 2010 to 2024. Variables including patient demographics, tumour and defect dimensions, defect location, reconstruction, timing of CSF leak, management of leak, and rates of meningitis were collected.

A total of 184 patients were analysed. The median postoperative day (POD) when CSF leak occurred was 7. Prior radiation, BMI less then 25, recurrent tumours, large defect size, defects located in the clivus, and CSF diversion were all associated with delays in presentation of postoperative CSF leak (all p less then 0.05). On multivariate analysis, BMI and history of radiation retained significance in association with delayed CSF leak. Timing of leak also appeared to be impacted by the number of, and specific layers used in reconstruction.

Several factors were found to impact the timing of CSF leak after ESBS including patient, intraoperative, and postoperative factors. Understanding timing of postoperative CSF leaks may provide insights for prevention and secondary management.