Continuous sitting position during the postoperative period as an intervention to reduce risk of cerebrospinal fluid leak after endoscopic endonasal surgery.

Introduction/objectives: In recent decades, endoscopic endonasal surgery for skull base tumours has modified the way in which this region is approached. One of the most feared complications is the cerebrospinal fluid leak. It has been shown in different publications about CSF physiology that changes in the position modify the pressure of the CSF (pCSF). With this background, it is proposed as a viable, noninvasive, and very low-risk option, the continuous sitting position in patients during their hospital stay after endoscopic endonasal surgery as an adjuvant intervention to reduce the risk of CSF leak in patients considered to be at high risk. The objective is to demonstrate that the continuous sitting position in the postoperative period is a useful adjuvant intervention for the prevention of CSF leak in endoscopic endonasal surgery.

Methods: This is a retrospective, observational, cross-sectional, comparative study. It included patients over 18 years of either sex, intervened by endoscopic endonasal surgery with intraoperative CSF leak observed and with advanced reconstruction technique realized. A continuous sitting position (between 70 ° and 90 °) was considered when the patient remained in this position from the immediate postoperative period until the hospital discharge.

Results: A total of 60 patients were included. No statistically significant difference was found on all the variables studied, except when patients were stratified into sitting and non-sitting patients (p = 0.045). OR of 0.12 (95% CI 0.002-1.03) was observed. In the sitting group, only 1 patient (6.67%) had CSF leak, which was resolved with non-surgical treatment. The average length of hospital stay was 18 days (7-38) for sitting patients and 14 days (5-80) for non-sitting patients, with statistical significance stablished by the dispersion of the data (p = 0.023).

Conclusions: The continuous sitting position during the immediate postoperative period is an intervention that shows a decrease in the risk of CSF leak in patients intervened by endoscopic endonasal approach, included extended routes.