2026 Poster Presentations
P265: RESCUE FLAP STRATEGY FOR SKULL BASE SURGERY: SELECTIVE CONVERSION TO NASOSEPTAL FLAP ONLY IN TRANSOPERATIVE CSF LEAK.
Santiago Nunez-Velasco, MD1; Estefania Ramirez-Medina, MD1; Andrea P Ramos-Mora, MD1; Gabriel Gomez-Zamora, MD1; Jose J Jauregui-Gamboa, MD1; Ana C Orozco Navarro, MD2; Enrique G Ortiz-Hernandez, MD2; 1Neurosurgery Department, Hospital Civil de Guadalajara; 2Otorhynolaringology Departmant, Hospital Civil de Guadalajara
Introduction: Cerebrospinal fluid (CSF) leaks are a major complication of transnasal endoscopic pituitary surgery, traditional risk factors are tumor size, invasion, and patient factors such as overweight and diabetes. The classic nasoseptal flap is elevated at the beginning of surgery to ensure vascularized coverage but at the cost of greater nasal morbidity. The “rescue flap” is a selective, vascularized reconstruction technique designed to prevent postoperative leaks while minimizing morbidity, it allows to preserve the vascularity and could be elevated only if reconstruction is required.
Objective: Evaluate the effectiveness of selectively use of the nasoseptal flap for intraoperative CSF leaks in skull base surgery.
Methods: We reviewed the medical records of 114 patients diagnosed with pituitary adenomas who underwent transnasal endoscopic surgery between 2021-2025 to assess associations between intraoperative CSF leak grade, nasoseptal rescue flap use and postoperative CSF leak. We used Chi-square test to analyze the association between intraoperative leak grade and nasoseptal flap use and students t-test to establish the relationship between weight or BMI and postoperative leaks
Results: The mean age was 47.7 years (16–86). Women represented 61%. The mean BMI was 28.0, 18% of the patients had a diagnosis of diabetes. The distribution of intraoperative cerebrospinal fluid leak grades was: grade 0 in 64, 1 in 19, 2 in 20, and 3 in 11 cases. Postoperative CSF leak was documented in 5 cases (4.4%), mainly concentrated in the extreme grades (0 and 3); this association was not statistically significant (p=0.10). A nasoseptal flap was used in 30 patients (26%) and showed a proportional relationship with the severity of the intraoperative leak, reaching statistical significance (p<0.0001). No significant associations were found between weight, BMI, Hardy, or Knosp classification and the presence or grade of intraoperative CSF leak.
Discussion: The rate of postoperative CSF leakage was low at 4.4%, consistent with earlier studies. Intraoperative leak grade strongly guided nasoseptal flap use (p <0.0001), supporting selective rather than routine reconstruction. Leak grade did not significantly predict postoperative leaks (p = 0.10), and tumor extension, weight, and BMI showed no association. Surgical and anatomical factors are more important than demographics or tumor classifications for predicting outcomes.
Conclusion: In this case series, intraoperative CSF leak grade was the only determinant factor guiding the selective use of the nasoseptal rescue flap in transnasal endoscopic pituitary surgery. Only two patients in whom the flap was not applied developed postoperative CSF leaks, demonstrating that a selective, intraoperative leak–based indication is safe and effective. Patients with higher-grade intraoperative leaks benefited most from flap reconstruction, while low-grade or absent leaks showed a low risk of postoperative complications. These findings support a tailored approach that minimizes unnecessary morbidity without compromising leak prevention.