2026 Poster Presentations
P242: IMPACT OF FRONTAL SINUS CLOSURE METHODS ON POSTOPERATIVE CEREBROSPINAL FLUID LEAKAGE IN THE BASAL INTERHEMISPHERIC APPROACH
Osamu Akiyama, MD, PhD; Yuzaburo Shimizu, MD, PhD; Takuma Kodama, MD; Ryo Miyahara; Akihide Kondo; Department of Neurosurgery, Faculty of Medicine, Juntendo University, Tokyo, Japan
Background: The basal interhemispheric approach (BIA) is a useful surgical route for lesions in the suprasellar and anterior skull base regions. However, when the frontal sinus is opened, postoperative cerebrospinal fluid (CSF) leakage due to insufficient closure becomes a major concern. Various techniques for frontal sinus closure have been reported, but the optimal method has not yet been established. We retrospectively analyzed cases of BIA at our institution, focusing on closure techniques and postoperative complications.
Methods: Between 2018 and 2024, 102 patients underwent BIA at Juntendo University Hospital. After excluding recurrent cases and pediatric patients younger than 15 years, 76 patients were included. Closure methods were categorized as fibrin glue only (F), fibrin glue plus DuraGen (D+F), fibrin glue plus bone paste (F+B), fibrin glue plus pericranial flap (P+F), and combined methods (P+F+D, D+F+B). Postoperative complications including CSF leakage, olfactory dysfunction, and infection were evaluated.
Results: The median follow-up period was 57.5 months (range, 5–100). The median age of the 76 patients was 56.5 years (range, 24–79), with a male-to-female ratio of 36:40. Diagnoses included meningioma in 39 cases, craniopharyngioma in 16, glioma in 6, PitNET in 6, and others in 8. The mean BMI was 23.3 (range, 16.2–36.4), and 3 patients (3.9%) had diabetes. The mean extent of frontal sinus opening was 47.2 mm (range 12.7–85.1), and the ethmoid sinus was opened in 11 cases (14.5%). Postoperative CSF leakage occurred in 3 patients (3.9%), olfactory dysfunction in 2 (2.6%), and no infections were observed. CSF leakage rates by closure method were: F (n=18), 0%; D+F (n=17), 0%; F+B (n=1), 0%; D+F+B (n=1), 0%; P+F (n=29), 3.4%; and P+F+D (n=10), 20%. All CSF leaks occurred in patients reconstructed with a pericranial flap, particularly in the P+F+D group. Olfactory dysfunction also occurred only in the P+F group. BMI and diabetes were not significantly associated with complications.
Discussion: The overall incidence of postoperative CSF leakage was low, but differences were observed among closure methods. No CSF leakage occurred in the F or D+F groups; these cases had sufficiently tight primary dural suturing, which likely contributed to the low complication rate. In contrast, complications clustered in the pericranial flap groups. The pericranial flap is often used in cases with larger frontal sinus openings, which may increase the risk of CSF leakage. BMI and diabetes had no significant impact. These findings suggest that the choice of closure method should be tailored to case-specific factors.
Conclusion: Frontal sinus closure in BIA can be performed safely, with an overall CSF leakage rate of 3.9%. However, the use of a pericranial flap was associated with increased risk, indicating that closure strategy should consider the extent of frontal sinus opening. This study provides useful insights for establishing safe strategies for frontal sinus management in BIA.