2025 Proffered Presentations
S186: PROSPECTIVE EVALUATION OF SKULL BASE RECONSTRUCTION ENHANCEMENT PATTERNS, SURGICAL REPAIR TECHNIQUES, AND ASSOCIATION WITH CEREBROSPINAL FLUID LEAK
Jakob Fischer; Sara K Yang, MD; Melodyanne Y Cheng, MS; Noriko Salamon, MD, PhD; Marvin Bergsneider, MD; Won Kim, MD; Jeffrey D Suh, MD; Daniel M Beswick, MD; Jivianne T Lee, MD; Marilene B Wang, MD; University of California, Los Angeles (UCLA)
Background: The endoscopic trans-nasal trans-sphenoidal(TNTS) approach to the anterior skull base is the preferred technique to address sellar lesions. The nasoseptal flap(NSF) provides a pedicled flap that has reduced the rates of cerebrospinal fluid(CSF) leaks in anterior skull base surgery. Despite this, there has been limited evaluation into the vascularity of these pedicled flaps in the perioperative period. Previously, we performed a retrospective review of all primary pituitary patients at our institution and found that up to 40% of NSF had at least a partial hypovascularity of their NSF in the immediate post-operative period that resolved by 3-months. This study was limited by its retrospective nature and potential selection bias as immediate post-op MRIs were often used to evaluate for surgical complications. The goal of this currently recruiting study is to prospectively evaluate the vascularity of our skull base reconstructions and determine the impact it may have on peri-operative CSF leak as well as other surgical factors.
Methods: This prospective study evaluated patients having undergone TNTS for an anterior skull base lesion between February 2024 and July 2024 at a tertiary academic practice who underwent contrast-enhanced MRI of the pituitary within four days of surgery. Demographic data, operative details, reconstruction techniques, and peri-operative complications were reviewed. When available, 3-month post-operative MRIs were evaluated to determine changes in vascularization patterns of skull base reconstruction over time. Vascularization patterns, adjuvant reconstruction techniques, and complication rates were evaluated.
Results: In total, 23 patients(13 female[56.5%];mean[SD] age,50.5[14.8] years having undergone resection of anterior skull base lesion vis TNTS with post-operative MRI within 4 days of surgery available to review were included. 13(56.5%) of patients had anterior skull base reconstruction via NSF while 9(39.13%) had reconstruction via septal free mucosal graft. The majority of patients (17,78.3%) underwent surgery for pituitary adenoma, and the majority of patients (19,82.6%) were undergoing primary surgical resection. Among patients undergoing NSF reconstruction (13,56.5%), 53.9%(n=7) patients had sellar reconstruction with bone or absorbable plate, while 38.5% (n=5) had their NSF bolstered via a foley catheter. Post-operative MRIs showed at least partial enhancement of the NSF in 84.6%(n=11) patients. Four(17.4%) patients experienced a post-operative CSF Leak a median of 7 days post-operatively, three of which occurred in patients having undergone NSF reconstruction. All NSF-related CSF leaks occurred in patients with a grade-3 intraoperative CSF leak, had skull base bolstering via foley catheter, and had a complete sellar sphenoid pneumatization noted pre-operatively. There was no difference in CSF leak rates based on post-operative MRI vascularity(p=0.98), or sellar pneumatization (complete sellar vs other pneumatization,p=0.078). NSF bolstering via foley catheter was associated with higher rates of CSF leaks compared to bone/plate reconstruction (p=0.018).
Conclusion: There was no association between patterns of nasoseptal flap enhancement on MRI and CSF leaks in the peri-operative period, but there was a notable association with the use of intranasal foley bolstering of the nasoseptal flap with post-operative CSF leak. Sphenoid pneumatization patterns may have associations with rates of CSF leak, but more data is necessary to further evaluate this potential association.
