2026 Poster Presentations
P047: 'EARLY INFERIOR TO LATERAL DISSECTION TECHNIQUE' OF MEDIAL WALL RESECTION OF THE CAVERNOUS SINUS IN FUNCTIONING PITUITARY NEUROENDOCRINE TUMOR: TECHNICAL STEPS AND PITFALLS OF ENDOSCOPIC PITUITARY SURGERY
Sae Min Kwon, Dr1; Min Kyun Na, Dr2; Joonho Byun3; 1Dongsan Medical Center; 2Hanyang University Seoul Hospital; 3Korea University Guro Hospital
Background: Functioning pituitary neuroendocrine tumors (PitNETs) often show persistent hypersecretion or recurrence despite gross total resection, largely due to microscopic remnants within the cavernous sinus medial wall. Although endoscopic transsphenoidal medial wall resection (MWR) has been reported, the procedure remains technically demanding because of its proximity to the internal carotid artery (ICA) and the inferior hypophyseal artery (IHA). We present a refined, stepwise approach to cavernous sinus medial wall resection designed to enhance reproducibility and safety, and report our initial outcomes.
Methods: We retrospectively reviewed 10 consecutive patients with functioning PitNETs (7 acromegaly, 3 Cushing’s disease) who underwent endoscopic transsphenoidal surgery with cavernous sinus medial wall resection between January 2020 and June 2024 at three tertiary centers. Patients with prior surgery or medical therapy, or with Knosp grade 4 tumors showing definite cavernous sinus invasion, were excluded. Only cases with an intact medial wall on preoperative MRI were included. Surgical steps emphasized interdural dissection, systematic identification of anatomical landmarks, and stepwise division of the inferior parasellar ligament, IHA, and carotid–clinoid ligament. Outcomes included extent of resection, endocrinologic remission, and perioperative complications.
Results: Gross total resection with medial wall removal was achieved in all patients. Biochemical remission was confirmed in 9 of 10 patients during follow-up, while one patient is pending endocrine evaluation. Intraoperative cerebrospinal fluid (CSF) leakage occurred in 4 patients (3 grade 1, 1 grade 2), all managed successfully with multilayer reconstruction. No patient experienced ICA injury, permanent cranial nerve deficit, or flap necrosis.
Conclusion: This refined, stepwise technique for cavernous sinus medial wall resection provides a reproducible framework for safe extension of endoscopic resection in functioning PitNETs. By utilizing the interdural plane and emphasizing key anatomical steps, the approach minimizes complications while improving the likelihood of biochemical remission. This method may serve as both a practical surgical strategy and an educational guide for neurosurgeons aiming to incorporate medial wall resection into their practice.