Diaphragma Sellotomy: A Safe Technique to Confirm Adequate Decompression of Optic Chiasm

Abstract

Optic chiasm decompression for preservation of vision is often the primary surgical goal for patients with pituitary tumors. Descent of the diaphragma sellae (DS) is an intraoperative surrogate marker of adequate chiasm decompression. DS may not always descend in an obvious or symmetrical manner, leaving uncertainty to whether the operation was successful. We propose a technique of intentionally incising the DS to ensure adequate chiasm decompression. Here we present patients with pituitary tumors who underwent transsphenoidal surgery and DS incision when the DS was not easily identified and/or did not descend. The approximately 3-mm incision under endoscopic guidance allowed for direct visualization of the suprasellar cistern and optic chiasm. Cerebrospinal fluid (CSF) leak was repaired using a nasoseptal flap in 4 cases, while intradural substitute and thrombin glue were utilized in another case. Five patients with pituitary macroadenomas (average size: 6.4 cm3) had endoscopic endonasal transsphenoidal resection. Vision improved in all cases postoperatively. There were no postoperative complications or CSF leaks at 1 year. Diaphragma sellotomy ensures chiasm decompression with minimal risk to the patient with current reconstructive techniques and without the need for intraoperative magnetic resonance imaging (iMRI) and reduction of the need for repeated surgical intervention.