Deliberate Design of the Posterior Septectomy during Transsphenoidal Endoscopic Skull Base Surgery to Harvest Septal Tissue for Potential Skull Base Reconstruction

Background: The use of autologous free bone and mucosal grafts in reconstructing small skull base defects not requiring the nasoseptal flap is well described. A posterior septectomy is routinely performed during transsphenoidal endoscopic skull base surgery. However, formal planning of the septectomy to harvest septal tissue (free mucosal and bone grafts) for skull base reconstruction has not been described.

Objective: The purpose of this study is to describe a modified technique of posterior septectomy with septal tissue harvest for skull base reconstruction.

Study Design: Surgical technique modification was examined.

Methods: We describe our modified technique during transsphenoidal skull base approaches. A nasoseptal flap is not routinely harvested at the outset. Instead, prior to sphenoidotomy, the pedicle is preserved by incising the anterior sphenoid face mucosa inferior to the ostium and reflecting it inferiorly. The septectomy is planned next, primarily based on required exposure. Within limits, it can be enlarged to harvest larger grafts. The anterior margin is cut, usually 1–1.5 cm, from the sphenoid rostrum, but may extend to the anterior aspect of the middle turbinate. The inferior border is level with the sphenoid floor, preserving the nasoseptal flap pedicle. Superiorly, the limb is cut below the sphenoid roof, preserving olfactory epithelium. A needle tip Bovie is used for septectomy, cutting through mucosa, bone and contralateral mucosa. The posterior attachment to the sphenoid rostrum is then carefully detached. Septectomy in this fashion yields trilaminar septal tissue harvested en bloc (two free mucosal grafts and one free bone graft, approximately 1–2 × 1–2cm in size). Small sellar defects can be repaired with this bone, and mucosal grafts can be used to line the sphenoid, bone graft, or an exposed carotid artery to assist with early mucosalization.

Conclusions: A simple modification, with deliberate planning of the posterior septectomy and harvest of septal tissue, expands skull base reconstructive options. Free mucosal and bone grafts can be obtained without adding additional morbidity to transsphenoidal endoscopic skull base surgery. It can potentially be used for cases without large defects or high-pressure high-volume CSF leaks, sparing the need for nasoseptal flap or other grafts. With this modification, a nasoseptal flap can still be harvested for reconstruction if needed.