Introduction: The use of autologous free bone and mucosal grafts in reconstructing small skull base defects not requiring the naso-septal flap is well described. A posterior septectomy is routinely performed during transsphenoidal endoscopic skull base surgery. However, deliberate planning of the septectomy to harvest septal tissue (free mucosal and bone grafts) for skull base reconstruction has not been formally described.
Methods: During transsphenoidal approaches, a naso-septal flap is not routinely harvested at the outset. Instead, prior to sphenoidotomy, the pedicle is preserved by incising the anterior sphenoid face mucosa at the level of the superior border of the naso-septal flap pedicle, and reflecting it inferiorly. The anterior margin of the septectomy is cut usually 1.5cm from the sphenoid rostrum; this can be extended to the anterior middle turbinate border for suprasellar exposure. The inferior border is level with the sphenoid floor, preserving the naso-septal flap pedicle. Superiorly, the septectomy is planned below the sphenoid roof to preserve olfactory epithelium. A needle tip bovie is used, 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 that can harvested en-bloc. Two square or rectangular free mucosal grafts and one free bone graft can now be separated, approximately 1-2 cm in size. Small sellar defects can be repaired with this bone, and mucosal grafts can be used to line the sphenoid or bone graft to assist with early mucosalization.
Results: Deliberate planning of the posterior septectomy and mindful harvest of the septal tissue, expands skull base reconstructive options.
Conclusions: Using a properly planned septectomy, free mucosal and bone grafts can be obtained without adding additional morbidity to the procedure. It may spare the need for naso-septal flaps in cases without large defects or high-pressure, high-volume CSF leaks.
Patient Care: By using a properly planned septectomy, surgeons will be able to obtain critical tissue for reconstructing the skull base thus hopefully obviating the need for aggressive flaps or separate insisions to harvest tissue from the abdomen or thigh for selected cases.
Learning Objectives: By the conclusion of this session, participants should be able to: 1) Describe the importance of properly planning the septectomy for transphenoidal approaches, 2) Discuss in detail, in small groups,the surgical technique employed, and 3) Recognize the importance of septal tissue harvest for reconstructive skull base options.