Bilateral Mucosal and Septal Olfactory Strip (SOS) Preserving “Rescue” Flaps: A Novel Vascular Pedicle Saving Technique for Endonasal Endoscopic Skull Base Surgery

Abstract

Background: The Hadad-Bassagasteguy nasoseptal flap (NSF) has reduced the incidence of postoperative cerebrospinal fluid (CSF) leaks in endonasal endoscopic skull base surgery. However, in our experience, although an NSF is typically used in extended approaches with a large dural opening and a grade 3 CSF leak, it is rarely needed for smaller dural defects (grades 1 and 2 CSF leaks) encountered in the removal of more common sellar lesions such as pituitary adenomas and Rathke’s cleft cysts. In the traditional endonasal approach, the vascular pedicle that would supply an NSF is sometimes sacrificed during the sphenoidotomy, thus eliminating the flap as a potential reconstruction option should a large CSF leak be encountered. A unilateral “rescue” flap, preserving the sphenopalatine artery on one side, which allows it to be available for the potential elevation of an NSF should it become necessary, has previously been described. In this series, we introduce the concept of bilateral mucosal and septal olfactory strip (SOS) preserving “rescue” flaps for use in the majority of endonasal endoscopic cases in which an NSF is not expected to be needed. In addition to protecting the bilateral vascular pedicles for future use, this technique also preserves more nasal-septal mucosa including the bilateral septal olfactory strip (SOS flap), promotes more rapid healing, and potentially reduces the incidence of postoperative sphenopalatine artery epistaxis and anosmia.