Systematic review of olfactory outcomes after nasoseptal flap harvest for endoscopic skull base surgery: Does using cold steel or olfactory strip preservation matter?

Abstract

Background: Several studies have described techniques aimed at mitigating olfactory dysfunction after nasoseptal flap (NSF) harvest for endoscopic skull base surgery (ESBS). No consensus exists as to whether popular methods including using cold steel (CS) versus electrocautery (EC) or septal olfactory strip (SOS) preservation offer an advantage. This systematic review was performed to examine the impact of these two technical variations of NSF harvest on postoperative olfactory outcomes.Methods: Following PRISMA guidelines, PubMed, Scopus, and Web of Science were searched for articles reporting olfactory outcomes in ESBS cases employing an NSF. Original articles focusing on technique variations of the NSF and reporting at least one objective olfactory measure were included. Results: Nine studies comprising 610 patients were included. Various, olfactory testing outcomes were reported, and postoperative follow-up ranged from 6 weeks to 12 months. Three studies, including a randomized controlled trial, compared the use of CS and EC for the superior incision of the NSF. No significant difference was found in objective olfactory function (p > 0.05) when comparing these techniques. Five studies comprising 504 patients reported results from SOS-sparing. SOS-sparing technique in NSF harvest demonstrated smell preservation in the postoperative setting when compared with preoperative measures (p > 0.05); however, no direct comparison to non-SOS-sparing techniques was made. Conclusion:The use of CS as opposed to EC for the superior NSF incision does not appear to confer an advantage in preserving postoperative olfactory function (grade B evidence). SOS preservation may be associated with better olfactory outcomes in NSF harvest (grade C evidence).

The Arterial Pattern of the Upper Nasal Septum (S‐Point) and Potential Role in Severe Epistaxis

“…This may be related to the findings of a cadaveric study that well described that the olfactory fibers present greater distribution in superior and middle turbinates than the superior portion of the nasal septum mucosa. Besides that, the anterior half of the superior nasal septum, in which the S‐point area is contained, presents a lower number of olfactory fibers than the posterior half of the superior nasal septum among the cribriform plate 20,21 …”

“…Besides that, the anterior half of the superior nasal septum, in which the S-point area is contained, presents a lower number of olfactory fibers than the posterior half of the superior nasal septum among the cribriform plate. 20,21 A recent review collected data pointed that the isolated electrocauterization of bleeding site may be a promising treatment for refractory severe epistaxis. 22 We believe that isolated cauterization of the SPA can resolve a reasonable number of severe epistaxis cases from the S-point.…”