Clinical value of olfactory function tests after endoscopic sinus surgery: a short-term result

Functional endoscopic sinus surgery (FESS) is now the surgical procedure of choice for treating chronic sinusitis in patients of all ages. We performed the olfactory function test before and after FESS and assessed its clinical value. From February 1996 through July 1996, 50 bilateral sinusitis patients had received FESS, butanol threshold test, and odor identification test, performed preoperatively, at postoperative 1 month, and at postoperative 2 months. We analyzed preoperative computed tomography to determine the grade of sinusitis and status of the olfactory cleft. The status of the olfactory cleft significantly influenced the preoperative olfactory threshold score (p < 0.001). At 2 months postoperatively, the subjective symptoms of the patients were improved in 96% and objective olfactory threshold were improved in 68% of patients. There was no correlation between subjective symptoms and olfactory threshold improvement. Our study suggests that the olfactory threshold test may help predict the result of FESS, but for more accurate and reliable assessment, we should consider other objective methods like anterior rhinomanometry, acoustic rhinometry, ciliary beat frequency, and postoperative endoscopic findings.