How acute is postoperative olfactory function after sinus surgery for chronic rhinosinusitis (CRS) with (CRSwNP) and without (CRSsNP) polyps?
Olfaction can be improved by sinus surgery in about every second patient, especially if the patient had CRSwP, was anosmic, and had no prior surgery. A deterioration of sense of smell after surgery is rare.
Background: CRSwNP represents about a third of all patients undergoing surgery for the disease. Whereas many studies report on the positive effects of nasal sinus surgery on patients’ symptoms, quality of life, and nasal endoscopy, only limited data are available on the effect of sinus surgery on olfaction, and olfactory impairment value in CRS patients is often underestimated.
Study design: Literature review of 24 studies published through June 2018, comprising 1,956 patients (959 CRSwNP, 516 CRSsNP).
Setting: PubMed database.
Synopsis: The more sophisticated the olfactory test, the higher the percentage of impairment: Studies that used more than one modality showed impairment rates from 72% to 100%. The main distinguishing factor for a positive outcome in these studies was the presence of polyps, revision versus primary surgery, or anosmia versus hyposmia preoperatively. Of the 11 studies that described the grouped results of CRSwNP and CRSsNP, only four saw an improvement in olfaction in both groups, while seven reported improvement only in the CRSwNP group.
In three studies, previous surgery was not associated with a reduced outcome in olfaction recovery; in one, revision surgery showed a trend of improved outcome compared to the first surgery. Anosmia presence led to an improvement in sense of smell after surgery. In studies describing short-term results, a significant improvement in test scores for olfaction was described after only two or four weeks. In patients with CRSwNP, a continual improvement over time was traced until six months after surgery. Patients that showed olfaction improvement after surgery range from 19% to 74%. Olfaction deterioration was likely in 0% to 10% of patients.
Citation: Haxel BR. Recovery of olfaction after sinus surgery for chronic rhinosinusitis: a review. Laryngoscope. 2019;129:1053-1059.