Recovery of olfaction after sinus surgery for chronic rhinosinusitis: A review

Abstract

Objective Investigation of the postoperative olfactory function after sinus surgery for chronic rhinosinusitis (CRS) with and without polyps in a review. Data Sources PubMed. Review Methods A comprehensive literature search was conducted through June 2018 using relevant keywords. The titles/abstracts were reviewed to identify studies evaluating the sense of smell in CRS‐patients pre‐ and postoperatively by either using the whole or parts of the University of Pennsylvania Smell Identification Test or the Sniffin’ Sticks test. Study characteristics and outcome data of the included studies were extracted. Results In total, 106 studies were retrieved. Twenty‐four studies comprising 1,956 patients were included after quality assessment. The number of patients investigated per study was 19 to 206. In the 24 studies, 959 patients with nasal polyps and 516 without nasal polyps were described. The follow‐up times varied between 0.5 and 28 months. Twenty‐three studies reported an improved sense of smell, at least in certain subgroups. An overall improvement was seen in approximately 50% of the included patients. Nasal polyposis and preoperative anosmia were associated with a higher chance of improvement in olfaction. In those studies that commented on deterioration after sinus surgery, a decrease in olfaction was found in a range from 0% to 10% of cases. Conclusion Olfaction can be improved by sinus surgery in about every second patient, especially if the patient had chronic rhinosinusitis with polyps, was anosmic, and had no prior surgery. A deterioration of sense of smell after surgery is rare. Laryngoscope, 129:1053–1059, 2019

The sense of smell in chronic rhinosinusitis

“…Other therapies such as antileukotrienes, corticosteroid sinus implants, or aspirin desensitization have also been shown to improve smell loss in patients with CRS. Because recent studies have demonstrated a poor middle-to long-term efficacy of endoscopic sinus surgery in smell loss, the role of CRS surgery in improving the sense of smell, apart from the effect of first surgeries, 8 remains under debate and should not be used as the unique indication criteria for CRS surgery.…”

Reversibility of mucociliary clearance and olfaction impairment following endoscopic sinus surgery: a prospective observational study

“…Various studies, including systematic reviews, have shown improvements in olfaction following FESS, as in the current study. 3,12,26,27 The added gains in chronic rhinosinusitis with nasal polyps patients may again be due to the removal of the obstructive pathology. However, reports have also shown a lack of olfactory improvement after FESS, 28 with no predictive correlation to the severity of chronic rhinosinusitis, presence of nasal polyps or allergy status.…”

Olfactory Function After Surgical Treatment of CRS: A Comparison of CRS Patients to Healthy Controls

“…Olfactory dysfunction is a "cardinal" symptom in CRS and affects the majority of patients with this disease. 7,8 Furthermore, patients identify OD as one of the top three most important symptoms in which they would like to see post-treatment improvement. 17 Prior work suggests that some amount of the OD seen in patient with CRS may be related to non-CRS factors such as age and medical comorbidity.…”

“…18 While ESS improves olfaction for certain patients, the results can be unpredictable and difficult to counsel patients surrounding post-operative expectation. 8 One primary limitation evident within the available literature on this subject is the lack of comparisons of OD in healthy, control populations. As such, previous findings of olfactory outcomes after ESS may be confounded by the fact that OD is multi-factorial and that some patients with CRS suffer from levels of OD similar to normative data.…”

“…8,10 While ESS improves OD for many patients, a proportion of patients have a degree of persistent OD postoperatively. 8 It is currently unknown if this residual OD is related to CRS, potentially from on-going sinonasal inflammation or permanent damage to the olfactory epithelium or if it is related to non-CRS factors such as aging. Further limiting our understanding of the prevalence, incident rates, and causes of persistent postoperative OD is the fact that existing studies on olfactory improvement following ESS have not incorporated control populations to aid in determinations of relative risk measures associated with CRS.…”