Curr Opin Otolaryngol Head Neck Surg. 2012 Feb;20(1):29-32. doi: 10.1097/MOO.0b013e32834dfb3d.

Olfactory improvement after endoscopic sinus surgery.

Rudmik L1, Smith T 2


Olfactory dysfunction is a common complaint in patients with chronic rhinosinusitis (CRS). The purpose of this article is to review the current evidence on the impact of endoscopic sinus surgery (ESS) on CRS-related olfactory dysfunction.


The recent literature suggests that olfactory outcomes after ESS are challenging to predict. Some evidence supports a positive impact of ESS on improving olfactory outcomes in patients with preoperative nasal polyposis and anosmia. However, despite improvements in smell, most of these patients remain with severe hyposmia. One study suggests ESS has no impact on olfactory outcomes.


CRS-related olfactory dysfunction is a complex clinical scenario and it is challenging to predict improvement following ESS. CRS patients with anosmia and nasal polyposis preoperatively may have a higher likelihood of olfactory improvement following ESS.

PMID: 22143338 [PubMed - indexed for MEDLINE] PMCID: PMC3343214

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From the article

Early studies supported the role of ESS to improve CRS-related olfactory dysfunction. However, several recent larger prospective studies have improved our understanding of the impact of ESS on CRS-related olfactory dysfunction and have begun to elucidate the predictive factors associated with olfactory improvement.

In 2009, Litvack et al. reported a prospective trial of 111 patients with olfactory impairment undergoing ESS for medically refractory CRS.

Absolute SIT scores were categorized into olfactory severity categories based on robust gender-adjusted, normative data

The results demonstrated that olfactory impairment

The improvements for anosmic patients were stable after 1 year follow-up.

They hypothesized that

The only predictive factor for post-ESS olfactory improvement was the presence of nasal polyposis.

Factors such as

were not predictive factors.

A large prospective 2008 study by Pade et al. evaluated 206 patients with olfactory impairment who elected ESS for CRS. They demonstrated that

The results suggested that the presence of nasal polyposis and eosinophilia predicted olfactory improvement

In contrast to the above studies, a recent 2008 study by Jiang et al. evaluated the impact of ESS on olfactory outcomes in patients with medically refractory CRS.

In a subsequent 2009 article by Jiang et al. they attempted to identify predictive factors for olfactory improvement following ESS. The results demonstrated no predicative correlation between olfactory improvement following ESS and the

In 2010, Soler et al. evaluated the impact of histologic markers on olfactory outcomes following ESS.

This suggests that most patients with CRS and olfactory impairment suffer from some form of permanent neuroepithelial injury.

The evidence suggests that

Future research will need to further investigate the role of histologic markers as predictive factors in olfactory improvement following ESS.


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Otolaryngol Head Neck Surg. 2009 Mar;140(3):312-9. doi: 10.1016/j.otohns.2008.12.006.

Does olfactory function improve after endoscopic sinus surgery?

Litvack JR1, Mace J, Smith TL.

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To examine the impact of endoscopic sinus surgery (ESS) on olfactory impairment in patients with chronic rhinosinusitis (CRS) over intermediate and long-term follow-up. We hypothesized that patients with mild olfactory dysfunction (hyposmia) would benefit from ESS, whereas patients with severe olfactory dysfunction (anosmia) would not.


Prospective, multi-institutional cohort study.


A total of 111 patients presenting for ESS for treatment of CRS were examined preoperatively, and at 6 and 12 months postoperatively. Demographic, comorbidity, and Smell Identification Test (SIT) data were collected at each time point. Univariate and multivariate analyses were performed.


The prevalence of gender-adjusted olfactory dysfunction prior to surgery was 67.5 percent.


Improvement was sustained at 12-month follow-up (21.7 +/- 10.7; P = 0.001). Multivariate linear regression analysis showed that baseline olfactory category and nasal polyposis were significantly associated with improvement in postoperative olfactory function (P = 0.035, P = 0.002).


Contrary to our hypotheses, patients with severe olfactory dysfunction significantly improved after ESS and sustained improvement over time, whereas patients with mild olfactory dysfunction did not.

Comment in

PMID: 19248934 [PubMed - indexed for MEDLINE] PMCID: PMC2668517

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From the Discussion

In contrast to our initial hypothesis, we found that anosmic patients improved after ESS whereas hyposmic patients did not.

Interestingly, this interaction between nasal polyposis and other variables in CRS and olfactory outcomes studies has been noted by us and others in prior studies.6,19 The potential for nasal polyposis to interact with other variables should be addressed in the analyses of outcomes data and should be investigated in future studies.

Table I

Patients' baseline demographic data and clinical characteristics by olfactory status (n=111).

Normosmics (n=36) Hyposmics (n=56) Anosmics (n=19) p-value

Age (mean SD) 42.2 13.2 50.2 15.3 50.9 13.1 0.028

Gender %(n)

Male 44.4% (16) 46.4% (26) 47.4% (9)

Female 55.6% (20) 53.6% (30) 52.6% (10) 0.974

Clinical characteristics %(n)

Nasal polyposis 27.8% (10) 28.6% (16) 73.7% (14) 0.001

Asthma 38.9% (14) 30.4% (17) 73.7% (14) 0.004

Aspirin intolerance 2.8% (1) 7.1% (4) 26.3% (5) 0.012

Allergic rhinitis 30.6% (11) 26.8% (15) 5.3% (1) 0.096

Septal deviation 33.3% (12) 30.4% (17) 10.5% (2) 0.170

Hypertrophy turbinate 8.3% (3) 8.9% (5) 5.3% (1) 0.878

Prior sinus surgery 52.8% (19) 66.1% (37) 63.2% (12) 0.435

Smoker 5.6% (2) 5.4% (3) 0(0) 0.582

Medication Usage %(n)

Systemic 19.4% (7) 23.2% (13) 31.6% (6) 0.599


Disease Severity Measures (mean SD)


CT scores 10.1 6.0 11.8 6.4 18.4 5.0 <0.001


endoscopy score 5.1 5.0 6.1 4.4 9.4 5.0 0.006

Table II

Olfactory scores in patients with and without topical corticosteroid use

Topical corticosteroid use No topical corticosteroid use p-value

Normosmic (mean SD)

Preoperative 35.8 1.5 (n=23) 35.7 1.1 (n=13) 0.974

12 month postoperative 34.8 3.2 (n=27) 34.0 4.8 (n=9) 0.886

Hyposmic (mean SD)

Preoperative 28.3 4.8 (n=35) 29.7 3.9 (n=21) 0.336

12 month postoperative 29.3 6.1 (n=43) 29.8 6.5 (n=13) 0.460

Anosmic (mean SD)

Preoperative 10.0 2.1(n=12) 9.1 1.8 (n=7) 0.384

12 month postoperative 22.6 10.2 (n=17) 20.3 12.2 (n=2) 0.421


Am J Rhinol Allergy. 2013 Jul-Aug;27(4):e96-100. doi: 10.2500/ajra.2013.27.3939.

Objective olfactory outcomes after revision endoscopic sinus surgery.

Hsu CY1, Wang YP, Shen PH, Weitzel EK, Lai JT, Wormald PJ.



Patients who suffer from hyposmia and anosmia report a negative effect on their overall quality of life. Smell disturbance of patients with chronic rhinosinusitis (CRS) can improve after endoscopic sinus surgery (ESS). Although several studies have shown that 50-83% of patients may notice an improvement in olfactory function after ESS, the olfactory improvement after revision ESS (RESS), especially by objective measurements, is still lacking.


Olfactory function was assessed by the traditional Chinese version of the University of Pennsylvania Smell Identification Test (UPSIT-TC, forced choice, score range 0 - 40) preoperatively and postoperatively, recorded as smell identification test (SIT) score. Olfactory outcomes from anosmia to hyposmia/normosmia, or from hyposmia to normosmia, were considered as "improvement." Postoperative assessments were divided into two periods: period 1 (P1) is defined as >6 but <12 months postoperatively; period 2 (P2) is defined as >12 but <24 months postoperatively.


32 patients with smell disturbance preoperatively (period 0 [P0]) and confirmed by UPSIT-TC were enrolled into this study.

The presence of

The overall improvement rates were


RESS resulted in objective evidence of olfactory improvement in approximately one-half of our cohort over 16 months of follow-up and offers a treatment option for an otherwise poor prognosis condition.

PMID: 23883800 [PubMed - indexed for MEDLINE]


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