Retronasal and orthonasal olfactory ability after laryngectomy.

OBJECTIVE

To characterize orthonasal and retronasal olfactory ability in patients who have had a total laryngectomy (TL).

DESIGN

Prospective psychophysical evaluation of orthonasal and retronasal olfactory function.

SETTING

Academic center outpatient clinic.

PATIENTS: Volunteer sample of 36 subjects who underwent laryngectomy 0.5 to 25.0 years after TL (median, 3.5 years) and 36 age-, sex-, and smoking history-matched controls.

MAIN OUTCOME MEASURES: Scores on established psychophysical tests of orthonasal and retronasal olfaction and self-rating scores of smell assessed with a visual analog scale.

RESULTS

Assessment of orthonasal olfactory ability yielded a mean composite score of 4.3 (maximum score, 7) for the TL group and 5.3 for the control group (P = .002). Evaluation of retronasal olfactory ability resulted in a mean score of 11.0 (maximum score, 20) for the TL group vs 14.3 for the control group (P<.001). The mean self-rating scores of smell were 2.9 and 6.6 (maximum score, 10) for the TL and control groups, respectively (P<.001). Self-ratings of smell positively correlated with orthonasal (r(S) = 0.42; P<.001) and retronasal (r(S) = 0.50; P<.001) olfactory ability.

CONCLUSIONS

Laryngectomy is associated with measurable decreases in olfactory function that are also subjectively perceived. Quantification of decrements in orthonasal and retronasal olfactory function can be used to characterize the severity of hyposmia and to assess the potential for, and efficacy of, olfactory rehabilitation. Although self-assessment with a simple visual analog scale successfully identifies many laryngectomy patients who have objective evidence of olfactory dysfunction, further investigation is necessary to evaluate and compare its validity and reliability with other available survey instruments that purport to measure olfaction.