Prevalence of nasal polyps in Northern Portugal: a cadaver endoscopic study

Epidemiological studies on chronic rhinosinusitis with nasal polyps are scarce and mostly based on questionnaires. Data obtained with such approaches can be unreliable, thus endoscopy is a prerequisite for an accurate estimate of the prevalence of nasal polyps. The objective of this study was to establish the frequency of nasal polyps in Northern Portugal, using nasal endoscopy in cadavers from a District Hospital.

The cadaver specimens deposited in the mortuary room of the hospital, every early morning on week days, from December 2012 to August 2013, were submitted to a systematic endoscopic examination of both nasal cavities, using a 25°, 2.y mm rigid endoscope from R.Wolf®. A review of the medical record of the cadavers was done, to search for cause of death, co-morbidities and past ENT history.

A group of 200 consecutive Caucasian cadaver specimens were analyzed, 83 women and 117 men, with a mean age of death of 77.23 ± 12.29 years (range 34-97). The prevalence of nasal polyps was 5.5% (95% confidence interval, 2.34-8.66). No statistically significant association between the studied clinical variables (sex, allergic rhinitis, lower respiratory diseases and smoking) and the presence of nasal polyps was identified.

The study provides the first endoscopic based epidemiological data on nasal polyps in Portugal, showing a prevalence for old age group in accordance with previous studies in Europe.