This study was conducted in the Department of Otorhinolaryngology Head and Neck Surgery, University Hospitals, in the period from February 2018 to January 2020. The study included adult patients (> 18 years) who had bilateral NP. Syndromic patient, nasopharyngeal masses (including antrochoanal polyp), and previous nasal surgery or ventilation tube insertion were excluded.
Thorough history taking (including the duration of the NP), otorhinolaryngology examination (including otoscopic ear examination), and routine laboratory tests (to exclude systemic disease associated with NP) were performed. Any associated acute infection was properly treated first.
Tympanometry was done using MADSEN Zodiac 901 tabletop tympanometer from Otometrics Copenhagen.
Staging of NP
The tridimensional staging of de Sousa et al.  was used: the endoscopic evaluations were carried out by one single examiner, with a 4-mm sinuscope.
The examination started in the right nasal cavity, inspecting its floor, all the way to the choana. Whenever possible, we visualized the spheno-ethmoidal recess, then the middle meatus and the superior region of the nasal cavities, trying to see the NP in the three planes.
After doing all the examinations, they were copied to a single DVD disk, of which copies were made and handed over to the other two examiners simultaneously.
This staging provides information on the location of the NP within the nasal cavity in the three dimensions of the space; in the horizontal, vertical, and anteroposterior planes.
In the horizontal plane (H), polyps were classified as follows:
H1—Polyps restricted to the middle meatus
H2—Polyps expand beyond the middle meatus, without touching the nasal septum.
HT—Polyps expand beyond the middle meatus and touch the septum.
In the vertical plane (V), the polyps were classified as follows:
V1—Polyps in the middle meatus only
VI—Polyps extending inferiorly to the middle meatus, going beyond the upper border of the inferior turbinate
VSPolyps extending superiorly to the middle meatus, between the septum and the middle turbinate
VTPolyps occupying the entire vertical aspect of the nasal cavity
In the anteroposterior plane (P), the polyps were classified as follows:
P1Polyps in the middle meatus only
PAPolyps extending anteriorly to the middle meatus, reaching the head of the inferior turbinate
PPPolyps extending posterior to the middle meatus, reaching the tail of the inferior and middle turbinate
PTPolyps occupying the entire anteroposterior aspect of the nasal cavity
Diagnosis of ET function
Tympanometric examinations were performed 1 day before endoscopic staging. The tympanometric results were distinguished into 3 grades  as classified by Jerger  and modified by Poulsen and Tos ; type A, normal curve (pressure +50/−90 daPa); type C (negative pressure); and type B (flat curve). The diagnosis of otitis media with effusion (OME) was considered in type B, also, in cases with enlarged tympanogram width (wide tympanogram) or reduced tympanogram gradient which were considered stages of development or resolving of OME whether associated with type A or type C tympanograms [9,10,11,12].
Tympanometry was done twice in a sweep procedure allowing the examiner to compare the second sweep and measure the pressure difference if any. The second tympanogram was done after the patient was instructed to create an over-pressure (positive pressure) in the middle ear by closing the mouth, holding the nose, and blowing to create the over-pressure in the throat, then swallowing was done to open the ET. Opening the tube was achieved by instructing the patient to drink a glass of water, relieving the positive pressure if the ET Function was normal. The sweep following Valsalva was more positive and the one following swallowing was more negative compared to the original one if the ET was properly functioning.
Comparison between data of preoperative and postoperative evaluations was done by v2 test (version 17, SPSS Statistical Package for Social Sciences; SPSS, Inc., Chicago, IL). P < 0.05 was considered significant.