Factors of the blockage of ventilation tubes in the immediate postoperative period.

Postoperative ventilation tube (VT) blockage is relatively common with a reported incidence of 0.0-13.1%. The purpose of this study was to evaluate the factors that contribute to postoperative VT blockage. A retrospective chart review was carried out to compare rates of VT blockage within 2 weeks postsurgery. Analyzed factors included: otic drop, nature, and amount of middle ear (ME) effusion, presence of ME mucosa edema or granulation, bleeding during surgery, number of prior VT insertion, and the status of the tympanic membrane (TM). One hundred and twenty-eight ears from 79 patients were enrolled in this study. Eleven VTs (8.6%) were obstructed within 2 weeks postsurgery. Ears using ciprobay and tarivid otic drops showed a significantly higher rate of tube blockage (14.1%) compared to ears that were not exposed to otic drops (1.8%). Glue effusion caused the highest rates (14.8%) of tube blockage compared to mucoid (9.6%) and serous (3.0%) effusions. The amount of effusion, the presence of mucosal edema or granulation, bleeding during surgery, number of prior VT insertions and the status of the TM were not associated with postoperative VT blockage. The results of this study suggest that the routine use of antibiotic-containing otic drops after the insertion of VT may not be useful. Viscosity of the effusion appears to have an effect on the postoperative VT blockage. Thus, more attention should be focused on the ears with glue or mucoid effusions after surgery.