Subannular ventilation tubes in the pediatric population: Clinical outcomes of over 1000 insertions

Objectives: Long-term transtympanic tube insertions for chronic middle ear disease are associated with high rates of complications. The objective of this study was to examine the clinical outcomes achieved with an alternate technique, the subannular tube insertion, by determining mean tube lifespan, cumulative incidence of post-operative events and complications, audiometric changes and risk factors associated with earlier tube extrusion in the pediatric population. Methods: A retrospective chart review of all patients operated for subannular tube insertion between January 2007 and 2013 was conducted in a single pediatric tertiary care center. Exploratory Cox regression analysis was performed to identify potential risk factors. Results: A total of 1014 tubes from 459 patients were included in the study. Mean subannular tube lifespan was 41.3 months with median time of 35.0 months. Cumulative incidence of post-operative events in decreasing frequency were otorrhea (21.7%), tube blockage (16.0%), tympanic membrane retraction (12.5%), otitis media with effusion (10.0%), acute otitis media (6.4%), perforation (4.6%) and cholesteatoma formation (1.1%). For patients with available pre- and post-operative audiograms, mean air-bone gap improved from 19.5 dB to 7.0 dB after subannular tube insertion (p < 0.01). Increasing age and previous subannular tube insertion carried hazard ratios of 1.029 (p < 0.01) and 1.749 (p < 0.01) for tube extrusion respectively, while craniofacial anomalies and concomitant tympanoplasty at the time of tube insertion had hazard ratios of 0.795 (p < 0.01) and 0.680 (p = 0.03). Conclusions: Subannular tube insertion appears to be a safe and effective alternate technique for middle ear ventilation in cases of intractable disease.