The role of obliteration in the achievement of a dry mastoid bowl

Objective: To evaluate the impact of mastoid obliteration on the achievement of a dry mastoid bowl and frequency of maintenance care. Study Design: Retrospective chart review. Setting: Academic medical center. Patients: There were 63 canal-wall-down mastoidectomies for chronic otitis media with or without cholesteatoma between 2007 and 2014 with follow-up of at least 6 months. Eighteen mastoids were nonobliterated and 45 were obliterated. Thirteen underwent secondary obliteration of existing mastoid bowls with chronic drainage, whereas 32 underwent primary obliteration at the original canal-wall-down procedure. Intervention: Mastoid obliteration. Main Outcome Measures: Achievement of a dry healed mastoid cavity and frequency of outpatient visits. Results: In more than 80% of the cases, a dry ear was achieved, with no significant difference between the obliterated and nonobliterated cases (p=0.786). Eleven of the 13 secondary cases experienced cessation of otorrhea, achieving dry ears at rates similar to that of the primary and nonobliterated cases. The secondary obliteration population was also significantly younger than the primary group (22.1 versus 43.5 years, p=0.002). Multivariable-mixed effects analysis demonstrated a reduction in 0.1 visits per 6-month period following surgery overtime (p<0.001). Conclusions: Mastoid obliteration may be valuable in the management of the well-developed and chronically wet mastoid cavity, particularly when the drainage emanates from mucosal disease or cell tracts in a deep sinodural angle. Younger patients may require secondary obliteration because of continued craniofacial maturation several years following canal-wall-down surgery.