Air space reduction tympanomastoidectomy repairs difficult perforations more reliably than tympanoplasty.

Abstract

Air space reduction tympanomastoidectomy improves outcomes over tympanoplasty in repairing tympanic membrane perforations in the presence of unfavorable risk factors. Retrospective review of 67 subjects' 87 operations. Interventions were tympanoplasty versus air space reduction tympanomastoidectomy. Risk factors were contracted mastoid air cells, previous failed operations, descent from the indigenous peoples of the Americas, and middle/ear mastoid volumes l<3 CC. Favorable outcomes were closure of the perforation, no decline in hearing, and creation of a self-cleaning mastoid bowl. Five out of 46 air space reduction tympanomastoidectomies failed to close their perforations (11%). Pure-tone threshold (PTA) worsened in 13/46 ears (28%). Four of 46 required mastoid bowl cleaning (9%). In contrast, 21 of 41 tympanoplasties failed to close (51%). PTA worsened in 9/34 ears (26%). All four tympanoplasty failures treated with an air space reduction tympanomastoidectomy closed. Three of the seven tympanoplasty failures treated with a second tympanoplasty did not close. Statistical analysis found two risk factors more prevalent among the air space reduction tympanomastoidectomies: contracted mastoids (P = .019) and middle ear volumes <3 CC (P = .0001). Increased closure of perforations occurring after the air space reduction tympanomastoidectomy was also statistically significant (P = .0002). Descendants of indigenous peoples of the Americas trended toward better PTAs after their air space reduction tympanomastoidectomies than their tympanoplasties and showed statistically significant increases in closure of perforation (P = .0046). Air space reduction tympanomastoidectomy is an effective and safe method for closing tympanic membrane perforations.