Tympanoplasty following Blast Injury

Abstract

Objectives To assess outcomes following tympanoplasty for blast-induced tympanic membrane perforations in a military population. Study Design Case series with chart review. Setting Tertiary care medical centers. Subjects and Methods Military personnel (N = 254) undergoing tympanoplasty for blast-related tympanic membrane perforations sustained between April 2005 and July 2014 were identified from the Expeditionary Medical Encounter Database. Descriptive statistics were obtained regarding demographics, primary and revision surgery success rates, hearing status pre- and postsurgery, and frequency of ossicular reconstruction. Rates of successful perforation closure were assessed against perforation size and character (central vs marginal) and time to surgery. Rates and types of complications were additionally explored. Results There were a total of 352 operations among 254 subjects, with an 82.1% rate of successful closure following primary surgery. For successful primary tympanoplasty, the mean improvement in pure tone average was 11.7 ± 12.1 dB. Ossiculoplasty was performed in 9.1% (32 of 352) of cases. There was no significant relationship between successful perforation closure and perforation size, perforation character, or time between injury and surgery. Cholesteatoma complicated 4.3% (15 of 352) of cases. A significant relationship was identified between risk of cholesteatoma development and increasing perforation size and marginal perforations. Conclusion Tympanoplasty success rates for blast-induced tympanic membrane perforations are lower than for other common injury mechanisms. Due to appreciable rates of postoperative cholesteatoma development, close clinical surveillance is recommended.

Pathological Mechanisms of Blast-Induced Cholesteatomas

“…In addition, it has remained controversial whether the onset of a BIC is related to perforation size and location. Some authors have suggested a significant relationship between the risk of cholesteatoma development and increasing perforation size, 2,5 but this relationship was not observed in other studies. Some studies have revealed that patients with marginal perforations had a higher risk of cholesteatoma, 2,5 while others have shown that a marginal perforation was not related to the onset of BIC.…”

“…Some authors have suggested a significant relationship between the risk of cholesteatoma development and increasing perforation size, 2,5 but this relationship was not observed in other studies. Some studies have revealed that patients with marginal perforations had a higher risk of cholesteatoma, 2,5 while others have shown that a marginal perforation was not related to the onset of BIC. 5,12 We presume that the onset of BIC is not related to the movement of microscopic fragments of epithelium, but that it is related to the wet middle ear environment.…”

“…Based on the current literature, when TM perforation and spontaneous healing occur after blast exposure, magnetic resonance imaging should be an integral component of clinical follow-up. Although some authors reported an incidence of BIC ranging from 4.3% to 11.7%, 2–5 and a few case reports have been published, 6–8 most published articles have not included information regarding the incidence of BICs in a larger group of patients with blast injury. 9–11 Thus, the relationship between cholesteatomas and blast injury is unclear in patients exposed to blasts.…”

Commentary on “Tympanoplasty following Blast Injury”

“…Funding source: None. We recently read the article entitled "Polypoid Change of the Middle Turbinate and Paranasal Sinus Polyposis Are Distinct Entities," by Brunner et al, 1 with great interest. They concluded that polypoid change of the middle turbinate (PCMT) is a unique physical finding with clinical associations that distinguish it from paranasal sinus polyposis and that PCMT has greater association with allergic rhinitis.…”

“…It was a pleasure for us to read the article titled "Otoacoustic Emissions in Rural Nicaragua: Cost Analysis and Implications for Newborn Hearing Screening," by Wong et al, 1 in your esteemed journal. It is a well-written article, and we commend the authors on their remarkable effort.…”