Esterified Hyaluronic Acid Placed in the Middle Ear Does Not Improve Outcomes in Cholesteatoma Surgery

BACKGROUND: The aim of this article is to assess the efficacy of esterified hyaluronic acid as a barrier to formation of adhesions and improvement of tympanomastoid ventilation. METHODS: A prospective cohort analysis was performed at a tertiary referral centre. 126 ears were analysed in children with cholesteatoma. Esterified hyaluronic acid was placed on the promontory of 63 ears at primary canal wall intact surgery for cholesteatoma. No esterified hyaluronic acid was used in 63 control ears. Cholesteatoma recurrence, histopathological analysis of scar tissue following second-stage procedure, and middle ear pressure were the main outcome measures. RESULTS: At 5 years, esterified hyaluronic acid (7%) and non-esterified hyaluronic acid (10%) did not differ in cholesteatoma recurrence (KaplanMeier log rank analysis, P= .52). Esterified hyaluronic acid (n =11) and non-esterified hyaluronic acid (n = 2) ears formed scar at the site of packing material (n =11) (Fisher's exact test, P = .04). Foamy histiocytes/macrophages were found in esterified hyaluronic acid (n = 15) and non-esterified hyaluronic acid ears (n =1) (Fisher's exact test, P <.001). Middle ear pressure was measurable in 32/43 (74%) esterified hyaluronic acid ears and 36/52 (69%) non-esterified hyaluronic acid ears (P = .58, chi-square test). Median post-operative middle ear pressure in esterified hyaluronic acid (-115.0 daPa) and non-esterified hyaluronic acid ears (-85 daPa) did not differ significantly (Mann-Whitney U-test, -30.0 daPa, P = .33). Middle ear pressure was normal (> -125 daPa) in 44% (14/32) esterified hyaluronic acid ears and 42% (15/36) non-esterified hyaluronic acid ears (P = 1.0, Fisher's exact test). CONCLUSIONS: We have discontinued the use of esterified hyaluronic acid in cholesteatoma surgery due to lack of detectable benefit. Esterified hyaluronic acid in the middle ear neither reduces cholesteatoma recurrence nor appears to improve the ventilation of the middle ear. Furthermore, esterified hyaluronic acid alters the inflammatory process within the middle ear, the significance of which remains unclear.