“Benefits of the pedicled osteoplastic flap as a surgical approach of mastoidectomy in cochlear implant surgery”

Abstract

Objective To evaluate the esthetic and functional results of an osteoplastic flap for mastoid cavity closure in cochlear implant surgery. Study design Double-blind, prospective, randomized clinical trial. Setting: tertiary referral center. Intervention(s) On hundred and twenty-six patients were randomized in 2 groups for cochlear implant surgery. Cases ( n : 63) underwent simple mastoidectomy using an anteriorly pedicled osteoplastic flap for mastoid closure. In controls ( n : 63), a traditional periosteal flap was used. Evaluation with the POSAS questionnaire was performed 1 year after surgery to assess surgical wound esthetics. Sixteen patients from each group had postoperative CT-scans and wideband tympanometry to assess mastoid aeration and middle ear absorbance. Gender and time after surgery were correlated. Main outcome measure(s) Evaluation of the quality of the surgical wound with the application of a questionnaire validated in the medical literature and translated into Portuguese language called POSAS, considering the perception of the blinded patient and doctor regarding the surgical technique proceeded. A lower POSAS score suggests better esthetics of the surgical wound. Secondary outcomes are volumetric measurement of aeration inside mastoid cavity using 3D computer tomography exam, which aims to analyze the influence of fibrocicatricial retraction in the surgical wound into the mastoid and the interference of its aeration volume in the absorption of sound in the middle ear, using the wideband tympanometry exam. Results The POSAS questionnaire in the Case group showed a lower level of local pain and itchiness, a skin color and thickness more similar to the surrounding skin and less irregularity and stiffness, with no influence from time after surgery and gender compared to the Control group. The median tomographic volume was 6.37 cc in the cases and 4.60 cc in controls. Wideband tympanometry showed general smaller sound absorbance in the Case group results, specially, at 1000 Hz frequency. No intraoperative or postoperative complications were observed with the osteoplastic flap. Conclusions This technique is an effective and safe alternative to alleviate common problems of mastoid surgery for cochlear implantation. In addition to esthetic benefits, it has less interference in middle ear physiology of sound absorbance and less fibrous tissue into the mastoid cavity during the follow-up of more than 1 year. Supplementary Information The online version contains supplementary material available at 10.1007/s00405-021-06907-1.