Canalplasty using underwater bone drilling in transcanal endoscopic myringoplasty for patients with a narrow external auditory canal

Background Canalplasty is important in microscopic ear surgery, but it has rarely been studied in otoendoscopic surgery.Objectives The aim of this study was to investigate the application of canalplasty due to external auditory canal stenosis caused by bony bulges in endoscopic myringoplasty.Materials and methods The procedures and effects of canalplasties and myringoplasties were analysed. During the canalplasties, depending on the location of the bulges, the meatal skin flaps were elevated in different manners, and the underwater bone drilling technique was adopted to remove the bulges to enlarge the osseous canals.Results Canalplasties were performed in 18.5% (33/178) of myringoplasties. All surgeries were completed exclusively via the transcanal endoscopic approach. No iatrogenic injuries were found. Most of the canalplasties required drilling off bulges on multiple walls. The mean total duration of the canalplasties and myringoplasties was 76.6 ± 4.5 min, and the proportion of time required for the canalplasties was 47.3 ± 2.4%.Conclusion Only approximately one in five endoscopic myringoplasties require antecedent canalplasties due to concurrent canal stenosis. With the underwater bone drilling technique, transcanal endoscopic canalplasty can be safely and efficiently conducted.