IntroductionChildren with Down syndrome (DS) have a high incidence of chronic middle ear disease. Surgery to manage this disease is challenging due to the severity of illness and narrow ear canal dimensions. Endoscopic ear surgery is used to manage tympanic membrane and middle ear disease with the advantages of improved visualization and avoidance of post-auricular incisions. However, its application in children with DS has not been reported. We aim to compare the outcomes of endoscopic versus microscopic ear surgery in children with DS. MethodsAll patients with DS who underwent tympanoplasty without mastoidectomy between 2012 and 2018 were identified, and their charts retrospectively reviewed. Rate of residual perforation, hearing, surgical time, and surgical details were recorded. Results37 surgeries in 26 patients were identified that met inclusion criteria. Two subgroups were analyzed. The first included 14 cases that were done using traditional microscopic visualization (MV). The second included 17 cases that had substantial or exclusive use of endoscopic visualization (EES). Due to a learning curve, the number of cases done endoscopically increased over time. The average age in MV was 13.9 years vs 11.0 in EES. The MV cases included 2 with cholesteatoma vs 4 in EES. In cases with adequate follow up, residual perforations were found in 1/13 MV, and 4/17 EES. All of the residual perforation cases in EES used acellular porcine submucosa grafts. None of the cases in MV used this material. Average air bone gap reduction was seen in both groups; 4.2 dB in MV, 9.8 dB in EES. Average surgical time was similar between groups; 124 min in MV, 115 min in EES. All cases in MV required a post-auricular incision and approach to the middle ear. Only four cases in EES required this approach. Six cases in EES did not require any incision outside of the ear canal for either graft harvest or middle ear approach. ConclusionEndoscopic and microscopic ear surgery in children with DS have similar outcomes. There were no statistical differences in hearing results, surgical times, or residual tympanic membrane perforations, although the rate of perforations in the endoscopic group trended higher. Most endoscopic cases did not require conversion to a post-auricular approach. Endoscopic surgery allows some DS patients to avoid any incision outside of the ear canal.