LAUSR

In response to Letter to the Editor entitled ‘‘It is prudent to consider use of endoscopic tympanoplasty to treat complicated middle ear disease’’. In reply: we would like to thank the authors for this Letter to the Editor regarding our study. We are grateful to reply to the letter according to your comments. The followings are our responses to the letter. First, the letter writes: ‘‘Many surgeons are uncomfortable when operating one-handed and viewing a two-dimensional image with no depth-of-field’’. The author had her learning curve in practicing endoscopic ear surgeries at the beginning. The operation time in the later period was shorter than that at the beginning in the endoscopic group. Besides, in the pediatric group, the study of Cohen et al.: Pediatric Endoscopic Ear Surg in Clinical Practice [1] showed that during the initial 6 months, the endoscope was used mainly for inspection or dissection, and only one TEES (transcanal endoscopic ear surgery) case was performed. However, in the final 6 months of the study, 75% of cases were performed using TEES. Therefore, in the point of view, TEES was found to have a shallow learning curve, consistent with other authors’ experiences [2]. In Tseng et al. [3], the quantitative data about endoscopic tympanoplasty type I were shown. The learning curves had significant progress for the surgeon during the first 50 patients, considering the graft success rate. For the mean operating time, the surgeon reached an advanced level after the 150th patient. Moreover, in Sedat et al. [4], mastering endoscopic tympanoplasty took 60 operations for a surgeon who had already trained in microscopic tympanoplasty. In fact, the learning curve is required for a surgeon to become familiar with endoscopic surgery even with prior experience in microscopic techniques. When it comes to the lack of a third dimension in the view of endoscopes, it seems to be difficult to perform perfect ossicular chain reconstruction. The way we do it is to move the endoscope back and forth to minimize measurement error of distance and avoid the wrong choice of the prosthesis. In addition, three-dimensional (3D) endoscopes provide an improvement in stereoscopic depth perception (SDP) and also the brightness of the surgical field [5], enabling improved hand–eye coordination [6]. In addition, we did not compare the size or position of the perforations, or the Eustachian tube status in this study. We will arrange and collect more related information for further analysis. However, the size of the perforation in our study included from less than 10% to near-total perforation, and also adhesive otitis media cases, such as a retracted drum, in both groups. It was randomized relatively and we believe that endoscopic surgeries could treat adhesive otitis media as well. The letter also writes: ‘‘Temporalis fascia becomes soft and contracts on contact with blood, and is difficult to spread when operating one-handedly’’. We used an oven lamp to heat the fascia. This procedure makes the fascia drier and harder, so it is much easier to place the fascia in This reply refers to the comment available at doi:10.1007/s00405-017-4624-6.