Dear Editors,

We read with great interest the letter to the editor entitled ‘The comparison of endoscopic butterfly-inlay and push-through myringoplasty’, by Z Lou. In the letter, the author stated some concerns that may limit the power of our study, as follows: (1) the depth of the circumferential groove on the butterfly-shaped graft; (2) cholesteatoma or epithelial pearl formation following butterfly-inlay tympanoplasty; and (3) the technical difficulty of the butterfly-inlay technique.

According to our clinical experience, approximately 1 mm groove depth is sufficient for the butterfly-inlay technique. In the vast majority of our cases, we had no problems with graft stabilisation in the butterfly-inlay technique with 1 mm circumferential groove depth on the cartilage graft. Furthermore, Kim et al.^{Reference Kim, Park, Suh and Song1} and Akyigit et al.^{Reference Akyigit, Karlidag, Keles, Kaygusuz, Yalcın and Polat2} performed butterfly-inlay cartilage tympanoplasty by creating circumferential grooves on the cartilage graft of 1 mm and 0.5–1 mm depth, respectively, and both authors reported comparable functional and anatomical outcomes in their articles.

In the discussion section of our article, we stated that cholesteatoma formation is theoretically possible.^{Reference Gülşen and Erden3} However, in the current English-language literature, neither cholesteatoma or epithelial pearl formation have yet been reported following butterfly-inlay cartilage tympanoplasty. This may be explained by the theory that the healing process of the tympanic membrane perforation starts from the fusion of the graft with the lamina propria layer of the tympanic membrane remnant.^{Reference Eavey4,Reference Zahnert, Hüttenbrink, Mürbe and Bornitz5} In addition, we observed that excess perichondrium and the cartilage part of the chondroperichondrial graft lateral to the tympanic membrane remnant became necrotic in a short period of time (between the second week and one month) post-operatively. In addition, at the post-operative three-month control examination, we observed that epithelialisation over the cartilage graft was complete in all of the cases except graft failures. Cholesteatoma or epithelial pearl formation is not an expected issue after the completion of epithelisation over the cartilage graft. In this context, a period of six months’ follow up post-operatively is adequate following butterfly-inlay cartilage tympanoplasty regarding cholesteatoma or epithelial pearl formation. Moreover, our average follow-up period following butterfly-inlay cartilage tympanoplasty was 8.2 months.^{Reference Gülşen and Erden3}

According to our personal experience, preparing the butterfly-shaped chondroperichondrial graft is not a challenging issue, even for beginners. As shown in our study (Figure 1), precise measurement of the perforation diameter using a disposable paper ruler is a very practical and cost-effective method, and based on this measurement adjusting the size of the butterfly-shaped graft is an easy procedure.^{Reference Gülşen and Erden3} On the contrary, packing the middle ear, particularly the orifice of the Eustachian tube, with an absorbable sponge can sometimes be a difficult procedure in the push-through myringoplasty technique. In the beginning, in some cases, after pushing the graft through the perforation, we observed that middle-ear support was not adequate, and we then removed the graft and added additional absorbable sponges. Vice versa, in cases where we packed the middle ear more than required, we had difficulties pushing the graft through, and then had to remove some sponge pieces. Hence, determining the amount of middle-ear packing requires experience in the beginning.

As a result, we disagree with the opinion that the points mentioned by the author of the letter limit the power of our study.