Dear Editors,

We would like to address the manuscript by Carr et al. entitled ‘Factors affecting myringoplasty success’.Reference Carr, Strachan and Raine ¹ This is an interesting study and constitutes excellent work. The authors evaluated the success of myringoplasty from the following five perspectives: experience of the surgeon, dry ear or not, the condition of the contralateral middle ear, perforation size, and the simultaneous performance of cortical mastoidectomy. It was concluded that, in adults, a significant association was evident between the tympanic membrane perforation site and the closure rate. Anterior and subtotal perforations had significantly lower closure rates. None of the factors evaluated significantly influenced tympanic membrane closure in a paediatric group. However, we believe that the factors assessed were not comprehensive. Also, the use of different graft materials has confused the findings.

The authors write, in the Methods section:

The authors did not assess the Eustachian tube or record concomitant myringosclerosis. Furukawa et al. suggested that removal of myringosclerosis at the edge of a perforation was beneficial when simple underlay myringoplasty was planned, improving the operative success rate and post-operative hearing threshold, especially when the myringosclerosis extended over the entire tympanic membrane.Reference Furukawa, Hayashi, Narabayashi, Kasai, Okada and Haruyama ² Migirov and Volkov believed that appropriate freshening of the perforation edges, with removal of sclerotic plaques, improved the success rate when tympanoplasty was performed in patients with concomitant myringosclerosis.Reference Migirov and Volkov ³ Pinar et al. found that the absence of myringosclerosis and a low middle-ear risk index were significantly (and independently) prognostic of successful tympanoplasty.Reference Pinar, Sadullahoglu, Calli and Oncel ⁴ The Eustachian tube plays a significant role in the success of myringoplasty. One effect of Eustachian tube dysfunction in paediatric populations is that the middle-ear cavity is under negative pressure, which can cause retraction of the tympanic membrane, triggering failure of myringoplasty.Reference Iacovou, Vlastarakos, Papacharalampous, Kyrodimos and Nikolopoulos ⁵ Collins et al. reported that Eustachian tube dysfunction was associated with a poor success rate of tympanoplasty.Reference Collins, Telischi, Balkany and Buchman ⁶ Onal et al. performed a multivariate analysis of otological, surgical and patient-related factors, and concluded that smoking status increased the myringoplasty failure rate.Reference Onal, Uguz, Kazikdas, Gursoy and Gokce ⁷ In addition, follow-up time may affect the success rates recorded in retrospective studies. Two studies reported re-perforation rates of 5–10 per cent in the first year after type I tympanoplasty, and rates of 10–15.5 per cent over the next 3–10 years.Reference Mohamad, Khan and Hussain ^{8 ,} Reference Kirazli, Bilgen, Midilli and Ogut ⁹ Thus, factors affecting the success rate of myringoplasty should be analysed more thoroughly in future studies.

The authors write (in the Methods section): ‘Several different graft materials were used: temporalis fascia, perichondrium, perichondrium and cartilage, fat, and periosteum’. Five different graft materials were, in fact, used in the study. The indications for, and success rates associated with, different graft materials during myringoplasty differ. Fat grafts are used to repair small chronic tympanic membrane perforations. Konstantinidis et al. showed that fat graft myringoplasty was most successful when used to repair perforations smaller than 30 per cent of the pars tensa; the success rates decreased significantly when the perforations were larger.Reference Konstantinidis, Malliari, Tsakiropoulou and Constantinidis ¹⁰ Kim et al. also found that patients with perforations of more than 30 per cent had poor closure rates after fat graft myringoplasty.Reference Kim, Park, Yeo, Kim, Kim and Kim ¹¹ In addition, several studies have shown that tympanoplasty using cartilage (with or without perichondrium) was associated with better anatomical success rates than tympanoplasty employing temporalis fascia.Reference Mohamad, Khan and Hussain ^{8 ,} Reference Vashishth, Mathur, Choudhary and Bhardwaj ^{12 –} Reference Khan and Parab ¹⁴ Ozbek et al. found that tympanoplasty using palisade cartilage was associated with a significantly higher graft acceptance rate (100 per cent) than tympanoplasty using fascia (70.2 per cent; p = 0.008).Reference Ozbek, Ciftçi, Tuna, Yazkan and Ozdem ¹⁵ Most scholars suggest that temporalis fascia will degenerate and shrink over time, triggering eardrum atrophy and re-perforation.Reference Vashishth, Mathur, Choudhary and Bhardwaj ^{12 –} Reference Khan and Parab ^{14 ,} Reference England, Strachan and Buckley ¹⁶ However, cartilage perichondrium can receive nutrients by diffusion, maintain bradytrophic metabolism and resist deformation by pressure variations.Reference Vashishth, Mathur, Choudhary and Bhardwaj ^{12 –} Reference Khan and Parab ^{14 ,} Reference Levinson ¹⁷ Thus, factors affecting myringoplasty outcomes should be evaluated using the same graft material in future studies.