Outcome of Interlay Grafting in Type 1 Tympanoplasty for Large Central Perforation

A prospective, cohort, clinical study was conducted at Dr. D. Y. Patil Hospital, Kolhapur from August 2010 to August 2013. The aim was to evaluate the results of type 1 interlay tympanoplasty with respect to graft uptake, hearing improvement and complications. Total of 100 cases with a mucosal type of chronic suppurative otitis media and a large central perforation (involving more than 50 % of tympanic membrane) were operated for type 1 tympanoplasty where the graft was placed by interlay method (below the fibro-squamous layer and above the mucosal or endothelial layer). Patients were followed up with ear microscopy at each follow up visit and an audiometry at the end of 3rd month. Statistical analysis was done by statcal software using paired t test and two sample t test for proportion. 96 (96 %) cases had a successful graft uptake. The mean pre-operative air-bone gap was 36.42 ± 12.0 dB; whereas the mean post-operative air-bone gap was 9.7 ± 6.71 dB. Except for residual perforation in four patients and partial tympanomeatal flap necrosis in two patients no other complications were encountered. Thus, we conclude that, the interlay tympanoplasty is a safe and effective method of graft placement for large central perforation.