Outcome of Tympanoplasty Type - I by Underlay Technique

OBJECTIVE: To observe the factors influencing the success of type-I tympanoplasty by underlay technique, in closing tympanic membrane perforation of variable size and location with temporalis fascia graft. DESIGN: Prospective study. PLACE AND DURATION OF STUDY: Department of Otorhinolaryngology, Head & Neck Surgery, Jinnah Postgraduate Medical Centre, Karachi from April 2004 to November 2006. PATIENT & METHODS: Hundred (100) consecutive patients of dry tympanic membrane perforation undergoing type-I tympanoplasty were included. Specific inclusion and exclusion criteria were set. Data were collected regarding age, gender, cause, site and size of tympanic membrane perforation, pre and postoperative audiogram results. The data were entered in a set performa and was analyzed using SPSS version 14.0 RESULTS: The male: female ratio was 2:3 with age varying from 18 to 40 years (mean age 31.2). Overall success rate was 81% (81 out of 100 perforations closed successfully). There was no significant effect of age, gender and size of perforation on closure. All patients with traumatic perforation had successful closure (100% with a p-value of <0.05). Out of the 100 patients tested, the mean air conduction threshold was 40db preoperatively and 28 db postoperatively, while the mean bone conduction threshold remained the same pre & postoperatively i.e. 15 db. On postoperative audiometric analysis air bone gap closed completely in 4 patients, 51 ears had a postoperative air-bone gap of 10 db or less, reduced up to 15db in 26 patients, while in the remaining 19 ears there was no uptake of graft . CONCLUSION: Underlay technique for type-I tympanoplasty is an effective method for closure of uncomplicated tympanic membrane perforations. Patients with a traumatic perforation have a high success rate. Postoperatively these patients have record improvement in hearing on pure tone audiogram.