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

Abstract

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 airbone 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.

Interlay myringoplasty: hearing gain and outcomein large central tympanic membrane perforation

“…Jain S et al [4] studied 500 cases and reported the success rate of 96.6 and Patil et al [7] reported 96% which is slightly better than our results. Komune S et al [6] studied interlay myringoplasty in 69 ears and achieved success rate of 94.2%, either blunting of the anterior tympanomeatal angle nor lateralization of the tympanic membrane was observed in any of their cases.…”

“…In the study by Kawatraet al [2] ABG improved from 27.50 dB preoperatively to 13.67 dB postoperatively after 16 weeks and in study by Patil et al [7] the mean preoperative ABG was 36.42 ± 12.01 dB which improved to 9.7 ± 6.71 dB at the end of 3rd month.…”

“…Interlay technique is considered better than both overlay as well as the underlay techniques as getting an interlay plane is easier and faster, there is no reduction in the middle ear space, the bed size for the graft is not limited, faster healing time andno fear of residual epithelium and epithelial pearl formation. There are lesschances of graft medialization or lateralization, blunting of the anterior meatal recess and there is no fear of residual epithelium [7].…”

A Comparative study of the techniques of Myringoplasty - Overlay Underlay & Interlay

“…crovetto [23] in their series showed post-operative air bone gap in the range 0 to <20 db in 88.4% of Underlay and 83.0% of Overlay patients, She [22] reported the mean reduction in air bone gap to be 4.9 db in the Underlay and 9.7 db in Over-Under group however, Patil [24] in their series of 100 cases who were approached using Interlay method showed a phenomenal reduction in air bone gap from a pre-operative mean value of 36.42±12.0 db to 9.7±6.71 db, thus showing a reduction of almost 26.72 db.…”

Interlay Technique Tympanoplasty: Surgical Difficulties with Variable Grafts

“…It is classified based on the placement of graft in relation to the remnant tympanic membrane as: a) The underlay technique: graft is placed medial to the mucosal layer, b) The overlay technique: graft is placed lateral to the fibrous layer of tympanic membrane after elevating all squamous epithelium, and c) The interlay technique: graft is placed between the fibrous layer and the endothelial (mucosal) layer of the drum remnant [7] .…”