Abstract
Purpose
Chronic otitis media surgery is the most common procedure in otology in developing countries. Subtotal and total tympanic membrane (TM) perforation with inadequate anterior remnant is associated with higher rate of graft failure. It was the goal of this study to test the anatomical and functional outcomes of a modified underlay myringoplasty technique.
Materials and methods
In a prospective clinical study, 45 patients with subtotal or total TM perforation and inadequate anterior remnant underwent tympanoplasty (+/− mastoidectomy). The anterior tip of the temporalis fascia was secured in a mucosal pocket on the lateral wall of eustachian tube orifice. Data on graft take rate, preoperative and postoperative hearing status, and intraoperative findings were analyzed.
Results
We achieved the graft success rate of 91.1%, without lateralization, blunting, atelectasia, or epithelial pearls. Approximately 24% patients had air-bone gap within 25 dB before intervention, which increased to 71% postoperatively ( P < .001).
Conclusion
We believe that this technique could be a convenient and suitable method for cases with subtotal or total TM perforation and inadequate anterior remnant.
1
Introduction
The goals of chronic otitis media (COM) surgery are to achieve an intact tympanic membrane (TM), a middle ear cavity lined with normal mucosa, and a long-standing and effective sound-conducting mechanism.
The 2 classic methods for repair of TM perforation include overlay (lateral) and underlay (medial) techniques.
Underlay technique is perhaps more commonly used worldwide; it is easier to perform and less time consuming . In this technique, the graft is placed medial to the entire TM remnant and also to the malleus handle and is more suitable for posterior perforations .
Some of the commonly faced disadvantages include decreased mesotympanic space and less success rate in subtotal and anterior perforations .
In overlay technique, which is usually applied to anterior and subtotal perforations, the epithelial layer is elevated precisely, and the graft is placed lateral to fibrous layer of TM remnant and annulus . Despite its higher success in repairing anterior and subtotal perforations, there is a consensus about its being more technically challenging, and some potential complications may occur such as graft lateralization, anterior blunting, delayed healing, stenosis of the external canal, epithelial pearls, and iatrogenic cholesteatoma .
On the whole, TM grafting has a better outcome in central or posterior perforations when compared with anterior and subtotal perforations .
Repairing this type of perforation remains a challenge especially when using underlay technique, perhaps because of inadequate blood supply, lack of residual TM as a source of epithelium, and poor exposure.
As a solution, tragal cartilage has been introduced as a graft material for anterior subtotal perforations, but some reports have shown no significant difference in success rate when compared with temporalis fascia .
This study aimed to apply a modification of underlay technique by creating a tunnel beneath the mucosa of lateral wall of eustachian tube for placement of temporalis fascia graft to increase its take rate.
2
Materials and methods
2.1
Patients
This prospective study was performed in Dastgheib Hospital (a tertiary care center for otologic surgery in the south of Iran) and was approved by the local institutional review board of Shiraz University of Medical Sciences.
From April 2009 to May 2011, 54 patients who had subtotal and total TM perforation with inadequate anterior remnant were included and underwent the procedure, and ultimately, 45 patients completed the minimum 6-month follow-up period.
Exclusion criterion was prior otologic surgery (except for myringotomy and ventilation tube insertion in childhood).
All chronically active COM cases were treated with topical antibiotics and debridement, but irresponsiveness to the therapy and continued active otorrhea were not considered as exclusion criteria.
Preoperative pure-tone audiogram was performed at frequencies of 250, 500, 1000, 2000, 4000, and 8000 Hz.
Postoperative visits and otomicroscopic examination were scheduled at 1 week, 1 month, 3 months, and 6 months after surgery and then every 6 months.
At every visit except the one in the first week, postoperative audiograms were also taken.
Ossicular reconstruction as indicated was performed in a separate stage at least 6 months after a primary successful tympanoplasty, and further audiogram was taken 2 months after second stage to evaluate the effectiveness of new established conductive mechanism.
2
Materials and methods
2.1
Patients
This prospective study was performed in Dastgheib Hospital (a tertiary care center for otologic surgery in the south of Iran) and was approved by the local institutional review board of Shiraz University of Medical Sciences.
From April 2009 to May 2011, 54 patients who had subtotal and total TM perforation with inadequate anterior remnant were included and underwent the procedure, and ultimately, 45 patients completed the minimum 6-month follow-up period.
Exclusion criterion was prior otologic surgery (except for myringotomy and ventilation tube insertion in childhood).
All chronically active COM cases were treated with topical antibiotics and debridement, but irresponsiveness to the therapy and continued active otorrhea were not considered as exclusion criteria.
Preoperative pure-tone audiogram was performed at frequencies of 250, 500, 1000, 2000, 4000, and 8000 Hz.
Postoperative visits and otomicroscopic examination were scheduled at 1 week, 1 month, 3 months, and 6 months after surgery and then every 6 months.
At every visit except the one in the first week, postoperative audiograms were also taken.
Ossicular reconstruction as indicated was performed in a separate stage at least 6 months after a primary successful tympanoplasty, and further audiogram was taken 2 months after second stage to evaluate the effectiveness of new established conductive mechanism.
3
Surgical technique
All patients were operated on under general anesthesia by the senior author (A. Faramarzi) with postauricular approach.
A rim of tissue was removed from the edges of perforation to ensure complete de-epithelialization of medial surface of TM remnant and also to promote future migration of epithelium.
An incision was placed 0.5 to 1 cm posterior to postauricular skin crease. Areolar tissue was dissected to expose deep fascia of temporalis muscle, which was harvested and prepared as the graft material.
After incising the posterior canal skin 3 to 4 mm below the suprameatal spine, the external auditory canal was entered. The tympanomeatal flap was elevated along with posterior annulus to enter middle ear space and evaluate ossicular chain status and also the presence of any pathology. Intact canal wall or canal wall down mastoidectomy was done as indicated. Anterior canaloplasty was performed by elevation of a medially based anterior canal skin flap and drilling of the bony wall, in cases of anterior bony overhang.
The freshened anterior edge of perforation was touched gently with a round knife to separate the mucosal layer from adjacent fibrous layer and annulus ( Fig. 1 ); continuing this dissection anteriorly, a pocket was created between the bony lateral wall of eustachian tube orifice and its overlying mucosa ( Fig. 2 ).
The attachments of this mucosal pocket were kept intact superiorly and inferiorly.
After reflecting the posterior tympanomeatal flap anteriorly, the graft (fascia of temporalis muscle) was placed medial to the TM remnant and malleus handle.
Anterior tip of the graft was then directed into the created pocket.
Betamethasone-soaked gelfoam was placed to fill the opening of the eustachian tube and exert a laterally directed force to redrape the elevated mucosa back to its native position. So, the small pocket containing the tip of the graft was closed tightly to keep the graft in close contact with anterior remnant of TM and annulus, then the middle ear was packed with enough gelfoam and tympanomeatal flap, and its associated posterior annulus was returned back to hold graft in posterior sulcus tympanicus ( Fig. 3 ).
Pieces of gelfoam were also placed lateral to the graft and TM remnant, and posterior auricular incision was closed in 2 layers.
A pressure dressing was applied for the first 24 hours to prevent hematoma formation and was changed to a light dressing the day after.
According to the guidelines of American Academy of Otolaryngology and Head and Neck Surgery Committee on hearing and equilibrium , Successful closure of TM perforation was defined as the presence of intact TM without perforation, retraction, blunting, and lateralization at the end of a 6-month follow-up period. Air-bone gap (ABG) closure was considered successful if final postoperative ABG was within 25 dB or had greater than 10 dB decrease after operation. SPSS statistics 17 (SPSS, Inc, Chicago, IL) software was used for data analysis. Paired-sample t test was used to compare the differences in audiometric findings before and after surgery, and P < .05 was considered significant.
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
