A comparative study of audiological and surgical results in partial versus complete strip cartilage reinforcement tympanoplasty

Different techniques used in cartilage tympanoplasty are palisade technique, shield graft, in-lay butterfly graft, and island flap cartilage.


Introduction and rationale
Since Wullstein and Zoellner popularized tympanoplasty in the 1950s, various materials have been used for the procedure, including fascia, skin, vein, dura, and cartilage [1]. Currently, temporalis muscle fascia is the most frequently used grafting material in tympanoplasty [2], but unfortunately in atelectatic ears the fascia and perichondrium have been shown to undergo atrophy and subsequent failure during the postoperative period. Thus, it would be better to choose a grafting material that can resist the continuous negative middle ear pressure. Cartilage might be a better choice than fascia to resist the negative middle ear pressure because it is rigid and more stable [3,4].
Cartilage contributes minimally to an inflammatory tissue reaction and is well incorporated with the tympanic membrane layers; it also provides firm support to prevent retraction. The greatest advantage of the cartilage graft has been thought to be its very low metabolic rate. It receives its nutrients by diffusion, is easy to work with because it is pliable, and it can resist deformation from pressure variations. Perichondrium and cartilage share with fascia the quality of being mesenchymal tissue, but they are thicker and stiffer. However, they mechanically reduce the vibratory pattern of the tympanic membrane, contributing to some impairment in the functional results, especially in the higher tones [5].
Different techniques used in cartilage tympanoplasty are palisade technique, shield graft, in-lay butterfly graft, and island flap cartilage.
The aim of this study was to compare between the complete and partial strip tympanoplasty regarding the audiological and graft take results.

Participants
A total of 60 patients were selected, with central perforation of the tympanic membrane. These 60 patients (with age ranging from 18 to 40 years) were divided into two equal study groups of 30 patients each. The first group underwent complete strip cartilage reinforcement tympanoplasty and the second group underwent partial strip cartilage reinforcement tympanoplasty with homograft cartilage between 2012 and 2013 in Demerdash Hospital, Ain Shams A comparative study of audiological and surgical results in partial versus complete strip cartilage reinforcement tympanoplasty Hesham A. AbdelKader a , Ahmed G. Khafagy a , Tayseer T. Abdel Rahman b

Hypothesis
Different techniques used in cartilage tympanoplasty are palisade technique, shield graft, in-lay butterfly graft, and island flap cartilage.

Purpose
The aim of the study was to compare audiological and graft take results in partial versus complete strip cartilage reinforcement tympanoplasty.

Materials and methods
A total of 60 patients with central perforation of the tympanic membrane and age ranging from 18 to 40 years were selected. They were divided into two equal study groups of 30 patients each. The first group underwent complete strip cartilage reinforcement tympanoplasty and the second group underwent partial strip cartilage reinforcement tympanoplasty. and in sufficient quantities to permit reconstruction of the entire tympanic membrane. Typically, the piece of cartilage is 15 mm in length and 10 mm in width in children and somewhat larger in adults.
The tragal perichondrium was placed lateral to the cartilage and medial to the edges of the perforation and extended posteriorly onto the canal wall, when present (underlay technique). Next, a complete strip of cartilage 2 mm in width was removed vertically from the center of the cartilage (extending from upper edge to inferior one) to accommodate the entire malleus handle versus partial strip (extending from superior edge to midway between superior and inferior edge) to accommodate part of the malleus. In both methods, the outer perichondrium toward the external auditory canal was left intact. The postauricular incision was closed in two layers and pieces of gelfoam impregnated in antibiotic ointment were placed in the ear canal ( Fig. 1).

Postoperative care
Patients were given water precautions and caution against vigorous nose blowing. Sutures were removed 1 week after surgery, and the gelfoam was suctioned from the ear canal 3 weeks postoperatively. Antibiotic steroid-containing drops were used for further 2 weeks to clear the ear of residual gelfoam, which can lead to granulation and fibrous tissue formation if not completely removed from the tympanic membrane.
An audiogram was performed 2 months after surgery, and the tympanic membrane was examined. If the hearing result was good and the tympanic membrane was clear, the ear was examined after 6 months. University, with 6 months follow-up. Tragal cartilage and perichondrium were used as graft material.
The sampling method was convenience sampling, and participants were comprised of patients who were hospitalized with chronic otitis media and who underwent homograft cartilage tympanoplasty. The exclusion criteria were patients with membrane retraction pocket, with severe atelectasis, patients who underwent middle ear intact canal cholesteatoma surgery, patients with air-bone gap (ABG) more than 35 dB, and patients who refused to come for the follow-up visits.
The study protocol was approved by the Ethics Committee of Ain Shams University Hospital, Ain Shams University, and informed consents were obtained from all patients after explaining the study protocol and aims.

Methods
All patients were subjected to the following: (1) Complete history taking and otological examination were carried out. (2) Basic audiological evaluation: Pure-tone audiometry including air and bone conduction and speech audiometry including speech reception threshold using bisyllabic words and speech discrimination using Arabic phonetically balanced words were carried out (Soliman, 1976) [6].

Surgical procedure
All procedures were performed by the senior author according to the well-established principles of ear surgery; the ear must be free of disease before the reconstruction of the hearing mechanism.
A postauricular approach was used under general anesthesia supplemented with local infiltration of 2% lidocaine with 1 : 100 000 epinephrine.
The edges of the perforation were scrupulously denuded to promote good capillary blood flow. All tympanic membrane remnants with tympanosclerosis were removed. The middle ear was explored and any pathologic material was removed. A cut through the skin and cartilage was made on the medial side of the tragus, leaving 2 mm of cartilage in the dome of the tragus for cosmesis.
The tragal cartilage was harvested together with the perichondrium. This cartilage is ideal as it is thin, flat, Partial strip cartilage graft (one of our study patients).

Statistical analysis
The data were analyzed using SPSS for Windows (version 18; SPSS Inc., Chicago, Illinois, USA). The pure-tone average (PTA)-ABG for each audiogram, preoperative and postoperative PTA-ABG, and graft take results were compared between the two study groups using the c 2 -test and the Mann-Whitney U-tests. P-value of less than 0.05 was considered statistically significant for analyses.

Results
There were 60 patients in this study; these patients underwent tympanoplasty with homograft cartilage and their follow-up period was 6 months. The study population was divided into two groups: group 1 (complete strip) and group 2 (partial strip) ( Tables 1-5).

Discussion
In our study, there was a significant difference in the mean of PTA-ABG before and after surgery. Closure of the tympanic membrane was achieved at a rate of 83.3% in the complete strip technique and 86.66% in the partial strip technique.
The present data were in agreement with previous studies based on the overall results of cartilage reinforcement tympanoplasty. In both study groups, there was statistically significant difference between audiological results before and after operation. Furthermore, audiological and graft take results were better in the partial strip technique but with no statistically significant difference.
In the study by Dornhoffer [1], the mean of ABG before and after tympanoplasty with homograft cartilage was similar to that in our study. Hashemi  also showed similar results to our study [8].

Conclusion
The findings of this study demonstrated that partial strip cartilage tympanoplasty was more effective technique for tympanic membrane closure with acceptable hearing results compared with the complete strip technique.