Underlay cartilage tympanoplasty: different ways of application of the graft

© 2018 The Egyptian Journal of Otolaryngology | Publish Introduction The objective of this study was to evaluate underlay tympanoplasty technique of perichondrium cartilage graft according to the position of the graft with respect to the handle of malleus and remnant of tympanic membrane. Patients and methods In all, 150 patients with chronic suppurative otitis media (safe type) underwent tympanoplasty with or without mastoidectomy. The patients were divided into three groups (50 patients in each group). Group I graft was placed medial to the handle of malleus, group II graft was placed at the plane of malleus, group III graft was placed lateral to the malleus between it and remnant of tympanic membrane. Results Success rate (graft taken with no residual perforation) in all cases is 98% (147 cases). Success rate in groups I–III is 98% (49 cases), 100% (50 cases) and 96% (48 cases), respectively. There is significant statistical improvement of postoperative pure tone audiogram. Conclusion Underlay cartilage tympanoplasty was associated with a high rate of graft taken and good hearing results despite the position of the graft in relation to the handle of malleus.


Introduction
Tympanoplasty surgery was applied in 1950, and various techniques and graft material were used [1]. The underlay and the overlay procedure were developed as two classical techniques [2]. The underlay technique is widely used as it is relatively easily to perform [3]. Various graft material can be used as cartilage, perichondrium, temporalis fascia, vein tissue and fat [4]. But the most popular graft used is cartilage and temporalis fascia. Cartilage graft can be used as a total, shield or palisade graft in ear surgery [5].
In this study, we evaluated the underlay tympanoplasty technique of the perichondrium cartilage graft according to the position of the graft with respect to the handle of malleus and remnant of tympanic membrane.

Patients and methods
This study is a prospective, analytic, randomized and longitudinal study, which was performed in the Otolaryngology Department of El-Minia University Hospital from March 2006 to May 2011.
Underlay tympanoplasty with or without cortical mastoidectomy was performed on 150 patients.
This study was designed in three groups according to the relation of the graft to the handle of malleus and remnant of tympanic membrane, each group included 50 patients.
Group I: graft medial to the handle of malleus. Group II: graft at the plane of the malleus. Group III: graft lateral to the malleus/over-underlay technique.

Exclusion criteria
(1) Age of the patient less than 12 years old.
(2) Previous otological surgery. This is an open access journal, and articles are distributed under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 License, which allows others to remix, tweak, and build upon the work non-commercially, as long as appropriate credit is given and the new creations are licensed under the identical terms.
The study was conducted according to the Declaration of Helsinki and was approved by Minia Faculty of Medicine Institutional Review Board.

Surgical procedure
All procedures were performed under general anesthesia by the same surgeon (author of the paper).
Postauricular approach was used. Explore middle ear to exclude any pathology and to examine mobility of ossicles. A cut through the skin and cartilage was done leaving 2 mm of cartilage in the dome of tragus. Cartilage with attached perichondrium is dissected medially from the overlying skin and laterally from soft tissue by dissection. Perichondrium from side of cartilage towards the ear canal is dissected off. Epithelial cells along the perforation margin of the tympanic membrane were carefully stripped. Gel foam is packed in the middle ear. Graft is placed in an underlaying manner (lateral, medial or at the level of the handle of malleus).

Group I (medial to the handle of malleus)
A complete strip of cartilage 2 mm wide is removed vertically from the center of the graft to accommodate the entire malleus handle. The graft is placed in an underlay fashion, with the malleus fitting into the groove. The cartilage is placed toward the promontory, with the perichondrium immediately adjacent to the tympanic membrane remnant, both of which are medial to the malleus (Fig. 1).

Group II (at the plane of the malleus)
A V-shaped notch is removed from the cartilage to accommodate the malleus handle. The cartilage graft is placed on the same plane as the manubrium of the malleus and medial to the tympanic membrane remnant (Fig. 2).
Group III (lateral to the malleus/over-underlay technique) We dissected the remnant of the tympanic membrane from the handle of the malleus and then the graft was placed between the remnant of the tympanic remnant and the handle (Fig. 3).
Informed consent was obtained from all the patients.

Postoperative care and follow-up
Aural pack is removed on the fifth day and stitches on the seventh day. Follow-up of the patients on 2, 4, 6 and 12 weeks for assessment of graft taken. Postoperative pure tone was assessed on the 12th week (Tables 1-3).

Statistical analysis
Results were expressed as mean±SD or number (%). Comparison between categorical data was performed using the χ 2 -test. The data were considered significant if P value less than 0.01. Statistical analysis was performed Medial to the handle of malleus (group 1).

Fig. 2
At the plane of the malleus (group 2).

Fig. 3
Lateral to the handle of malleus and medial to remnant of tympanic membrane, over-underlay technique (group 3). with the aid of SPSS computer program (version 12 Windows).

Results
Patient's ages ranged from 12 to 39 years with an average age of 22.44±5.72. Of these, 63 (42%) patients were men and 87 (58%) patients were women, the follow-up period was 12 weeks.

Discussion
Cartilage tympanoplasty is a safe and a reliable technique in tympanic membrane reconstruction [6] and achieves good anatomical and audiologic results [7]. Cartilage graft resists negative middle ear pressure and infection [8], it has low reperforation rates [9]. As it has very low metabolic rates, it is nourished by diffusion [10], and incorporated into the tympanic membrane easily [11]. It can be used as a cartilage perichondrium composite island graft, palisade and thin or thick plates not covered by the perichondrium [5]. The cartilage covered by the perichondrium had better metabolism than naked cartilage [1]. In this study, the overall graft taken rate is 98% (147 patients) and there is significant statistical improvement of postoperative pure tone audiogram (PTA). These results are similar to the results of Demirpehlivent et al. [9] and Onal et al. [12]. Demirpehlivent et al. [9], made a study on 34 patients (with intact ossicular chain, normal middle ear mucosa and subtotal perforation), patients younger than 15 years and patients with cholesteatoma were excluded from this study, graft taken was 97.7% with significant statistical improvement of postoperative PTA. Onal et al. [12], made their study on 44 patients (with intact ossicular chain, normal middle ear mucosa and dry ear for ≥1 month), graft taken rate was 93.2% with significant statistical improvement of postoperative PTA. In this study, group I graft taken and postoperative PTA is better than groups II and III but with no statistical significance. Cavaliere et al. [13], made their study on 100 patients as in group II in this study and graft taken was 100% with significant statistical improvement of postoperative PTA. Also Yurttas et al. [14], made their study on 87 patients using the technique as in group II in this study and graft taken was 93% but they use conchal cartilage and 27 patients had central perforation, 43 had subtotal perforation, six with adhesive otitis media and 10 patients with total perforation. Kulduk et al. [15] made their study on 114 patients with chronic suppurative otitis media; they divided them into two groups. Tympanoplasty (underlay technique with graft medial to the handle of malleus) was used in 61 patients (first group) and tympanoplasty (underlay technique with graft   at plane of malleus) was used in 53 patients and they found a success rate of 89.1 and 90.5%, respectively, with no statistical significance; there was significant improvement of postoperative PTA in both groups [15]. In Kulduk et al. [15], the study success rate is less than this study as we exclude patients with total and subtotal perforations but they made study on patients with large perforations more than 50% of the tympanic membrane.

Conclusion
Underlay cartilage tympanoplasty was associated with a high rate of graft taken and good hearing results despite the position of the graft in relation to the handle of malleus.

Financial support and sponsorship
Nil.

Conflicts of interest
There are no conflicts of interest.