Med. J. Cairo Univ., Vol. 73 , No. 3, Sept,2005
Performance of Alloderm and Lyophilized Dura Grafts in Tympanoplasty
MAHMOUD EL-MALLAH,M.D.;AHMAD S.EL-KADY,M.D.;HOSAM ABD EL-AZEM, M.D.; SHERIF F.SAFWAT,M.D.*and SOBHEY ABO EL-FETOH,M.D.
The Department of Otorhinlaryngology, Faculty of Medicine and National Institute of Enhanced Laser Sciences*, Benha and Cairo* Universities.
Abstract
Grafting of tympanic membrane is nowadays a relatively an easy surgical procedure as long as suitable material is available for closure, but still every material has advantage and disadvantage. The most commonly used autograft is the temporalis fascia but cases need revision tympanoplasty the grafting material may be not available. There are new alternative donor in the form of allografts and xenografts to replace the usually autografts if not available as alloderm and lyophilized dura respectively. The aim of this study was to assess the healing and hearing results of these materials in grafting of tympanic membrane perforation versus commonly used temporalis fascia.
This study included 60 patients with drum perforation, according to the grafts used in operation, the cases were divided into 3 groups: Group (I) 20 patients with perforation grafted by alloderm, Group (II) 20 patients with perforated drum grafted by lypholized dura, Group (III) 20 patients with perforation grafted temporalis fascia.
The cases were selected in this study with the following criteria; dry safe perforation, patent Eustachian tube (E.T), air-bone gab (A.B.G.) must be less than 30 d.B and without history of pervious operation to the ear.
Tympanoplasty type I with underlay technique through post auricular approach was done for all cases in this study. Pure tone audiometry was done 2 months postoperatively to measure the change in the A.B.G. postoperatively.
Complete healing of tympanic membrane was occurred in 19 cases of group I, 16 cases of group II and 17 cases of group III. Statistical analysis showed insignificant results regarding healing among the 3 groups.
The mean of percentage change of A.B.G post operatively in group (I) was 46.49, group (II) was 21.77, while in group (III) was 34.71, the hearing improvement was marked, moderate and mild in group I, III and II respectively. Statistical analysis showed significant difference in the percentage change of A.B.G. between group (I) and group (II) only.
Conclusion: Both alloderm and lyophilized dura are considered as a good material in tympanoplasty. The recommendation in this work is that, the use of alloderm is superior to lyophilized dura especially in revision tympanoplasty due to its better healing results. Also, it has the advantage of saving time, minimize the manipulation and decreasing the morbidity of the patient as it overcome insufficient temporalis fascia in revision tympanoplasty.
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