Prof. Yasser Haroun Mohamed Abo-Essa :: Publications:

البحث الرابع دراسة للجيب النسيجي للغشاء الطبلي عن طريق الاستئصال الجراحي و تركيب هواية و دراسة التغير النسيجي بواسطة المجهر الضوئي و الالكتروني . بحث مشترك منشور في مجلة الزقازيق الطبية المجلد 9 العدد 5 سبتمبر 2003 Retraction pocket of the pars tensa. Surgical and histological studies. Yasser H Mohamed, MD, Mohsen M Abd El razek, Ahmed El-Shal, MD, Sobhy Abou EL-Fotouh,MD and Eman El-Nashar, MD* Departments of ENT and Histology*,Benha faculty of medicine, Zagazig university. Abstract: Retraction of the pars tensa can result in erosion of the assicles leading to hearing loss and eventually cholesteatoma. Different types of treatment have been described for retraction pocket and the pathology has a little attention, so the aim of this work was to assess the outcome following simple excision and ventilation tube insertion of retraction pockets of the pars tensa and to study the histopathological and ultrastructural changes to the excised parts. The study was conducted on 22 patients with a total of 29 ears. The ear drums were graded according to Sade et al., (1982) classification. There were 5 cases with grade I (7 ears), 10 with grade II (14ears) and 7 with grade III (8ears). Grade IV excluded from this study. All cases with grade I (7 ears) and 8 cases with grade II (10 ears) showed complete normal healing. While 2 cases from grade II showed pocket recurrence in 3 ears and persistent perforation in one ear and 5 cases from grade III ( 5 ears) showed pocket recurrence and the remainder 2 cases (3 ears) showed persistent perforation. The 9 cases (12 ears) with pocket recurrence and persistent perforation undergone a second surgery with tympanoplasty by tragal cartilage pericondrium graft. There was curling of the surface epithelium of the tympanic membrane. Various degrees of papillay ingrowth towards the lamina propria were seen. There was much greater amount of keratin on the outer surface. The squamous epithelium appeared to be thickened because of the presence of a large number of the cell layers than usual. The lamina propria was edematous and showed round cell infiltration mostly lymphocytes and remnants of collagen fibers. By Masson trichrome stain no collagen fibers could be detected in 6 ears, remnants of collagen fibers were seen in the other 23 ears. By periodic acid-Schiff (PAS), positive gland to PAS were seen in 7 cases. The medial epithelium of the retraction pocket specimen showed increased PAS positive granules. In 10 cases there was complete absence of mucosal lining. The semi-thin sections stained with toluidine blue showed finger like projection of stratified squamous epithelium. The lamina propria was infiltrated with round cells and there were no collagen fibers. The ultrastructural study showed thickening of the horny layer (hyperkeratosis). The epithelium showed projection of the basal cell layers of the cell membrane inside the lamina proparia. The lamina propria was devoid of collagen fibers in most cases. In 4 cases remnants of collagen fibers were seen. In the fibrous layer, there was degeneration of the circular and radial fibers. There were dilated blood vessels in the lamina propria. In addition inflammatory cells could be seen. Conclusion:- The less the grade of the retraction the best result with ventilation tube insertion. Simple excision should be considered in the first instance for grade I and II rather than reinforcement tympanplasty using cartilage graft which recommended from the start for grades III and IV. The marked decrease or loss of collagen fibers on the lamina propria and the loss of the thin medial epithelial layer of the excised specimens may play a role in the pathophsiology of retraction pocket. The hyperkeratosis seen in this part of the drum is a factor in the creation of cholesteatomatous pocket. The thinness and even loss of the medial epithelial layer of retracted part may also explain why the posterior aspect of the pars tensa is more prone to retraction than other parts of the pars tensa.