BACKGROUND: Cochlear implant has become a routine procedure for management of severe sensorineural hearing loss. Cochlear implant extrusion is one of the most devastating complication of this procedure. A double layer closure of pericranial flap and scalp rotational flap has being showed to decrease the rate of late implant extrusion.OBJECTIVE:The purpose of this study is to evaluate the use of the pericranial flap as second layer coverage after cochlear implant extrusion.PATIENTS AND METHODS:Eight patients with cochlear implant extrusion in Al-Shaheed Gazi Al-Hariri hospital were operated on by using two layer closure ; the pericranial flap as salvage layer used to cover the cochlear implant and scalp rotational flap as a routine coverage, with mean postoperative follow- up period of 6 months.RESULTS: Eight patients with late cochlear implant extrusion where operated on by using double layers closure, seven of them had no evidence of extrusion during the 6 months follow-up period. No complications were notice apart from one case who developed flap necrosis and the implant was removed later on, and another patient who had postoperative hematoma, which was surgically evacuated and the flap healed uneventfully. The results show that using pericranila flap as salvage second layer coverage in patients with cochlear implant extrusion had significant role in prevention of secondary cochlear implant extrusion. CONCLUSION: We concluded that the use of combination of pericranial flap as first layer with scalp rotational flap as secondary coverage of implant had superior result in prevention of secondary cochlear implant extrusion.
In this article four samples of HgBa2Ca2Cu2.4Ag0.6O8+δ were prepared and irradiated with different doses of gamma radiation 6, 8 and 10 Mrad. The effects of gamma irradiation on structure of HgBa2Ca2Cu2.4Ag0.6O8+δ samples were characterized using X-ray diffraction. It was concluded that there effect on structure by gamma irradiation. Scherrer, crystallization, and Williamson equations were applied based on the X-ray diffraction diagram and for all gamma doses, to calculate crystal size, strain, and degree of crystallinity. I
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