A case of middle ear foreign body due to weldment

Abstract

A 40-year-old male presented with a complaint of unilateral mixed hearing loss after a welding accident, and a middle ear foreign body caused by weldment was diagnosed. Otoscopic findings showed a large eardrum perforation, and moderate mixed hearing loss in the left side was recognized by pure tone audiometry. He complained no vertigo and no disequillibrium sensation. High resolution temporal bone CT scan revealed a 1mm diameter high density material supposedly a metal piece in the tympanic orifice of eustachian tube near the internal carotid artery. Tympanoplasty was performed to remove the foreign body and to close the eardrum perforation under general anesthesia. There were a lmm-2mm width of thin metal piece and a lmm-2mm width carbide piece on mucous membrane in the tympanic orifice of eustachian tube. The rest of the middle ear mucosa, ossicles, round window membrane, chorda tympani and facial nerve were all intact. The foreign bodies were extracted through mesotympanum and tympanoplasty type I was performed with a piece of temporal bone periost into the fibrous annulus. Postoperative high resolution temporal bone CT scan revealed no rest of metal foreign body in the middle ear, and pure tone audiometry showed 10 to 20 dB hearing improvement in low frequencies two month after the surgery. Case of metallic middle ear foreign body is uncommon, but it seems to be necessary that detailed investigation employing high resolution temporal bone CT scan should be conducted in the case of traumatic eardrum perforation due to welding or explosion accident.