![]() This technique involves accessing the granuloma from a position just below the cochlea of the inner ear. There are a number of different approaches that the surgeon may use to access the cyst however, the most frequently used technique is the infracochlear approach. Cholesterol granulomas affecting the petrous apex are fluid-filled cysts, so the primary treatment involves draining the cyst. The treatment of petrous apex lesions depends on the type of lesion, the severity of the patient’s symptoms, and the amount of damage that the growth has caused to the surrounding structures of the ear. Some congenital cholesteatomas occur outside the petrous apex between the dura and the temporal bone. Both congenital and acquired cholesteatomas can become quite large and impinge on nerves and other nearby inner ear structures. Acquired cholesteatomas are normally caused by Eustachian tube dysfunction, or rarely from trauma to or surgery in the ear. The cells form a skin cyst known as a cholesteatoma. Congenital cholesteatomas are typically caused by skin cells left behind during embryonic development. The purpose of the Eustachian tube, which connects the tympanic cavity to the back of the nose, is to allow air to enter behind the eardrum while also allowing fluid and mucus to drain.Ĭholesteatomas involving the petrous apex may be congenital, meaning the condition is present at birth, or it may be acquired during the patient’s lifetime. Cholesterol granulomas may also be linked to dysfunctions involving the Eustachian tube. It is believed that cholesterol granulomas may develop as the result of air infiltrating the bone marrow and creating pockets that then fill with blood and trigger the formation of a cyst. The exact cause of some petrous apex lesions is not clear. Surgery for Hearing Loss Reconstruction.Integrative Neurosensory Rehabilitation (INR) Therapy.Squamous Cell Carcinoma of Ear and Temporal Bone.Early diagnosis of this condition is important as aggressive management is necessary to avoid morbidiy and mortality. Differential diagnosis includes cholestatoma and squamous cell carcinoma of the EAC. Temporal bone osteomyelitis is seen as increased density of the bone, with linear periosteal reaction, and accompanied by a soft tissue density around the EAC and mastoid. Involvement of the TM joint is seen as widening of the joint space, with irregularity of the articular margins. Involvement of the temporalis muscle leads to formation of a temporalis abscess, which is seen as diffuse muscle thickening with hypodensity. CT scan demonstrates the presence of an asymmetric soft tissue density in the EAC, with or without extension into the surrounding structures. The infection soon spreads into the adjacent structures such as the temporomandibular (TM) joint, middle ear, mastoid air cells, and skull base. It is commonly seen in the elderly and in diabetic patients. Malignant otitis externa is a result of infection of the EAC with Pseudomonas aeruginosa. Mortality has currently decreased to 20% from 30-40% due to good improved antibiotics. Malignant otitis externa is a misnomer as it is not a malignant condition it is termed “malignant” because of the aggressive clinical behavior and high mortality associated with it. 3D reconstructed images should demonstrate the volume of the middle ear cavity and also the distance from the middle ear structures to the atretic EAC and reveal any other anomalies of the external ear. Additional anomalies need to be looked for as well, such as the presence of severe incudomallear dysplasia, which when present has to be resected, as well as dysplastic stapes, which may need to be replaced by a prosthesis. In addition, we also need to look for structures that may cause problems during surgery such as reduced volume of the middle ear cavity and poor pneumatization of the temporal bone. Preoperatively, the radiologist should look for contraindications for surgery such as atretic oval and or round window and unfavorable course of the facial nerve. HRCT of the temporal bone is indicated for preoperative planning. The outcome of surgeries performed in the presence of middle and inner ear dysplasia are not encouraging. Isolated EAC atresias are amendable to surgery. Atresia of the EAC can occur in isolation or it may be associated with middle ear and inner ear dysplasia.
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