A New Surgical Approach for Direct Acoustic Cochlear Implant: A Temporal Bone Study

OBJECTIVES: The direct acoustic cochlear implant (DACI) is among the latest developments in the field of implantable acoustic prostheses. The surgical procedure requires a mastoidectomy and a posterior-inferior tympanotomy, with access to the facial recess at the level of the oval window, in a complex and lengthy surgical approach. Here, we report a new and considerably shorter surgical approach. METHODS: The new approach involves positioning of artificial incus above the oval window through the superior-anterior tympanotomy. We performed DACI placement in temporal bone specimens (n=5) to assess the feasibility of the new approach. RESULTS: The average time for the DACI implant in the temporal bones was only 112 minutes (range, 94 to 142 minutes) and there was little clinical risk associated with the procedure. Access was easy and drilling was minimal. CONCLUSION: Our approach simplified the surgical procedure and consequently reduced the time required for DACI placement.

Mitochondrial DNA [MTDNA] alterations and dysfunctions in presbyacusis

The aim of the study was to investigate the presence of mitochondrial DNA [mtDNA] alterations and mitochondrial metabolic dysfunctions in patients with presbyacusis, and also to discover correlations between presbyacusis and eventually the degree of hearing loss and mitochondrial damage. Seventy patients with presbyacusis were examined, including forty Egyptian patients and thirty Italian patients. Forty eight normal persons were included as control group, including twenty four Egyptian persons and twenty four Italian persons. No common point mutation; A1555G, A3243G, A7445G were detected in all patients and controls. Haplogroup U was significantly common in patients in comparison to controls. Mutation of antioxidant genes [GSTT1,GSTM1] were significantly detected in only Italian patients in comparison to Italian controls