Hearing results for ossicular reconstruction using a cartilage-connecting hydroxyapatite prosthesis with a spearhead.

Objective: Assessment of the efficacy of ossicular reconstruction using a cartilage-connecting hydroxyapatite prosthesis designed with a spearhead to reduce extrusion and dislocation of the implant.

Patients: All patients undergoing ossicular reconstruction after chronic ear surgery, connecting the cartilage to the prosthesis, with a minimum of 1 year of postoperative follow-up.

Main Outcome Measures: Postoperative change in pure-tone averages.

Direct inner ear infusion of dexamethasone attenuates noise-induced trauma in guinea pig.

The protective effect of dexamethasone (DEX) against noise-induced trauma, as reflected in hair cell destruction and elevation in auditory brainstem response (ABR) sensitivity, was assessed in guinea pigs. The animals were administered DEX (1, 10, 100, and 1000 ng/ml) or artificial perilymph (AP) via a mini-osmotic pump directly into scala tympani and, on the fourth day after pump implantation, exposed to 120 dB SPL octave band noise, centered at 4 kHz, for 24 h. Animals receiving DEX demonstrated a dose-dependent reduction in noise-induced outer hair cell loss (significant at 1, 10 and 100 ng/ml DEX animals compared to AP control animals) and a similar attenuation of the noise-induced ABR threshold shifts, observed 7 days following exposure (significant at 100 ng/ml DEX animals compared to AP control animals).

Intra-cochlear administration of dexamethasone attenuates aminoglycoside ototoxicity in the guinea pig.

This study demonstrates the attenuation of aminoglycoside ototoxicity by cochlear infusion of dexamethasone (Dex) using a microcannulation-osmotic pump delivery system. The results indicate that treating the cochlea with Dex both before and after kanamycin administration was more effective in preventing ototoxicity than Dex treatment only after kanamycin administration. A concentration of 1 ng/ml Dex showed the greatest protective effect on both kanamycin-induced threshold shift of the auditory brainstem response and outer hair cell survival.