Meniers Disease. Or is it successful.

Have profound hearing loss to 90% in left ear from childhood ,use to had vertigo once or twice a month and tinnitus from childhood  but from last 2 years got meniers disease ,faced very rough time in starting continue dizziness and imbalance unsteady was not able to walk for 6 months properly ,docs applied grommet and put dexona 2-2 drops on regular basis got recoverd almost 70% but again dizziness started gets trigger from almost anything , now the docs are saying the final step is only of applying gentamicin injection and making ear dead so that dizziness can be stop but hearing loss will be 100% . I wanna ask is it the only step except surgery if it is , do it have any other side effect or is it  successful.