This article is a useful summary of the options available when intratympanic gentamicin (ITG) fails to adequately control vertigo episodes in Meniere’s patients. The authors describe the anatomical reasons that may impede drug delivery to the round window with the ITG technique, such as thickened membrane, adhesions of the RW or narrow niche, as described in other literature.
To help illustrate the treatment pathway in their unit they used a flow chart describing at what point patients achieved control – they found medical control was achieved in 86% and of the intractable vertigo group, 86% achieved control with ITG.
Of the remaining patients where ITG had failed, all seven patients underwent exploratory tympanotomy. They described the surgical steps of performing the exploration, aided with line diagrams. Anatomical barriers were addressed and gentamicin soaked Gelfoam was applied to both round and oval windows. In their series of seven patients, they achieved control in five patients – interestingly, three of these did not have any identifiable anatomical barrier to address. Therefore, the authors concluded that the improvement may have been the result of a more sustained delivery of gentamicin by the proximity of the Gelfoam to the windows. One further point of note was that hearing loss was slightly more common with this technique than with ITG, both demonstrated by this small group and a review of the literature. Although the paper was an interesting read, the numbers were too small to draw any conclusions. Despite this, an exploratory tympanotomy is relatively low risk and may be considered in patients who are refractory to ITG but do not yet want to go down the route of labyrinthectomy.
