This article is a frank discussion of the authors’ experience implanting these devices. The principle of the device is surgical implantation of a bilobed magnet within a bony well in the cranium (similar position to BAHA). The implant is a magnet only and the external device transmits sound via its baseplate, vibrating the surrounding tissues to both ears. Due to the diminution of sound, the candidacy for the Sophono is less than the BAHA (up to 45dB vs. up to 65dB for BAHA.) The surgical technique for insertion is described with explanations for implant placement and therefore the incision considerations. There are certain areas where the authors admit to deviating from the surgical manual, which include advocating skin thickness of 1cm rather than the advised 4-6mm, for the reasons of reducing postoperative pain and improving wearability. Interestingly, they also describe their experience with placement of the external device. They found that placing these too soon required stronger magnets (to overcome the post-operative swelling) which then ultimately resulted in skin irritation and decreased wear. They therefore advocated external placement six weeks post op and a graduated period of wear to avoid these issues. Their complications were outlined, which were few and included a haematoma (resolved conservatively), an infection (resolved with antibiotics) and a paediatric case with limited skull thickness such that Alloderm was used to provide increased soft tissue thickness to prevent skin irritation post op.
This article was a truly helpful and honest description of their experience, especially for those embarking on fitting these implants at the early stages. Of particular note was their list of ‘pearls’ – key points of tried and tested surgical usefulness for this technique!