5/11/2023 0 Comments Mastoid obliteration![]() The preserved mastoid keratinous epithelium is trimmed of any redundant or abnormal parts and placed over the flap, and a steroid- and antibiotic-soaked ribbon gauze pack is then inserted gently. ![]() Homologous bone pate and Tisseel are used to smooth over any gaps and irregularities, particularly spaces around the side of the flap and the obliterated cavity. Anchor sutures are applied from the base of the flap to sternomastoid in order to maintain its position inside the cavity until the ear has been closed and packed. The flap is now inverted into the revised cavity ( Figure 3). The musculopericranial flap is narrower at its tip, compared to its base, and these dimensions are 10 mm and 25 mm respectively. The mastoid cavity is revised, preserving as much of its healthy keratinous squamous epithelium as possible, which is then used to reline the revised obliterated cavity. All patients were unable to use a conventional hearing aid due to otorrhoea. This technique was used for good effect in six cases, for patients with a unilateral discharging mastoid cavity not amenable to medical treatment along with a conductive hearing loss. We present a method of combined BAHA and mastoid obliteration utilising the soft tissue from the BAHA soft tissue reduction to obliterate the cavity. The postauricular periosteal pericranial flap for mastoid obliteration has been shown to have up to a 90% success rate when looking at primary outcome measures such as the creation of a small dry low-maintenance cavity and secondary outcomes of haematoma, infection, flap necrosis, and meatal stenosis. Successful mastoid obliteration with temporalis muscle or abdominal fat has been documented in conjunction with cochlear implantation previously. Many techniques have been used for obliteration, including muscle flaps, bone dust, hydroxyapatite crystals, and cartilage. Obliteration of the cavity leads to a smaller, shallower, less-troublesome cavity. The components of revision mastoid cavity surgery include the eradication of disease and granulation tissue, performing an appropriate meatoplasty, lowering the facial ridge, obliterating the cavity, and covering all exposed bone with fascia. In many such cases, surgery is the only option to provide a dry ear. The otorrhoea is likely to be exacerbated in patients with mastoid cavities, not simply due to the above reasons, but also factors such as presence of a meatal stenosis, high facial ridge, deep sump, recurrent cholesteatoma, or exposed mucosa. This is due to a variety of factors, including reduced ventilation, increased humidity, and impairment of skin migration pathways. The tissue from the soft tissue reduction is routinely discarded.īAHAs can be used with great benefit in patients with conductive deafness, but it is in the rehabilitation of patients with active chronic ear disease where they out perform most other amplification devices as some patients develop otorrhoea when wearing a conventional hearing aid. There are multiple reasons for the soft tissue reduction: (a) to reduce signal loss and decay from mechanical energy being absorbed by the surrounding myofascial tissues from the titanium implant (b) to achieve thin immobile around the abutment preventing the creation of granulation tissue at the skin BAHA junction as can happen with mobile skin (c) to create hairless skin to enable easy use and cleaning of the BAHA (d) to reduce skin height ensuring that the BAHA is easy to fit and the aid does not touch the skin reducing the energy imparted to the abutment. Soft tissue reduction is then performed prior to inserting a titanium fixture (and abutment) and replacing the skin graft. The standard technique involves harvesting a split skin graft, centred on the point of optimal insertion 55 mm behind and 30 mm above the external auditory canal (EAC). In selected groups, the satisfaction ratings are very high (98%), with the number of nonusers low. Their indications include patients with conductive, sensorineural, and mixed ipsilateral losses and for contralateral stimulation in single-sided deafness. Bone-anchored hearing aids (BAHAs) are an essential component of an ENT surgeons' armamentarium for treating patients with impaired hearing.
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