Modified incisions for reduction of soft tissue for one-stage, bone-anchored hearing aid implantation.

Abstract

INTRODUCTION The majority of patients who require a hearing aid can be fitted with an air-conduction hearing aid. If an air-conduction hearing aid cannot be used because of recurrent otorrhea or atresia of the auditory canal, it may be possible to fit a bone-conduction hearing aid. An alternative to the conventional bone-conductor aid is the boneanchored hearing aid (BAHA). The BAHA has both cosmetic and acoustic advantages over any conventional aid and hence is a popular choice today. The BAHA is coupled to a percutaneous titanium implant anchored in the temporal bone. The absence of interposing soft tissues (direct bone conduction) gives better quality sound, requires less energy, and offers much greater comfort. A skin graft of thin non–hair-bearing skin is required at the implant site. Insertion of percutaneous implant into the temporal bone for the coupling of a BAHA can be performed in two stages. Most centers perform a one-stage procedure in adults and a two-stage procedure in children. We have found that a one-stage procedure with the following modification allows the avoidance of a two-step procedure and reduces other wound-related complications. We believe this enables quicker healing and ensures timely fitting of the BAHA. SURGICAL STEPS The surgical steps can be divided into anesthesia and skin preparation, incision and soft tissue reduction, placement of fixtures, skin graft replacement, abutment positioning, and dressings and aftercare. 1. The procedure is performed with the patient under local anesthesia (except in children). 2. We describe modified incisions to facilitate soft tissue reduction under direct visual control. An area of circular skin 1.5 to 2 cm in diameter is excised and subcutaneous tissue under this area is removed to allow the edges of the skin to drop down to the periosteum without any tension (as an alternative, a splitthickness skin graft or an inferiorly based skin flap can be harvested or raised at the implant site). 3. Soft tissue reduction around this circular island is facilitated by four radial incisions 1 cm in length extending from the circumference (Fig. 1). 4. Soft tissue reduction is performed under direct visual control with a cutting diathermy and hemostasis is achieved using a coagulation diathermy (Fig. 2). The soft tissue reduction must be generous, especially in the superior semicircle. Ignoring this step would result in the soft tissue’s sagging with gravity, which may interfere with the fit of the aid. 5. The drilling procedure and insertion of the flange fixture are performed by the standard Branemark technique. 6. A free skin graft is harvested from the postauricular skin, thinned to remove roots of hair follicles, and sutured over the fixture. The skin around the implant then makes direct contact with bone tissue. From the Department of Otolaryngology—Head and Neck Surgery, Staffordshire General Hospital, Staffordshire, United Kingdom. Editor’s Note: This Manuscript was accepted for publication May 4, 2000. Send Correspondence to T. Narayana Reddy, FRCS, DLO, Consultant ENT Surgeon, Staffordshire General Hospital, Weston Road, Stafford ST16 3SA, United Kingdom.