LOS ANGELES — Bone-anchored hearing aid implantation may be better performed in two stages in children to reduce postoperative complications, a retrospective study suggests.
Postoperative complications reported in the literature vary widely from 0% to 19% for extrusion of the titanium fixture and 8% to 61% for skin reactions—the two most common complications in both pediatric and adult populations.
Surgery is considered so simple and straightforward, however, that reports are surfacing of implantation being performed in the office setting under local anesthesia.
Surgery may be better performed under general anesthesia using a two-stage technique for children so that proper osseointegration can occur between stages, Hae-Ok Ana Kim, M.D., said at the annual meeting of the American Academy of Otolaryngology-Head and Neck Surgery Foundation. General anesthesia is recommended to allow for meticulous surgical technique in creating the skin flap and establishing hemostasis, and for the comfort of both the patient and the surgeon.
In a single-stage technique, both the titanium fixture and skin flap procedures are performed at the same time. In a two-stage technique, the titanium fixture is installed in the skull and covered by the overlying soft tissue until it has osseointegrated with the surrounding bone. Approximately 3–5 months later, stage two is performed in which the soft tissue surrounding the titanium fixture is debulked and the skin flap created.
The series included 37 patients with 47 implants who received bone-anchored implants at the University of Michigan in Ann Arbor between 1997 and 2004, according to the study performed by Dr. Kim, a neurotology/otology fellow, and senior author H. Alexander Arts, M.D., a neurotologist and professor of otorhinolaryngology and surgery at the university.
Patients ranged in age from 3 years to 80 years, with 26 adult and 11 pediatric patients.
The most common indications for implantation were hearing loss after acoustic neuroma surgery, otosclerosis, sudden idiopathic hearing loss in the single-sided deafness category, and congenital aural atresia in the conductive/mixed hearing loss category.
The most common early postoperative complication was granulation tissue around the abutment post requiring local wound care in 11 implants (23.4%), hypertrophic scarring in 5 implants (10.6%), and implant extrusion requiring wound revision in 3 (6.4%). Granulation tissue was more common in adults than children (9 vs. 2), and occurred anywhere from 1 week to 8 weeks postoperatively. The incidence did not vary by the type of skin flap used, but was more common with the single-stage technique.
All three cases of implant extrusion occurred with the 3-mm titanium fixture implanted in a single stage.
Both of the pediatric extrusions occurred in patients who had skull thickness less than 3 mm.
Patients with greater skull thickness were more likely to have skin graft complications.
Early postoperative granulation tissue around the abutment is the most common complication and requires wound care.
Hypertrophic scar growth over the abutment requires wound revision and occurred in 5 of 47 implants in one series. Photos courtesy Dr. Hae-Ok Ana Kim