LOS ANGELES — Revision surgery for cochlear implant is feasible and children continue to benefit with the new implant, according to a retrospective analysis of 27 cases.
The feasibility of postrevision cochlear implants was evaluated after a review of the literature revealed problems achieving the same depth of insertion with a revision surgery, Jose N. Fayad, M.D., said at the annual meeting of the American Academy of Otolaryngology-Head and Neck Surgery Foundation.
About 5% of children undergoing cochlear implant surgery subsequently require revision surgery, most commonly due to device failure.
“Once it has been confirmed that the implant has failed, it is important to replace it as soon as possible so the child can continue to develop communication skills and language,” Dr. Fayad said in an interview.
The analysis included 496 children, aged 18 months to 16 years, treated at the House Clinic/House Ear Institute in Los Angeles between 1987 and 2005. The interval between surgeries was as short as 8 weeks and up to 6 years. Of the 27 patients who had revision surgery, 18 were reinsertions, and 9 were wound revisions without explantation.
Two patients had their primary surgery performed at another institution, resulting in a reimplantation rate of 3.3% for the institute.
The cause of revision surgery without explantation was mainly infection; device failure (14 patients), trauma (3 patients), and wound infection (1 patient) preceded the reinsertions. Device failure was not significantly related to device type, although more failures occurred among the older ceramic CLARION CI and CII models, which since have been recalled by Advanced Bionics Corp.
With the exception of one patient with a severe cochlear malformation, a new device was fully inserted without difficulty in all patients at the time of revision surgery.
Soundfield thresholds obtained at 250 Hz, 500 Hz, 1,000 Hz, 2,000 Hz, and 4,000 Hz were completely stable before and after the operation, indicating the audibility levels of the patients did not change between the pre-device failure and postrevision periods, he said.
There was no change in speech recognition, with most patients able to understand nouns and some sentences post revision surgery.
Statistical analysis using paired t-tests and the Wilcoxon signed ranks tests indicated that differences in clinical outcomes between pre-device failure and postrevision did not reach statistical significance.
Dr. Fayad, of the House Ear Clinic in Los Angeles, suggested leaving the electrode within the cochlea as a stent until the surgeon is ready to reinsert to avoid tissue collapsing into the cochlea.