Cochlear Implant Surgery: How Young Is Too Young?

The patients who received CIs did so with parental informed consent and as soon as an accurate diagnosis was obtained and all pre-operative surgical protocols had been completed, Dr. Colletti and his team reported. Patients’ hearing function was assessed at regular intervals throughout the 48-month period of post-implant follow-up.

Dr. Colletti stressed to ENT Today that additional in-depth electrophysiological evaluations were performed in order “to obtain the correct information on the hearing levels [in children] under six months of age.” Such testing, he noted, helped to ensure that children were optimal candidates for CI surgery.

Results Detailed

The mean age of the patients in Group 1 (3.9 months) “is the lowest described in the literature,” Dr. Colletti reported. And in those infants, some of the most impressive results were observed. For example, speech perception scores in Group 1, as measured by the Categories of Auditory Performance (CAP II) test, were statistically significantly higher than in all of the other implanted children, the investigators reported (P <0.001).

Moreover, both receptive vocabulary and speech production in the youngest group were comparable with a control group of normal-hearing children “and significantly better than growth rates achieved by children implanted after six months.”

The complications that occurred during the study were all deemed minor. For example, two children in the study (aged 13 and 24 months) experienced transitory bronchospasm and hypotension as a result of anesthesia. In both cases, the reactions resolved with medical treatment.

For Dr. Colletti, the results confirmed that infants younger than six months of age can be safely and effectively implanted and given a chance to achieve “their full [hearing and developmental] potential, offsetting the need to learn at a faster than normal rate to attain age-appropriate norms.”

The investigators stressed several important limitations to the study. First and foremost, they noted, was the small sample size of infants younger than six months of age who were fitted with CIs. Given those small numbers, they reported, it is difficult to generalize the low incidence of complications seen in that cohort. Moreover, the study was uncontrolled and observational and included “personal audiological

criteria and…limited support from the literature.” Given those limitations, they struck a cautious tone in their conclusion: “The data … must be considered explorative, necessitating a more extensive study.”

“For me, if the child is not old enough to [undergo] a behavioral audiogram, I’m not even going to consider…CI surgery.”

—Bruce Gantz, MD

Experts Voice Caution—and Concern

Blake Papsin, MD, director of the Cochlear Implant Program at the Hospital for Sick Children in Toronto, Ontario, said he appreciated the investigator’s conservative conclusions. But he voiced concern that some surgeons may nevertheless read the study and assume it supports a more aggressive approach to CI surgery in infants.