Medical and surgical complications of the second 100 adult cochlear implant patients in Birmingham.

One hundred consecutive adult cochlear implant patients, numbered 101 to 200 in an ongoing series, were prospectively monitored and data collected using the same protocol as for the first 100 patients. The study period was 1999 to 2001. The total number of procedures was 122. Changes in practice following the first 100 implants included a standard surgical technique with a smaller incision and lesser flap mobilization, and routine facial nerve monitoring. As far as was practicable, the same commercial type of implant was used. There were 111 (91 per cent) implantation episodes, five (4 per cent) explantation episodes, four (3.3 per cent) reimplantation episodes and two (1.6 per cent) revision procedures. Eighty-nine patients underwent unilateral implantation and 11 underwent bilateral implantation. Major complications included flap breakdown (1.6 per cent), extrusion of electrode array (0.8 per cent) and device failure (0.8 per cent). The overall major complication rate was 3.2 per cent (4/122). The overall minor complication rate was 18 per cent. In addition, 7.3 per cent experienced transient vertigo and 5.7 per cent experienced local discomfort lasting three days on average with complete resolution. The overall complication rate in the second 100 implant patients was lower than in the first 100. Smaller incision and lesser flap mobilization reduced the minor complication rate.