Comparison of Cochlear Implant Device Fixation-Well Drilling Versus Subperiosteal Pocket. A Cost Effectiveness, Case-Control Study.

OBJECTIVE:To compare surgical characteristics and complications between well drilling (WD) and subperiosteal pocket techniques (SPT) for receiver/stimulator (R/S) fixation of cochlear implant (CI), and conduct cost-effectiveness analysis. STUDY DESIGN:Retrospective clinical study, decision-analysis model. SETTING:Tertiary referral center. PATIENTS:Three-hundred and eighty-eight CI recipients with a minimum of 6-months follow-up. INTERVENTIONS:CI surgery using either WD or SPT for R/S fixation. A decision-analysis model was designed using data from a systematic literature review. MAIN OUTCOME MEASURES:Surgical operation time, rates of major and minor long-term complications were compared. Incremental cost-effectiveness was also estimated, comparing the two methods of fixation. RESULTS:We compared 179 WD with 209 SPT. Surgery time was significantly shorter in SPT (148 versus 169 min, p = 0.001) and remained significant after adjustment for possible confounders. Higher rates of major complications requiring surgical intervention were found with SPT (10.5% versus 4.5%, p = 0.042), however, the difference was not significant after adjusting for follow-up time (47.8 versus 32.5 months for SPT, WD respectively; p < 0.001). The incremental cost-effectiveness ratio for WD (compared with SPT) was $48,795 per major complication avoided, which was higher than the willingness-to-pay threshold of $47,700 (average cost of 2 h revision surgery). CONCLUSIONS:SPT was found to be faster but potentially risks more complications, particularly relating to device failure. Further long-term studies are required to validate these differences. Based on data from the current literature, neither of the methods is compellingly cost-effective over the other, and surgeons can base their choice on personal preference, comfort, and previous training.