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

Abstract

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.

Current Issues With Pediatric Cochlear Implantation

“…One such modification is the direct subperiosteal pocket technique, in which a posterosuperior subperiosteal pocket is made with a periosteal elevator just larger than the size of the receiver-stimulator, allowing for appropriate positioning without the need for drilling or fixation. Sweeney, et al [47] performed a retrospective chart review of 193 patients undergoing implantation with creation of this tight subperiosteal pocket and found an 18.9% decrease in operative time, as well as no evidence of receiver-stimulator migration [47][48][49]. Cohen, et al [50] also reported on their outcomes with the subperiosteal pocket on six children ≤1 year old; the authors found no evidence of device migration in this patient population.…”

“…Historically, surgeons would drill a depression in the skull in order to accommodate the receiver-stimulator, which had a much larger thickness/profile than at present. This may expose dura in the case of children with thin skulls as well as increase operative times during cochlear implantation [47,48]. Instead, surgeons at present have made several different modifications.…”

A monocenter, patient-blinded, randomized, parallel-group, non-inferiority study to compare cochlear implant receiver/stimulator device fixation techniques (COMFIT) with and without drilling in adults eligible for primary cochlear implantation

“…Other complications that have been reported (but occur very rarely) and associated with this technique are late-onset hematomas, epi-/subdural hematoma, tentorial herniation, and cerebral infarction, as well as meningitis [ 5 , 7 – 11 ]. To avoid such risks, in recent years ENT surgeons have adopted less invasive techniques [ 1 – 3 , 10 , 12 – 20 ]. Additionally, later CI models have a lower profile and a flatter bottom.…”

“…Since the publication of the study by Balkany et al in 2009, many ENT specialists are applying the tight subperiosteal technique [ 1 , 2 , 12 – 14 , 16 – 18 , 20 , 30 – 33 ]. However, since the R/S device is not fixated in a bony recess or by sutures, migration of the device is a point of concern due to the complications that can occur.…”