Retrosigmoidal placement of an active transcutaneous bone conduction implant: surgical and audiological perspectives in a multicentre study

Abstract

SUMMARY Introduction The retrosigmoidal (RS) placement of the Bonebridge system (BB) has been advocated for cases of unfavourable anatomical or clinical conditions which contraindicate transmastoid-presigmoidal positioning. However, these disadvantageous conditions, combined with the considerable dimensions of the implant, may represent a challenge, especially for surgeons with no skull base experience. Moreover, the literature reports only limited experience concerning RS implantation of the BB system. Methods A multicentre, retrospective study was conducted to analyse the surgical and functional outcomes of a wide population of patients undergoing RS placement of the BB system by means of a surgical technique specifically developed to overcome the intraoperative issues related to this surgery. Twenty patients with conductive or mixed hearing loss and single sided deafness were submitted to RS implantation of the BB system. Results Audiological assessment concerning the measurement of the functional and effective gain by pure-tone audiometry (28 dB HL and -12.25 dB HL, respectively) and speech audiometry (24.7 dB HL and -21 dB HL, respectively) was conducted. A high overall subjective improvement of quality of life was recorded with the Glasgow Benefit Inventory questionnaire. No major complications, such as device extrusions or other conditions requiring revision surgery, were reported during the follow-up period (median: 42 months). Conclusions In our study, which has one of the largest cohort of patients reported in the literature, RS placement of the BB system was safe and effective. Our functional results showed comparable hearing outcomes with presigmoidal placement. The effective gain, rarely investigated in this field, may be the object of further research to improve our understanding of bone conduction mechanisms exploited by bone conduction hearing implants.

Multi-Magnet Cochlear Implant Technology and Magnetic Resonance Imaging: The Safety Issue

“…In the current literature, several strategies have been explored to improve MRI image quality in the presence of the CI magnet, including the adaptation of CI angular position or distance from the external auditory canal [ 27 , 28 ], patient head orientation [ 29 ], and MRI algorithm manipulation [ 30 ]. In this respect, the application of metal artifact reduction sequences (MARS) has recently been shown to be a valuable additional strategy for improving image quality in the presence of CIs, particularly in the case of skull base disorders requiring MRI monitoring [ 31 , 32 ].…”

Current trends on subtotal petrosectomy with cochlear implantation in recalcitrant chronic middle ear disorders

“…Profoundly deaf patients require an effective hearing rehabilitation and when deafness is concomitant with chronic refractory middle ear pathologies, hearing rehabilitation must be combined with the successful eradication of the disease. While some bone conduction hearing implants can be positioned away from an open cavity or a chronically discharging middle ear 19 , cochlear implantation in these scenarios seems hazardous. SP overcomes these limits, resulting in a “safe and dry” cavity that is optimal for COI positioning 5 .…”

Long-Term Follow-Up in Active Transcutaneous Bone Conduction Implants

“…Three other studies report average EGs for CMHL using the bone conduction in the implanted ear rather than the ear with the best bone conduction. These studies report EGs ranging from −16.9 to −11.0 dB (17,31,32). We found only one study that used the bone conduction of the best hearing ear and reported EGs of −8.8 and −11.3 dB for 10 subjects with mixed hearing loss and 15 subjects with SSD, respectively (18).…”

“…In our study, the CMHL group had an average total GBI of 31.7 and this is in concordance with other studies (16,36). Some studies only report combined results for SSD and CMHL groups, which makes the results difficult to interpret (31,37,38). In our study, the proportion of constant users was significantly higher in the CMHL group than in the group with SSD (Table 2).…”