Three-Year Clinical and Audiological Outcomes of Percutaneous Implants for Bone Conduction Devices: Comparison Between Tissue Preservation Technique and Tissue Reduction Technique.

Objectives: To evaluate the three-year clinical and audiological outcomes of soft-tissue preservation compared to softtissue reduction in linear incision surgery for percutaneous implant for bone conduction (BC) devices. Methods: Twenty-five patients (25 implants) were enrolled in a prospective cohort for implant surgery with linear incision and tissue preservation. The control group consisted of 25 patients (25 implants) from a previous randomized controlled trial in which a linear incision with soft-tissue reduction was applied. Follow-up visits were scheduled at 7 and 21 days (fitting of sound processor); 12 weeks; 6 months; and at 1, 2, and 3 years after implantation. Main outcome measures were skin sensibility, soft-tissue status, Implant Stability Quotient (ISQ), skin height, implant survival, revision surgery, scar assessment, and hearing thresholds (BC in-situ between 250 Hz and 8 kHz with BC device on testband and abutment, and BC thresholds at 250Hz-4 kHz with a B71 bone conductor). Results: Tissue preservation resulted in superior sensibility (mean percentage correct responses 99.7% [SD 1.7] vs 92.0% [SD 9.2], p = 0.0001). No spontaneous implant loss occurred in either group. The abutment was removed in two tests and in one control patient. Two control patients needed skin revision surgery. Although not statistically significant, more adverse soft-tissue reactions (Holgers >= 2) were observed in the test-group (n = 9 [36%] vs n = 3 [12%], p = 0.095). ISQ increased significantly more in the test group compared to the control group (7.64 [SD 4.05] vs 4.29 [SD 3.93]). Skin thickening, scar assessment, and hearing outcomes were comparable. Conclusion: Tissue preservation demonstrated superior skin sensibility compared to tissue reduction while other clinical outcomes were comparably excellent.