Long-Term Outcomes of the Minimally Invasive Ponto Surgery vs. Linear Incision Technique With Soft Tissue Preservation for Installation of Percutaneous Bone Conduction Devices

Abstract

Objective: Comparing the surgical outcomes of the Minimally Invasive Ponto Surgery (MIPS) technique with the linear incision technique with soft tissue preservation (LITT-P) for bone conduction devices after a follow-up of 22 months. Methods: In this multicenter randomized controlled trial, there was the inclusion of 64 adult patients eligible for unilateral surgery. There was 1:1 randomization to the MIPS (test) or the LITT-P (control) group. The primary outcome was an (adverse) soft tissue reaction. Secondary outcomes were pain, loss of sensibility, soft tissue height/overgrowth, skin sagging, implant loss, Implant Stability Quotient measurements, cosmetic scores, and quality of life questionnaires. Results: Sixty-three subjects were analyzed in the intention-to-treat population. No differences were found in the presence of (adverse) soft tissue reactions during complete follow-up. Also, there were no differences in pain, wound dehiscence, skin level, soft tissue overgrowth, and overall quality of life. Loss of sensibility (until 3-month post-surgery), cosmetic scores, and skin sagging outcomes were better in the MIPS group. The Implant Stability Quotient was higher after the LITT-P for different abutment lengths at various points of follow-up. Implant extrusion was nonsignificantly higher after the MIPS (15.2%) compared with LITT-P (3.3%). Conclusion: The long-term results show favorable outcomes for both techniques. The MIPS is a promising technique with some benefits over the LITT-P. Concerns regarding nonsignificantly higher implant loss may be overcome with future developments and research. Clinical Trial Registration: www.ClinicalTrials.gov, identifier: NCT02438618.

Keywords: MIPS; bone conduction device (BCD); hearing loss; minimally invasive ponto surgery; soft tissue reactions; surgical outcomes; surgical technique; tissue preservation.

Conflict of interest statement

MLJ, SJ, and MH are paid employees of Oticon Medical. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Copyright © 2021 Strijbos, Straatman, Calon, Johansson, de Bruijn, van den Berge, Wagenaar, Eichhorn, Janssen, Jonhede, van Tongeren, Holmberg and Stokroos.

Figures

Figure 1

Subject flow chart.

Figure 2

(A) Stacked bar chart for the highest observed Holgers Index scores during standard follow-up visits. In the right-sided figure (B), missing data were corrected with the last observation carried forward technique. Last visit (“2 years”) was at 22 months of follow-up.

Figure 3

Boxplots of ISQ measurements during standard follow-up visits with a subdivision for different abutment lengths. ISQ measurements are displayed for ISQ Low (A) en ISQ High (B). Asterisks (*) indicate a significant difference as calculated with a Mann–Whitney U-test (level of significance p < 0.05). Last visit (“2 years”) was at 22 months of follow-up.