Minimally Invasive Ponto Surgery compared to the linear incision technique without soft tissue reduction for bone conduction hearing implants: study protocol for a randomized controlled trial

Abstract

BackgroundOver the last years, less invasive surgical techniques with soft tissue preservation for bone conduction hearing implants (BCHI) have been introduced such as the linear incision technique combined with a punch. Results using this technique seem favorable in terms of rate of peri-abutment dermatitis (PAD), esthetics, and preservation of skin sensibility. Recently, a new standardized surgical technique for BCHI placement, the Minimally Invasive Ponto Surgery (MIPS) technique has been developed by Oticon Medical AB (Askim, Sweden). This technique aims to standardize surgery by using a novel surgical instrumentation kit and minimize soft tissue trauma.MethodsA multicenter randomized controlled trial is designed to compare the MIPS technique to the linear incision technique with soft tissue preservation. The primary investigation center is Maastricht University Medical Center. Sixty-two participants will be included with a 2-year follow-up period. Parameters are introduced to quantify factors such as loss of skin sensibility, dehiscence of the skin next to the abutment, skin overgrowth, and cosmetic results. A new type of sampling method is incorporated to aid in the estimation of complications. To gain further understanding of PAD, swabs and skin biopsies are collected during follow-up visits for evaluation of the bacterial profile and inflammatory cytokine expression.The primary objective of the study is to compare the incidence of PAD during the first 3 months after BCHI placement. Secondary objectives include the assessment of parameters related to surgery, wound healing, pain, loss of sensibility of the skin around the implant, implant extrusion rate, implant stability measurements, dehiscence of the skin next to the abutment, and esthetic appeal. Tertiary objectives include assessment of other factors related to PAD and a health economic evaluation.DiscussionThis is the first trial to compare the recently developed MIPS technique to the linear incision technique with soft tissue preservation for BCHI surgery. Newly introduced parameters and sampling method will aid in the prediction of results and complications after BCHI placement.Trial registrationRegistered at the CCMO register in the Netherlands on 24 November 2014: NL50072.068.14. Retrospectively registered on 21 April 2015 at ClinicalTrials.gov: NCT02438618. This trial is sponsored by Oticon Medical AB.Electronic supplementary materialThe online version of this article (doi:10.1186/s13063-016-1662-0) contains supplementary material, which is available to authorized users.

Cytokine expression profile in the bone‐anchored hearing system: 12‐week results from a prospective randomized, controlled study

“…The study protocol has previously been published 6. Patients were recruited at the out‐patient ENT department at MUMC+.…”

“…Prior to incision, skin thickness was measured to determine the appropriate abutment length according to the surgical manual 19, 20. Surgical techniques included the linear incision technique with soft‐tissue preservation6, 21 or the MIPS technique 6, 22. An elaborate description is provided in the protocol publication 6.…”

“…After removal of the cannula, the BAHS was placed with 40–50 Ncm insertion torque setting. An installation indicator was used to aid in the estimation of complete insertion 6, 20, 23…”

“…Apart from discomfort and morbidity, recurrent episodes of inflammation can limit the use of the sound processor and in some cases lead to the extrusion of the fixture or voluntary implant removal. To assess the soft tissue surrounding the abutment, Holgers index is commonly used in clinical practice and it is frequently described as an endpoint analysis in trials, although questions regarding its validity warrant further study 5, 6, 7…”

“…To assess the soft tissue surrounding the abutment, Holgers index is commonly used in clinical practice and it is frequently described as an endpoint analysis in trials, although questions regarding its validity warrant further study. [5][6][7] Materials implanted in hard or soft tissue stimulate different cell types. For instance, inflammatory cells produce cytokines, such as interleukin-1 (IL-1), IL-6, IL-10, and tumor necrosis factor-a (TNF-a), which are involved in regulating the immune response and wound healing.…”