Objective:To compare the surgical outcomes of the Minimally Invasive Ponto Surgery (MIPS) technique with those of the linear incision technique with soft-tissue preservation for bone-anchored hearing systems (BAHS).Design:Sponsor-initiated multicenter, open, randomized, controlled clinical trial.Setting:Maastricht University Medical Centre, Ziekenhuisgroep Twente and Medisch Centrum Leeuwarden, all situated in The Netherlands.Participants:Sixty-four adult patients eligible for unilateral BAHS surgery.Interventions Single-stage BAHS surgery with 1:1 randomization to the linear incision technique with soft-tissue preservation (control) or the MIPS (test) group.Primary and Secondary Outcome Measurements:Primary objective: compare the incidence of inflammation (Holgers Index ≥ 2) during 12 weeks’ follow-up after surgery. Secondary objectives: skin dehiscence, pain scores, loss of sensibility around the implant, soft-tissue overgrowth, skin sagging, implant extrusion, cosmetic results, surgical time, wound healing and Implant Stability Quotient measurements.Results:Sixty-three subjects were analyzed in the intention-to-treat population. No significant difference was found for the incidence of inflammation between groups. Loss of skin sensibility, cosmetic outcomes, skin sagging, and surgical time were significantly better in the test group. No statistically significant differences were found for dehiscence, pain, and soft-tissue overgrowth. A nonsignificant difference in extrusion was found for the test group. The Implant Stability Quotient was statistically influenced by the surgical technique, abutment length, and time.Conclusion:No significant differences between the MIPS and the linear incision techniques were observed regarding skin inflammation. MIPS results in a statistically significant reduction in the loss of skin sensibility, less skin sagging, improved cosmetic results, and reduced surgical time. Although nonsignificant, the implant extrusion rate warrants further research.

To standardize the reporting of hearing results after middle ear surgery, the Committee on Hearing and Equilibrium of the American Academy of Otolaryngology-Head and Neck Surgery proposed 2 levels of guidelines: level 1 for reporting summary data and level 2 for reporting raw data. The Committee encourages the reporting of raw data from each individual case. However, in studies in which the examined population is too large, this can yield difficulties. With respect to this point, we designed a method for a simple visual presentation of hearing results in an attempt to provide data from each individually operated ear in a patient group. In this method the relation between the preoperative and postoperative bone-conduction levels is evaluated to assess overclosure and iatrogenic cochlear damage, and the relation between postoperative gain in air conduction and the preoperative air-bone gap is evaluated as a measure of technical success rate. This results in 2 plots, which we called the Amsterdam Hearing Evaluation Plots. Audiometric data from 451 stapes operations were used to demonstrate the use of the Amsterdam Hearing Evaluation Plots.

The Committee on Hearing and Equilibrium of the American Academy of Otolaryngology-Head and Neck Surgery proposed guidelines to provide more uniformity in reporting hearing results after middle ear surgery. One of the proposals was to include the hearing thresholds at 0.5, 1, 2, and 3 kHz in a 4-frequency pure-tone average (PTA) and to use post-operative bone-conduction (BC) levels rather than preoperative BC levels in describing postoperative air-bone gaps (ABGs). The hearing results of 451 stapes operations were evaluated to analyze to what extent the choice of different audiologic criteria affects success rates. It appeared that choice of PTA significantly affects postoperative gain in air-conduction thresholds and ABG levels. If one takes the improvements in speech-reception thresholds as the gold standard, the gain in air-conduction correlates best with a gain in speech-reception threshold if a higher frequency, such as 3 or 4 kHz, is included in a 4-frequency PTA. Also, choice of preoperative or postoperative BC in computing postoperative ABGs had a significant effect on the mean postoperative ABG levels, showing more favorable results with the use of preoperative BC thresholds.

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.