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

Health Economic Cost Analysis for Percutaneous Bone Conduction Devices: The Minimally Invasive Ponto Surgery Versus Linear Incision Technique with Tissue Preservation

OBJECTIVES

To identify differences in mean cost per patient between the Minimally Invasive Ponto Surgery (MIPS) and the linear incision technique with tissue preservation (LITT-P).

STUDY DESIGN

Health economic cost analysis.

SETTING

The analysis was performed in a randomized multicenter controlled trial cohort.

PATIENTS

Adult patients eligible for unilateral bone conduction device surgery.

INTERVENTIONS

MIPS versus LITT-P surgery for bone conduction device implantation.

MAIN OUTCOME MEASURES

Perioperative and postoperative costs were identified and compared.

RESULTS

The difference in mean cost per patient between both techniques was €77.83 in favor of the MIPS after 22 months follow-up. The mean costs per patient were lower in the MIPS cohort for surgery (€145.68), outpatient visits (€24.27), systemic antibiotic therapy with amoxicillin/clavulanic acid (€0.30) or clindamycin (€0.40), abutment change (€0.36), and abutment removal (€0.18). The mean costs per patient were higher for implant and abutment set (€18.00), topical treatment with hydrocortison/oxytetracycline/polymyxine B (€0.43), systemic therapy with azithromycin (€0.09) or erythromycin (€1.15), local revision surgery (€1.45), elective explantation (€1.82), and implant extrusion (€70.42). Additional analysis of scenarios in which all patients were operated under general or local anesthesia or with recalculation when using current implant survival rates showed that differences in mean cost per patient were also in favor of the MIPS.

CONCLUSION

The difference between the MIPS and the LITT-P in mean cost per patient was €77.83 in favor of the MIPS after 22 months of follow-up. The MIPS is an economically responsible technique and could be promising for the future.

Ex vivo Evaluation of a New Drill System for Placement of Percutaneous Bone Conduction Devices

The procedure for installation of a percutaneous bone-conducting device has undergone significant improvements since its introduction 40 years ago. Today, the linear incision technique with tissue preservation (LITT-P) and the minimally invasive procedure (MIPS) are the most commonly used approaches. In both these techniques, a gradual increase of the osteotomy using a three-step drilling sequence is utilized, as this approach can allow a stepwise deepening and widening of the osteotomy in the mastoid and can prevent bone overheating. A new minimally invasive procedure (MONO) has been developed that allows an osteotomy to be performed and enables complete removal of the bone volume in one single drill step for a 4 mm implant using a novel parabolic twist drill. Here, the feasibility of the MONO procedure was qualitatively and quantitatively evaluated in terms of the dura response to drill trauma in comparison with the outcomes achieved with guide drills used for the LITT-P and MIPS techniques. Fresh frozen temporal bone from a human cadaver was subjected to penetration by three drills beyond the base of the mastoid bone to different depths. The sites were evaluated, and the damage to and possible penetration of the dura were determined. The results showed that for a drill depth exceeding mastoid bone thickness by not more than 1 mm, damage to the dura was limited or nonexistent, whereas for a drill depth exceeding bone thickness by 2 mm, damage increased, or the dura was penetrated. There was a trend toward more damage and penetration for both the round burr and MIPS guide drill compared with the MONO drill bit. From this experimental ex vivo study, it can be concluded that if the dura is encountered, the MONO system is not more inclined to penetrate the dura than the conventional LITT-P and MIPS systems.

A Clinical Evaluation of Minimally Invasive Ponto Surgery With a Modified Drill System for Inserting Bone-Anchored Hearing Implants

OBJECTIVE

To compare 6-months outcomes of the modified minimally invasive Ponto surgery (m-MIPS) to both the linear incision technique with soft tissue preservation (LIT-TP), and original MIPS (o-MIPS) for inserting bone-anchored hearing implants (BAHIs).

STUDY DESIGN

Exploratory pilot study with one test group and two historical control groups.

SETTING

Tertiary referral center.

PATIENTS

In the test group, 24 patients (25 implants) were prospectively included. Each control group comprised 25 patients (25 implants) who participated in previously conducted clinical trials.

INTERVENTIONS

The test group received a BAHI using m-MIPS. The two control groups underwent surgery using the LIT-TP and o-MIPS, respectively.

MAIN OUTCOME MEASURES

Implant survival, implant stability, and surgery-related variables were compared between the test and control groups. Soft tissue status, skin sensibility, and subjective numbness were compared between m-MIPS and LIT-TP only.

RESULTS

Implant survival was comparable between m-MIPS and LIT-TP, whereas implant stability measurements were slightly lower for m-MIPS. M-MIPS resulted in comparable adverse skin reactions and skin sensibility, significantly reduced surgical time and slightly improved subjective numbness, compared with LIT-TP. Between m-MIPS and o-MIPS, no statistically significant differences in implant survival, implant stability and surgical time were observed.

CONCLUSIONS

A trend toward lower implant loss rates after m-MIPS was observed, when compared with o-MIPS. M-MIPS seems to be a good alternative to LIT-TP for inserting BAHIs, since most clinical outcomes were either comparable or slightly better for m-MIPS. Upon deciding on which technique to use, larger studies on implant survival should be performed. Furthermore, other aspects such as costs, training aspects and surgical experience should be evaluated.

Tissue Preservation Techniques for Bone-Anchored Hearing Aid Surgery

OBJECTIVE

Compare outcomes of surgical techniques in percutaneous bone-anchored hearing implant surgery.

STUDY DESIGN

Matched retrospective cohort study.

SETTING

Tertiary referral center.

PATIENTS

Electronic review of adult and pediatric patients who underwent bone conduction device surgery by either the Minimally-invasive Ponto Surgery (MIPS) technique or the linear incision with no soft tissue removal (LnSTR) technique or between August 2015 and April 2018 at our facility.

INTERVENTION

Patients in MIPS group underwent Minimally invasive Ponto Surgery (MIPS) technique, while those in LnSTR group underwent LnSTR technique.

MAIN OUTCOME MEASURE

Major outcome was presence/severity of localized skin reaction. Secondary outcomes included cosmetic outcome, revision surgery, minor adverse events, device utilization, and postoperative aided speech recognition thresholds (SRTs) across 250 to 4000 Hertz (Hz).

RESULTS

Fifty patients met inclusion criteria. There was a significantly lower rate of localized cutaneous reactions for the MIPS group (4.5%) compared with LnSTR group (33.3%; p = 0.026). Rate of revision surgery was significantly less for MIPS (13.6%) compared with LnSTR (20.8%; p = 0.008). Occurrence of poor cosmetic outcome was noted significantly less for the MIPS group (9.1%) compared with LnSTR patients (20.8%; p = 0.005). Minor adverse events and aided SRTs were comparable between groups.

CONCLUSIONS

MIPS leads to a statistically significant decrease in localized cutaneous reaction compared with LnSTR. Both the LnSTR and MIPS techniques are safe and effective in the treatment of hearing loss, however MIPS may be superior in certain cases by offering improved healing, decreasing needs for wound care, and possibly decreasing need for frequent follow up.

Six-Month Clinical Outcomes for Bone-Anchored Hearing Implants: Comparison Between Minimally Invasive Ponto Surgery and the Linear Incision Technique With Tissue Preservation

OBJECTIVES

The aim of this study is to investigate and compare the clinical outcomes of minimally invasive ponto surgery (MIPS) to the linear incision technique with soft tissue preservation (LIT-TP) for percutaneous bone-anchored hearing implants (BAHI).

STUDY DESIGN

Prospective cohort study with a historical control group.

SETTING

Tertiary referral center.

PATIENTS

Twenty-five patients were prospectively included in the test group. The control group consisted of 25 patients who previously participated in another clinical trial and already underwent BAHI surgery.

INTERVENTION

All patients were implanted with a 4.5-mm-wide implant, using MIPS in the test group and the LIT-TP in the control group. Follow-up visits were scheduled 7 days, 21 days (sound processor fitting), 12 weeks and 6 months after surgery.

MAIN OUTCOME MEASURES

The primary outcome measure was skin sensibility around the abutment 6 months after surgery. Secondary outcomes were subjective numbness, surgery time, wound healing, adverse soft tissue reactions, cosmetic outcomes, implant stability quotient (ISQ), implant survival, and sound processor use.

RESULTS

Skin sensibility, adverse soft tissue reactions, and sound processor use were comparable between groups. The test group had a shorter surgery time and better cosmetic outcomes. More skin dehiscences and a statistically nonsignificant higher implant loss rate (12% vs 0%, p = 0.079) were observed in the test group.

CONCLUSION

MIPS is comparable to the LIT-TP regarding skin sensibility at 6 months and soft tissue tolerability. With MIPS, surgery time is further reduced and better cosmetic outcomes are reported. More research into MIPS, exact drill protocol, used instruments, and associated implant loss is warranted.

Multimodal Analysis of the Tissue Response to a Bone-Anchored Hearing Implant: Presentation of a Two-Year Case Report of a Patient With Recurrent Pain, Inflammation, and Infection, Including a Systematic Literature Review

Osseointegration is a well-established concept used in applications including the percutaneous Bone-Anchored Hearing System (BAHS) and auricular rehabilitation. To date, few retrieved implants have been described. A systematic review including cases where percutaneous bone-anchored implants inserted in the temporal bone were retrieved and analyzed was performed. We also present the case of a patient who received a BAHS for mixed hearing loss. After the initial surgery, several episodes of soft tissue inflammation accompanied by pain were observed, leading to elective abutment removal 14 months post-surgery. Two years post-implantation, the implant was removed due to pain and subjected to a multiscale and multimodal analysis: microbial DNA using molecular fingerprinting, gene expression using quantitative real-time polymerase chain reaction (qPCR), X-ray microcomputed tomography (micro-CT), histology, histomorphometry, backscattered scanning electron microscopy (BSE-SEM), Raman spectroscopy, and fluorescence in situ hybridization (FISH). Evidence of osseointegration was provided via micro-CT, histology, BSE-SEM, and Raman spectroscopy. Polymicrobial colonization in the periabutment area and on the implant, including that with Staphylococcus aureus and Staphylococcus epidermidis, was determined using a molecular analysis via a 16S-23S rDNA interspace [IS]-region-based profiling method (IS-Pro). The histology suggested bacterial colonization in the skin and in the peri-implant bone. FISH confirmed the localization of S. aureus and coagulase-negative staphylococci in the skin. Ten articles (54 implants, 47 patients) met the inclusion criteria for the literature search. The analyzed samples were either BAHS (35 implants) or bone-anchored aural epitheses (19 implants) in situ between 2 weeks and 8 years. The main reasons for elective removal were nonuse/changes in treatment, pain, or skin reactions. Most samples were evaluated using histology, demonstrating osseointegration, but with the absence of bone under the implants’ proximal flange. Taken together, the literature and this case report show clear evidence of osseointegration, despite prominent complications. Nevertheless, despite implant osseointegration, chronic pain related to the BAHS may be associated with a chronic bacterial infection and raised inflammatory response in the absence of macroscopic signs of infection. It is suggested that a multimodal analysis of peri-implant health provides possibilities for device improvements and to guide diagnostic and therapeutic strategies to alleviate the impact of complications.

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

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.

Do patients report quality of life improvements after fitting of their unilateral bone conducting hearing implant?

OBJECTIVE

The audiological benefits of a bone conducting hearing implant are well documented; however, there is a paucity of literature comparing pre- and post-operative quality of life benefits. This study assessed the quality of life status before and after the device is implanted.

METHODS

A prospective study was conducted of all adult bone conducting hearing implants inserted in a teaching hospital between 2012 and 2017. All patients completed the Glasgow Health Status Inventory, a validated quality of life questionnaire, before and three to six months after implantation.

RESULTS

Sixty-two patients received a unilateral bone conducting hearing implant. All scores except the social score improved post-operatively. The paired t-test showed that the differences in the means for the Glasgow Health Status Inventory total, general and physical scores were statistically significant at the 5 per cent level (p < 0.0001).

CONCLUSION

This study, one of the few to assess quality of life pre- and post-implantation, showed a vast improvement in patients' perceived quality of life from the pre- to the post-operative phase.

Post-operative infection rates in linear vs. punch technique for bone anchored hearing systems

PURPOSE

This study investigates the post-operative infection rates between two surgical approaches: linear incision and the punch technique for bone anchored hearing systems. Secondarily, it investigates the impact of smoking, comorbid disease, and operative conditions on post-operative skin reactions and infections.

METHODS

A retrospective study was conducted at a single tertiary care institution. A single surgeon completed either of the two techniques on adult patients with mixed, conductive hearing loss, or single sided-deafness. Patients included had at least 6 months follow-up, and were evaluated for preexisting illnesses, perioperative complications, length of surgery, and post-operative complications including infection after surgery. Post-operative soft tissue around the abutment was assessed with Holgers Classification scale.

RESULTS

Fifty-one patients were included in this study, 28 female and 23 males with an average age of 68.8. Thirty-three patients underwent linear incision surgery and 18 had the punch technique. Overall 9 patients (17.6%) had post-operative infections requiring topical or oral antibiotic treatment. Six (18.2%) were in the linear group and 3 (16.7%) in the punch group. There was no statistically significantly difference (p = 1). A multivariate analysis compared age, sex, obesity, DM, operative time, skin thickness, and abutment size to post-operative skin infection rates requiring treatment. Only DM was statistically correlative with infection (p = 0.02).

CONCLUSION

No significant differences in post-operative infections were identified comparing linear incision and the punch techniques. Patients with diabetes had a higher incidence of post-operative skin infections rates.

Do Postoperative Antibiotics Improve Skin Reactivity Following Percutaneous Auditory Osseointegrated Implant Placement?

OBJECTIVE

To determine if the routine use of postoperative antibiotics following percutaneous auditory osseointegrated implant placement reduces skin reactivity.

STUDY DESIGN

Retrospective matched case-controlled series.

SETTINGS

Tertiary academic medical center.

SUBJECT AND METHODS

A total of 44 patients who underwent percutaneous auditory osseointegrated implant placement were divided into those who received 5 days of postoperative antibiotics (AB) and those who received no antibiotics (NAB). All surgery was performed using the same surgical technique (Minimally Invasive Ponto Surgery). Variables recorded included patient demographics, Holgers skin reaction score, complications, and need for further intervention.

RESULTS

A total of 23 patients received prophylactic postoperative antibiotics (AB) while 21 patients did not (NAB). At the first postoperative visit (AB 12.7 d versus NAB 12.3 d, p = 0.9) there were no differences in average Holgers score (AB 0.3 ± 0.7 versus NAB 0.2 ± 0.5, p = 0.27). The odds ratio for skin reactivity at the first visit was 0.11 (95% CI 0.01-2.32). There were also no statistical differences in Holgers score (AB 0.05 ± 0.2 versus NAB 0.1 ± 0.3, p = 0.25) at most recent followup visit (AB mean 97.5 d versus NAB 102.8 d, p = 0.84). The odds ratio for skin reactivity at the most recent visit was 0.16 (95% CI 0.01-3.64).

CONCLUSIONS

The use of postoperative antibiotics does not appear to confer significant difference in skin reactivity in patients receiving percutaneous osseointegrated auditory implants. Such findings support the theory that skin reactivity, when it does occur, may not be an infectious-mediated process.

First experiences with the Ponto™ SuperPower osseointegrated device

Osseointegrated hearing devices Power and SuperPower present indications for bone thresholds of 55 and 65 dB respectively. We conducted a prospective observational study of a series of six cases with mixed hearing loss for whom implantation of the DAO Ponto™ Super-Power was performed. Tonal and verbal evaluations without and with background noise (HINTS) were performed prior to implantation and six months after adaptation. All the participants showed improvement in tonal and verbal results, varying according to the degree of contralateral hearing loss. The verbal results with background noise were noteworthy, where most of the patients obtained a signal-to-noise ratio between 2 and 4 dB. The results in the APHAB and GBI questionnaires showed a reduction in the perception of the problem and an improvement in quality of life respectively. The results presented reflect the possibility of treatment of mixed hearing loss with the Ponto™ SuperPower device.

Microbiome on the Bone-Anchored Hearing System: A Prospective Study

The bone-anchored hearing system (BAHS) has evolved to a common treatment option for various types of hearing revalidation. The BAHS consists of an implant in the skull that breeches the skin. Soft tissue reactions are a common complication associated with BAHS and are generally poorly understood. This study aims to investigate the influence of BAHS and associated skin reactions around the implant. A total of 45 patients were prospectively followed from implantation up to at least 1 year. Swabs were obtained at baseline, 12 weeks follow-up and during cases of inflammation (Holgers score ≥2). The microbiota was assessed using IS-pro^TM, a bacterial profiling method based on the interspace region between the 16S–23S rRNA genes. Detection of operational taxonomic units, the Shannon Diversity Index, sample similarity analyses and Partial Least Squares Discriminant Analysis (PLS-DA) were employed. Staphylococcus epidermidis, Streptococcus pneumoniae/mitis, Propionibacterium acnes, Staphylococcus capitis, Staphylococcus hominis, Bifidobacterium longum, Haemophilus parainfluenzae, Lactobacillus rhamnosus, Bordetella spp., Streptococcus sanguinis, Peptostreptococcus anaerobius, Staphylococcus aureus, Lactococcus lactis, Enterobacter cloacae, and Citrobacter koseri were the most commonly found bacterial species. S. pneumoniae/mitis was significantly more often observed after implantation, whereas P. acnes was significantly less observed after implantation compared with baseline. The relative abundance of S. epidermidis (17%) and S. aureus (19.4%) was the highest for the group of patients with inflammation. The Shannon Diversity Index was significantly increased after implantation compared with pre-surgical swabs for Firmicutes, Actinobacteria, Fusobacteria, Verrucomicrobia (FAFV), but not for other phyla. When combining all phyla, there was no significant increase in the Shannon Diversity Index. The diversity index was similar post-surgically for patients experiencing inflammation and for patients without inflammation. With a supervised classifier (PLS-DA), patients prone to inflammation could be identified at baseline with an accuracy of 91.7%. In addition, PLS-DA could classify post-surgical abutments as non-inflamed or inflamed with an accuracy of 97.7%. This study shows the potential of using IS-pro^TM to describe and quantify the microbiota associated with the percutaneous BAHS. Furthermore, the results indicate the possibility of an early identification of patients susceptible to adverse skin reaction following implantation. Both S. aureus and S. epidermidis should be considered as relevant bacteria for BAHS-associated inflammation.

Bone-anchored hearing implant surgery: our experience with linear incision and punch techniques

SUMMARY

In recent years, bone-anchored hearing implants (BAHIs) have found wider application in the treatment of conductive and mixed hearing loss. Several surgical techniques have been developed to reduce complications, enhance healing and improve audiological and aesthetic results. We report our experience on the use of three BAHI surgery techniques: Group 1, linear incision with thinning of the subcutaneous tissue; Group 2, linear incision without thinning of the subcutaneous tissue; Group 3, punch technique (Minimally Invasive Ponto Surgery, MIPS). We retrospectively analysed patients undergoing BAHI surgery; results were evaluated on the basis of any intra-operative complication, duration of surgery and occurrence of adverse effects at the implantation site over 1 year of follow-up. We collected a total of 30 implantations (12 for Group 1, 8 for Group 2, 10 for Group 3) with an intra-operative complication rate of 25%, 0% and 10%, respectively. The average surgical time was 62.08 minutes, 34.37 minutes and 18.7 minutes respectively. During follow-up, we reported the occurrence of adverse effects in 10.63% of observations in Group 1, 3.12% in Group 2 and 2.5% in Group 3. This study confirms the low rate of intra and postoperative complications during BAHI surgery and documents the simplicity of execution of the novel MIPS technique, with a significant reduction in surgical time compared to the other two techniques, and positive effects in terms of health care costs.

Osseointegrated Auditory Devices: Bone-Anchored Hearing Aid and PONTO

Osseointegrated auditory devices (OADs) are hearing devices that use an external receiver/processor that stimulates bone conduction of sound via a titanium prosthesis that is drilled into the bone of the cranium. Since their introduction in 1977, OADs have undergone substantial evolution, including changes in manufacturing of the implant, improvements in the external sound processor, and simplification of implantation techniques. Expansion of criteria for patient candidacy for implantation has occurred corresponding with changes in the implants and processors.

Wide diameter bone-anchored hearing system implants: a comparison of long-term follow-up data between tissue reduction and tissue preservation techniques

OBJECTIVE

To present long-term data on the Wide Ponto implant bone-anchored hearing system (BAHS) in regards to implant stability, soft tissue reaction and implant loss for two case series undergone either the tissue reduction- or the tissue preservation surgical technique.

METHODS

Comparison of two consecutive, prospective case series. Each case series enrolled 24 patients. The case series underwent one-stage implantation of the Wide Ponto implant BAHS using either a linear incision technique with subcutaneous reduction or a linear incision technique without subcutaneous reduction. Implant stability quotient (ISQ) values were measured using resonance frequency analysis and soft tissue reactions were graded according to Holgers' classification system. Follow-up visits were performed at 10 days, 6 weeks, 6 months, 12 months and annually up to 4 years (tissue preservation) or 5 years (tissue reduction) postoperatively.

RESULTS

The two case series had homogenous patient populations and followed an identical postoperative scheme. The ISQ values increased consistently the first 12 months for both groups (p ≤ 0.001), and were higher in the tissue preservation case series, (p = 0.04, 9 mm abutment). More than 91% of the soft tissue observations were assessed as Holgers' grade 0 or 1. One implant (2.1%) was lost due to trauma.

CONCLUSION

In both case series, the Wide Ponto implant showed increasing implant stability during the follow-up period from the time of surgery, irrespective of surgical technique, indicating good osseointegration. Soft tissue reactions were rare and of minor severity. Implant survival was high.

Long term follow-up demonstrating stability and patient satisfaction of minimally invasive punch technique for percutaneous bone anchored hearing devices

OBJECTIVE

Minimally Invasive Ponto Surgery (MIPS) was recently described to facilitate the placement of percutaneous bone anchored hearing devices. As early adopters of this new procedure, we sought to perform a quality assurance project using our own small prospective cohort to justify this change in practice. We chose to examine device stability and to gauge our patients' perspective of the surgery and their overall satisfaction with the process.

METHODS

A total of 12 adult patients who underwent MIPS between 2016 and 2017 with a minimum post-operative follow-up of 12 months were included in this study. A prospective MIPS research clinic was used to follow patients, assess the implant site soft tissue status and gather qualitative information through patient interviews and surveys.

RESULTS

The mean (SD) soft tissue status score averages using the IPS Scale were low for inflammation 0.1 (0.1), pain 0.1 (0.1), skin height 0.2 (0.1) and total IPS score 0.4 (0.3) indicating minimal soft tissue changes. Patient experiences with MIPS were overwhelmingly positive in reports through the MIPS modified SSQ-8. All patients reported speedy recoveries and no long-term complications. There were zero device losses.

CONCLUSION

The series presented in this paper represents the first MIPS cohort with long term follow-up to be published to date in North America. Our findings conclude both device stability and patient satisfaction with no loss of fixtures. Consequently, we have adopted MIPS as our procedure of choice for the placement of all percutaneous BAHDs.

Minimally Invasive Ponto Surgery Versus the Linear Incision Technique With Soft Tissue Preservation for Bone Conduction Hearing Implants: A Multicenter Randomized Controlled Trial

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.

Percutaneous bone-anchored hearing implant surgery: linear incision technique with tissue preservation versus linear incision technique with tissue reduction

OBJECTIVES

To identify differences in skin thickening and soft tissue reactions between the linear incision technique with tissue reduction (LITT-R) and the linear incision technique with tissue preservation (LITT-P).

STUDY DESIGN

Retrospective cohort study.

METHODS

All adult patients who underwent the LITT-R or LITT-P between August 2005 and December 2016 at a large general teaching hospital with a minimum follow-up of 6 months were included.

RESULTS

A total of 83 implants were included using the LITT-R with a median follow-up of 74.0 months. In the LITT-P cohort 58 implants were included with a median follow-up of 16.5 months. Skin thickening was seen in seven implants (8.4%) in LITT-R cohort and 11 implants (19.0%) in the LITT-P cohort in the first 2 years of follow-up (p = 0.024). Skin thickening in need of treatment was registered in 5 (6.0%), respectively, 6 (10.3%) implants (p = 0.100). Moreover, treatment was successful in all cases. A soft tissue reaction (Holgers ≥ 1) was noticed in 28 (33.7%) implants in the LITT-R group compared to 16 implants (27.6%) in the LITT-P group (p = 0.679). An adverse soft tissue reaction (Holgers ≥ 2) was registered in 16 (19.2%), respectively, 2 (3.4%) implants. This difference was significant (p = 0.040).

CONCLUSION

LITT-P has a significantly higher rate of skin thickening and LITT-R has a significantly higher proportion of adverse soft tissue reactions. Nevertheless, combined with the advantages of LITT-P described in other studies, this can be advocated as the preferred technique.

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

Objective

To study the effect of implanting the percutaneous bone‐anchored hearing system (BAHS) itself and inflammation of the peri‐abutment skin warrant clarification. In this study, we aimed to acquire further insight into the immune responses related to BAHS surgery and peri‐implant skin inflammation.

Materials and Methods

During surgery and 12 weeks post‐implantation, skin biopsies were obtained. If applicable, additional biopsies were taken during cases of inflammation. The mRNA expression of IL‐1β, IL‐6, IL‐8, TNFα, IL‐17, IL‐10, TGF‐ß, MIP‐1α, MMP‐9, TIMP‐1, COL1α1, VEGF‐A, FGF‐2 TLR‐2, and TLR‐4 was quantified using qRT‐PCR.

Results

Thirty‐five patients agreed to the surgery and 12‐week biopsy. Twenty‐two patients had mRNA of sufficient quality for analysis. Ten were fitted with a BAHS using the minimally invasive Ponto surgery technique. Twelve were fitted with a BAHS using the linear incision technique with soft‐tissue preservation. Five biopsies were obtained during episodes of inflammation. The post‐implantation mRNA expression of IL‐1β (P = .002), IL‐8 (P = .003), MMP9 (P = .005), TIMP‐1 (P = .002), and COL1α1 (P < .001) was significantly up‐regulated. IL‐6 (P = .009) and FGF‐2 (P = .004) mRNA expression was significantly down‐regulated after implantation. Within patients, no difference between post‐implantation mRNA expression (at 12 weeks) and when inflammation was observed. Between patients, the expression of IL‐1β (P = .015) and IL‐17 (P = .02) was higher during cases of inflammation compared with patients who had no inflammation at 12‐week follow‐up.

Conclusions

As part of a randomized, prospective, clinical trial, the present study reports the molecular profile of selected cytokines in the soft tissue around BAHS. Within the limit of this study, the results showed that 12 weeks after BAHS implantation the gene expression of some inflammatory cytokines (IL‐8 and IL‐1β) is still relatively high compared with the baseline, steady‐state, expression. The up‐regulation of anabolic (COL1α1) and tissue‐remodeling (MMP‐9 and TIMP1) genes indicates an ongoing remodeling process after 12 weeks of implantation. The results suggest that IL‐1β, IL‐17, and TNF‐α may be interesting markers associated with inflammation.

Hearing improvement with softband and implanted bone-anchored hearing devices and modified implantation surgery in patients with bilateral microtia-atresia

OBJECTIVE

To evaluate auditory development and hearing improvement in patients with bilateral microtia-atresia using softband and implanted bone-anchored hearing devices and to modify the implantation surgery.

METHODS

The subjects were divided into two groups: the softband group (40 infants, 3 months to 2 years old, Ponto softband) and the implanted group (6 patients, 6-28 years old, Ponto). The Infant-Toddler Meaning Auditory Integration Scale was used conducted to evaluate auditory development at baseline and after 3, 6, 12, and 24 months, and visual reinforcement audiometry was used to assess the auditory threshold in the softband group. In the implanted group, bone-anchored hearing devices were implanted combined with the auricular reconstruction surgery, and high-resolution CT was used to assess the deformity preoperatively. Auditory threshold and speech discrimination scores of the patients with implants were measured under the unaided, softband, and implanted conditions.

RESULTS

Total Infant-Toddler Meaning Auditory Integration Scale scores in the softband group improved significantly and approached normal levels. The average visual reinforcement audiometry values under the unaided and softband conditions were 76.75 ± 6.05 dB HL and 32.25 ± 6.20 dB HL (P < 0.01), respectively. In the implanted group, the auditory thresholds under the unaided, softband, and implanted conditions were 59.17 ± 3.76 dB HL, 32.5 ± 2.74 dB HL, and 17.5 ± 5.24 dB HL (P < 0.01), respectively. The respective speech discrimination scores were 23.33 ± 14.72%, 77.17 ± 6.46%, and 96.50 ± 2.66% (P < 0.01).

CONCLUSIONS

Using softband bone-anchored hearing devices is effective for auditory development and hearing improvement in infants with bilateral microtia-atresia. Wearing softband bone-anchored hearing devices before auricle reconstruction and combining bone-anchored hearing device implantation with auricular reconstruction surgery may bethe optimal clinical choice for these patients, and results in more significant hearing improvement and minimal surgical and anesthetic injury.

Direct cost comparison of minimally invasive punch technique versus traditional approaches for percutaneous bone anchored hearing devices

Background

Minimally Invasive Ponto Surgery (MIPS) was recently described as a new technique to facilitate the placement of percutaneous bone anchored hearing devices.

The procedure has resulted in a simplification of the surgical steps and a dramatic reduction in surgical time while maintaining excellent patient outcomes. Given these developments, our group sought to move the procedure from the main operating suite where they have traditionally been performed. This study aims to test the null hypothesis that MIPS and open approaches have the same direct costs for the implantation of percutaneous bone anchored hearing devices in a Canadian public hospital setting.

Methods

A retrospective direct cost comparison of MIPS and open approaches for the implantation of bone conduction implants was conducted. Indirect and future costs were not included in the fiscal analysis.

A simple cost comparison of the two approaches was made considering time, staff and equipment needs. All 12 operations were performed on adult patients from 2013 to 2016 by the same surgeon at a single hospital site.

Results

MIPS has a total mean reduction in cost of CAD$456.83 per operation from the hospital perspective when compared to open approaches. The average duration of the MIPS operation was 7 min, which is on average 61 min shorter compared with open approaches.

Conclusion

The MIPS technique was more cost effective than traditional open approaches. This primarily reflects a direct consequence of a reduction in surgical time, with further contributions from reduced staffing and equipment costs. This simple, quick intervention proved to be feasible when performed outside the main operating room. A blister pack of required equipment could prove convenient and further reduce costs.