Auricular reconstruction using Medpor combined with different hearing rehabilitation approaches for microtia

Comparison of auricle reconstruction with expanded flaps and auricle reconstruction with non-expanded flaps in patients with microtia: A meta-analysis

OBJECTIVE

We conducted this meta-analysis to compare the efficacy of these two surgical methods by comparing the incidence of major evaluation indicators.

METHODS

The databases such as PubMed, Embase, the Cochrane Library, China National Knowledge Infrastructure, Wanfang, and VIP information databases were searched.

RESULTS

The satisfaction rate of patients with auricle reconstruction using expanded flaps was 86.5%, and the satisfaction rate of patients with auricle reconstruction using non-expanded flaps was 87.9%. The incidence of postoperative hematoma was 3.2% in patients with auricle reconstruction using expanded flaps and 18.9% in patients with auricle reconstruction using non-expanded flaps. The incidence of postoperative skin necrosis was 2.2% in patients with auricle reconstruction using expanded flaps and 4.1% in patients with auricle reconstruction using non-expanded flaps. The incidence of postoperative incision infection was 3.1% in patients with auricle reconstruction using expanded flaps and 0.9% in patients with auricle reconstruction using non-expanded flaps. The incidence of cartilage framework exposure was 2.2% in patients with auricle reconstruction using expanded flaps and 1.9% in patients with auricle reconstruction using non-expanded flaps. The incidence of postoperative scar hyperplasia was 3.8% in patients with auricle reconstruction using expanded flaps and 3% in patients with auricle reconstruction using non-expanded flaps. The publication bias of included literature was evaluated by Egger test. There was no publication bias in this Meta-analysis (P > .05).

CONCLUSION

The auricle reconstruction using non-expanded flaps is dominant in four of the six evaluation indexes. Therefore, we believe that the auricle reconstruction using non-expanded flaps has better therapeutic effect in patients with microtia. Due to the limitations of this meta-analysis, the conclusions of this meta-analysis still need to be further verified.

Paediatric percutaneous bone anchored hearing aid implant failures: Comparing the experience of a tertiary centre with a systematic review of the literature and meta-analysis

BACKGROUND

Despite the proven audiological benefits of Percutaneous Bone Anchored Hearing Aids (BAHAs) in paediatric patients with conductive or mixed hearing loss, their adoption has been limited due to concerns over implant failure and associated complications. This paper conducts a systematic review and meta-analysis to assess the prevalence of implant failure in paediatric populations, combined with a case series from our tertiary referral centre.

METHODS

A comprehensive literature search identified 562 articles, from which 34 were included in the review, covering 1599 implants in 1285 patients. Our retrospective case series included consecutive patients from our tertiary referral centre who underwent percutaneous BAHA implantation from 2003-2019.

RESULTS

Meta-analysis revealed an overall implant failure rate of 11%, predominantly attributed to traumatic extrusion. Our retrospective case series comprised 104 implantations in 76 patients, with a 4.8% failure rate.

DISCUSSION

Factors contributing to the lower-than-expected failure rates in the case series likely included consistent use of 4 mm fixtures from a single manufacturer and older age at implantation. The study underscores the need for standardised reporting formats in bone conduction implants research, given the systematic review's limitations in study design heterogeneity, especially with the expected rise in the adoption of novel active devices.

Reconstructive Techniques in Pediatric Congenital Microtia: A Systematic Review and Meta-analysis

Autografts and allografts are commonly used in microtia reconstruction. We aimed to systematically review and compare these reconstructive materials in pediatric congenital microtia reconstruction. A systematic review of the literature was performed. MEDLINE, Embase, PubMed, Web of Science, and CINAHL databases were searched for original studies on congenital microtia reconstruction in pediatric patients since database inception to 2021. Microtia grade was stratified as high or low. Meta-analysis of pooled proportions and continuous variables was performed using inverse variance weighting with a random effects model to compare between the autograft and allograft groups. Sixty-eight studies with a total of 5,546 patients used autografts (n = 5,382) or alloplastic implants (n = 164). Four other studies used prosthesis, cadaveric homografts, or tissue engineering. The allograft group was on average younger than the autograft group (8.4 vs. 11.1 years). There were no syndromic patients in the allograft group, compared to 43% in the autograft group. Patients treated with allografts had higher microtia grade than those treated with autograft (98 vs. 72%). Autografts were more commonly utilized by plastic surgeons and allografts by otolaryngologists (95 vs. 38%). No autografts and 41% of allografts were done concurrently with atresiaplasty or bone conduction implant. Satisfaction rates were similarly high (>90%) with similar complication rates (<10%). Microtia reconstruction using autografts and allografts had similar satisfaction and complication rates. Allografts were preferred for younger patients and concurrent hearing restoration. Further large-scale studies are required to evaluate the long-term efficacy of these reconstructive techniques.

The application and progress of tissue engineering and biomaterial scaffolds for total auricular reconstruction in microtia

Microtia is a congenital deformity of the ear with an incidence of about 0.8-4.2 per 10,000 births. Total auricular reconstruction is the preferred treatment of microtia at present, and one of the core technologies is the preparation of cartilage scaffolds. Autologous costal cartilage is recognized as the best material source for constructing scaffold platforms. However, costal cartilage harvest can lead to donor-site injuries such as pneumothorax, postoperative pain, chest wall scar and deformity. Therefore, with the need of alternative to autologous cartilage, in vitro and in vivo studies of biomaterial scaffolds and cartilage tissue engineering have gradually become novel research hot points in auricular reconstruction research. Tissue-engineered cartilage possesses obvious advantages including non-rejection, minimally invasive or non-invasive, the potential of large-scale production to ensure sufficient donors and controllable morphology. Exploration and advancements of tissue-engineered cartilaginous framework are also emerging in aspects including three-dimensional biomaterial scaffolds, acquisition of seed cells and chondrocytes, 3D printing techniques, inducing factors for chondrogenesis and so on, which has greatly promoted the research process of biomaterial substitute. This review discussed the development, current application and research progress of cartilage tissue engineering in auricular reconstruction, particularly the usage and creation of biomaterial scaffolds. The development and selection of various types of seed cells and inducing factors to stimulate chondrogenic differentiation in auricular cartilage were also highlighted. There are still confronted challenges before the clinical application becomes widely available for patients, and its long-term effect remains to be evaluated. We hope to provide guidance for future research directions of biomaterials as an alternative to autologous cartilage in ear reconstruction, and finally benefit the transformation and clinical application of cartilage tissue engineering and biomaterials in microtia treatment.

Comparison of Outcomes of Surgery Versus Implantable Device for the Treatment of Hearing Loss Associated With Congenital Aural Atresia: A Systematic Review and Meta-Analysis

OBJECTIVE

To compare audiometric outcomes, complications, and revisions required for implantable bone-conduction devices (BCDs) versus atresia surgery for the treatment of hearing loss associated with congenital aural atresia.

DATABASES REVIEWED

PubMed, Scopus, CINAHL.

METHODS

Databases were searched for English articles from inception to July 1, 2022, for studies reporting audiometric outcomes or complications for either BCDs or atresia surgery for the treatment of congenital aural atresia. Main outcome measures included pure-tone audiometry, air-bone gap, speech reception threshold, associated complications, and rates of revision for each treatment option.

RESULTS

We identified 973 abstracts, of which 89 were selected for data extraction and analysis. A total of 2,611 patients were included, 1,901 in the atresia surgery group and 710 in the BCDs group. A meta-analysis of single means was conducted for age and audiometric outcomes, and a meta-analysis of proportions was conducted for complications and revisions. The average short-term improvement in pure-tone audiometry for the BCDs group was 34.4 ± 1.6 dB compared with 22.4 ± 1.5 dB for the atresia surgery group, representing a significant difference (12.0 dB; 95% confidence interval, 11.9-12.2; p < 0.0001). A smaller proportion of complications were reported in the devices group (16.9%) compared with the atresia surgery group (45.7%). In addition, a smaller proportion of cases in the devices group required some degree of revision (17.8%) compared with the atresia surgery group (23.0%).

CONCLUSIONS

This study demonstrates that implantable BCDs have significantly better audiometric outcomes as well as a lower rate of complications and revisions required compared with atresia surgery.

An automated parametric ear model to improve frugal 3D scanning methods for the advanced manufacturing of high-quality prosthetic ears

Ear prostheses are commonly used for restoring aesthetics to those suffering missing or malformed external ears. Traditional fabrication of these prostheses is labour intensive and requires expert skill from a prosthetist. Advanced manufacturing including 3D scanning, modelling and 3D printing has the potential to improve this process, although more work is required before it is ready for routine clinical use. In this paper, we introduce a parametric modelling technique capable of producing high quality 3D models of the human ear from low-fidelity, frugal, patient scans; significantly reducing time, complexity and cost. Our ear model can be tuned to fit the frugal low-fidelity 3D scan through; (a) manual tuning, or (b) our automated particle filter approach. This potentially enables low-cost smartphone photogrammetry-based 3D scanning for high quality personalised 3D printed ear prosthesis. In comparison to standard photogrammetry, our parametric model improves completeness, from (81 ± 5)% to (87 ± 4)%, with only a modest reduction in accuracy, with root mean square error (RMSE) increasing from (1.0 ± 0.2) mm to (1.5 ± 0.2) mm (relative to metrology rated reference 3D scans, n = 14). Despite this reduction in the RMS accuracy, our parametric model improves the overall quality, realism, and smoothness. Our automated particle filter method differs only modestly compared to manual adjustments. Overall, our parametric ear model can significantly improve quality, smoothness and completeness of 3D models produced from 30-photograph photogrammetry. This enables frugal high-quality 3D ear models to be produced for use in the advanced manufacturing of ear prostheses.

Repair of exposure and fracture of the porous high-density polyethylene framework after ear reconstruction

OBJECTIVE

To assess the repair method of exposure or fracture of the porous high-density polyethylene ear framework after total auricle reconstruction.

STUDY DESIGN

A prospective case study.

METHODS

From April 2018 to October 2021, 11 patients with framework exposure or fracture after total auricle reconstruction were admitted to the hospital for repair. In these 11 patients, the repair was performed using (1) a temporal muscle flap combined with free skin graft in 5 patients, (2) a mastoid fascia flap combined with free skin graft in 2 patients, (3) a simple local skin flap in 1 patient, (4) combination of a temporalis muscle flap and a mastoid fascia flap together with free skin graft in 2 patients, and (5) a Su-Por helix material combined with a temporal muscle flap and free skin graft in 1 patient.

RESULTS

After follow-up for 3-36 months, except for one patient in whom local exposure again occurred at the same site, the framework was in a good shape in the other patients, and all the skin graft survived.

CONCLUSION

The defect of the upper part of the auricle can be repaired using a temporal muscle flap combined with temporal muscle fascia and skin graft. The defect of the middle and lower part of the auricle can be repaired using a mastoid fascia flap combined with skin graft. For framework fracture, the damaged site can be first strengthened with another ear material and then combined with the adjacent fascia flap and free skin graft.