Reconstruction of Microtia:

A Modified Two-Flap Method for First-Stage Ear Reconstruction in Lobule-Type Microtia

BACKGROUND

Autologous ear reconstruction typically involves a lengthy treatment period, often spanning 2 to 4 stages or utilizing skin expansion, to achieve satisfactory results. Consequently, an alternative procedure capable of shortening this treatment period would be advantageous for patients. We have made significant enhancements to the safety and outcomes of single-stage autologous ear reconstruction through a multitude of technical improvements. Herein, we propose a novel procedure capable of reconstructing a complete ear contour with postauricular sulcus in the first stage, with the option for subsequent tragus revision if needed.

METHODS

The key techniques of our first-stage ear reconstruction are as follows: preoperative design of the postauricular skin flap, meticulous elevation of a super-thin postauricular skin flap, fabrication of a modified three-layer framework, elevation of a postauricular fascial flap, postauricular skin grafting, and earlobe transposition.

RESULTS

Between June 2020 and October 2023, 245 patients with lobule-type microtia underwent ear reconstruction surgery using our technique. The follow-up period ranged from 6 to 39 months. Ninety-one percent of the patients and their families were satisfied with the outcomes. The overall complication rate was 7.5%.

CONCLUSION

This modified first-stage autologous ear reconstruction technique can yield satisfactory and safe results in cases of lobule-type microtia.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors   www.springer.com/00266 .

A Cartilage-Saving Technique for Tragus and Antitragus Fabrication in Auricular Reconstruction

Background: For auricular reconstruction surgery using autologous costal cartilage, younger patients typically have a limited amount of costal cartilage available. Objective: We introduce a cartilage-saving technique for fabricating the tragus and antitragus, and evaluate its effectiveness based on aesthetic score and complications. Methods: For tragus fabrication, the residual part of the seventh costal cartilage was reoriented by 90° to increase its height and carved into a seagull-shaped structure. The antitragus was constructed by bending the antihelix and stabilizing it on the broadened base frame. Postoperative aesthetic outcomes and complications were documented and analyzed. Results: This study included a total of 658 patients with lobule-type microtia, of whom 356 (54.1%) were male and 302 (45.9%) were female. The average age was 6.5 ± 0.7 years, and the average follow-up period was 13.6 ± 3.5 months. The average aesthetic outcome score was 9.0 ± 0.7. Wound dehiscence at the tragus was seen in four patients, while circulation disturbance at the incisura intertragica area was noted in six patients. Conclusions: This cartilage-sparing technique demonstrated effectiveness in shaping aesthetic tragus and antitragus.

Comparative analysis of small-incision and traditional techniques in costal cartilage harvesting: Outcomes on thoracic deformities and scar appearance

OBJECTIVE

This study aims to compare the postoperative thoracic deformity and scar aesthetic outcomes of auricular reconstruction between the conventional large-incision technique and small-incision technique with perichondrium preservation for costal cartilage harvesting.

METHODS

A retrospective analysis was performed on 134 patients who underwent auricular reconstruction using tissue expanders and autologous costal cartilage harvested from the right chest wall between January 2021 and September 2023. Patients were divided into two groups according to the harvesting technique: the traditional large-incision group (n = 64) and the small-incision group with perichondrium preservation (n = 70). Preoperative and postoperative chest CT scans were reviewed for thoracic deformities by measurements of the modified Haller Index (mHI) and modified correction index (mCI). Thoracic scar dimensions were measured in postoperative follow-up.

RESULTS

In the conventional group, significant difference were observed between the left and right hemithorax in anterior-posterior diameter, maximum transverse diameter, cross-sectional area, and mHI values (p < 0.05), showing thoracic deformities. In contrast, within the small-incision group, there were no significant differences between hemithoraces. Additionally, postoperative thoracic scars were significantly smaller in the small-incision group, with shorter scar length (5.63 ± 1.33 cm vs. 11.44 ± 1.31 cm) and width (1.41 ± 0.55 cm vs. 3.75 ± 1.54 cm; p < 0.001).

CONCLUSION

The small-incision technique with perichondrium preservation significantly reduces postoperative thoracic deformities and results in smaller, less conspicuous scars compared to the traditional large-incision method. This approach minimizes disruption to the chest wall structure and reduces donor-site morbidity, offering improved patient outcomes.

"Man vs. Machine: 3D Milling of Auricular Frameworks"

OBJECTIVE

Autologous rib harvest with manual framework production is the current gold standard for microtia reconstruction. Recent clinical success with implantation of cadaveric costal cartilage grafts opens the possibility of point of care auricular framework production. This paper assesses the feasibility and efficiency of 3D milling of cadaveric costal cartilage for auricular framework production.

DESIGN

A Nagata/Firmin style auricular framework was manually carved en bloc out of soap and 3D scanned to design a milling toolpath on a desktop 3-axis computer numerical control (CNC) machine. An en bloc framework was then milled from cadaveric costal cartilage. Time to mill a complete framework was recorded. The dimensional/volumetric analyses were performed.

MAIN OUTCOME MEASURE(S)

The main outcome measures were total time to mill a complete auricular framework out of cadaveric cartilage and dimensional/volumetric comparisons to the model ear.

RESULTS

Total milling time for the cartilage framework was approximately 7 min. Finalizing steps took an extra 20 min. Total time to produce a final framework ready for implantation was approximately 27 min, compared to the traditional 1-2 h by manual carving. All dimensional comparisons were within 2 mm to the manually carved model. Volumetric analysis showed 71% similarity.

CONCLUSIONS

En bloc cadaveric costal cartilage framework milling is both feasible and efficient. 3D milling significantly reduces framework production time and allows for accurate reconstruction of the complex ear geometry, which can translate to cost savings, optimized patient safety, and potential for patient-specific reconstruction. The next step toward achieving clinical application is ensuring framework sterility.

Development and Preliminary Evaluation of A Soft Tissue Microtia Simulator

Surgical simulation has been used extensively for learning microtia reconstruction and has almost exclusively involved framework creation. However, soft tissue reconstruction in microtia is equally challenging and would benefit from a simulation platform. This study aimed to describe the development and preliminary evaluation of a high-fidelity soft tissue microtia simulator. Three-dimensional modeling software, fused deposition 3-dimensional printing, adhesive techniques, silicones, and polyurethane rubbers were utilized to create a right lobular-type microtia simulator that comprises skin, subcutaneous tissue, and cartilage. Two expert microtia surgeons performed a microtia reconstruction on the simulator and evaluated its value and realism using a Likert-type questionnaire. The surgeons utilized a previously developed synthetic framework and successfully performed the critical steps of the soft tissue reconstruction, including marking, incising, dissection, removal of the cartilage remnant, drain insertion, insertion of the framework, closing of the skin, and demonstration of the soft tissue conforming over the framework using suction. A preliminary assessment of the simulator demonstrated that the simulator is anatomically accurate, realistic, and highly valuable as a training tool. A high-fidelity soft tissue microtia simulator was successfully developed and tested. The simulator provides a valuable training platform for learning a critical component of microtia reconstruction.

Optimal timing for plastic surgical procedures for common congenital anomalies: A review

Apart from listening to the cry of a healthy newborn, it is the declaration by the attending paediatrician in the labour room that the child is normal which brings utmost joy to parents. The global incidence of children born with congenital anomalies has been reported to be 3%-6% with more than 90% of these occurring in low- and middle-income group countries. The exact percentages/total numbers of children requiring surgical treatment cannot be estimated for several reasons. These children are operated under several surgical disciplines, viz, paediatric-, plastic reconstructive, neuro-, cardiothoracic-, orthopaedic surgery etc. These conditions may be life-threatening, e.g., trachea-oesophageal fistula, critical pulmonary stenosis, etc. and require immediate surgical intervention. Some, e.g., hydrocephalus, may need intervention as soon as the patient is fit for surgery. Some, e.g., patent ductus arteriosus need 'wait and watch' policy up to a certain age in the hope of spontaneous recovery. Another extremely important category is that of patients where the operative intervention is done based on their age. Almost all the congenital anomalies coming under care of a plastic surgeon are operated as elective surgery (many as multiple stages of correction) at appropriate ages. There are advantages and disadvantages of intervention at different ages. In this article, we present a review of optimal timings, along with reasoning, for surgery of many of the common congenital anomalies which are treated by plastic surgeons. Obstetricians, paediatricians and general practitioners/family physicians, who most often are the first ones to come across such children, must know to guide the parents appropriately and convincingly impress upon the them as to why their child should not be operated immediately and also the consequences of too soon or too late.

New Strategies for Remnant Ear Treatment in Microtia Reconstruction Based on Morphometric Studies

OBJECTIVE

Given the lack of specific evaluation indices, it is difficult to determine whether to transpose or abandon remnant ears in lobule-type microtia reconstruction. The authors illuminate referable parameters beneficial for proper treatment of remnant ear in an efficient manner.

METHODS

A series of 359 lobule-type microtia patients underwent autogenous costal cartilage auricular reconstruction between 2016 and 2021. Fourteen measuring points and defined distances as well as six ratios of specific distances based on position, plumpness, similarity and the width-to-length ratio of the remnant ear have been described, and relevant tactics for appropriate treatments are introduced.

RESULTS

Definite morphometric results contribute to attaining satisfactory contours of reconstructed auricles with harmonious earlobes, which exhibit highly similar dimensions and appearances compared to the contralateral normal ears.

CONCLUSION

With the help of the proposed locating points and measuring approaches, the procedure of remnant ear treatment is systematically clarified. This technique ensures operation safety and contributes to the aesthetic contour of the auricle.

LEVEL OF EVIDENCE

IV Laryngoscope, 134:2741-2747, 2024.

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.

Modified Technique for Auricular Helical Rim Reconstruction in Adult Patients with Subtotal Helical Rim Defects

BACKGROUND

In adults, the volume of costal cartilage is enough for reconstruction, but floating cartilage is hard, brittle, and easily broken due to calcification, in addition to being short, making it unsuitable for helical rim reconstruction in such age groups.

AIM OF STUDY

This study describes a novel technique in which adult patients underwent 2-stage helical rim reconstruction using the syncytium of sixth and seventh costal cartilage.

MATERIAL AND METHODS

A single-arm clinical trial involves 35 adults with total and subtotal helical rim defects, either congenital, post-traumatic, postburn, or postvascular malformation excision. Twenty-nine unilateral and 6 bilateral cases. The age of patients ranged between 19 and 40 years. In the period between April 2021 and April 2023. Follow-up was 6 months.

RESULTS

There were no technique-related complications, such as broken helix. In most cases, scars were invisible, with the normal contour of helical rim. Among the 35 patients, 19 were graded as excellent, 13 as good, and 3 as fair. In objective photographic evaluation, all patients were evaluated with high (3 or 4) ratings; the score was 3 in 19 patients and 4 in 16 patients. All patients were satisfied with the size, contour, position and details of the new helix.

CONCLUSION

Using the syncytium of the sixth and seventh costal cartilage to fabricate the helical rim in adult patients gives a suitable volume of cartilage graft as regards the length and width, which suits the reconstruction of the helical rim, and shows a good configuration with satisfactory surgical results.

Total rebuilding of the ear after unsatisfactory initial microtia reconstruction: 30-year experience using autogenous costal cartilage framework

BACKGROUND

This study describes the author's experience with long-term follow-up analysis of secondary procedures in patients with unsatisfactory initial microtia reconstruction.

METHODS

A total of 134 patients who underwent secondary operations between 1992 and 2021 were reviewed by examining medical records and photographic data. A total of 110 patients followed between 6 months and 26 years (average 33.2 months) were included for evaluation of aesthetic outcomes.

RESULTS

Primary reconstruction was performed with costal cartilage in 113 patients, porous polyethylene implant in 7 patients, silicone implant in 6 patients, and others in 8 patients. The major external features at the time of the secondary reconstruction were lump (91 cases), deficient convolution (19 cases), and no framework with scarred mastoid skin (22 cases). All secondary reconstructions were performed with an autogenous costal cartilage framework. The framework was covered using temporoparietal fascia flap techniques in 118 patients, mastoid skin coverage technique in 12 patients, and others in 4 patients. One major complication (exposure of cartilage framework due to partial necrosis of fascial flap) and three minor complications (loss of moderate-sized full-thickness skin, grafted on the fascia) were recorded. The average score given for aesthetic outcomes, rated on a four-point Likert scale (i.e., 1 = poor, 2 = fair, 3 = good, and 4 = excellent) was 3.17 (median 3.00). A total of 42% of the patients were rated excellent and 36% were rated good.

A Hollow Tridimensional Silicone Template for Microtia Reconstruction and Postoperative Scar Compression

Microtia poses a great challenge in auricular reconstruction, due to a great number of anatomical details on the anterior aspect, and its tridimensional shape. Numerous techniques have been described in an attempt to optimize results. We have designed a hollow tridimensional silicon template to serve as an intrasurgical guide for ear's anatomy, size and projection, according to the normal side, which allows better results of auricular reconstruction. It also can be used as a customized post-operative compression method. We believe it could be a valuable tool for microtia reconstruction surgery. LEVEL OF EVIDENCE V: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Quantitative Analysis on Cartilage Growth Between Ipsilateral and Contralateral Donor Sites in Microtia Patients

BACKGROUND

Costal cartilage harvest is required in patients with unilateral microtia when autologous reconstruction is being considered. However, whether an ipsilateral or contralateral donor site should be used remains controversial. This is the first study to compare cartilaginous growth between ipsilateral and contralateral donor sites in patients with unilateral microtia.

METHODS

In this retrospective study of 58 patients, the lengths of the sixth to ninth costal cartilages and 3 position-defining measurements with respect to the sixth to ninth costochondral junctions were calculated using 3-dimensional costal cartilage imaging. Patients were divided into subgroups, and the lateral differences between isolated microtia and hemifacial microsomia and between the growing and adult age groups, were compared.

RESULTS

In the isolated group, the sixth and seventh costal cartilages were longer on the contralateral side. The transverse dimension on the contralateral side, with respect to the sixth and seventh costochondral junctions, was also larger than that on the ipsilateral side in growing patients. However, no significant difference was observed between the 2 sides in the hemifacial microsomia group; there was also no difference between the age-related groups in this regard (P > 0.05).

CONCLUSIONS

These findings suggest that age- and side-related differences in donor sites should be considered in patients with isolated microtia.

Ear Reconstruction: Empirical Data of 406 Cases of Carving the Convex Structures of the Framework

OBJECTIVE

In auricular reconstruction, the convex structures of the framework determine the esthetics, and young doctors often need sufficient training to determine the best carving techniques. This study aimed to recommend optimal carving methods and provide measured data of convex structures of the carved costal cartilage framework to prevent complications, improve esthetics, and reduce the learning curve.

METHODS

From 2018 to 2021, 406 patients with microtia who underwent costal cartilage carving were enrolled. The helix is formed by the eighth costal cartilage. The complex of the antihelix was fabricated from part of the eighth costal cartilage or the ninth costal cartilage. The tragus was constructed using residual cartilage pieces from the base frame. These components were measured, and those from the new ear graded "excellent" were used for data analysis. The statistical analysis was principally processed using Excel software.

RESULTS

A total of 112 ears were graded "excellent". The following are the mean and standard deviation of each group of data: antihelix thickness, 0.31 ± 0.06 cm; antihelix width, 0.40 ± 0.06 cm; superior crus thickness, 0.18 ± 0.04 cm; superior crus width, 0.38 ± 0.09 cm; inferior crus width, 0.22 ± 0.04 cm; inferior crus thickness, 0.28 ± 0.05 cm; helix thickness, 0.31 ± 0.04 cm; the four-point height of the helix, 0.52 ± 0.08 cm/0.51 ± 0.07 cm/0.46 ± 0.06 cm/0.41 ± 0.06 cm; and tragus height, 0.98 ± 0.15 cm.

CONCLUSION

These data may help beginners in reducing the learning curve of ear reconstruction. Framework fabrication based on these data allows attaining a harmonious ear framework and satisfactory three-dimensional auricle outline, yielding acceptable results and few complications.

LEVEL OF EVIDENCE

4 Laryngoscope, 133:569-575, 2023.

Auricular Reconstruction in Adult Patients With Unprepared Congenital Microtia: A Single Institution's Experience

METHODS

From January 2015 to January 2021, auricular reconstruction was performed in 38 adult patients (39 ears) of congenital microtia based on autologous costal cartilage. The whole procedure was divided into 2 stages: stage I, the individualized framework carved with autologous costal cartilage was inserted into subcutaneous pocket in the mastoid region; then, the earlobe was transposed backward; and stage II, ear elevation, harvesting the retroauricular fascial flap to cover the support scaffold and closing the defect with free skin graft, was performed.

RESULTS

All patients successfully underwent ear reconstruction. The follow-up time ranged from 3 months to 3 years. Infection occurred in 1 patient. The ear frameworks were partially broken at the helix in 4 cases. Retroauricular graft skin survival was poor in 1 patient. Retroauricular hypertrophic scars occurred in 2 cases. Bad projection of the reconstructed ear occurred in 1 case. Totally 38 patients were satisfied with the results.

CONCLUSIONS

According to the physiological characteristics of the costal cartilage and skin soft tissues of adult patients, improvements are made to details based on the Nagata's method, so that the adult patients with microtia can obtain satisfactory surgical results.

Strategies for ear elevation and the treatment of relevant complications in autologous cartilage microtia reconstruction

Despite various surgical techniques for ear elevation in autogenous cartilage microtia reconstruction, it is still challenging for plastic surgeons to obtain a satisfactory depth of the cephaloauricular sulcus and stable projection of the reconstructed ear. Here, the authors demonstrate individualized options for surgical approaches and relevant details for complication management. Between January 2014 and June 2020, a series of 895 patients who underwent the second stage of microtia reconstruction were reviewed. Complications occurred in 103 patients aged between 8 and 34 years. Recommended surgical selections, as well as appropriate strategies for complication prophylaxis and treatment, were shown to minimize the negative influence on the contour of the cephaloauricular sulcus according to individual conditions. We found that 78% of the patients were satisfied with the auricle contour with harmonious integrity. Individualized strategies for ear elevation and complication treatment contribute to symmetry and satisfactory projection of the reconstructed auricle.

Strategies for the Treatment of Auricular Complications after the First Stage of Autologous Cartilage Microtia Reconstruction

BACKGROUND

Effective handling of auricular complications after the first stage of autologous cartilage microtia reconstruction remains one of the most demanding challenges for plastic surgeons. Here, the authors discuss relevant details for treatment of such complications in various conditions.

METHODS

A total of 1739 microtia patients underwent the first stage of auricular reconstruction with autogenous costal cartilage between 2007 and 2019. Different complications occurred in 136 cases. The details of complications are described, and relevant tactics for appropriate prevention and treatment are introduced.

RESULTS

Selective methods for the management of different complications in a prompt and effective manner after the first stage of ear reconstruction have been shown to salvage and maintain the contour of the reconstructed auricle to the maximum extent.

CONCLUSION

Auricular complications can be well treated and prevented through careful preoperative preparation, meticulous intraoperative manipulation, and proper postoperative management.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Three-Dimensional-Printed External Scaffolds Mitigate Loss of Volume and Topography in Engineered Elastic Cartilage Constructs

OBJECTIVE

A major obstacle in the clinical translation of engineered auricular scaffolds is the significant contraction and loss of topography that occur during maturation of the soft collagen-chondrocyte matrix into elastic cartilage. We hypothesized that 3-dimensional-printed, biocompatible scaffolds would "protect" maturing hydrogel constructs from contraction and loss of topography.

DESIGN

External disc-shaped and "ridged" scaffolds were designed and 3D-printed using polylactic acid (PLA). Acellular type I collagen constructs were cultured in vitro for up to 3 months. Collagen constructs seeded with bovine auricular chondrocytes (BAuCs) were prepared in 3 groups and implanted subcutaneously in vivo for 3 months: preformed discs with ("Scaffolded/S") or without ("Naked/N") an external scaffold and discs that were formed within an external scaffold via injection molding ("Injection Molded/SInj").

RESULTS

The presence of an external scaffold or use of injection molding methodology did not affect the acellular construct volume or base area loss. In vivo, the presence of an external scaffold significantly improved preservation of volume and base area at 3 months compared to the naked group (P < 0.05). Construct contraction was mitigated even further in the injection molded group, and topography of the ridged constructs was maintained with greater fidelity (P < 0.05). Histology verified the development of mature auricular cartilage in the constructs within external scaffolds after 3 months.

CONCLUSION

Custom-designed, 3D-printed, biocompatible external scaffolds significantly mitigate BAuC-seeded construct contraction and maintain complex topography. Further refinement and scaling of this approach in conjunction with construct fabrication utilizing injection molding may aid in the development of full-scale auricular scaffolds.

Chondrocyte-laden GelMA hydrogel combined with 3D printed PLA scaffolds for auricle regeneration

The current gold standard for auricular reconstruction after microtia or ear trauma is the autologous cartilage graft with an autologous skin flap overlay. Harvesting autologous cartilage requires an additional surgery that may result in donor area complications. In addition, autologous cartilage is limited and the auricular reconstruction requires complex sculpting, which requires excellent clinical skill and is very time consuming. This work explores the use of 3D printing technology to fabricate bioactive artificial auricular cartilage using chondrocyte-laden gelatin methacrylate (GelMA) and polylactic acid (PLA) for auricle reconstruction. In this study, chondrocytes were loaded within GelMA hydrogel and combined with the 3D-printed PLA scaffolds to biomimetic the biological mechanical properties and personalized shape. The printing accuracy personalized scaffolds, biomechanics and chondrocyte viability and biofunction of artificial auricle have been studied. It was found that chondrocytes were fixed in the PLA auricle scaffolds via GelMA hydrogels and exhibited good proliferative properties and cellular activity. In addition, new chondrocytes and chondrogenic matrix, as well as type II collagen were observed after 8 weeks of implantation. At the same time, the transplanted auricle complex kept full and delicate auricle shape. This study demonstrates the potential of using 3D printing technology to construct in vitro living auricle tissue. It shows a great prospect in the clinical application of auricle regeneration.

Comparison of Auricle Reconstruction Using Tissue Expanders With Skin Grafting and Auricle Reconstruction Using Tissue Expanders Without Skin Grafting: A Single-Arm Meta-Analysis

OBJECTIVE

The authors conducted this meta-analysis to compare the efficacy of auricle reconstruction using tissue expanders with skin grafting and auricle reconstruction using tissue expanders without skin grafting by comparing the 6 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

By comparison, the authors found that, the satisfaction rate, the incidence of postoperative hematoma, the incidence of postoperative incision infection, and the incidence of cartilage framework exposure of patients with auricle reconstruction using tissue expanders with skin grafting were all lower than those with auricle reconstruction using tissue expanders without skin grafting. However, the incidence of postoperative skin necrosis, the incidence of leakage or exposure of expanders in patients with auricle reconstruction using tissue expanders with skin grafting were all higher than those with auricle reconstruction using tissue expanders without skin grafting.

CONCLUSIONS

Auricle reconstruction using tissue expanders with skin grafting has advantages in reducing the incidence of postoperative hematoma, the incidence of postoperative incision infection, and the incidence of cartilage framework exposure. Auricle reconstruction using tissue expanders without skin grafting has advantages in improving the satisfaction rate, reducing the incidence of postoperative skin necrosis, and the incidence of leakage or exposure of expanders. From the comparison of specific data, there is no significant difference in the treatment effect between the 2 surgical methods.

New strategies for base frame fabrication in microtia reconstruction

The base frame provides a stable support for the helix, antihelix, and tragus–antitragus complex in microtia reconstruction, and this support is vital to attain a highly defined outline for a reconstructed auricle. The success of base frame sculpting depends on appropriate treatment of the cartilage, mainly the sixth and seventh costal cartilages, which may have different characteristics. The aim of this study was to demonstrate the relevant details for base frame fabrication under various scenarios. Between 2016 and 2019, a total of 352 patients with microtia underwent autologous auricular reconstruction. Concerning the different sizes and characteristics of the costal cartilage used for the base frame reconstruction, we describe the related methods for fabrication and introduce corresponding strategies for proper management. We found that 90% of the patients responded at follow-up, and 76% of them were satisfied with the cosmetically refined auricle with harmonious integrity. The elaborate design and appropriate utilization of costal cartilage for base frame sculpting is one of the most significant and fundamental processes in microtia reconstruction. It contributes to achieving a clearly defined outline of the auricle with harmonious integrity, which is as important as the other projected subunits.

Treacher Collins Mandibular Distraction

Treacher Collins syndrome (TCS) is a genetic disorder that presents with a variety of craniofacial deformities. One classic feature of TCS is a steep, counterclockwise rotation of the occlusal plane, and microretrognathia with bony deficiencies in both the body and ramus of the mandible. This morphology commonly necessitates reconstruction by the craniofacial surgeon. This article discusses strategies and considerations for surgically correcting the mandibular deformity associated with TCS using mandibular distraction osteogenesis and other related techniques. The proper implementation of these techniques can yield excellent results that greatly improve quality of life in this challenging patient population.

Postoperative outcomes of autologous rib graft for microtia repair in children: A NSQIP study

OBJECTIVE

To compare the effect of surgical specialty and patient factors on 30-day postoperative outcomes and complications for children undergoing autologous costochondral grafting for microtia reconstruction.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program Pediatric (NSQIP-P) database was searched from 2012 through 2017 for patients who underwent autologous rib grafting (CPT 21230). The group was further filtered for coexisting ICD 9 or 10 code for microtia (744.23, Q17.2) as an indication for surgery. Outcomes analyzed included patient demographics, medical comorbidities, admission type (inpatient vs. outpatient), operative time, surgeon specialty, length of hospital stay (LOS), complications, and readmission.

RESULTS

A total of 375 pediatric patients were identified of which 157 were female and 218 were male. Mean age at time of surgery was 9.6 years. Postoperative complications and readmission occurred in 5.6% and 3.5% of patients, respectively. Surgical site infection was the most common complication. Average operative time was 246.9 min. When comparing Otolaryngology to Plastic Surgery with multivariate analysis, there was no difference in admission type (OR 1.00, p = 0.993), complication rate (OR 0.91, p = 0.744), readmission (OR 0.68, p = 0.576), operative time (p = 0.471) or total LOS (p = 0.266).

CONCLUSION

The present study demonstrated postoperative complications and readmission rates following microtia repair as reported by the NSQIP-P database. Overall complication and readmission rates were low. No significant risk factors were identified on multivariate analysis. There were no differences between surgical specialty for complication rate, operative time, hospital stay or readmission when accounting for demographic data and comorbidities.

Preclinical assessment of clinically streamlined, 3D-printed, biocompatible single- and two-stage tissue scaffolds for ear reconstruction

Auricular reconstruction is a technically demanding procedure requiring significant surgical expertise, as the current gold standard involves hand carving of the costal cartilage into an auricular framework and re-implantation of the tissue. 3D-printing presents a powerful tool that can reduce technical demands associated with the procedure. Our group compared clinical, radiological, histological, and biomechanical outcomes in single- and two-stage 3D-printed auricular tissue scaffolds in an athymic rodent model. Briefly, an external anatomic envelope of a human auricle was created using DICOM computed tomography (CT) images and modified in design to create a two-stage, lock-in-key base and elevating platform. Single- and two-stage scaffolds were 3D-printed by laser sintering poly-L-caprolactone (PCL) then implanted subcutaneously in five athymic rats each. Rats were monitored for ulcer formation, site infection, and scaffold distortion weekly, and scaffolds were explanted at 8 weeks with analysis using microCT and histologic staining. Nonlinear finite element analysis was performed to determine areas of high strain in relation to ulcer formation. Scaffolds demonstrated precise anatomic appearance and maintenance of integrity of both anterior and posterior auricular surfaces and scaffold projection, with no statistically significant differences in complications noted between the single- and two-staged implantation. While minor superficial ulcers occurred most commonly at the lateral and superior helix coincident with finite element predictions of high skin strains, evidence of robust tissue ingrowth and angiogenesis was visible grossly and histologically. This promising preclinical small animal model supports future initiatives for making clinically viable options for an ear tissue scaffold.

Biofabrication of a shape-stable auricular structure for the reconstruction of ear deformities

Bioengineering of the human auricle remains a significant challenge, where the complex and unique shape, the generation of high-quality neocartilage, and shape preservation are key factors. Future regenerative medicine–based approaches for auricular cartilage reconstruction will benefit from a smart combination of various strategies. Our approach to fabrication of an ear-shaped construct uses hybrid bioprinting techniques, a recently identified progenitor cell population, previously validated biomaterials, and a smart scaffold design. Specifically, we generated a 3D-printed polycaprolactone (PCL) scaffold via fused deposition modeling, photocrosslinked a human auricular cartilage progenitor cell–laden gelatin methacryloyl (gelMA) hydrogel within the scaffold, and cultured the bioengineered structure in vitro in chondrogenic media for 30 days. Our results show that the fabrication process maintains the viability and chondrogenic phenotype of the cells, that the compressive properties of the combined PCL and gelMA hybrid auricular constructs are similar to native auricular cartilage, and that biofabricated hybrid auricular structures exhibit excellent shape fidelity compared with the 3D digital model along with deposition of cartilage-like matrix in both peripheral and central areas of the auricular structure. Our strategy affords an anatomically enhanced auricular structure with appropriate mechanical properties, ensures adequate preservation of the auricular shape during a dynamic in vitro culture period, and enables chondrogenically potent progenitor cells to produce abundant cartilage-like matrix throughout the auricular construct. The combination of smart scaffold design with 3D bioprinting and cartilage progenitor cells holds promise for the development of clinically translatable regenerative medicine strategies for auricular reconstruction.

•

First application of human auricular cartilage progenitor cells for bioprinting.

•

Dual-printing of hybrid ear-shaped constructs with excellent shape fidelity over time.

•

Strategy and design ensured adequate deposition of cartilage-like matrix throughout large auricular constructs.

Total Auricular Reconstruction Using a Single Extended Postauricular Flap Without Skin Grafting in Two Stages: Experiences of 106 Cases

BACKGROUND

Postauricular fascial flap with skin grafting is popular as a solution in total auricular reconstruction, which might result in visible scars and mismatched color, especially in Asian people. Other methods using an expanded postauricular flap to avoid skin grafting often require three or more operations, which increases suffering for patients. This work aims to introduce a modified technique for auricular reconstruction using a single expanded postauricular flap without skin grafting in a two-stage operation.

METHODS

An 80-ml kidney-shaped expander was implanted in the mastoid area as the first-stage operation after preoperative evaluation. After a gradual expansion period and a 2-month rest time, the flap achieved the appropriate size and thickness. In the second stage, a three-layer cartilage framework was fabricated and inserted into the pocket through an incision at the remnant ear, and the earlobe and tragus were rebuilt simultaneously.

RESULTS

From September 2013 to October 2017, 106 microtia patients were selected for auricular reconstruction applying this method in our hospital. Patients were followed up to 6 months to 4 years. Most of them (93.4%) were satisfied with the reconstructed ears, especially with respect to suitable color and invisible scars. Complications of expander exposure or framework exposure happened in three cases, and all of them finally got a satisfactory result.

CONCLUSION

A single large expanded postauricular flap without a skin graft is an effective and efficient technique for auricular reconstruction with satisfying results. It can reconstruct an exquisite ear without a skin graft and can be finished in only two stages of operations.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Tissue Engineering and Regenerative Medicine: Achievements, Future, and Sustainability in Asia

Exploring innovative solutions to improve the healthcare of the aging and diseased population continues to be a global challenge. Among a number of strategies toward this goal, tissue engineering and regenerative medicine (TERM) has gradually evolved into a promising approach to meet future needs of patients. TERM has recently received increasing attention in Asia, as evidenced by the markedly increased number of researchers, publications, clinical trials, and translational products. This review aims to give a brief overview of TERM development in Asia over the last decade by highlighting some of the important advances in this field and featuring major achievements of representative research groups. The development of novel biomaterials and enabling technologies, identification of new cell sources, and applications of TERM in various tissues are briefly introduced. Finally, the achievement of TERM in Asia, including important publications, representative discoveries, clinical trials, and examples of commercial products will be introduced. Discussion on current limitations and future directions in this hot topic will also be provided.

Autologous Ear Reconstruction for Microtia Does Not Result in Loss of Cutaneous Sensitivity

BACKGROUND

Cutaneous sensitivity of microtia reconstruction has been sparsely documented. The purpose of this study was to evaluate whether there is a loss of cutaneous sensitivity following two-stage autologous ear reconstruction for unilateral microtia.

METHODS

A prospective study was performed including unilateral microtia patients who underwent two-stage autologous ear reconstruction performed by a single plastic surgeon between 2011 and 2016. Standardized sensory testing (i.e., temperature discrimination and Semmes-Weinstein monofilaments) was executed at 11 predefined anatomical points of the affected and unaffected ears preoperatively and at 6 and 12 months postoperatively.

RESULTS

Thirty-eight patients were included. Affected and unaffected sides presented similar (all p > 0.05) preoperative cutaneous sensitivity. Most (72.7 percent) of the tested points showed (all p < 0.05) preservation or recovery of cutaneous sensitivity at 12 months postoperatively. When comparing the reconstructed ears with the unaffected ears, there was no significant difference (all p > 0.05) in most (72.7 percent) of the tested points, except (all p < 0.05) at those points involving the postauricular sulcus.

CONCLUSION

There is a temporary cutaneous sensitivity loss after a two-stage autologous microtia reconstruction, which returned to similar preoperative sensitivity at 12-month follow-up, except in the postauricular sulcus.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Surgical-Based Classification for Microtia

The known classifications for microtia have been cumbersome and difficult to apply in daily consultation. The lack of a progressive surgical behavior according to each degree of affection also contributes to confusion and in a lower success rate in clinical application. The authors propose a progressive surgical classification that takes into consideration the principal anatomical defect and the corresponding correction with modern techniques, having eliminated from previous classifications, those elements that are now considered deformations of the ear, capable of conservative treatment in early stages of life.

Co-culture of adipose-derived stem cells and chondrocytes on three-dimensionally printed bioscaffolds for craniofacial cartilage engineering

OBJECTIVES/HYPOTHESIS

Reconstruction of craniofacial cartilagenous defects are among the most challenging surgical procedures in facial plastic surgery. Bioengineered craniofacial cartilage holds immense potential to surpass current reconstructive options, but limitations to clinical translation exist. We endeavored to determine the viability of utilizing adipose-derived stem cell-chondrocyte co-culture and three-dimensional (3D) printing to produce 3D bioscaffolds for cartilage tissue engineering. We describe a feasibility study revealing a novel approach for cartilage tissue engineering with in vitro and in vivo animal data.

METHODS

Porcine adipose-derived stem cells and chondrocytes were isolated and co-seeded at 1:1, 2:1, 5:1, 10:1, and 0:1 experimental ratios in a hyaluronic acid/collagen hydrogel in the pores of 3D-printed polycaprolactone scaffolds to form 3D bioscaffolds for cartilage tissue engineering. Bioscaffolds were cultured in vitro without growth factors for 4 weeks and then implanted into the subcutaneous tissue of athymic rats for an additional 4 weeks before sacrifice. Bioscaffolds were subjected to histologic, immunohistochemical, and biochemical analysis.

RESULTS

Successful production of cartilage was achieved using a co-culture model of adipose-derived stem cells and chondrocytes without the use of exogenous growth factors. Histology demonstrated cartilage growth for all experimental ratios at the post-in vivo time point confirmed with type II collagen immunohistochemistry. There was no difference in sulfated-glycosaminoglycan production between experimental groups.

CONCLUSION

Tissue-engineered cartilage was successfully produced on 3D-printed bioresorbable scaffolds using an adipose-derived stem cell and chondrocyte co-culture technique. This potentiates co-culture as a solution for several key barriers to a clinically translatable cartilage tissue engineering process.

LEVEL OF EVIDENCE

NA. Laryngoscope, 128:E251-E257, 2018.

Costal Cartilage Assessment in Surgical Timing of Microtia Reconstruction

BACKGROUND

Rib cartilage growth is closely related to age and determines the feasibility and outcomes of auricular reconstruction. Ear reconstruction is performed as early as age 6 in efforts to treat children before school matriculation while allowing for sufficient rib growth. But there is controversy over the optimal timing of microtia reconstruction. This study employs CT imaging and surface scanning to guide the timing of auricular reconstruction in children.

METHODS

A retrospective analysis was performed on 6-year-old microtia patients between January 2016 and June 2016. A total of 37 patients were underwent preoperative 3D rib-cage CT measurements and normal auricle scanning measurement including: the length of 6th, 7th, and 8th costal cartilage, the width of 6th,and 7th costal cartilage, and the length of normal auricle. Then the data of costal cartilage were compared with the data of the auricle.

RESULTS

The average length of the 6th, 7th, and 8th rib cartilage on the right was 76.1 ± 9.2 mm (range, 61.1-94.9 mm), 102.6 ± 9.9 mm (range, 84.5-119.1 mm), and 75.4 ± 19.3 mm (range, 47.3-118.5 mm), respectively, and the the average helical length was 90.5 ± 6.8 mm (range, 76.9-101.5 mm). Comparing the above data, it was revealed that the age of 6 years was an optimal time for ear reconstruction with tissue-expanding technique.

CONCLUSIONS

3D rib-cage CT for preoperative measurement of costal cartilage could be a useful method for planning microtia reconstruction. According to our study, the amount of costal cartilage of almost all 6-year-old microtia patients is enough for ear reconstruction. So age 6 years is the optimal timing of auricular reconstruction with tissue-expanding method.

Accurate Measurements of the Skin Surface Area of the Healthy Auricle and Skin Deficiency in Microtia Patients

Background:

The limited cranial skin covering auricular implants is an important yet underrated factor in auricular reconstruction for both reconstruction surgery and tissue engineering strategies. We report exact measurements on skin deficiency in microtia patients and propose an accessible preoperative method for these measurements.

Methods:

Plaster ear models (n = 11; male:female = 2:1) of lobular-type microtia patients admitted to the University Medical Center Utrecht in The Netherlands were scanned using a micro-computed tomographic scanner or a cone-beam computed tomographic scanner. The resulting images were converted into mesh models from which the surface area could be calculated.

Results:

The mean total skin area of an adult-size healthy ear was 47.3 cm², with 49.0 cm² in men and 44.3 cm² in women. Microtia ears averaged 14.5 cm², with 15.6 cm² in men and 12.6 cm² in women. The amount of skin deficiency was 25.4 cm², with 26.7 cm² in men and 23.1 cm² in women.

Conclusions:

This study proposes a novel method to provide quantitative data on the skin surface area of the healthy adult auricle and the amount of skin deficiency in microtia patients. We demonstrate that the microtia ear has less than 50% of skin available compared with healthy ears. Limited skin availability in microtia patients can lead to healing problems after auricular reconstruction and poses a significant challenge in the development of tissue-engineered cartilage implants. The results of this study could be used to evaluate outcomes and investigate new techniques with regard to tissue-engineered auricular constructs.

Direct electrospinning of 3D auricle-shaped scaffolds for tissue engineering applications

Thirty-two poly(ε)caprolactone (PCL) scaffolds have been produced by electrospinning directly into an auricle-shaped mould and seeded with articular chondrocytes harvested from bovine ankle joints. After seeding, the auricle shaped constructs were cultured in vitro and analysed at days 1, 7, 14 and 21 for regional differences in total DNA, glycosaminoglycan (GAG) and collagen (COL) content as well as the expression of aggrecan (AGG), collagen type I and type II (COL1/2) and matrix metalloproteinase 3 and 13 (MMP3/13). Stress-relaxation indentation testing was performed to investigate regional mechanical properties of the electrospun constructs. Electrospinning into a conductive mould yielded stable 3D constructs both initially and for the whole in vitro culture period, with an equilibrium modulus in the MPa range. Rapid cell proliferation and COL accumulation was observed until week 3. Quantitative real time PCR analysis showed an initial increase in AGG, no change in COL2, a persistent increase in COL1, and only a slight decrease initially for MMP3. Electrospinning of fibrous scaffolds directly into an auricle-shape represents a promising option for auricular tissue engineering, as it can reduce the steps needed to achieve an implantable structure.

Rib Cartilage Assessment Relative to the Healthy Ear in Young Children with Microtia Guiding Operative Timing

BACKGROUND

The optimal age at which to initiate for auricular reconstruction is controversial. Rib cartilage growth is closely related to age and determines the feasibility and outcomes of auricular reconstruction. We developed a method to guide the timing of auricular reconstruction in children with microtia ranging in age from 5 to 10 years.

METHODS

Rib cartilage and the healthy ear were assessed using low-dose multi-slice computed tomography. The lengths of the eighth rib cartilage and the helix of the healthy ear (from the helical crus to the joint of the helix and the earlobe) were measured. Surgery was performed when the two lengths were approximately equal.

RESULTS

The preoperative eighth rib measurements significantly correlated with the intraoperative measurements (P < 0.05). From 5 to 10 years of age, eighth rib growth was not linear. In 76 (62.8%) of 121 patients, the eighth rib length was approximately equal to the helix length in the healthy ear; satisfactory outcomes were achieved in these patients. In 18 (14.9%) patients, the eighth rib was slightly shorter than the helix, helix fabrication was accomplished by adjusting the length of the helical crus of stent, and satisfactory outcomes were also achieved. Acceptable outcomes were achieved in 17 (14.0%) patients in whom helix fabrication was accomplished by cartilage splicing. In 9 (7.4%) patients with insufficient rib cartilage length, the operation was delayed. In one (0.8%) patient with insufficient rib cartilage length, which left no cartilage for helix splicing, the result was unsatisfactory.

CONCLUSIONS

Eighth rib cartilage growth is variable. Rib cartilage assessment relative to the healthy ear can guide auricular reconstruction and personalize treatment in young patients with microtia.

Auricular reconstruction using biofabrication-based tissue engineering strategies

Auricular malformations, which impose a significant social and psychological burden, are currently treated using ear prostheses, synthetic implants or autologous implants derived from rib cartilage. Advances in the field of regenerative medicine and biofabrication provide the possibility to engineer functional cartilage with intricate architectures and complex shapes using patient-derived or donor cells. However, the development of a successful auricular cartilage implant still faces a number of challenges. These challenges include the generation of a functional biochemical matrix, the fabrication of a customized anatomical shape, and maintenance of that shape. Biofabrication technologies may have the potential to overcome these challenges due to their ability to reproducibly deposit multiple materials in complex geometries in a highly controllable manner. This topical review summarizes this potential of biofabrication technologies for the generation of implants for auricular reconstruction. In particular, it aims to discuss how biofabrication technologies, although still in pre-clinical phase, could overcome the challenges of generating and maintaining the desired auricular shapes. Finally, remaining bottlenecks and future directions are discussed.

Chondrogenesis of Human Adipose-Derived Stem Cells by In Vivo Co-graft with Auricular Chondrocytes from Microtia

OBJECTIVE

To evaluate the efficiency of chondrogenesis of human adipose-derived stem cells (ADSCs) induced by auricular chondrocytes from microtia via subcutaneous co-graft in nude mice.

METHODS

Human ADSCs and auricular chondrocytes were mixed at the ratio of 7:3 and suspended in 0.2 ml of Pluronic F-127 (5.0 × 10(7) cells/ml), and injected into Balb/c nude mice as the experimental group (Exp group). The same quantity of auricular chondrocytes (Ctr.1 group) or ADSCs (Ctr.2 group) in 0.2 ml of Pluronic F-127 was set as positive and negative control groups. The mixture of auricular chondrocytes (1.5 × 10(7) cells/ml) in 0.2 ml of Pluronic F-127 was set as the low concentration of chondrocyte control group (Ctr.3). At 8 weeks after grafting, the newly generated tissue pellets were isolated for morphological examination, haematoxylin and eosin staining, toluidine blue staining and safranin O staining of glycosaminoglycan (GAG), Masson's trichrome staining and immunohistochemical staining of type II collagen, and Verhoeff-iron-hematoxylin staining of elastic fibers. GAG content was determined by Alcian blue colorimetric method, and mRNA expression of type II collagen and aggrecan were examined by real-time PCR.

RESULTS

Cartilage-like tissue with a white translucent appearance and good elasticity was generated in the Exp and Ctr.1 groups. The tissue pellets in the Ctr.2 and Ctr.3 groups were much smaller than those in the Ctr.1 group. The mature cartilage lacunas could be observed in the Exp and Ctr.1 groups, while were rarely seen in the Ctr.3 group and not observed in the Ctr.2 group. The expression of cartilage-specific extracellular matrix such as type II collagen, GAG content, aggrecan, and elastic fibers in the Exp group was similar to that in the Ctr.1 group, whereas the expression of these extracellular matrix substances was significantly lower in the Ctr.2 and Ctr.3 groups (both P < 0.01).

CONCLUSION

Auricular chondrocytes from microtia can efficiently promote the chondrogenic differentiation and chondrogenesis of ADSCs by co-grafting in vivo.

NO LEVEL ASSIGNED

This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors http://www.springer.com/00266 .

Microtia reconstruction: autologous rib and alloplast techniques

Microtia represents a spectrum of maldevelopment of the external ear. Reconstructive techniques may utilize an autogenous rib cartilage framework and require 2-4 stages; alternatively, an alloplastic framework can be used and typically requires 1-2 stages. Successful reconstruction of microtia with either technique can provide a significant quality of life improvement, and both techniques are described in this article.

Successful creation of tissue-engineered autologous auricular cartilage in an immunocompetent large animal model

Tissue-engineered cartilage has historically been an attractive alternative treatment option for auricular reconstruction. However, the ability to reliably generate autologous auricular neocartilage in an immunocompetent preclinical model should first be established. The objectives of this study were to demonstrate engineered autologous auricular cartilage in the immunologically aggressive subcutaneous environment of an immunocompetent animal model, and to determine the impact of in vitro culture duration of chondrocyte-seeded constructs on the quality of neocartilage maturation in vivo. Auricular cartilage was harvested from eight adult sheep; chondrocytes were isolated, expanded in vitro, and seeded onto fibrous collagen scaffolds. Constructs were cultured in vitro for 2, 6, and 12 weeks, and then implanted autologously in sheep and in control nude mice for 6 and 12 weeks. Explanted tissue was stained with hematoxylin and eosin, safranin O, toluidine blue, collagen type II, and elastin. DNA and glycosaminoglycans (GAGs) were quantified. The quality of cartilage engineered in sheep decreased with prolonged in vitro culture time. Superior cartilage formation was demonstrated after 2 weeks of in vitro culture; the neocartilage quality improved with increased implantation time. In nude mice, neocartilage resembled native sheep auricular cartilage regardless of the in vitro culture length, with the exception of elastin expression. The DNA quantification was similar in all engineered and native cartilage (p>0.1). All cartilage engineered in sheep had significantly less GAG than native cartilage (p<0.02); significantly more GAG was observed with increased implantation time (p<0.02). In mice, the GAG content was similar to that of native cartilage and became significantly higher with increased in vitro or in vivo durations (p<0.02). Autologous auricular cartilage was successfully engineered in the subcutaneous environment of an ovine model using expanded chondrocytes seeded on a fibrous collagen scaffold after a 2-week in vitro culture period.

Treacher collins syndrome

Treacher Collins syndrome is a genetic disorder resulting in congenital craniofacial malformation. Patients typically present with downslanting palpebral fissures, lower eyelid colobomas, microtia, and malar and mandibular hypoplasia. This autosomal dominant disorder has a variable degree of phenotypic expression, and patients have no associated developmental delay or neurologic disease. Care for these patients requires a multidisciplinary team from birth through adulthood. Proper planning, counseling and surgical techniques are essential for optimizing patient outcomes. Here the authors review the features, genetics, and treatment of Treacher Collins syndrome.

Auricular cartilage repair using cryogel scaffolds loaded with BMP-7-expressing primary chondrocytes

The loss of cartilage tissue due to trauma, tumour surgery or congenital defects, such as microtia and anotia, is one of the major concerns in head and neck surgery. Recently tissue-engineering approaches, including gene delivery, have been proposed for the regeneration of cartilage tissue. In this study, primary chondrocytes were genetically modified with plasmid-encoding bone morphogenetic protein-7 (BMP-7) via the commercially available non-viral Turbofect vector, with the aim of bringing ex vivo transfected chondrocytes to resynthesize BMP-7 in vitro as they would in vivo. Genetically modified cells were implanted into gelatin-oxidized dextran scaffolds and cartilage tissue formation was investigated in 15 × 15 mm auricular cartilage defects in vivo in 48 New Zealand (NZ) white rabbits for 4 months. The results were evaluated via histology and early gene expression. Early gene expression results indicated a strong effect of exogenous BMP-7 on matrix synthesis and chondrocyte growth. In addition, histological analysis results exhibited significantly better cartilage healing with BMP-7-modified (transfected) cells than in the non-modified (non-transfected) group and as well as the control.

The temporoparietal fascia flap: a versatile tool in head and neck reconstruction

PURPOSE OF REVIEW

The article reviews recent significant advances and current applications of the temporoparietal fascia flap (TPFF) in head and neck surgery.

RECENT FINDINGS

The recent literature describes a wide span of new applications of the TPFF in many areas. Significant developments and refinements in the reconstruction of orbitomaxillary composite defects and orbital exenteration cavities are reported. The TPFF combined with alloplastic framework is gaining in importance in external ear reconstruction. Innovative prefabricated skin or soft-tissue grafts based on the TPFF are used to restore facial contour or in the reconstruction of complex facial defects. The free TPFF finds a role in laryngotracheal reconstruction as a vascular carrier to support cartilage grafts.

SUMMARY

Owing to its reliability and unequalled structural properties, the TPFF still plays a central role in facial reconstruction. Future investigation will likely incorporate the free TPFF as a vascular carrier of bioengineered tissues, such as cartilage and mucosa, for various head and neck indications.

The tissue-engineered auricle: past, present, and future

The reconstruction, repair, and regeneration of the external auricular framework continue to be one of the greatest challenges in the field of tissue engineering. To replace like with like, we should emulate the native structure and composition of auricular cartilage by combining a suitable chondrogenic cell source with an appropriate scaffold under optimal in vitro and in vivo conditions. Due to the fact that a suitable and reliable substitute for auricular cartilage has yet to be engineered, hand-carved autologous costal cartilage grafts and ear-shaped porous polyethylene implants are the current treatment modalities for auricular reconstruction. However, over the last decade, significant advances have been made in the field of regenerative medicine and tissue engineering. A variety of scaffolds and innovative approaches have been investigated as alternatives to using autologous carved costal cartilage or porous polyethylene implants. A review of recent developments and the current state of the art and science is presented, focusing on scaffolds, cell sources, seeding densities, and mechanical characteristics of tissue-engineered auricular cartilage.

Formation of tissue engineered composite construct of cartilage and skin using high density polyethylene as inner scaffold in the shape of human helix

BACKGROUND

Formation of external ear via tissue engineering has created interest amongst surgeons as an alternative for ear reconstruction in congenital microtia.

OBJECTIVE

To reconstruct a composite human construct of cartilage and skin in the shape of human ear helix in athymic mice.

METHODS

Six human nasal cartilages were used and digested with Collagenase II. Chondrocytes were passaged in 175 cm(2) culture flasks at a density of 10,000 cells/cm(2). Frozen human plasma was then mixed with human chondrocytes. Six human skin samples were cut into small pieces trypsinized and resuspended. The keratinocytes were plated in six-well plate culture dishes at a density of 2×105 cells per well. Dermis tissues were digested and the fibroblast cells resuspended in six-well plate at the density of 10,000 cells per well. Fibrin-fibroblast layer and fibrin-keratinocytes were formed by mixing with human plasma to create 6 bilayered human skin equivalent (BSE) constructs. The admixture of fibrin chondrocytes layers was wrapped around high density polyethylene (HDP), and implanted at the dorsum of the athymic mice. The construct was left for 4 weeks and after maturation the mice skin above the implanted construct was removed and replaced by BSE for another 4 weeks.

RESULTS

Haematoxylin and Eosin showed that the construct consists of fine arrangement and organized tissue structure starting with HDP followed by cartilage, dermis and epidermis. Safranin-O staining was positive for proteoglycan matrix production. Monoclonal mouse antihuman cytokeratin, 34βE12 staining displayed positive result for human keratin protein.

CONCLUSIONS

The study has shown the possibility to reconstruct ear helix with HDP and tissue engineered human cartilage and skin. This is another step to form a human ear and hopefully will be an alternative in reconstructive ear surgery.

Engineering ear constructs with a composite scaffold to maintain dimensions

Engineered cartilage composed of a patient's own cells can become a feasible option for auricular reconstruction. However, distortion and shrinkage of ear-shaped constructs during scaffold degradation and neocartilage maturation in vivo have hindered the field. Scaffolds made of synthetic polymers often generate degradation products that cause an inflammatory reaction and negatively affect neocartilage formation in vivo. Porous collagen, a natural material, is a promising candidate; however, it cannot withstand the contractile forces exerted by skin and surrounding tissue during normal wound healing. We hypothesised that a permanent support in the form of a coiled wire embedded into a porous collagen scaffold will maintain the construct's size and ear-specific shape. Half-sized human adult ear-shaped fibrous collagen scaffolds with and without embedded coiled titanium wire were seeded with sheep auricular chondrocytes, cultured in vitro for up to 2 weeks, and implanted subcutaneously on the backs of nude mice. After 6 weeks, the dimensional changes in all implants with wire support were minimal (2.0% in length and 4.1% in width), whereas significant reduction in size occurred in the constructs without embedded wire (14.4% in length and 16.5% in width). No gross distortion occurred over the in vivo study period. There were no adverse effects on neocartilage formation from the embedded wire. Histologically, mature neocartilage extracellular matrix was observed throughout all implants. The amount of DNA, glycosaminoglycan, and hydroxyproline in the engineered cartilage were similar to that of native sheep ear cartilage. The embedded wire support was essential for avoiding shrinkage of the ear-shaped porous collagen constructs.