Webbed Neck Deformity Reconstruction in Patients with Turner Syndrome: Technical Considerations in Treating Congenital Pterygium Colli

Importance: Present an excellent outcome for a rare pterygium colli reconstruction. Objective: Establish techniques that have yielded a successful aesthetic and functional outcome for a patient with pterygium colli in a procedure that lacks consensus. Design, Setting, and Participants: Surgical pearls-description of considerations for a successful reconstruction. An academic practice. Pediatric patient with Turner's syndrome who underwent neck and auricular reconstruction.

Incorporating a Three-Dimensional Printed Airway into a Pediatric Flexible Bronchoscopy Curriculum

Background

Although hands-on simulation plays a valuable role in procedural training, there are limited tools available to teach pediatric flexible bronchoscopy (PFB). Fellowship programs rely on patient encounters, with inherent risk, or high-cost virtual reality simulators that may not be widely available and create education inequalities.

Objective

Our objective was to study the educational value and transferability of a novel, low-cost, three-dimensional-printed pediatric airway model (3D-AM) for PFB training. Our central hypothesis was that the 3D-AM would have high educational value and would be easily transferrable to learners at different teaching hospitals.

Methods

The 3D-AM was designed to teach technical bronchoscopy skills, airway anatomy, airway pathology, and bronchoalveolar lavage (BAL). The curriculum was offered to incoming fellows in pediatric pulmonology, pediatric surgery, and pediatric critical care across three different teaching institutions. After course completion, each participant assessed the simulation model(s) with a 5-point Likert scale across six domains: physical attributes, realism of experience, ability to perform tasks, value, relevance, and global impression. The expert instructors assessed the learners' competency using a modified version of the Bronchoscopy Skills and Tasks Assessment Tool.

Results

A total of 14 incoming fellows participated in the course. The mean scores for the 3D-AM across all six domains and across the three institutions was between 4 and 5, suggesting that learners generally had a favorable impression and a similar experience across different institutions. All learners "agreed" or "strongly agreed" that the course was a valuable use of their time, helped teach technical skills and airway anatomy, and would be useful for extra training during fellowship. Most of the learners correctly identified anatomy, bronchomalacia, and performed a BAL. Wall trauma was observed in 36% of learners.

Conclusion

The utility, low cost, and transferability of this model may create opportunities for PFB training across different institutions despite resource limitations in the United States and abroad.

A Validated 3D Printed Laryngeal Suturing Simulator for Endoscopic Laryngeal Cleft Repair

OBJECTIVES

Endoscopic laryngeal cleft repair (ELCR) with endolaryngeal suturing is an advanced surgical skill. This study objective was to assess the validity of 3-dimensionally (3D) printed laryngeal suturing simulator for ELCR.

STUDY DESIGN

Development and validation of a simulator for ELCR.

METHODS

An ELCR model was developed using 3D printed and readily available materials. Participants were surveyed before and after a simulation session using five-point Likert scale questions. Performance data was assessed using blinded expert video review and rated using a novel objective structured assessment of technical skills (OSATS) for endoscopic laryngeal suturing.

RESULTS

Twenty-one participants ranging from residents to attendings completed the simulation session. Survey respondents reported on a five-point Likert scale that the model was "easy to use" and "quite realistic" (both mean of 4). Confidence improved significantly in 86% of participants (p < 0.01). Overall OSATS scores (out of a total of 55) showed a median improvement in technical skills of 11.7 points (p = 0.004). OSATS demonstrated good intra-rater (κ = 0.689 and 0.677) and moderate inter-rater (κ = 0.573) reliability. Completion times improved from the first to the last suture by a median time of 512 to 350 s (decrease of 202 s, p = 0.002). Participants with no prior ELCR experience improved more than those with in vivo experience.

CONCLUSION

This study demonstrates the validity of a simulator utilizing 3D printed larynges for ELCR. A novel OSATS for endoscopic laryngeal suturing was successfully implemented. Confidence, technical skills, and completion times improved with the use of the model across a variety of participants. Laryngoscope, 133:785-791, 2023.

Comparison of Caregiver- and Child-Reported Quality of Life in Children With Sleep-Disordered Breathing

OBJECTIVE

Caregivers frequently report poor quality of life (QOL) in children with sleep-disordered breathing (SDB). Our objective is to assess the correlation between caregiver- and child-reported QOL in children with mild SDB and identify factors associated with differences between caregiver and child report.

STUDY DESIGN

Analysis of baseline data from a multi-institutional randomized trial SETTING: Pediatric Adenotonsillectomy Trial for Snoring, where children with mild SDB (obstructive apnea-hypopnea index <3) were randomized to observation or adenotonsillectomy.

METHODS

The Pediatric Quality of Life Inventory (PedsQL) assessed baseline global QOL in participating children 5 to 12 years old and their caregivers. Caregiver and child scores were compared. Multivariable regression assessed whether clinical factors were associated with differences between caregiver and child report.

RESULTS

PedsQL scores were available for 309 families (mean child age, 7.0 years). The mean caregiver-reported PedsQL score was higher at 75.2 (indicating better QOL) than the mean child-reported score of 67.9 (P < .001). The agreement between caregiver and child total PedsQL scores was poor, with intraclass correlation coefficients of 0.03 (95% CI, -0.09 to 0.15) for children 5 to 7 years old and 0.21 (95% CI, 0.03-0.38) for children 8 to 12 years old. Higher child age and health literacy were associated with closer agreement between caregiver and child report.

CONCLUSION

Caregiver- and child-reported global QOL in children with SDB was weakly correlated, more so for young children. In pediatric SDB, child-perceived QOL may be poorer than that reported by caregivers. Further research is needed to assess whether similar trends exist for disease-specific QOL metrics.

Integrated microtia and aural atresia management

Objectives

To present recommendations for the coordinated evaluation and management of the hearing and reconstructive needs of patients with microtia and aural atresia.

Methods

A national working group of 9 experts on microtia and atresia evaluated a working document on the evaluation and treatment of patients. Treatment options for auricular reconstruction and hearing habilitation were reviewed and integrated into a coordinated care timeline.

Results

Recommendations were created for children with microtia and atresia, including diagnostic considerations, surgical and non-surgical options for hearing management and auricular reconstruction, and the treatment timeline for each option. These recommendations are based on the collective opinion of the group and are intended for otolaryngologists, audiologists, plastic surgeons, anaplastologists, and any provider caring for a patient with microtia and ear canal atresia. Close communication between atresia/hearing reconstruction surgeon and microtia repair surgeon is strongly recommended.

A national pediatric otolaryngology fellowship virtual dissection course using 3D printed simulators

OBJECTIVE

Our objective was to create and evaluate a novel virtual platform dissection course to complement pediatric otolaryngology fellowship training in the setting of the COVID-19 pandemic.

METHODS

A four-station, four-simulator virtual course was delivered to pediatric otolaryngology fellows virtually using teleconferencing software. The four stations consisted of microtia ear carving, airway graft carving, cleft lip repair, and cleft palate repair. Fellows were asked to complete pre- and post-course surveys to evaluate their procedural confidence, expertise, and attitudes towards the course structure.

RESULTS

Statistical analysis of pre-course survey data showed fellows agreed that simulators should play an important part in surgical training (4.59 (0.62)); would like more options for training with simulators (4.31 (0.88)); and would like the option of saving their simulators for later reference (4.41 (0.85)). Fellows found the surgical simulators used in the course to be valuable as potential training tools (3.96 (0.96)), as competency or evaluation tools (3.91 (0.98)), and as rehearsal tools (4.06 (0.93)). Analysis showed a statistically significant improvement in overall surgical confidence in performing all four procedures.

CONCLUSION

This virtual surgical dissection course demonstrates 3D printed surgical simulators can be utilized to teach fellows advanced surgical techniques in a low-risk, virtual environment. Virtual platforms are a viable, highly-rated option for surgical training in the setting of restricted in-person meetings and as a mechanism to increase access for fellows by reducing costs and travel requirements during unrestricted periods.

Novel treatment for hypotonic airway obstruction and severe obstructive sleep apnea using a nasopharyngeal airway device with 3D printing innovation

STUDY OBJECTIVES

Pediatric obstructive sleep apnea impacts child and familial well-being. Airway management in patients with hypotonic pharyngeal conditions is complex. Some patients may benefit from continuous positive airway pressure or bilevel positive airway pressure, others may require further invasive measures for treatment. There is critical need for treatment alternatives for patients with pharyngeal hypotonia.

METHODS

This is a retrospective case series. Collaboratively with patients, families, biomedical engineers, and medical professionals, a long-term nasopharyngeal airway (NPA) was created to bypass upper airway obstruction. Two patients used a safety pin and tape attachment, and two patients used a novel 3D-printed, self-supporting nasal securement. All 4 patients had polysomnography before and during NPA use. Paired 1-tailed t-tests were conducted to compare apnea-hypopnea index, hypopnea index, obstructive index, and oxygen nadir.

RESULTS

Compared to baseline polysomnography, repeat polysomnography with the NPA in place demonstrated statistically significant improvement for apnea-hypopnea index (75.8 ± 36.6 events/h to 8.9 ± 2.9 events/h, P = .03), hypopnea index (45.4 ± 25.8 events/h to 7.7 ± 3.2 events/h, P = .04), and oxygen saturation nadir (60.3 ± 13.0% to 79.3 ± 8.7%, P = .01). The NPA had been used for over 1 year in 3 of the 4 children. Those using the safety pin and tape did report skin irritation due to adhesive required to keep device in place.

CONCLUSIONS

Current management of severe upper airway obstruction and obstructive sleep apnea in hypotonic pharyngeal conditions requires a team-based approach to care. A long-term NPA device may be an alternative or temporizing option to continuous positive airway pressure, upper airway surgery, or tracheostomy in children with pharyngeal hypotonia and severe obstructive sleep apnea. Larger studies of this approach are underway to assess efficacy in a range of obstructive sleep apnea severity in this population.

CITATION

Powell AR, Srinivasan S, Helman JL, et al. Novel treatment for hypotonic airway obstruction and severe obstructive sleep apnea using a nasopharyngeal airway device with 3D printing innovation. J Clin Sleep Med. 2022;18(10):2497-2502.

Development of a High-Fidelity, 3D Printed Otoplasty Surgical Simulator

IMPORTANCE

Prominotia has functional and esthetic impact for the child and family and proficiency in otoplasty requires experiential rehearsal.

OBJECTIVES

To design and validate an anatomically accurate, 3D printed prominotia simulator for rehearsal of otoplasties.

METHODS

A 3D prominotia model was designed from a computed tomographic (CT) scan and edited in 3-matic software. Negative molds were 3D printed and filled with silicone. Expert surgeons performed an otoplasty procedure on these simulators and provided Likert-based feedback.

RESULTS

Six expert surgeons with a mean of 14.3 years of practice evaluated physical qualities, realism, performance, and value of the simulator. The simulator was rated on a scale of 1 (no value) to 5 (great value) and scored 3.83 as a training tool, 3.83 as a competency evaluation tool, and 4 as a rehearsal tool.

CONCLUSIONS

Expert validation rated the otoplasty simulator highly in physical qualities, realism, performance, and value. With minor modifications, this model demonstrates valuable educational potential.

Neurobehavioral morbidity of pediatric mild sleep-disordered breathing and obstructive sleep apnea

STUDY OBJECTIVES

Obstructive sleep apnea is associated with neurobehavioral dysfunction, but the relationship between disease severity as measured by the apnea-hypopnea index and neurobehavioral morbidity is unclear. The objective of our study is to compare the neurobehavioral morbidity of mild sleep-disordered breathing versus obstructive sleep apnea.

METHODS

Children 3-12 years old recruited for mild sleep-disordered breathing (snoring with obstructive apnea-hypopnea index < 3) into the Pediatric Adenotonsillectomy Trial for Snoring were compared to children 5-9 years old recruited for obstructive sleep apnea (obstructive apnea-hypopnea 2-30) into the Childhood Adenotonsillectomy Trial. Baseline demographic, polysomnographic, and neurobehavioral outcomes were compared using univariable and multivariable analysis.

RESULTS

The sample included 453 participants with obstructive sleep apnea (median obstructive apnea-hypopnea index 5.7) and 459 participants with mild sleep-disordered breathing (median obstructive apnea-hypopnea index 0.5). By polysomnography, participants with obstructive sleep apnea had poorer sleep efficiency and more arousals. Children with mild sleep-disordered breathing had more abnormal executive function scores (adjusted odds ratio 1.96, 95% CI 1.30-2.94) compared to children with obstructive sleep apnea. There were also elevated Conners scores for inattention (adjusted odds ratio 3.16, CI 1.98-5.02) and hyperactivity (adjusted odds ratio 2.82, CI 1.83-4.34) in children recruited for mild sleep-disordered breathing.

CONCLUSIONS

Abnormal executive function, inattention, and hyperactivity were more common in symptomatic children recruited into a trial for mild sleep-disordered breathing compared to children recruited into a trial for obstructive sleep apnea. Young, snoring children with only minimally elevated apnea-hypopnea levels may still be at risk for deficits in executive function and attention.

TRIAL REGISTRATION

Pediatric Adenotonsillectomy for Snoring (PATS), NCT02562040; Childhood Adenotonsillectomy Trial (CHAT), NCT00560859.

A Longitudinal Comparison of Telemedicine Versus In-Person Otolaryngology Clinic Efficiency and Patient Satisfaction During COVID-19

OBJECTIVES

Telemedicine was increasingly adopted in otolaryngology as a result of the COVID-19 pandemic, but how it compares to in-person visits over the longitudinal course of the pandemic has not been characterized. This study compares telemedicine visits to in-person visits on measures of clinical efficiency and patient satisfaction.

METHODS

We examined all in-person and telemedicine encounters that occurred during the 13-month period from April 1, 2020 to April 30, 2021 at a pediatric otolaryngology clinic associated with a large tertiary care children's hospital. We compared patient demographics, primary encounter diagnoses, completions, cancellations, no-shows, cycle time, and patient satisfaction.

RESULTS

A total of 19 541 (90.5%) in-person visits and 2051 (9.5%) telemedicine visits were scheduled over the study period. There was no difference in patient age or gender between the visit types. There was a difference in race (75% White or Caucasian for in-person and 73% for telemedicine, P = .007) and average travel distance (53.3 miles for in-person vs 71.0 for telemedicine, P = .000). The most common primary diagnosis was Eustachian tube dysfunction for in-person visits (11.8%) and sleep disordered breathing for telemedicine visits (13.7%). Completion rate was greater for telemedicine visits (52.4% in-person vs 62.5% telemedicine). Cancellations were greater for in-person visits (42.6% in-person vs 24.2% telemedicine), but no-shows were greater for telemedicine (5.0% in-person vs 13.3% telemedicine, all P = .000). Average cycle time was shorter for telemedicine visits (56.5 minutes in-person vs 47.6 minutes telemedicine, P = .000). Patient satisfaction with provider interactions and overall care experience was high for both visit types.

CONCLUSIONS

Telemedicine was utilized more during months of heightened COVID-19 cases, with higher completion rates, fewer cancellations, shorter cycle times, saved travel distance, and comparable patient satisfaction to in-person visits. Telemedicine has the potential to remain an efficient mode of care delivery in the post-pandemic era.

Early preclinical evaluation of a novel, computer aided designed, 3D printed, bioresorbable posterior cricoid scaffold

OBJECTIVES

The posterior cricoid split with rib graft is a procedure that elegantly corrects pediatric posterior glottic stenosis and subglottic stenosis. Currently, the procedure requires harvesting of rib cartilage which leaves room for optimization. With use of three dimensional printing technology, our objective was to design a device that would negate the need for costal cartilage harvesting in this procedure.

METHODS

An optimized, novel polycaprolactone scaffold was designed using computer aided design software and three dimensional printing. A pilot proof of concept study was conducted with implantation of the device in three porcine animal subjects. Device was evaluated by post-procedural clinical course, endoscopic exams, post-mortem exam, and histological evaluation.

RESULTS

A series of variably sized scaffolds were created. The scaffolds showed structural integrity and successfully expanded the cricoid cartilage in the porcine model study. Post-operative endoscopy and clinical exams demonstrated no signs of implant instability or failure. Gross and histologic exams showed successful mucosalization over the scaffold and cartilage ingrowth by six weeks.

CONCLUSION

This porcine animal pilot study demonstrated early success of a computer-aided designed, 3D printed, bioresorbable PCL posterior graft scaffold. The scaffolds eliminate the need for costal cartilage harvesting and had excellent surgical usability. The scaffolds functioned as designed, offering proof of concept and grounds for further evaluation to expand on this small pilot study with larger animal studies and continued design refinement.

Hybrid Three-Dimensional-Printed Ear Tissue Scaffold With Autologous Cartilage Mitigates Soft Tissue Complications

OBJECTIVES/HYPOTHESIS

To analyze the use of highly translatable three-dimensional (3D)-printed auricular scaffolds with and without novel cartilage tissue inserts in a rodent model.

STUDY DESIGN

Preclinical rodent animal model.

METHODS

This prospective study assessed a single-stage 3D-printed auricular bioscaffold with or without porcine cartilage tissue inserts in an athymic rodent model. Digital Imaging and Communications in Medicine computed tomography images of a human auricle were segmented to create an external anatomic envelope filled with orthogonally interconnected spherical pores. Scaffolds with and without tissue inset sites were 3D printed by laser sintering bioresorbable polycaprolactone, then implanted subcutaneously in five rats for each group.

RESULTS

Ten athymic rats were studied to a goal of 24 weeks postoperatively. Precise anatomic similarity and scaffold integrity were maintained in both scaffold conditions throughout experimentation with grossly visible tissue ingrowth and angiogenesis upon explantation. Cartilage-seeded scaffolds had relatively lower rates of nonsurgical site complications compared to unseeded scaffolds with relatively increased surgical site ulceration, though neither met statistical significance. Histology revealed robust soft tissue infiltration and vascularization in both seeded and unseeded scaffolds, and demonstrated impressive maintenance of viable cartilage in cartilage-seeded scaffolds. Radiology confirmed soft tissue infiltration in all scaffolds, and biomechanical modeling suggested amelioration of stress in scaffolds implanted with cartilage.

CONCLUSIONS

A hybrid approach incorporating cartilage insets into 3D-printed bioscaffolds suggests enhanced clinical and histological outcomes. These data demonstrate the potential to integrate point-of-care tissue engineering techniques into 3D printing to generate alternatives to current reconstructive surgery techniques and avoid the demands of traditional tissue engineering.

LEVEL OF EVIDENCE

NA Laryngoscope, 131:1008-1015, 2021.

Addressing the Pandemic Training Deficiency: Filling the Void with Simulation in Facial Reconstruction

OBJECTIVE/HYPOTHESIS

To assess the use of a three-dimensional (3D) printed, multilayer facial flap model for use in trainee education as an alternative method of teaching surgical techniques of facial reconstruction.

STUDY DESIGN

Cohort study.

METHODS

A 3D printed facial flap simulator was designed from a computed tomography scan and manufactured out of silicone for low-cost, high-fidelity simulation. This simulator was tested by a group of Otolaryngology-Head and Neck Surgery trainees at a single institution. The simulator group was compared to a control group who completed an exercise on a traditional paper facial flap exercise. Both groups underwent didactic lectures prior to completing their respective exercises. Pre- and post-exercise Likert scale surveys measuring experience, understanding, effectiveness, and realism were completed by both groups. Central tendency, variability, and confidence intervals were measured to evaluate the outcomes.

RESULTS

Trainees completing the facial flap simulator reported a statistically significant (p < 0.05) improvement in overall expertise in facial flap procedures, design of facial flaps, and excision of standing cutaneous deformities. No statistically significant improvement was seen in the control group.

CONCLUSIONS

Trainees found the facial flap simulator to be an effective and useful training tool with a high level of realism in surgical education of facial reconstruction. Surgical simulators can serve as an adjunct to trainee education, especially during extraordinary times such as the novel coronavirus disease 2019 pandemic, which significantly impacted surgical training.

LEVEL OF EVIDENCE

NA Laryngoscope, 131:E2444-E2448, 2021.

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.

Adoption of Telemedicine for Multidisciplinary Care in Pediatric Otolaryngology

OBJECTIVE

The COVID-19 pandemic has introduced a period of social isolation that has challenged the ability of providers to uphold in-person patient care. Although commonplace in pediatric otolaryngology, multidisciplinary clinics pose a unique challenge during this time due to increased infection risk from multiple patient-provider interactions. Guidance on the application of telemedicine for multidisciplinary clinics in pediatric otolaryngology is limited.

METHODS

We provide comprehensive guidance on best practices for conducting telemedicine visits for a number of multidisciplinary otolaryngology clinics using our experiences at a single tertiary care children's hospital. A review of literature to support the adoption of telemedicine in multidisciplinary pediatric otolaryngology is also incorporated.

RESULTS

Telemedicine was successfully adopted for 7 multidisciplinary pediatric clinics with a variety of specialists: aerodigestive disorders, congenital hearing loss, microtia/aural atresia, orofacial clefting, sleep disorders, tracheostomy care, and velopharyngeal dysfunction.

CONCLUSIONS

Telemedicine is feasible for a variety of multidisciplinary clinics and its optimization is critical for providing care to complex pediatric otolaryngology patients during the COVID-19 pandemic and beyond.

Delivery system can vary ventilatory parameters across multiple patients from a single source of mechanical ventilation

BACKGROUND

Current limitations in the supply of ventilators during the Covid19 pandemic have limited respiratory support for patients with respiratory failure. Split ventilation allows a single ventilator to be used for more than one patient but is not practicable due to requirements for matched patient settings, risks of cross-contamination, harmful interference between patients and the inability to individualize ventilator support parameters. We hypothesized that a system could be developed to circumvent these limitations.

METHODS AND FINDINGS

A novel delivery system was developed to allow individualized peak inspiratory pressure settings and PEEP using a pressure regulatory valve, developed de novo, and an inline PEEP 'booster'. One-way valves, filters, monitoring ports and wye splitters were assembled in-line to complete the system and achieve the design targets. This system was then tested to see if previously described limitations could be addressed. The system was investigated in mechanical and animal trials (ultimately with a pig and sheep concurrently ventilated from the same ventilator). The system demonstrated the ability to provide ventilation across clinically relevant scenarios including circuit occlusion, unmatched physiology, and a surgical procedure, while allowing significantly different pressures to be safely delivered to each animal for individualized support.

CONCLUSIONS

In settings of limited ventilator availability, systems can be developed to allow increased delivery of ventilator support to patients. This enables more rapid deployment of ventilator capacity under constraints of time, space and financial cost. These systems can be smaller, lighter, more readily stored and more rapidly deployable than ventilators. However, optimizing ventilator support for patients with individualized ventilation parameters will still be dependent upon ease of use and the availability of medical personnel.

Multi-institutional Comparison of Temporal Bone Models: A Collaboration of the AAO-HNSF 3D-Printed Temporal Bone Working Group

Objective

The American Academy of Otolaryngology–Head and Neck Surgery Foundation’s (AAO-HNSF’s) 3D-Printed Temporal Bone Working Group was formed with the goal of sharing information and experience relating to the development of 3D-printed temporal bone models. The group conducted a multi-institutional study to directly compare several recently developed models.

Study Design

Expert opinion survey.

Setting

Temporal bone laboratory.

Methods

The working group convened in 2018. The various methods in which 3D virtual models had been created and printed in physical form were then shared and recorded. This allowed for comparison of the advantages, disadvantages, and costs of each method. In addition, a drilling event was held during the October 2018 AAO-HNSF Annual Meeting. Each model was drilled and evaluated by attending-level working group members using an 15-question Likert scale questionnaire. The models were graded on anatomic accuracy as well as their suitability as a simulation of both cadaveric and operative temporal bone drilling.

Results

The models produced for this study demonstrate significant anatomic detail and a likeness to human cadaver specimens for drilling and dissection. Models printed in standard resin material with a stereolithography printer scored highest in the evaluation, though the margin of difference was negligible in several categories.

Conclusion

Simulated 3D temporal bones created through a number of printing methods have potential benefit in surgical training, preoperative simulation for challenging otologic cases, and the standardized testing of temporal bone surgical skills.

Association of Opioid Quantity and Caregiver Education with Pain Control after Pediatric Tonsillectomy

Objective

To examine whether a service guideline reducing postoperative opioid prescription quantities and caregiver-reported education to use nonopioid analgesics first are associated with caregiver-reported pain control after pediatric tonsillectomy.

Study Design

Prospective cohort study (July 2018–April 2019).

Setting

Pediatric otolaryngology service at a tertiary academic children’s hospital.

Subjects and Methods

Caregivers of patients aged 1 to 11 years undergoing tonsillectomy (N = 764) were surveyed 7 to 21 days after surgery regarding pain control, education to use nonopioid analgesics first, and opioid use. Respondents who were not prescribed opioids or had missing data were excluded. Logistic regression modeled caregiver-reported pain control as a function of service guideline implementation (December 2018) recommending 20 rather than 30 doses for postoperative opioid prescriptions and caregiver-reported analgesic education, adjusting for patient demographics.

Results

Among 430 respondents (56% response), 387 patients were included. The sample was 43% female with a mean age of 5.0 years (SD, 2.5). Pain control was reported as good (226 respondents, 58%) or adequate/poor (161 respondents, 42%). Mean opioid prescription quantity was 27 doses (SD, 7.9) before and 21 doses (SD, 6.1) after guideline implementation ( P < .001). Education to use nonopioids first was reported by 308 respondents (80%). In regression, prescribing guideline implementation was not associated with pain control (adjusted odds ratio, 1.3; 95% CI, 0.9-2.0; P = .22), but caregiver-reported education to use nonopioids first was associated with a higher odds of good pain control (adjusted odds ratio, 1.9; 95% CI, 1.1-3.2; P = .02).

Conclusion

Caregiver education to use nonopioid analgesics first may be a modifiable health care practice to improve pain control as postoperative opioid prescription quantities are reduced.

Pediatric Adenotonsillectomy Trial for Snoring (PATS): protocol for a randomised controlled trial to evaluate the effect of adenotonsillectomy in treating mild obstructive sleep-disordered breathing

INTRODUCTION

Mild obstructive sleep-disordered breathing (oSDB), characterised by habitual snoring without frequent apnoeas and hypopnoeas on polysomnography, is prevalent in children and commonly treated with adenotonsillectomy (AT). However, the absence of high-level evidence addressing the role of AT in improving health and behavioural outcomes has contributed to significant geographical variations in care and potential for surgery to be both overused and underused.

METHODS AND ANALYSIS

The Pediatric Adenotonsillectomy Trial for Snoring (PATS) is a single-blinded, multicentre randomised controlled trial designed to evaluate the effect of AT in treating mild oSDB. Four hundred sixty eligible children, aged 3.0-12.9 years old, will be randomised to either early adenotonsillectomy or to watchful waiting with supportive care (WWSC) with a 1:1 ratio. The study's coprimary endpoints are (1) change from baseline in executive behaviour relating to self-regulation and organisation skills as measured by the Behavioural Rating Inventory of Executive Function (BRIEF) Global Composite Score (GEC); and (2) change from baseline in vigilance as measured on the Go-No-Go (GNG) signal detection parameter (d-prime). A mixed effects model will be used to compare changes in the BRIEF GEC score and GNG score at 6 and 12 months from baseline between the AT arm and the WWSC arm.

ETHICS AND DISSEMINATION

The study protocol was approved by the institutional review board (IRB) at Children's Hospital of Philadelphia (CHOP) on 3 October 2014 (14-0 11 214). The approval of CHOP as the central IRB of record was granted on 29 February 2016. The results will be published in peer-reviewed journals and presented at academic conferences. The data collected from the PATS study will be deposited in a repository (National Sleep Research Resource, sleepdata.org) after completion of the study to maximise use by the scientific community.

TRIAL REGISTRATION NUMBER

NCT02562040; Pre-results.

Computer-Aided Design, 3-D-Printed Manufacturing, and Expert Validation of a High-fidelity Facial Flap Surgical Simulator

Importance

Facial flap procedures may be difficult for surgical trainees to conceptualize and challenging for supervising surgeons to allow entrustment early in training. Simulation outside of the operating room may accelerate and enhance the surgical education experience.

Objective

To design and manufacture a 3-dimensional (3-D)-printed, multilayer, anatomically accurate facial flap model for use in surgical education.

Design, Setting, and Participants

In this multicenter validation study, a 3-D-printed facial flap simulator was designed from a computed tomographic (CT) scan and manufactured for low-cost, high-fidelity simulation. Expert otolaryngology-head and neck surgeon feedback was acquired through surgical rehearsal and performance of 8 local facial flap procedures on the facial flap simulator by 7 otolaryngologists fellowship trained in facial plastic surgery.

Main Outcomes and Measures

Likert scale surveys were made based on evaluation criteria categorized into domains of realism, experience, and applicability of the simulator. Measures of central tendency, variability, and confidence intervals were generated to evaluate the outcomes.

Results

Seven expert otolaryngology-head and neck surgeons completed a Likert scale evaluation survey containing quantitative analysis of 6 questions on physical attributes, 12 questions on realism, 8 questions on experience, and 4 questions on the applicability of the simulator. All expert surgeons were additionally fellowship trained in facial plastic surgery with their mean years in practice being 11.9. Overall evaluation demonstrated valuable ability of the simulator for medical education with suggestions for future directions. Importantly, the simulator was rated on a scale of 1 (no value) to 4 (great value) as 3.86 as a training tool, 3.57 as a competency evaluation tool, and 3.43 as a rehearsal tool.

Conclusions and Revelance

Expert experience with the local facial flap simulator was rated highly for realism, experience, performance, and usefulness. With slight refinement, the model has strong potential for broad use in training in otolaryngology-head and neck surgery and facial plastic surgery.

Level of Evidence

NA.

Development of a high fidelity subglottic stenosis simulator for laryngotracheal reconstruction rehearsal using 3D printing

INTRODUCTION

Laryngotracheal reconstruction (LTR) with cartilage graft augmentation is an effective treatment for subglottic stenosis and a critical advanced procedure for Pediatric Otolaryngologists. Trainees almost exclusively learn this procedure intraoperatively on children due to the lack of adequate pediatric training models. An enhanced and accelerated educational experience may be possible if trainees can rehearse the key portions of the procedure on a simulation model.

OBJECTIVE

To design and manufacture a low-cost, high fidelity surgical simulation model of subglottic stenosis for LTR.

METHODS

This simulator is composed of two component models: rib cartilage and trachea. Additive manufacturing techniques, including Computer Aided Design and Three Dimensional (3D) printing, were utilized to create the simulator. Three expert Pediatric Otolaryngologists rated the functionality and realism of the simulator using Likert scale survey data.

RESULTS

The use of CAD and 3D printing techniques allowed for realistic, reproducible surgical simulation of key aspects of LTR. The validation evidence indicated good to excellent means across the five domains relevant to the simulator's fidelity and usability (M = 3.47 to 4.00) out of a maximum of 4 points. Lowest rated items were consistent with expert comments suggesting minor simulator improvements. Time of production is approximately 20 h from print to post-processing, and consumable material costs per model are $2.60 USD.

CONCLUSIONS

This subglottic stenosis airway simulator facilitated Laryngotracheal Reconstruction rehearsal and is a promising training tool for pediatric otolaryngologists. Our methods allow patient-specific, pre-surgical rehearsal for complex airway scenarios that could benefit the experienced airway surgeon and trainees alike. Future research aims to validate this device's utility for accelerating attainment of proficiency and improving surgical outcomes.

Tissue Engineering and 3-Dimensional Modeling for Facial Reconstruction

Three-dimensional (3D) printing has transformed craniofacial reconstruction over the last 2 decades. For cutaneous oncologic surgeons, several 3D printed technologies are available to assist with craniofacial bony reconstruction and preliminary soft tissue reconstructive efforts. With improved accessibility and simplified design software, 3D printing has opened the door for new techniques in anaplastology. Tissue engineering has more recently emerged as a promising concept for complex auricular and nasal reconstruction. Combined with 3D printing, several groups have demonstrated promising preclinical results with cartilage growth. This article highlights the applications and current state of 3D printing and tissue engineering in craniofacial reconstruction.

3D-printed, externally-implanted, bioresorbable airway splints for severe tracheobronchomalacia

OBJECTIVES/HYPOTHESIS

To report the clinical safety and efficacy of three-dimensional (3D)-printed, patient-specific, bioresorbable airway splints in a cohort of critically ill children with severe tracheobronchomalacia.

STUDY DESIGN

Case series.

METHODS

From 2012 to 2018, 15 subjects received 29 splints on their trachea, right and/or left mainstem bronchi. The median age at implantation was 8 months (range, 3-25 months). Nine children were female. Five subjects had a history of extracorporeal membrane oxygenation (ECMO), and 11 required continuous sedation, six of whom required paralytics to maintain adequate ventilation. Thirteen were chronically hospitalized, unable to be discharged, and seven were hospitalized their entire lives. At the time of splint implantation, one subject required ECMO, one required positive airway pressure, and 13 subjects were tracheostomy and ventilator dependent, requiring a median positive end-expiratory pressure (PEEP) of 14 cm H₂ O (range, 6-20 cm H₂ 0). Outcomes collected included level of respiratory support, disposition, and splint-related complications.

RESULTS

At the time of discharge from our institution, at a median of 28 days postimplantation (range, 10-56 days), the subject on ECMO was weaned from extracorporeal support, and the subjects who were ventilated via tracheostomy had a median change in PEEP (discharge-baseline) of -2.5 cm H₂ O (range, -15 to 2 cm H₂ O, P = .022). At median follow-up of 8.5 months (range, 0.3-77 months), all but one of the 12 surviving subjects lives at home. Of the 11 survivors who were tracheostomy dependent preoperatively, one is decannulated, one uses a speaking valve, six use a ventilator exclusively at night, and three remain ventilator dependent.

CONCLUSIONS

This case series demonstrates the initial clinical efficacy of the 3D-printed bioresorbable airway splint device in a cohort of critically ill children with severe tracheobronchomalacia.

LEVEL OF EVIDENCE

4 Laryngoscope, 129:1763-1771, 2019.

A multidisciplinary international collaborative implementing low cost, high fidelity 3D printed airway models to enhance Ethiopian anesthesia resident emergency cricothyroidotomy skills

BACKGROUND

Similar to other sub-Saharan countries, Ethiopia suffers from a severe shortage of adequately trained health professionals. Academic partnerships can support sustainable training programs and build capacity for low-resource settings. 3D modeling and simulation-based training provide necessary tools, especially for rarely-encountered clinical situations, such as needle cricothyroidotomy.

METHODS

Departments of Anesthesiology, Otolaryngology, and Learning Health Sciences collaborated to develop a low-cost, high-fidelity simulator and Cricothryoidotomy Skills Maintenance Program (CSMP). Twelve anesthesia residents at St. Paul's Hospital Medical Millennium College in Addis Ababa, Ethiopia participated in CSMP. The program consisted of a didactic session with presentation and demonstration and an immersive CICO scenario. Program evaluation was performed using pre/post-training knowledge and 2 procedural performance assessments-the CSMP Global Rating Scale and the Checklist. With consent, performances were videotaped and rated independently by 3 University of Michigan faculty.

RESULTS

Improvements were identified in all areas, including residents' knowledge, measured by mean summed test scores (Mpre = 3.31,Mpost = 4.46,p = 0.003), time to perform cricothyroidotomy (Mpre = 96.64,Mpost = 72.82,p = 0.12), residents' performance quality, measured by overall mean Global ratings, (Mpre = 0.20; Mpost = 0.70) with improvements identified at the item-level, p = 0.001 with moderate-large effect sizes, and residents' ability to complete tasks, measured by mean Checklist ratings (Mpre = 0.51,Mpost = 0.90, with item-level improvements observed, p ≤ 0.01, with small-large effect sizes. Residents' self-reported confidence also improved (Mpre = 1.69, Mpost = 3.08,p = 0.001).

CONCLUSION

Our work shows that cricothyroidotomy skills taught to anesthesia residents at SPHMMC with a 3D printed laryngotracheal model improves knowledge, skills, and confidence. The creation of a low-cost, high-fidelity simulator and a CSMP has the potential to impact patient care and safety world-wide.

Pore architecture effects on chondrogenic potential of patient-specific 3-dimensionally printed porous tissue bioscaffolds for auricular tissue engineering

OBJECTIVE

This study aims to determine the effect of auricular scaffold microarchitecture on chondrogenic potential in an in vivo animal model.

METHODS

DICOM computed tomography (CT) images of a human auricle were segmented to create an external anatomic envelope. Image-based design was used to generate 1) orthogonally interconnected spherical pores and 2) randomly interspersed pores, and each were repeated in three dimensions to fill the external auricular envelope. These auricular scaffolds were then 3D printed by laser sintering poly-l-caprolactone, seeded with primary porcine auricular chondrocytes in a hyaluronic acid/collagen hydrogel and cultured in a pro-chondrogenic medium. The auricular scaffolds were then implanted subcutaneously in rats and explanted after 4 weeks for analysis with Safranin O and Hematoxylin and Eosin staining.

RESULTS

Auricular constructs with two micropore architectures were rapidly manufactured with high fidelity anatomic appearance. Subcutaneous implantation of the scaffolds resulted in excellent external appearance of both anterior and posterior auricular surfaces. Analysis on explantation showed that the defined, spherical micropore architecture yielded histologic evidence of more robust chondrogenic tissue formation as demonstrated by Safranin O and Hematoxylin and Eosin staining.

CONCLUSIONS

Image-based computer-aided design and 3D printing offers an exciting new avenue for the tissue-engineered auricle. In early pilot work, creation of spherical micropores within the scaffold architecture appears to impart greater chondrogenicity of the bioscaffold. This advantage could be related to differences in permeability allowing greater cell migration and nutrient flow, differences in surface area allowing different cell aggregation, or a combination of both factors. The ability to design an anatomically correct scaffold that maintains its structural integrity while also promoting auricular cartilage growth represents an important step towards clinical applicability of this new technology.

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.

Massive Macroglossia After Posterior Cranial Fossa Surgery: A Case Report

A 16-year-old boy with Chiari 1 malformation presented for an elective suboccipital craniectomy and C1 laminectomy. His intraoperative course was uneventful. At the conclusion of the procedure, he met extubation criteria and followed commands. After extubation, he developed progressive upper airway obstruction and became obtunded. He was reintubated via videolaryngoscopy, which showed edema not only to the tongue, but also to the posterior pharynx and blisters over the vocal folds and epiglottis. The patient was transferred to the pediatric intensive care unit intubated and sedated. This report describes the clinical course of his massive macroglossia and discusses short- and long-term management.

Pediatric laryngeal cleft repair and dysphagia

OBJECTIVE

To describe changes in diet and swallow function in patients with a laryngeal cleft after surgical repair of the laryngeal cleft.

METHODS

Retrospective case series performed using chart review. Primary outcomes were diet and swallow function before and after laryngeal cleft repair. Clinical evaluation and video fluoroscopic swallow studies (VFSS) were used to assess pre- and post intervention swallowing.

RESULTS

16 pediatric patients were included in this study. Preoperatively, 14 (88%) patients had diet restrictions. Postoperatively, 12 (75%) patients tolerated a regular diet without limitation. 4 (25%) patients had no reduction in diet restrictions over the course of this study. For the 10 patients who transitioned to a regular diet postoperatively, a median of 300 days (range: 26 days - 3 years) passed to document achieving a regular diet. This was corroborated by an increase in normal oral and pharyngeal phase swallow function on VFSS postoperatively when compared with preoperative VFSS results.

CONCLUSION

Dysphagia improves in most patients after laryngeal cleft repair. The range in time to a normal diet was wide. This may facilitate improved preoperative counseling and preparation of families' expectations.

Auricular reconstruction from rib to 3D printing

The human ear imparts critical form and function and remains one of the most challenging facial features to reconstruct. Over the past century, surgeons have developed numerous techniques and materials for total auricular reconstruction. Refined costal cartilage techniques have remained the gold standard for the past half-century. Recent advancements with novel materials, tissue engineering and 3D printing provide immense potential; however, prohibitive costs and regulatory steps remain as barriers to clinical translation.

Laryngotracheal reconstruction and swallowing: A review

OBJECTIVES

Significant advances in laryngotracheal reconstruction over the last few decades have revolutionised the management of paediatric patients with complex congenital or acquired airway stenosis. The primary aim of laryngotracheal reconstruction has focused primarily on airway and surgery specific outcomes, often at the expense of voice, as well as swallowing function, which are all intricately related. There is currently a paucity of data on swallowing outcome. The goal of this paper is to review and discuss the existing research on the impact of laryngotracheal on swallowing.

METHODS

Narrative review.

RESULTS

Successful and safe oral feeding in children requires a highly complex and integrated sensorimotor system for proper timing and coordination, beginning with a well-coordinated suck-swallow-breathe sequence in infancy. Factors to consider include the normal laryngeal anatomy, nutrition as a stimulus and the development of feeding skills on swallowing, the underlying aetiology and other risk factors, LTR procedures and their adjuncts. All these impact on the children's growth. Swallow assessments and rehabilitation is therefore an important part of the post-operative care.

CONCLUSIONS

As airway reconstructive surgeries have improved in airway and surgery specific outcomes, swallowing function is an important secondary outcome that impacts on the children's and their families' life. Management in a multi-disciplinary manner will optimise the outcome and improve their quality of life.

Computer-Aided Design and 3-Dimensional Printing for Costal Cartilage Simulation of Airway Graft Carving

Autologous cartilage grafting during open airway reconstruction is a complex skill instrumental to the success of the operation. Most trainees lack adequate opportunities to develop proficiency in this skill. We hypothesized that 3-dimensional (3D) printing and computer-aided design can be used to create a high-fidelity simulator for developing skills carving costal cartilage grafts for airway reconstruction. The rapid manufacturing and low cost of the simulator allow deployment in locations lacking expert instructors or cadaveric dissection, such as medical missions and Third World countries. In this blinded, prospective observational study, resident trainees completed a physical simulator exercise using a 3D-printed costal cartilage grafting tool. Participant assessment was performed using a Likert scale questionnaire, and airway grafts were assessed by a blinded expert surgeon. Most participants found this to be a very relevant training tool and highly rated the level of realism of the simulation tool.

Airway Obstruction during Drug-Induced Sleep Endoscopy Correlates with Apnea-Hypopnea Index and Oxygen Nadir in Children

Objective

To determine if standardized intraoperative scoring of anatomic obstruction in children with obstructive sleep apnea correlates with the apnea-hypopnea index (AHI) and lowest oxygen saturation on preprocedural polysomnogram (PSG). A secondary objective was to determine if age, presence of a syndrome, or previous adenotonsillectomy affect this correlation.

Study Design

Case series with chart review.

Setting

Two tertiary care children’s hospitals.

Subjects

Patients with a preprocedural PSG who underwent drug-induced sleep endoscopy (DISE) over a 4-year period.

Methods

All DISEs were graded in a systematic manner with the Chan-Parikh (C-P) scoring system. AHI and nadir oxygen saturations were extracted from preprocedural PSG. Data were analyzed with a multivariate linear regression model that controlled for age at time of sleep endoscopy, syndrome diagnosis, and previous adenotonsillectomy.

Results

A total of 127 children underwent PSG prior to DISE: 56 were syndromic, and 21 had a previous adenotonsillectomy. Mean AHI was 13.6 ± 19.6 (± SD), and mean oxygen nadir was 85.4% ± 9.4%. Mean C-P score was 5.9 ± 2.7. DISE score positively correlated with preoperative AHI ( r = 0.36, P < .0001) and negatively correlated with oxygen nadir ( r = −0.26, P = .004). The multivariate linear regression models estimated that for every 1-point increase in C-P score, there is a 2.6-point increase in AHI (95% confidence interval: 1.4-3.8, P < .001) and a 1.1% decrease in the lowest oxygen saturation (95% confidence interval: –1.7 to −0.6, P < .001).

Conclusion

The C-P scoring system for pediatric DISE correlates with both AHI and lowest oxygen saturation on preprocedural PSG.

Biomechanical evaluation of human and porcine auricular cartilage

OBJECTIVES/HYPOTHESIS

The mechanical properties of normal auricular cartilage provide a benchmark against which to characterize changes in auricular structure/function due to genetic defects creating phenotypic abnormalities in collagen subtypes. Such properties also provide inputs/targets for auricular reconstruction scaffold design. Several studies report the biomechanical properties for septal, costal, and articular cartilage. However, analogous data for auricular cartilage are lacking. Therefore, our aim in this study was to characterize both whole-ear and auricular cartilage mechanics by mechanically testing specimens and fitting the results to nonlinear constitutive models.

STUDY DESIGN

Mechanical testing of whole ears and auricular cartilage punch biopsies.

METHODS

Whole human cadaveric ear and auricular cartilage punch biopsies from both porcine and human cartilage were subjected to whole-ear helix-down compression and quasistatic unconfined compression tests. Common hyperelastic constitutive laws (widely used to characterize soft tissue mechanics) were evaluated for their ability to represent the stress-strain behavior of auricular cartilage.

RESULTS

Load displacement curves for whole ear testing exhibited compliant linear behavior until after significant displacement where nonlinear stiffening occurred. All five commonly used two-term hyperelastic soft tissue constitutive models successfully fit both human and porcine nonlinear elastic behavior (mean R(2) fit >0.95).

CONCLUSIONS

Auricular cartilage exhibits nonlinear strain-stiffening elastic behavior that is similar to other soft tissues in the body. The whole ear exhibits compliant behavior with strain stiffening at high displacement. The constants from the hyperelastic model fits provide quantitative baselines for both human and porcine (a commonly used animal model for auricular tissue engineering) auricular mechanics.

LEVEL OF EVIDENCE

NA

Design control for clinical translation of 3D printed modular scaffolds

The primary thrust of tissue engineering is the clinical translation of scaffolds and/or biologics to reconstruct tissue defects. Despite this thrust, clinical translation of tissue engineering therapies from academic research has been minimal in the 27 year history of tissue engineering. Academic research by its nature focuses on, and rewards, initial discovery of new phenomena and technologies in the basic research model, with a view towards generality. Translation, however, by its nature must be directed at specific clinical targets, also denoted as indications, with associated regulatory requirements. These regulatory requirements, especially design control, require that the clinical indication be precisely defined a priori, unlike most academic basic tissue engineering research where the research target is typically open-ended, and furthermore requires that the tissue engineering therapy be constructed according to design inputs that ensure it treats or mitigates the clinical indication. Finally, regulatory approval dictates that the constructed system be verified, i.e., proven that it meets the design inputs, and validated, i.e., that by meeting the design inputs the therapy will address the clinical indication. Satisfying design control requires (1) a system of integrated technologies (scaffolds, materials, biologics), ideally based on a fundamental platform, as compared to focus on a single technology, (2) testing of design hypotheses to validate system performance as opposed to mechanistic hypotheses of natural phenomena, and (3) sequential testing using in vitro, in vivo, large preclinical and eventually clinical tests against competing therapies, as compared to single experiments to test new technologies or test mechanistic hypotheses. Our goal in this paper is to illustrate how design control may be implemented in academic translation of scaffold based tissue engineering therapies. Specifically, we propose to (1) demonstrate a modular platform approach founded on 3D printing for developing tissue engineering therapies and (2) illustrate the design control process for modular implementation of two scaffold based tissue engineering therapies: airway reconstruction and bone tissue engineering based spine fusion.

Computer aided-designed, 3-dimensionally printed porous tissue bioscaffolds for craniofacial soft tissue reconstruction

OBJECTIVE

To determine the potential of an integrated, image-based computer-aided design (CAD) and 3-dimensional (3D) printing approach to engineer scaffolds for head and neck cartilaginous reconstruction for auricular and nasal reconstruction.

STUDY DESIGN

Proof of concept revealing novel methods for bioscaffold production with in vitro and in vivo animal data.

SETTING

Multidisciplinary effort encompassing 2 academic institutions.

SUBJECTS AND METHODS

Digital Imaging and Communications in Medicine (DICOM) computed tomography scans were segmented and utilized in image-based CAD to create porous, anatomic structures. Bioresorbable polycaprolactone scaffolds with spherical and random porous architecture were produced using a laser-based 3D printing process. Subcutaneous in vivo implantation of auricular and nasal scaffolds was performed in a porcine model. Auricular scaffolds were seeded with chondrogenic growth factors in a hyaluronic acid/collagen hydrogel and cultured in vitro over 2 months' duration.

RESULTS

Auricular and nasal constructs with several types of microporous architecture were rapidly manufactured with high fidelity to human patient anatomy. Subcutaneous in vivo implantation of auricular and nasal scaffolds resulted in an excellent appearance and complete soft tissue ingrowth. Histological analysis of in vitro scaffolds demonstrated native-appearing cartilaginous growth that respected the boundaries of the scaffold.

CONCLUSION

Integrated, image-based CAD and 3D printing processes generated patient-specific nasal and auricular scaffolds that supported cartilage regeneration.

Treatment of severe porcine tracheomalacia with a 3-dimensionally printed, bioresorbable, external airway splint

IMPORTANCE

The study demonstrates use of a novel intervention for severe tracheobronchomalacia (TBM).

OBJECTIVE

To test a novel, 3-dimensionally (3D) printed, bioresorbable airway splint for efficacy in extending survival in a porcine model of severe, life-threatening TBM.

DESIGN AND PARTICIPANTS

A randomized, prospective animal trial was used to evaluate an external airway splint as treatment of severe, life-threatening TBM in a multi-institutional, multidisciplinary collaboration between a biomedical engineering department and an academic animal surgery center. Six 2-month-old Yorkshire pigs underwent tracheal cartilage division and inner tracheal lumen dissociation and were randomly assigned to splint treatment (n = 3) or control groups (n = 3). Two additional pigs had the splint placed over their normal trachea.

INTERVENTIONS

A 3D-printed, bioresorbable airway splint was assessed in a porcine animal model of life-threatening TBM. The open-cylindrical, bellow-shaped, porous polycaprolactone splint was placed externally and designed to suspend the underlying collapsed airway. Two additional animals were splinted without model creation.

MAIN OUTCOMES AND MEASURES

The observer-based Westley Clinical Croup Scale was used to assess the clinical condition of animals postoperatively. Animal survival time was noted.

RESULTS

Complete or nearly complete tracheal lumen collapse was observed in each animal, with resolution of symptoms in all of the experimental animals after splint placement. Using our severe TBM animal model, survival was significantly longer in the experimental group receiving the airway splint after model creation than in the control group (P = .0495).

CONCLUSIONS AND RELEVANCE

A multidisciplinary effort producing a computer-aided designed, computer-aided manufactured bioresorbable tracheobronchial splint was tested in a porcine model of severe TBM and was found to extend survival time. Mortality in the splinted group was ascribed to the TBM model based on the lack of respiratory distress in splinted pigs, long-term survival in animals implanted with the splint without TBM, and necropsy findings.

Full-thickness skin graft overlying a separately harvested auricular cartilage graft for nasal alar reconstruction

OBJECTIVE

To evaluate the aesthetic and functional outcomes of a full-thickness skin graft and a separately harvested auricular cartilage graft for nasal alar defects created by Mohs micrographic surgery.

DESIGN

Twenty patients with deep Mohs micrographic surgery defects of the nasal ala who underwent reconstruction with a full-thickness skin graft and an auricular cartilage graft were prospectively studied at a single tertiary care institution between 2010 and 2011 in a nonrandomized, nonblinded study. An ordinal 5-point Likert scale evaluation of overall outcomes was performed by 4 independent surgeon raters.

RESULTS

The mean outcome for use of the full-thickness skin and auricular cartilage graft construct was a score of 2.3 on a scale of 1 through 5, with 1 being excellent and 5 being poor. The mean duration of follow-up was 6 months, with a range of 5 weeks to 23 months. There were no clinically meaningful losses of constructs in the patients studied.

CONCLUSION

A full-thickness skin graft and a separately harvested auricular cartilage graft are valuable and reliable tools for reconstructing deep nasal alar defects that require support to prevent alar retraction or collapse, particularly when a single-stage procedure is preferred or necessary because of medical comorbidities.

Computer-Aided Designed and 3-Dimensionally Printed Porous Tissue Bioscaffolds for Craniofacial Soft-Tissue Reconstruction

Objectives:

Introduce our groups’ innovative processes using image-based design and several 3-dimensionally printed scaffolds for head and neck cartilaginous reconstruction. Applications for auricular reconstruction and nasal reconstruction are discussed. Study Design: Proof of concept revealing novel methods for bioscaffold production with in vitro and in vivo data demonstrating preliminary scaffold behavior.

Methods:

DICOM computed tomography (CT) images undergo segmentation and image-based Boolean design. Three-dimensional (3D) designed, bioresorbable, poly-L-caprolactone scaffolds are printed. Subcutaneous in vivo implantation of auricular and nasal scaffolds was performed in a porcine model. Auricular scaffolds were seeded with primary porcine auricular chondrocytes in a hyaluronic acid/collagen hydrogel, and cultured in a prochondrogenic bioreactor environment.

Results:

Auricular and nasal constructs with several micropore architectures are rapidly manufactured with high fidelity anatomic appearance. Subcutaneous in vivo implantation of auricular and nasal scaffolds resulted in excellent appearance. Histologic analysis demonstrated cartilaginous growth within and respecting the boundaries of the scaffold. Cartilage growth was not seen outside of the scaffold, potentially suggesting a prochondrogenic effect of the scaffold or prevention of chondrocyte dedifferentiation.

Conclusions:

Image-based design processes and 3D printing in the production of cartilaginous structures for several challenging reconstructive applications is introduced. Bioscaffolds may allow regeneration of soft tissue structures that are replaced with native extracellular matrix.

C-122, a novel antagonist of serotonin receptor 5-HT2B, prevents monocrotaline-induced pulmonary arterial hypertension in rats

Pulmonary arterial hypertension (PAH) is a chronic disease characterized by sustained elevation of pulmonary arterial pressure that leads to right ventricle failure and death. Pulmonary resistance arterioles in PAH undergo progressive narrowing and/or occlusion. Currently approved therapies for PAH are directed primarily at relief of symptoms by interfering with vasoconstrictive signals, but do not halt the microvascular cytoproliferative process. In this study we show that C-122 (2-amino-N-(2-{4-[3-(2-trifluoromethyl-phenothiazin-10-yl)-propyl]-piperazin-1-yl}-ethyl)-acetamide trihydrochloride, a novel antagonist of serotonin receptor 5-HT(2B) (Ki=5.2 nM, IC(50)=6.9 nM), when administered to rats for three weeks in daily oral 10mg/kg doses, prevents not only monocrotaline (MCT)-induced elevations in pressure in the pulmonary arterial circuit (19 ± 0.9 mmHg vs. 28 ± 2 mmHg in MCT-vehicle group, P<0.05) and hypertrophy of the right ventricle (right ventricular wt./body wt. ratio 0.52 ± 0.02 vs. 0.64 ± 0.04 in MCT-vehicle group, P<0.05), but also muscularization of pulmonary arterioles (23% vs. 56% fully muscularized in MCT-vehicle group, P<0.05), and perivascular fibrosis in the lung. C-122 is orally absorbed in the rat, and partitions strongly into multiple tissues, including heart and lung. C-122 has significant off-target antagonist activity for histamine H-1 and several dopamine receptors, but shows no evidence of crossing the blood-brain barrier after a single 10mg/kg oral dose in rats. We conclude that C-122 can prevent microvascular remodeling and associated elevated pressures in the rat MCT model for PAH, and offers promise as a new therapeutic entity to suppress vascular smooth muscle cell proliferation in PAH patients.