Development and validation of a high-fidelity phonomicrosurgical trainer

Development and Validation of a Laryngeal Microsurgery Simulation Training System for Otolaryngology Residents

OBJECTIVE

This study aims to create a synthetic laryngeal microsurgery simulation model and training program; to assess its face, content, and construct validity; and to review the available phonomicrosurgery simulation models in the literature.

STUDY DESIGN

Nonrandomly assigned control study.

SETTING

Simulation training course for the otolaryngology residency program at Pontificia Universidad Católica de Chile.

METHODS

Resident (postgraduate year 1 [PGY1]/PGY2) and expert groups were recruited. A laryngeal microsurgery synthetic model was developed. Nine tasks were designed and assessed through a set of programmed exercises with increasing difficulty, to fulfill 5 surgical competencies. Imperial College Surgical Assessment Device sensors applied to the participants' hands measured time and movements. The activities were video-recorded and blindly assessed by 2 laryngologists using a specific and global rating scale (SRS and GRS). A 5-point Likert survey assessing validity was completed by experts.

RESULTS

Eighteen participants were recruited (14 residents and 4 experts). Experts performed significantly better than residents in the SRS (p = .003), and GRS (p = .004). Internal consistency was demonstrated for the SRS (α = .972, p < .001). Experts had a shorter execution time (p = .007), and path length with the right hand (p = .04). The left hand did not show significant differences. The survey assessing validity resulted in a median 36 out of 40 points score for face validity; and 43 out of 45 points score, for global content validity. The literature review revealed 20 available phonomicrosurgery simulation models, only 6 with construct validity.

CONCLUSION

The face, content, and construct validity of the laryngeal microsurgery simulation training program were established. It could be replicated and incorporated into residents' curricula.

Development and validation of a 3D laryngeal model in surgical skills training

OBJECTIVE

To present and validate a new simulation model for endoscopic phonomicrosurgery training as an improved teaching method.

METHODS

A low-cost artificial model was assembled using 3D printing, silicone, and gelatin. The study was designed to test the model's ability to carry out training and teaching of endoscopic phonomicrosurgery. The synthetic model was built to simulate normal and pathological vocal folds such as polyps, intracordal cysts and keratoses, made of silicone and gelatin and embedded in a larynx framework made by 3D printing. Simulations of endoscopic surgical procedures were performed and documented through photographs and videos and the images were submitted to the evaluation of a group of 17 otorhinolaryngologists who used a Likert scale questionnaire. The responses were submitted to an agreement analysis using the sum of the scores obtained for the responses as an appropriate level of validation. Cronbach's alpha index was calculated to measure the degree of the questionnaire internal consistency.

RESULT

The evaluations indicated maximum approval for the model adequacy for use in practical classes and for the teaching of the procedures, as well as in the overall satisfaction with the model in the use of surgical training.

CONCLUSION

The present proposal for training laryngeal endoscopic surgery in a 3D synthetic model is a viable option according to the validation methodology used in the present study.

Phonosurgery Training in Human Larynx Preserved with Thiel's Embalming Method

BACKGROUND

To describe the suitability of larynges preserved with Thiel's embalming method for phonosurgery training.

METHODS

A training model for phonosurgery techniques simulating vocal pathology and glottal insufficiency is developed to compare and evaluate the perception of embalmed vocal cords through a voluntary and anonymous survey rated on a scale of 1-5. A total of 10 residents and young otolaryngologists participated in the surgical training in phonosurgery.

RESULTS

Ten larynges preserved in formalin and 10 Thiel's embalmed larynges were used for the investigation. Phonosurgery procedures were performed following microflap and injection laryngoplasty techniques. The larynges preserved with Thiel's method demonstrated vocal cords that maintain their pliability and good tissue quality allowing a sensation of realism compared to the living body and providing suitable conditions for realistic laryngeal training. Participants held a positive experience, believed them to be useful and that these models of embalmed larynges were similar to the clinical setting and improved skills and confidence in performing phonosurgery.

CONCLUSIONS

The human larynges embalmed with Thiel's method maintain the pliability of the vocal cords, thus representing a unique model to practice and reproduce training for endolaryngeal procedures without the risks of contamination, anatomical variation, or rigidity of other models.

An Open-Source Three-Dimensionally Printed Laryngeal Model for Injection Laryngoplasty Training

OBJECTIVES/HYPOTHESIS

A limited number of three-dimensionally (3D)-printed laryngeal simulators have been described in the literature, only one of which is specifically designed for percutaneous injection laryngoplasty (PIL) training and is currently of limited availability. This study describes the development and evaluation of a high-fidelity, open-source, low-cost 3D-printed simulator for PIL training, improving on existing models.

STUDY DESIGN

Simulator design and survey evaluation.

METHODS

Computed tomography scans of the upper airways were processed with 3D Slicer to generate a computer model of the endolarynx. Blender and Fusion 360 were used to refine the mucosal model and develop casts for silicone injection molding. The casted endolaryngeal structures were inserted into a modified version of a publicly available laryngeal cartilage model. The final models were evaluated by 10 expert laryngologists using a customized version of the Michigan Standard Simulation Experience Scale. Internal consistency and interrater reliability of the survey were evaluated using Cronbach's α and intraclass correlation, respectively.

RESULTS

Expert laryngologists highly rated the model for measures of fidelity, educational value, and overall quality (mean = 4.8, standard deviation = 0.5; 1 = strongly disagree, 5 = strongly agree). All reviewers rated the model as ready for use as is or with slight modifications. The filament needed for one cartilage model costs $0.96, whereas the silicone needed for one soft-tissue model costs $1.89.

CONCLUSIONS

Using 3D-printing technology, we successfully created the first open-source, low-cost, and anatomically accurate laryngeal model for injection laryngoplasty training. Our simulator is made freely available for download on Wikifactory with step-by-step tutorials for 3D printing, silicone molding, assembly, and use.

LEVEL OF EVIDENCE

NA Laryngoscope, 131:E890-E895, 2021.

Real-time robotic airway measurement: An additional benefit of a novel steady-hand robotic platform

OBJECTIVE

Describe the secondary capability of a robotic system to provide real-time measurements of airway dimensions with high fidelity.

METHODS

Seven unique phantoms of laryngotracheal stenosis (LTS) were modeled using a computer-aided design tool and were three dimensionally printed. These stenoses were of different dimensions and orientations, and some were purposefully oblique. The dimensions of the stenoses were then measured with the novel Robotic ENT (Ear, Nose, and Throat) Microsurgery System (REMS; Galen Robotics, Inc., Sunnyvale, CA) because it is capable of tool position memory in three dimensional (3D) space. Five participants (two laryngologists, two otolaryngology-head and neck surgery residents, one neurotology fellow) measured each axis of stenosis (anteroposterior, lateral, and craniocaudal) three times for each of the seven stenosis phantoms. These measurements were then compared to the known design dimensions. Mean magnitude of error (MOE) and interrater reliability (IRR) using an intraclass correlation coefficient (ICC) were then calculated.

RESULTS

Mean MOE and standard deviation for all measurements was 0.306 ± 0.247 mm. Mean MOE was 0.374 ± 0.292 mm, 0.300 ± 0.237 mm, and 0.244 ± 0.185 mm for the anteroposterior, lateral, and craniocaudal dimensions of stenosis, respectively. Eighty-two percent of all measurements had MOE < 0.5 mm. ICC was 0.945 (95% confidence interval [CI]: 0.847-0.989), 0.995 (95% CI: 0.984-0.999), and 0.993 (95% CI: 0.987-0.999) for anteroposterior, lateral, and craniocaudal dimensions, respectively, indicating excellent agreement among participants.

CONCLUSION

The REMS can be used to reliably and accurately measure airway dimensions in 3D regardless of the orientation of stenosis. This ability may be easily extrapolated to the measurement of any airway lesion during laryngotracheal surgery.

LEVEL OF EVIDENCE

4 Laryngoscope, 129:324-329, 2019.