Hands-on Training Methods for Vocal Fold Injection Education

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.

Thinking Beyond the Temporal Bone Lab: A Systematic Process for Expanding Surgical Simulation in Otolaryngology Training

The COVID-19 pandemic led to a temporary lapse in the development of otolaryngology trainee operative skills due to the cancellation of elective procedures and redeployment of trainees and attendings to COVID-19 units. Although transient, this disruption provided an opportunity for otolaryngology programs to develop contingency plans and formalize nascent simulation training curricula. Integration of formal simulation training alongside current didactic and surgical education may offset lost exposure during surgically lean times while providing the framework and resources for enhanced baseline training. Here, we provide an up-to-date overview of surgical simulation models in otolaryngology and identify easily implementable, low-cost, low fidelity models for junior trainees. By taking advantage of rapid advancements in technology and a paradigm shift to a more hands-on approach in medical education, formal simulation training may prove to be a beneficial tool at all stages of residency training, allowing for expanded peer-mentored skill development and providing a safe haven during unforeseen disruptions in surgical case volume.

The Otolaryngology boot camp: a scoping review evaluating commonalities and appraisal for curriculum design and delivery

OBJECTIVE

Surgical boot camps are becoming increasingly popular in Otolaryngology-Head and Neck Surgery (OHNS) residency programs. Despite pioneering virtual reality and simulation-based surgical education, these boot camps have lacked critical appraisal. The objective of this article was to examine the adoption and utility of surgical boot camps in OHNS residency training programs around the world.

DATA SOURCES

Ovid Medline and PubMed databases were systematically searched in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines for scoping reviews. Additionally, a grey literature search was performed.

REVIEW METHODS

Inclusion criteria were peer-reviewed publications and grey literature sources that reported on OHNS boot camps for the novice learner. The search was restricted to human studies published in English. Studies were excluded if they were not examining junior trainees.

RESULTS

A total of 551 articles were identified. Following removal of duplicates, screening, and full text review, 16 articles were included for analysis. Seven major boot camps were identified across various academic sites in the world. Most boot camps were one-day intensive camps incorporating a mixture of didactic, skill specific, and simulation sessions using an array of task trainers and high-fidelity simulators focusing on OHNS emergencies. Studies measuring trainee outcomes demonstrated improvement in trainee confidence, immediate knowledge, and skill acquisition.

CONCLUSION

Surgical boot camps appear to be an effective tool for short term knowledge and skill acquisition. Further studies should examine retention of skill and maintenance of confidence over longer intervals, as little is known about these lasting effects.

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.

Office-Based Procedure Training in Laryngology Fellowship Programs

OBJECTIVE

To assess the current practices and challenges of training office-based procedures to laryngology fellows in the United States.

METHODS

An anonymous web-based survey study was distributed to laryngology fellowship program directors, as listed by the American Laryngological Association. The survey was a 19-item questionnaire with free-text, Likert scale, and multiple-choice answers.

RESULTS

Twenty-two of 27 program directors (81.4%) replied to the survey. Many programs (8/16) have three or more laryngologists and do more than 10 procedures each week (10/16). Sixty-nine percent (11/16) of directors had not been trained for office procedures in their fellowship. The fellows are allowed to be primary surgeon on 68.75% and 75% of vocal fold augmentation and laser procedures, respectively. The expected competencies for these procedures on graduation are average-moderate and moderate. When program directors asked about the methods used for training, a minority of them use simulators (2/16), procedural checklists (2/16), or structured debriefing (2/16). The most commonly used methods were case-based troubleshooting (13/16) and unstructured debriefing (13/16). Patients being awake and patients' expectations are seen as the most important obstacles. Most of the directors thought office-based procedure training could be improved (14/16). The most common suggestions were using step-wise checklists, simulator-labs, and formal debriefings.

CONCLUSION

This is the first study evaluating the training of office-based laryngeal procedures during laryngology fellowship. Given the increasing importance of these procedures in practice and the herein identified barriers and need for improvement, fellowships should investigate the use of systematic training tools to improve fellow competency with office-based procedures. Laryngoscope, 131:2054-2058, 2021.

Real-time light-guided vocal fold injection as a simulation-based training tool

OBJECTIVE

Cricothyroid (CT) approach for vocal fold injection (VFI) has advantages of a low complication rate, suitability for in-office practice, and good patient compliance. However, it requires a high level of experience and a steep learning curve due to invisibility of needle. Recently, real-time light-guided VFI (RL-VFI) was developed for safe and precise injection into laryngeal structures under light guidance. Herein, we describe the development of a simulation-based training (SBT) program using RL-VFI for CT approach and report its preliminary application with in-training otolaryngologists.

METHODS

The workshop comprised 3 sessions: mini-lectures, and two hands-on training courses of conventional VFI and RL-VFI. Excised canine larynges and the device for RL-VFI were prepared for hands-on courses. Comfort levels for VFI was evaluated using visual analogue scale after each session. Trainees were requested to identify the needle tip on the target point lateral to vocal process. The time (s) to reach the target point was measured in all procedures. After workshop, all participants filled out questionnaires regarding their future preference for conventional VFI and RL-VFI.

RESULTS

Eleven otolaryngology residents participated in the study. The mean comfort levels were 1.7 ± 1.6, 5.5 ± 2.6, 4.8 ± 1.7, and 7.5 ± 1.6 for pre-workshop, post-lecture, post-conventional VFI, and post-RL-VFI (P < .001). The mean time (s) to reach the target point were 146.4 ± 90.1 and 42.7 ± 40.5 for conventional VFI and RL-VFI (P = .004). The mean preference scores were 4.2 ± 1.3 and 8.7 ± 1.3 for conventional VFI and RL-VFI (P = .004).

CONCLUSION

SBT program using RL-VFI might improve the comfort levels of trainees for VFI with CT approach. It would be helpful for trainees to practice VFI before trying it on actual patients.

LEVEL OF EVIDENCE

N/A.

Tumor phantom for training and research in transoral surgery

OBJECTIVE

With the paradigm shift towards minimally invasive surgical techniques such as transoral laser microsurgery and transoral robotic surgery for resection of head and neck malignancies, there is a need to enhance the surgical training of these techniques as well as provide a platform for testing new approaches and technologies. The steeper learning curve associated with minimally invasive surgical techniques may be mitigated with the use of tumor phantoms (TP) placed in cadaver models.

METHODS

An injectable TP was developed using an agar-gelatin base, unsalted chicken stock, deionized water, food coloring for visual mimicry, and iohexol for radiographic mimicry. Four percentage glutaraldehyde was used as a cross-linking agent for solidification of the TP. The TP was then injected in various mucosal anatomic sites in four unfixed cadaver heads. Visual, radiographic, and tactile mimicry was assessed via endoscopy, CT scan, and tumor dissection and palpation, respectively.

RESULTS

Tumor phantom injection was successfully achieved in all four cadaver heads. Visually and tactilely, the TP demonstrated similar color change, induration, and firmness of a typical squamous cell carcinoma (SCCa). However, ulceration that is often seen with SCCa could not be replicated. CT mimicry was compared with nine patients with known SCCa. Tumor radiodensity in the nine patients was between 77 and 110 HU (mean 86.3 HU) whereas TP radiodensity was 59 and 127 HU (mean 93.7 HU), with no significant difference between groups (P = .21).

CONCLUSION

This inexpensive, easy to apply, and unique tumor phantom could be used both to train transoral techniques and as a tool to further investigate new approaches and technologies for transoral surgery.

LEVEL OF EVIDENCE

NA.

Creating a Validated Simulation Training Curriculum in Otolaryngology

Purpose of Review

Simulation-based training is an integral component of surgical training. It allows practice of technical skills within a safe environment without compromising patient safety. This article seeks to review current virtual and non-virtual reality simulation models within the literature and review their validation status.

Recent Findings

Many simulation models exist within otolaryngology and are currently being used for education. New models are also continuously being developed; however, validity should be proven for the models before incorporating their use for educational purposes. Validity should be determined by experts and trainees themselves.

Summary

A validated simulation curriculum should be incorporated within the otolaryngology training programme. A curriculum based on the current training programme at our institution serves as an exemplar for local adoption.

Ex vivo ovine model for teaching open laryngotracheal surgery

Objective

To develop an animal model for teaching open laryngotracheal surgical procedures.

Methods

The heads and necks from 5 pre-pubescent sheep were harvested after humane anesthesia. After 2–5 days to allow for rigor mortis to resolve, a specimen was supported with sandbags on an operating table. Operative procedures including tracheotomy, medialization laryngoplasty, anterior cartilage grafting, tracheal resection with primary anastomosis, and laryngectomy with closure of the pharynx were attempted.

Results

The ovine head and neck provided an accurate model for simulation of all attempted procedures. Ovine tissue resembled that of humans in mechanical properties and handling. Postsurgical endoscopy confirmed graft alignment.

Conclusions

The sheep head and neck provides an inexpensive, realistic, and safe model for surgical training for a variety of open laryngotracheal procedures. This is particularly relevant given the recent emphasis on surgical simulation and the relative rarity of some of these procedures in residency training.

Current Status of Simulation in Otolaryngology: A Systematic Review

OBJECTIVE

Otolaryngology is a highly technical and demanding specialty and the requirements for surgical trainees to acquire proficiency remains challenging. Simulation has been purported to be an effective tool in assisting with this. The aim of this systematic review is to identify the available otolaryngology simulators, their status of validation, and evaluation the level of evidence behind each training model and thereby establish a level of recommendation.

DESIGN

PubMed, ERIC, and Google Scholar databases were searched for articles that described otolaryngology simulators or training models between 1980 and April 2016. Any validation studies for simulators were also retrieved. Titles and abstracts were screened for relevance using the preferred reporting items for systematic reviews and meta-analysis (PRISMA) guidelines. Level of evidence (LoE) and Level of recommendation (LoR) was awarded to each study and model, respectively.

RESULTS

A total of 70 studies were identified describing 64 simulators. Out of these, at least 54 simulators had 1 validation study. Simulators for the ear and temporal bone surgery were the most common (n = 32), followed by laryngeal and throat (n = 20) and endoscopic sinus surgery (n = 12). Face validity was evaluated by 29 studies, 20 attempted to show construct, 20 assessed content, 20 transfer, and only 2 assessed concurrent validity. Of the validation assessments, 2 were classified as Level 1b, 10 Level 2a, and 48 Level 2b. No simulators received the highest LoR, but 8 simulators received a LoR of 2.

CONCLUSIONS

Despite the lack of evidence in outcome studies and limited number of high-validity otolaryngology simulators, the role of simulation continues to grow across surgical specialties Hence, it is imperative that the simulators are of high validity and construct for trainees to practice and rehearse surgical skills to develop confidence.

Ex vivoovine model for suspension microlaryngoscopy training

Objective:

To develop an ovine model for teaching suspension laryngoscopy and phonosurgery.

Methods:

The head and neck from 10 pre-pubescent sheep were harvested following humane euthanasia at the end of anin vivoprotocol. No live animals were used in this study. The tissues were saline-perfused and refrigerated for 1–5 days. Suspension laryngoscopy was performed using adolescent Parsons and adult Kantor-Berci laryngoscopes suspended with a Benjamin-Parsons laryngoscope holder. Visualisation was achieved with 0° and 30° telescopes, and a three-chip camera and video system. Shapshay-Ossoff microlaryngeal instruments were used for endolaryngeal dissection.

Results:

Experienced laryngologists led a second year medical student through several procedures including injection laryngoplasty, hydrodissection and incision, endolaryngeal suturing, and partial cordectomy. Despite expected anatomical differences, the model proved highly realistic for suspension microlaryngoscopy.

Conclusion:

The sheep head and neck model provides an inexpensive, safe model for developing skills in suspension laryngoscopy and basic phonosurgery.

Phonomicrosurgery simulation: A low-cost teaching model using easily accessible materials

OBJECTIVES/HYPOTHESIS

To introduce the use of a new phonomicrosurgical trainer using easily accessible materials, and to establish the effectiveness of the model.

STUDY DESIGN

The model uses a grape imbedded in gelatin, a microscope, and microlaryngeal instruments. The study was designed to test baseline differences in training levels, as well as improvement in performance after training with the simulation model.

METHODS

Thirty subjects enrolled in the Stanford University School of Medicine otolaryngology training program performed microlaryngeal surgery tasks on a grape. Tasks were designed to model both excision of a vocal fold lesion and vocal fold injection. Anonymized video recordings comparing presimulation and postsimulation training were collected and graded by an expert laryngologist. Both objective comparison of skills and subjective participant surveys were analyzed.

RESULTS

Objectively, trainees in all groups made statistically significant improvements across all tested variables, including microscope positioning, creation of a linear incision, elevation of epithelial flaps, excision of a crescent of tissue, vocal fold injection, preservation of remaining tissue, and time to complete all tasks. Subjectively, 100% of participants felt that they had increased comfort with microlaryngeal instruments and decreased intimidation of microlaryngeal surgery after completing the simulation training. This appreciation of skills was most notable and statistically significant in the intern trainees.

CONCLUSION

Microlaryngeal surgical simulation is a tool that can be used to train residents to prepare them for phonomicrosurgical procedures at all levels of training. Our low-cost model with accessible materials can be easily duplicated and used to introduce trainees to microlaryngeal surgery or improve skills of more senior trainees.

LEVEL OF EVIDENCE

NA Laryngoscope, 126:2528-2533, 2016.

Simulation Model for Transcervical Laryngeal Injection Providing Real-time Feedback

Objective:

This study aimed to develop and evaluate a model for teaching transcervical laryngeal injections.

Methods:

A 3-dimensional printer was used to create a laryngotracheal framework based on de-identified computed tomography images of a human larynx. The arytenoid cartilages and intrinsic laryngeal musculature were created in silicone from clay casts and thermoplastic molds. The thyroarytenoid (TA) muscle was created with electrically conductive silicone using metallic filaments embedded in silicone. Wires connected TA muscles to an electrical circuit incorporating a cell phone and speaker. A needle electrode completed the circuit when inserted in the TA during simulated injection, providing real-time feedback of successful needle placement by producing an audible sound. Face validation by the senior authorconfirmed appropriate tactile feedback and anatomical realism. Otolaryngologists pilot tested the model and completed presimulation and postsimulation questionnaires.

Results:

The high-fidelity simulation model provided tactile and audio feedback during needle placement, simulating transcervical vocal fold injections. Otolaryngology residents demonstrated higher comfort levels with transcervical thyroarytenoid injection on postsimulation questionnaires.

Conclusion:

This is the first study to describe a simulator for developing transcervical vocal fold injection skills. The model provides real-time tactile and auditory feedback that aids in skill acquisition. Otolaryngologists reported increased confidence with transcervical injection after using the simulator.

Laryngeal support device enhances the learning of laryngeal anatomy and voice physiology

Multidisciplinary cooperation in health care requires a solid knowledge in the basic sciences for a common ground of communication. In speech pathology, these fundamentals improve the accuracy of descriptive diagnoses and support the development of new therapeutic techniques and strategies. The aim of this study is to briefly discuss the benefits of hands-on education on laryngeal anatomy and voice physiology in Brazilian graduate programs in speech pathology, as well as to describe a simple prototype that can be used as a useful educational tool for this purpose. The laryngeal anatomic support device was designed to provide a vertical frame to hold human or mammalian larynges with no preservation treatment, with the goal of allowing good visualization of the vocal folds during artificial phonation. The device was designed to provide the user the ability to manipulate the soft and cartilaginous structures of the larynx with near-natural biomechanical properties. The description of the project is detailed to allow the reproduction of this simple and inexpensive device. It may be used as an experimental feature in a variety of settings, from high-school programs to experimental research methods, and may suit a wide array of different educational models.

An integrated simulator for endolaryngeal surgery

The acquisition and maintenance of skills in transoral microlaryngeal surgery requires extended practice. Effective mentoring of such single-operator procedures is not possible, making it important for trainee surgeons to acquire basic skills outside of the operating room before participating in procedures on patients. Currently available training simulators use either synthetic materials or human tissue, both of which have limitations. We have designed a hybrid simulator that incorporates a porcine larynx in to an airway training manikin, providing both accurate airway anatomy and natural tissue handling characteristics. This model allows training in the skills required for suspension laryngoscopy and the resection of laryngeal lesions. Further applications could include development of surgical techniques and instruments, and use in accreditation of training and revalidation of trained surgeons.

Ergonomic analysis of microlaryngoscopy

OBJECTIVES/HYPOTHESIS

To apply ergonomic principles in analysis of three different operative positions used in laryngeal microsurgery.

STUDY DESIGN

Prospective case-control study.

METHODS

Laryngologists were studied in three different microlaryngeal operative positions: a supported position in a chair with articulated arm supports, a supported position with arms resting on a Mayo stand, and a position with arms unsupported. Operative positions were uniformly photographed in three dimensions. Full body postural data was collected and analyzed using the validated Rapid Upper Limb Assessment (RULA) tool to calculate a risk score indicative of potential musculoskeletal misuse in each position. Joint forces were calculated for the neck and shoulder, and compression forces were calculated for the L5/S1 disc space.

RESULTS

Higher-risk postures were obtained with unfavorably adjusted eyepieces and lack of any arm support during microlaryngeal surgery. Support with a Mayo stand led to more neck flexion and strain. Using a chair with articulated arm supports leads to decreased neck strain, less shoulder torque, and decreased compressive forces on the L5/S1 disc space. Ideal postures during microlaryngoscopy place the surgeon with arms and feet supported, with shoulders in an unraised, neutral anatomic position, upper arms neutrally positioned 20 degrees to 45 degrees from torso, lower arms neutrally positioned 60 degrees to 100 degrees from torso, and wrists extended or flexed <15 degrees.

CONCLUSIONS

RULA and biomechanical analyses have identified lower-risk surgeon positioning to be utilized during microlaryngeal surgery. Avoiding the identified high-risk operative postures and repetitive stress injury may lead to reduced occupationally related musculoskeletal pain and may improve microsurgical motor control.