Fabrication and validation of a low-cost, medium-fidelity silicone injection molded endoscopic sinus surgery simulation model

Three-Dimensional Printed Models to Accelerate Resident Surgical Learning Curve for Standard Endoscopic Sinus Surgery Techniques

Background: Endoscopic sinus surgery presents significant visuospatial challenges to surgical trainees. We tested the utility of novel 3D printed models to simulate sinus surgery tasks to improve endoscopic skillsets in resident trainees. Methods: This was a prospective quality improvement study of 10 ENT residents (PGY1-5). Participants rotated through 4 stations with different 3D simulation training modules designed to enhance endoscopic skillsets in the axial, sagittal and coronal planes (e.g., straight forceps to grasp a bead from a ledge, angled instruments to cannulate openings). Participants completed a self-assessment survey on the subjective sinus surgical skills using a visual analog scale before and after tasks. Two- tailed paired T-tests were used to analyze the data. Results: All residents rated their post-intervention "overall sinus surgery skills" higher than pre-intervention. They rated simulations to provide more significant utility as an adjunct to surgical education after the intervention. All but one participant reported improved spatial awareness working with the endoscopes and surgical instruments. There was subjectively improved proficiency in using 0-degree and angled endoscopes as well as cutting, grasping, and curved instruments after the intervention. The simulations led to subjective improvements in spatial awareness, bimanual dexterity, and increased confidence in selecting correct surgical instruments. Conclusion: Our set of novel 3D printed models to improve sinus surgery skillset was well accepted by the resident cohort. The 3D models can serve as an adjunct tool to traditional residency education.

Can high-fidelity 3D models be a good alternative for cadaveric materials in skill assessment for endoscopic sinus surgery? A comparison study in assessment for surgical performance in 3D models and cadavers

Introduction

Traditionally formal assessment of surgical skills has not been part of a surgeon's accreditation process. The widely adopted apprentice model of "on-the-job training" does create additional risk for the patients. In the past surgical training has used cadavers, but these are expensive, require dedicated wet-lab facilities and are in increasingly short supply. In many countries religious and cultural practices also preclude cadaveric use. Recent 3D-printed technology allows mass reproduction of high-fidelity 3D models. In this study, we examined the utility of 3D sinus models compared to cadaver dissection for surgical skill assessment for endoscopic sinus surgery (ESS).

Materials and methods

A total of 17 otolaryngologists performed Endoscopic Sinus Surgery (ESS) on 3D printed sinus models and then repeated these procedures on cadavers. Their surgical performance was assessed with the Objective Structured Assessment of Technical Skills (OSATS) score for ESS and time was taken to complete an ESS procedure. Their performance on the 3D models and cadavers was compared.

Results

There were no significant differences in the OSATS score between 3D models and cadavers (50.41 ± 13.31 vs. 48.29 ± 16.01, p = 0.36). There was a strong positive correlation between the score in 3D models and those in cadavers (r = 0.84, p < 0.001). No significant differences were found in time for a mini-ESS (21:29 ± 0:10 vs. 20:33 ± 0:07, p = 0.53). There were positive correlations between 3D models and cadavers in time taken for a mini-ESS (r = 0.55, p = 0.04).

Conclusion

The surgical performance on the 3D models was comparable to that on cadavers. This supports the utility of the 3D models as an inexhaustible alternative for cadavers in ESS surgical skill assessment.

An update on simulation training in rhinology: a systematic review of evidence

BACKGROUND

Rhinological procedures demand a high degree of technical expertise and anatomical knowledge. Because of limited surgical opportunities, ethical considerations and the complexity of these procedures, simulation-based training has become increasingly important. This review aimed to evaluate the effectiveness of simulation models used in rhinology training.

METHODS

Searches were conducted on PubMed, Embase, Cochrane and Google Scholar for studies conducted between July 2012 and July 2022. The Preferred Reporting Items for Systematic Reviews and Meta-Analysis ('PRISMA') protocol defined a final list of articles. Each validated study was assigned a level of evidence and a level of recommendation based on the Oxford Centre of Evidence-Based Medicine classification.

RESULTS

Following exclusions, 42 articles were identified which encompassed six types of simulation models and 26 studies evaluated validity. The rhinological skills assessed included endoscopic sinus surgery (n = 28), skull base/cerebrospinal fluid leak repair (n = 14), management of epistaxis and/or sphenopalatine artery ligation (n = 8), and septoplasty and septorhinoplasty (n = 6). All studies reported the beneficial impact of their simulation models on trainee development.

CONCLUSION

Simulation training in rhinology is a valuable adjunct to traditional surgical education. Although evidence is of moderate quality, the findings highlight the importance of simulation-based training in rhinology training.

Use of patient-specific 3D printed models in pre-operative counseling for pediatric skull base surgery

OBJECTIVES

Pediatric cranial base pathology is anatomically complex and surgical treatment is oftentimes difficult to conceptualize for patients and their families. Three-dimensional (3D) models of the sinuses and cranial base have the potential to enhance patient understanding in numerous domains. Our objective is to assess the use of 3D models in pre-operative parental and patient counseling prior to endoscopic endonasal skull base surgery in the pediatric population.

METHODS

A survey was designed to assess parent and patient-perceived utility of 3D-printed models in surgical counseling prior to pediatric skull base surgery.

RESULTS

A total of 10 patients were included. The median age was 9 years (range = 5 months-15 years). Pathology included juvenile nasopharyngeal angiofibroma (JNA) (N = 4), fibrous dysplasia of the maxilla and sphenoid (N = 1), juvenile ossifying fibroma (N = 1), nasal dermoid (N = 2, one with intracranial extension), encephalocele (N = 1), and parapharyngeal ectopic glial tissue (N = 1). Nearly all parents agreed or strongly agreed that 3D printed models were helpful in explaining the patient's skull base pathology (N = 10), surgical plan (N = 10), and possible complications (N = 9). All parents strongly agreed that 3D models should be used routinely in pre-operative counseling for endoscopic endonasal surgery. According to a majority of parents, patients older than 4 years old found the models helpful in understanding their pathology (75%) and surgery (88%).

CONCLUSION

By allowing direct three-dimensional visualization of the target pathology, 3D models serve as a useful adjunct in enhancing patient comprehension of the pathologic entity, planned surgery, and potential complications prior to pediatric endoscopic endonasal skull base surgery.

Can Non-Virtual Reality Simulation Improve Surgical Training in Endoscopic Sinus Surgery? A Literature Review

Simulation in endoscopic sinus surgery allows residents to learn anatomy, to achieve the correct handling of various rhinological instruments, and to practice different surgical procedures. Physically or non-virtual reality models are the main items in endoscopic sinus surgery simulation. The objective of this review is to identify and make a descriptive analysis of non-virtual endoscopic sinus surgery simulators which have been proposed for training. As a new state of the art, surgical simulators are developed continuously, so they can be used to learn basic endoscopic surgery skills by repetitive maneuvers, permitting detection of surgical error and incidents without risk for the patient. Of all training physical models, the ovine model stands out because of the similarities of the sinonasal pathways, the wide availability, and the low costs. Considering the similar nature of the tissues involved, the techniques and surgical instruments can be used almost interchangeably with minimal differences. Every surgical technique studied until now has a degree of risk and the only aspects that consistently reduced the number of complications are training, repetition, and hands-on experience.

A mechanically validated open-source silicone model for the training of gastric perforation sewing

BACKGROUND

Gastrointestinal perforation is commonly seen in emergency departments. The perforation of the stomach is an emergency situation that requires immediate surgical treatment. The necessary surgical skills require regular practical training. Owing to patient`s safety, in vivo training opportunities in medicine are restricted. Animal tissue especially porcine tissue, is commonly used for surgical training. Due to its limiting factors, artificial training models are often to be preferred. Many artificial models are on the market but to our knowledge, none that mimic the haptic- and sewing properties of a stomach wall at the same time. In this study, an open source silicone model of a gastric perforation for training of gastric sewing was developed that attempts to provide realistic haptic- and sewing behaviour.

METHODS

To simulate the layered structure of the human stomach, different silicone materials were used to produce three different model layups. The production process was kept as simple as possible to make it easily reproducible. A needle penetration setup as well as a systematic haptic evaluation were developed to compare these silicone models to a real porcine stomach in order to identify the most realistic model.

RESULTS

A silicone model consisting of three layers was identified as being the most promising and was tested by clinical surgeons.

CONCLUSIONS

The presented model simulates the sewing characteristics of a human stomach wall, is easily reproducible at low-costs and can be used for practicing gastric suturing techniques.

TRIAL REGISTRATIONS

Not applicable.

A three-dimensionally printed otological model for cholesteatoma mastoidectomy training

PURPOSE

To relate the creation and expert validation (face and content validity) of an affordable three-dimensional (3-D) printed model of temporal bones with chronic otitis media with cholesteatoma (COMC) as a simulator for mastoidectomy.

METHODS

We performed computed tomography (CT) of the temporal bones of a patient with COMC followed at the University of São Paulo (USP) Hospital with 3-D Slicer to create a 3-D model of the affected bone using light-curing resin and silicone (cholesteatoma). The final 3-D printed images were scored by 10 otologists using a customized version of the Michigan Standard Simulation Scale Experience (MiSSES). Internal consistency and inter-rater reliability were assessed using Cronbach's α and intraclass correlations.

RESULTS

Otologists consistently scored the model positively for fidelity, educational value, reactions, and the overall model quality. Nine otologists agreed that the model was a good educational device for surgical training of COMC. All experts deemed the model ready-or nearly ready-for use. The final cost of the model, including raw materials and manufacturing, was 120 USD.

CONCLUSIONS

Using 3-D printing technology, we created the first anatomically accurate, low-cost, disease-reproducing 3-D model of temporal bones for mastoidectomy training for cholesteatoma.

Mental workload during endoscopic sinus surgery is associated with surgeons' skill levels

Introduction

Surgeons' mental workload during endoscopic sinus surgery (ESS) has not been fully evaluated. The assessment was challenging due to the great diversity of each patient's anatomy and the consequence variety of surgical difficulties. In this study, we examined the mental workload of surgeons with various surgical skill levels during ESS under the standardized condition provided by novel-designed 3D sinus models.

Materials and methods

Forty-seven participants performed a high-fidelity ESS simulation with 3D-printed sinus models. Surgeons' mental workload was assessed with the national aeronautics and space administration-task load index (NASA-TLX). Associations between the total and subscales score of NASA-TLX and surgical skill index, including the board certification status, the number of experienced ESS cases, and the objective structured assessment of technical skills (OSATS), were analyzed. In addition, 10 registrars repeated the simulation surgery, and their NASA-TLX score was compared before and after the repetitive training.

Results

The total NASA-TLX score was significantly associated with OSATS score (p = 0.0001). Primary component analysis classified the surgeons' mental burden into three different categories: (1) the skill-level-dependent factors (temporal demand, effort, and performance), (2) the skill-level-independent factors (mental and physical demand), and (3) frustration. After the repetitive training, the skill-level-dependent factors were alleviated (temporal demand; z = -2.3664, p = 0.0091, effort; z = -2.1704, p = 0.0346, and performance; z = -2.5992, p = 0.0017), the independent factors were increased (mental demand; z = -2.5992, p = 0.0023 and physical demand; z = -2.2509, p = 0.0213), and frustration did not change (p = 0.3625).

Conclusion

Some of the mental workload during ESS is associated with surgical skill level and alleviated with repetitive training. However, other aspects remain a burden or could worsen even when surgeons have gained surgical experience. Routine assessment of registrars' mental burdens would be necessary during surgical training to sustain their mental health.

Assessment of a novel patient-specific 3D printed multi-material simulator for endoscopic sinus surgery

Background: Three-dimensional (3D) printing is an emerging tool in the creation of anatomical models for surgical training. Its use in endoscopic sinus surgery (ESS) has been limited because of the difficulty in replicating the anatomical details. Aim: To describe the development of a patient-specific 3D printed multi-material simulator for use in ESS, and to validate it as a training tool among a group of residents and experts in ear-nose-throat (ENT) surgery. Methods: Advanced material jetting 3D printing technology was used to produce both soft tissues and bony structures of the simulator to increase anatomical realism and tactile feedback of the model. A total of 3 ENT residents and 9 ENT specialists were recruited to perform both non-destructive tasks and ESS steps on the model. The anatomical fidelity and the usefulness of the simulator in ESS training were evaluated through specific questionnaires. Results: The tasks were accomplished by 100% of participants and the survey showed overall high scores both for anatomy fidelity and usefulness in training. Dacryocystorhinostomy, medial antrostomy, and turbinectomy were rated as accurately replicable on the simulator by 75% of participants. Positive scores were obtained also for ethmoidectomy and DRAF procedures, while the replication of sphenoidotomy received neutral ratings by half of the participants. Conclusion: This study demonstrates that a 3D printed multi-material model of the sino-nasal anatomy can be generated with a high level of anatomical accuracy and haptic response. This technology has the potential to be useful in surgical training as an alternative or complementary tool to cadaveric dissection.

Septoplasty Training During the COVID-19 Era: Development and Validation of a Novel Low-Cost Simulation Model

OBJECTIVE

In a context of increasingly limited surgical exposition, enhanced by the coronavirus disease 2019 (COVID-19) pandemic context, the objective of this article is to explain the development of a novel low-cost and simple replication animal-based septoplasty training model for otolaryngology residents, to assess its face and construct validity, and to validate a specific rating scale for each task.

STUDY DESIGN

Experimental study.

SETTING

Surgical simulation laboratory.

METHODS

Septoplasty experts divided the procedure into key tasks. A simulator model to perform tasks was developed using pig ears to imitate human nasal septum cartilage, and a Specific Rating Scale was constructed. Trainees and faculty performed all tasks in the model. The participants were videotaped, and operative time, hand movements, and path length were recorded using a motion sensor device. Two blinded experts evaluated the videos with Global and Specific Rating Scales. All participants answered a satisfaction survey.

RESULTS

Fifteen subjects were recruited (7 trainees and 8 faculty). Significantly higher Global Rating Scale score, shorter operative time and path length, and fewer hand movements were observed in the faculty group. The satisfaction survey showed high applicability to a real scenario (mean score of 4.6 out of 5). Specific Rating Scale showed construct and concurrent validity and high reliability.

CONCLUSION

This simulation model and its specific rating scale can be accurately used as a validated surgical assessment tool for endonasal septoplasty skills. Its low cost and simple replicability make it a potentially useful tool in any otolaryngology surgical training program.

Repetitive simulation training with novel 3D-printed sinus models for functional endoscopic sinus surgeries

Background

The purpose of this study was to find a utility of a newly developed 3D-printed sinus model and to evaluate the educational benefit of simulation training with the models for functional endoscopic sinus surgery (FESS).

Material and methods

Forty-seven otolaryngologists were categorized as experts (board-certified physicians with ≥200 experiences of FESS, n = 9), intermediates (board-certified physicians with <200 experiences of FESS, n = 19), and novices (registrars, n = 19). They performed FESS simulation training on 3D-printed models manufactured from DICOM images of computed tomography (CT) scan of real patients. Their surgical performance was assessed with the objective structured assessment of technical skills (OSATS) score and dissection quality evaluated radiologically with a postdissection CT scan. First we evaluated the face, content, and constructive values. Second we evaluated the educational benefit of the training. Ten novices underwent training (training group) and their outcomes were compared to the remaining novices without training (control group). The training group performed cadaveric FESS surgeries before and after the repetitive training.

Results

The feedback from experts revealed high face and content value of the 3D-printed models. Experts, intermediates, and novices demonstrated statistical differences in their OSATS scores (74.7 ± 3.6, 58.3 ± 10.1, and 43.1 ± 11.1, respectively, p < .001), and dissection quality (81.1 ± 13.1, 93.7 ± 15.1, and 126.4 ± 25.2, respectively, p < .001). The training group improved their OSATS score (41.1 ± 8.0 to 61.1 ± 6.9, p < .001) and dissection quality (122.1 ± 22.2 to 90.9 ± 10.3, p = .013), while the control group not. After training, 80% of novices with no prior FESS experiences completed surgeries on cadaver sinuses.

Conclusion

Repeated training using the models revealed an initial learning curve in novices, which was confirmed in cadaveric mock FESS surgeries.

Level of evidence

N/A.

Primary Dural Repair via an Endoscopic Endonasal Corridor: Preliminary Development of a 3D-Printed Model for Training

Objectives Endonasal suturing is an investigational method for dural repair that has been reported to decrease the incidence of cerebrospinal fluid fistula. This method requires handling of single-shaft instrumentation in the narrow endonasal corridor. In this study, we designed a low-cost, surgical model using three-dimensional (3D) printing technology to simulate dural repair through the endonasal corridor and subsequently assess the utility of the model for surgical training.

Methods Using an Ultimaker 2+ printer, a 3D-printed replica of the cranial base and nasal cavity was fitted with tissue allograft to recapitulate the dural layer. Residents, fellows, and attending surgeons were asked to place two sutures using a 0-degree endoscope and single-shaft needle driver. Task completion time was recorded. Participants were asked to fill out a Likert scale questionnaire after the experiment.

Results Twenty-six participants were separated into groups based on their prior endoscope experience: novice, intermediate, and expert. Twenty-one (95.5%) residents and fellows rated the model as “excellent” or “good” in enhancing their technical skills with endoscopic instrumentation. Three of four (75%) of attendings felt that the model was “excellent” or “good” in usefulness for training in dural suturing. Novice participants required an average of 11 minutes for task completion, as compared with 8.7 minutes for intermediates and 5.7 minutes for experts.

Conclusion The proposed model appears to be highly effective in enhancing the endoscopic skills and recapitulating the task of dural repair. Such a low-cost model may be especially important in enhancing endoscopic facility in countries/regions with limited access to cadaveric specimens.

Systematic review and meta-analysis of 3D-printing in otolaryngology education

INTRODUCTION

Three-dimensional (3D) printing has received increased attention in recent years and has many applications. In the field of otolaryngology surgery, 3D-printed models have shown potential educational value and a high fidelity to actual tissues. This provides an opportunity for trainees to gain additional exposure, especially as conventional educational tools, such as cadavers, are expensive and in limited supply. The purpose of this study was to perform a meta-analysis of the uses of 3D-printing in otolaryngology education. The primary outcomes of investigation were surgical utility, anatomical similarity, and educational value of 3D-printed models. Secondary outcomes of interest included country of implementation, 3D-printer materials and costs, types of surgical simulators, and the levels of training of participants.

METHODS

MEDLINE, Embase, Web of Science, Google Scholar and previous reviews were searched from inception until June 2021 for eligible articles. Title, abstract, and data extraction were performed in duplicate. Data were analyzed using random-effects models. The National Institute of Health Quality Assessment Tool was used to rate the quality of the evidence.

RESULTS

A total of 570 abstracts were identified and screened by 2 independent reviewers. Of the 274 articles reviewed in full text, 46 articles met the study criteria and were included in the meta-analysis. Surgical skill utility was reported in 42 studies (563 participants) and had a high degree of acceptance (84.8%, 95% CI: 81.1%-88.4%). The anatomical similarity was reported in 39 studies (484 participants) and was received positively at 80.6% (95% CI: 77.0%-84.2%). Educational value was described in 36 studies (93 participants) and had the highest approval rating by participants at 90.04% (87.20%-92.88%). A subgroup analysis by year of publication demonstrated that studies published after 2015 had higher ratings across all outcomes compared to those published prior to 2015.

CONCLUSION

This study found that 3D-printing interventions in otolaryngology demonstrated surgical, anatomical, and educational value. In addition, the approval ratings of 3D-printed models indicate a positive trend over time. Future educational programs may consider implementing 3D-printing on a larger scale within the medical curriculum to enhance exposure to otolaryngology.

Remote Training of Functional Endoscopic Sinus Surgery With Advanced Manufactured 3D Sinus Models and a Telemedicine System

Objective: Traditionally, cadaveric courses have been an important tool in surgical education for Functional Endoscopic Sinus Surgery (FESS). The recent COVID-19 pandemic, however, has had a significant global impact on such courses due to its travel restrictions, social distancing regulations, and infection risk. Here, we report the world-first remote (Functional Endoscopic Sinus Surgery) FESS training course between Japan and Australia, utilizing novel 3D-printed sinus models. We examined the feasibility and educational effect of the course conducted entirely remotely with encrypted telemedicine software.

Methods: Three otolaryngologists in Hokkaido, Japan, were trained to perform frontal sinus dissections on novel 3D sinus models of increasing difficulty, by two rhinologists located in Adelaide, South Australia. The advanced manufactured sinus models were 3D printed from the Computed tomography (CT) scans of patients with chronic rhinosinusitis. Using Zoom and the Quintree telemedicine platform, the surgeons in Adelaide first lectured the Japanese surgeons on the Building Block Concept for a three Dimensional understanding of the frontal recess. They in real time directly supervised the surgeons as they planned and then performed the frontal sinus dissections. The Japanese surgeons were asked to complete a questionnaire pertaining to their experience and the time taken to perform the frontal dissection was recorded. The course was streamed to over 200 otolaryngologists worldwide.

Results: All dissectors completed five frontal sinusotomies. The time to identify the frontal sinus drainage pathway (FSDP) significantly reduced from 1,292 ± 672 to 321 ± 267 s (p = 0.02), despite an increase in the difficulty of the frontal recess anatomy. Image analysis revealed the volume of FSDP was improved (2.36 ± 0.00 to 9.70 ± 1.49 ml, p = 0.014). Questionnaires showed the course's general benefit was 95.47 ± 5.13 in dissectors and 89.24 ± 15.75 in audiences.

Conclusion: The combination of telemedicine software, web-conferencing technology, standardized 3D sinus models, and expert supervision, provides excellent training outcomes for surgeons in circumstances when classical surgical workshops cannot be realized.

Three-dimensional printing in otolaryngology education: a systematic review

PURPOSE

The progressive expansion of the technology that facilitates the development of three-dimensional (3D) printing within the field of otorhinolaryngology has opened up a new study front in medicine. The objective of this study is to systematically review scientific publications describing the development of 3D models having applications in otorhinolaryngology, with emphasis on subareas with a large number of publications, as well as the countries in which the publications are concentrated.

METHODS

In this literature review, specific criteria were used to search for publications on 3D models. The review considered articles published in English on the development of 3D models to teach otorhinolaryngology. The studies with presurgical purposes or without validation of the task by surgeons were excluded from this review.

RESULTS

This review considered 39 articles published in 10 countries between 2012 and 2021. The works published prior to 2012 were not considered as per the inclusion criteria for the research. Among the 39 simulators selected for review, otology models comprised a total of 15 publications (38%); they were followed by rhinology, with 12 (31%); laryngology, with 8 (21%); and head and neck surgery, with 4 publications (10%).

CONCLUSION

The use of 3D technology and printing is well established in the context of surgical education and simulation models. The importance of developing new technological tools to enhance 3D printing and the current limitations in obtaining appropriate animal and cadaver models signify the necessity of investing more in 3D models.

Using 3D printed sinonasal models to visualize and optimize personalized sinonasal sinus irrigation strategies

BACKGROUND

Topical sinus irrigations (neti-pot, squeeze bottles) play a critical role in the management of sinonasal disease. However, due to intricate nasal anatomy, penetration of topical irrigations to targeted sinus regions may be highly variable, and difficult to objectively predict. Variables, including head positions, injection angles, flow rates, etc. may vary significantly depending on the individual's anatomy.

OBJECTIVE

The purpose of this study was to propose a novel idea: using a 3D printed model of sinonasal cavities to visualize and develop a patient-specific irrigation strategy.

METHODS

As a proof of concept, 3D replicas of one patient's sinonasal cavities pre- and post-surgery were printed with a Form2 SLA 3D printer based on their CT scans. The setup included rubber/silicon seals attached to the model's nostrils to create a watertight seal with the irrigation device and food color dye added for better visualization of irrigation results.

RESULTS

Irrigations were performed on the 3D models with various head positions, injection angles, and flow rates, and were successful to determine the optimal strategy to targeted sinuses. Significant differences were observed between different targeted sinuses and between pre and post-surgery models.

CONCLUSION

With more affordable 3D printing, this technology may potentially improve patient care and patient education, allowing clinicians and patients to develop a personalized irrigation strategy and have visual confirmation.

3D printed bone models in oral and cranio-maxillofacial surgery: a systematic review

AIM

This systematic review aimed to evaluate the use of three-dimensional (3D) printed bone models for training, simulating and/or planning interventions in oral and cranio-maxillofacial surgery.

MATERIALS AND METHODS

A systematic search was conducted using PubMed® and SCOPUS® databases, up to March 10, 2019, by following the Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA) protocol. Study selection, quality assessment (modified Critical Appraisal Skills Program tool) and data extraction were performed by two independent reviewers. All original full papers written in English/French/Italian and dealing with the fabrication of 3D printed models of head bone structures, designed from 3D radiological data were included. Multiple parameters and data were investigated, such as author's purpose, data acquisition systems, printing technologies and materials, accuracy, haptic feedback, variations in treatment time, differences in clinical outcomes, costs, production time and cost-effectiveness.

RESULTS

Among the 1157 retrieved abstracts, only 69 met the inclusion criteria. 3D printed bone models were mainly used as training or simulation models for tumor removal, or bone reconstruction. Material jetting printers showed best performance but the highest cost. Stereolithographic, laser sintering and binder jetting printers allowed to create accurate models with adequate haptic feedback. The cheap fused deposition modeling printers exhibited satisfactory results for creating training models.

CONCLUSION

Patient-specific 3D printed models are known to be useful surgical and educational tools. Faced with the large diversity of software, printing technologies and materials, the clinical team should invest in a 3D printer specifically adapted to the final application.

Medical Liability in Sinus Surgery: A Westlaw Database Analysis From 2000 to 2017

BACKGROUND

Medical malpractice occurs when a hospital or health-care provider through negligent act or omission results in an injury to a patient. More than 50% of otolaryngologists have faced at least 1 claim, with rhinology being the most litigated subspecialty. This study aims to analyze medical litigation trends in Rhinology from 2000 to 2017 in the United States.

METHODS

The Westlaw database was reviewed from 2000 to 2017. Data were compiled on the demographics of the plaintiffs, procedures, nature of damages, legal allegations, and the use of expert witnesses, physician demographics/practice characteristics, verdicts, indemnities, and county/state of case.

RESULTS

There were 75 cases that met inclusion criteria after review of 125 cases. Majority of cases went to trial over settlement (80%) and were found in the Northeast region of the United States (36%). Most common cited legal allegations were improper performance and failure to follow standard of care. The most common nature of injuries were eye injury (29%) and intracranial complications (27%). The highest payouts were for progression of disease followed by intracranial injury. Of the 75 total cases analyzed, 37 (49.3%) used expert witnesses. When an expert witness was used at trial, the verdict statistically favored the defendant (62.5%).

CONCLUSIONS

Our analysis reveals the importance of meticulous surgical techniques and thorough preoperative evaluations.

Rhinology: Simulation Training (Part 2)

Purpose of Review

Recently, there has been an expansion of novel technologies in simulation training. The aim of this review was to examine existing evidence about training simulators in rhinology, their incorporation into real training programmes and translation of these skills into the operating room. The first part focuses on the virtual and augmented reality simulators. The second part describes the role of physical (i.e. non-computer-based) models of endoscopic sinus surgery.

Recent Findings

We learned that an ideal sinus surgery model would score highly in all standard measures of validity whilst maintaining an attainable cost. This is a challenging goal that is worthy of pursuit given that simulation training has been shown to be cost-effective option in other domains. Non-AR or VR models are attractive ways to fill gaps in simulation training whilst reducing compared with computer-based models.

Summary

In an era of improved computer technology and improved 3D printing, it will be increasingly important to focus on both the manufacture and validation process. One area that will benefit from further technological advancement is the realistic simulation of bleeding as this would obviate the need for animal models. Future studies on ESS simulation will also need to robustly demonstrate the validity of each model with the emphasis on the ability of a model to predict performance in operative environment.

Rhinology: Simulation Training (Part 1)

Purpose of Review

Recently, there has been an expansion of novel technologies in simulation training. Different models target different aspects of training. The aim of this review was to examine existing evidence about training simulators in rhinology, their incorporation into real training programmes and translation of these skills into the operating room. The first part focuses on the virtual and augmented reality simulators. The second part describes the role of physical (i.e. non-computer-based) models of endoscopic sinus surgery.

Recent Findings

Virtual reality simulators are still evolving and facing challenges due to their inherent cost and lack of realism in terms of the type of haptic feedback they provide. On the other hand, augmented reality seems to be a promising platform with a growing number of applications in preoperative planning, intraoperative navigation and education. Limitations in validity, registration error and level of evidence prevent the adoption of augmented reality on a wider scale or in clinical practice.

Summary

Simulation training is a maturing field that shows reasonable evidence for a number of models. The incorporation of these models into real training programmes requires further evaluation to ensure that training opportunities are being maximized.

Three-dimensional printing as a tool in otolaryngology training: a systematic review

OBJECTIVE

Three-dimensional printing is a revolutionary technology that is disrupting the status quo in surgery. It has been rapidly adopted by otolaryngology as a tool in surgical simulation for high-risk, low-frequency procedures. This systematic review comprehensively evaluates the contemporary usage of three-dimensional printed otolaryngology simulators.

METHOD

A systematic review of the literature was performed with narrative synthesis.

RESULTS

Twenty-two articles were identified for inclusion, describing models that span a range of surgical tasks (temporal bone dissection, airway procedures, functional endoscopic sinus surgery and endoscopic ear surgery). Thirty-six per cent of articles assessed construct validity (objective measures); the other 64 per cent only assessed face and content validity (subjective measures). Most studies demonstrated positive feedback and high confidence in the models' value as additions to the curriculum.

CONCLUSION

Whilst further studies supported with objective metrics are merited, the role of three-dimensional printed otolaryngology simulators is poised to expand in surgical training given the enthusiastic reception from trainees and experts alike.

Assessment of a Patient-Specific, 3-Dimensionally Printed Endoscopic Sinus and Skull Base Surgical Model

Importance

Three-dimensional (3D) printing is an emerging tool in the creation of anatomical models for simulation and preoperative planning. Its use in sinus and skull base surgery has been limited because of difficulty in replicating the details of sinus anatomy.

Objective

To describe the development of 3D-printed sinus and skull base models for use in endoscopic skull base surgery.

Design, Setting, and Participants

In this single-center study performed from April 1, 2017, through June 1, 2017, a total of 7 otolaryngology residents and 2 attending physicians at a tertiary academic center were recruited to evaluate the procedural anatomical accuracy and haptic feedback of the printed model.

Interventions

A 3D model of sinus and skull base anatomy with high-resolution, 3D printed material (VeroWhite) was printed using a 3D printer. Anatomical accuracy was assessed by comparing a computed tomogram of the original patient with that of the 3D model across set anatomical landmarks (eg, depth of cribriform plate). Image-guided navigation was also used to evaluate accuracy of 13 surgical landmarks. Likert scale questionnaires (1 indicating strongly disagree; 2, disagree; 3, neutral; 4, agree; and 5, strongly agree) were administered to 9 study participants who each performed sinus and skull base dissections on the 3D-printed model to evaluate anatomical accuracy and haptic feedback.

Main Outcomes and Measures

Main outcomes of the study include objective anatomical accuracy through imaging and navigation and haptic evaluation by the study participants.

Results

Seven otolaryngology residents (3 postgraduate year [PGY]-5 residents, 2 PGY-4 residents, 1 PGY-3 resident, and 1 PGY-2 resident) and 2 attending physicians evaluated the haptic feedback of the 3D model. Computed tomographic comparison demonstrated a less than 5% difference between patient and 3D model measurements. Image-guided navigation confirmed accuracy of 13 landmarks to within 1 mm. Likert scores were a mean (SD) of 4.00 (0.71) for overall procedural anatomical accuracy and 4.67 (0.5) for haptic feedback.

Conclusions and Relevance

This study shows that high-resolution, 3D-printed sinus and skull base models can be generated with anatomical and haptic accuracy. This technology has the potential to be useful in surgical training and preoperative planning and as a supplemental or alternative simulation or training platform to cadaveric dissection.

Three-Dimensional Printing: Current Use in Rhinology and Endoscopic Skull Base Surgery

Background

In the discipline of rhinology and endoscopic skull base surgery (ESBS), 3-dimensional (3D) printing has found meaningful application in areas including preoperative surgical planning as well as in surgical education. However, its scope of use may be limited due to the perception among surgeons that there exists a prohibitively high initial investment in resources and time to acquire the requisite technical expertise. Nevertheless, given the ever decreasing cost of advancing technology coupled with the need to understand the complex spatial relationships of the paranasal sinuses and skull base, the use of 3D printing in rhinology and ESBS is poised to blossom.

Objective

Help the reader identify current or potential future uses of 3D printing technology relevant to their rhinologic clinical or educational practice.

Methods

A review of published literature relating to 3D printing in rhinology and ESBS was performed.

Results

Results were reviewed and organized into 5 overarching categories including an overview of the 3D printing process as well as applications of 3D printing including (1) surgical planning, (2) custom prosthetics and implants, (3) patient education, and (4) surgical teaching and assessment.

Conclusion

In the discipline of rhinology and ESBS, 3D printing finds use in the areas of presurgical planning, patient education, prosthesis creation, and trainee education. As this technology moves forward, these products will be more broadly available to providers in the clinical and educational setting. The possible applications are vast and have great potential to positively impact surgical training, patient satisfaction, and most importantly, patient outcomes.

Blinded Evaluation of Endoscopic Skill and Instructability After Implementation of an Endoscopic Simulation Experience

Background

Interest in endoscopic simulation is increasing. Past studies have used virtual reality or nonhuman models or residents with varying experience. Our aim was to evaluate the effect of simulation on procedural and psychomotor competence of medical students—surgical novices—performing endoscopic tasks on human cadavers and assess student perceptions.

Methods

Students (n = 22) completed a baseline sinus model skill evaluation graded by 2 blinded Rhinology fellows. Intervention and control groups with equal baselines were assigned. Intervention students practiced endoscopic tasks on the model for 45 minutes minimum over 2 weeks. All students reviewed sinus anatomy/disease and sinus surgery materials. The final cadaver evaluation was similar to the baseline. Fellows graded students on anatomy identification (sinuses, turbinates), psychomotor (navigation, camera alignment, instrument handling), and timed procedural (sinus object retrieval) skills, confidence, and instructability via fellow-guided frontal balloon placement.

Results

Participants included 16 males (72.7%) and 6 females (27.3%). Intervention and control groups contained 10 (45.4%) and 12 (54.6%) students, respectively. Intervention group final “Total Psychomotor” scores were higher (10.1/15 vs 7.8/15, P = .0231). “Surgical confidence” was 3.3/5 versus 2.5/5, and “Instructability” was 3.9/5 versus 3.4/5 in intervention versus control groups, respectively ( P < .050). Multivariate regression analysis demonstrated superior psychomotor skills, navigation, and confidence in the intervention group ( P < .036). Activity perception scores were higher in intervention students versus controls, 26.13 versus 18.36/40 ( P = .022).

Conclusion

In surgical novices, endoscopic simulation leads to superior endoscopic navigation and task performance in cadavers. This simulation presents a novel method for incorporating Otolaryngology simulation in medical student education.

Evaluating Simulator-Based Teaching Methods for Endoscopic Sinus Surgery

A multitude of simulator systems for endoscopic sinus surgery (ESS) are available as training tools for residents preparing to enter the operating room. These include human cadavers, virtual reality, realistic anatomic models, and low-fidelity gelatin molds. While these models have been validated and evaluated as independent tools for surgical trainees, no study has performed direct comparison of their outcomes. To address this deficiency, we aimed to evaluate the utility of high-fidelity and low-fidelity trainers as compared to a traditional control (no simulator exposure) for novice trainees acquiring basic ESS skills. Thirty-four first-year medical students were randomized to 3 groups and taught basic sinus anatomy and instrumentation. Two groups received training with either the high-fidelity or low-fidelity trainer, while 1 group served as control. These groups were then tested with cadaveric specimens. These sessions were recorded and graded by an expert. There was no statistical difference in performance between the 3 study groups with regard to identification of anatomy, endoscopic competency, or completion of basic tasks. When the high-fidelity and low-fidelity arms were grouped into a single "trained" cohort, they demonstrated significantly improved time to completion for basic anatomy (P = .043) and total time (P = .041). This is the first study to perform a direct comparison of performance between high-fidelity and low-fidelity ESS simulators and controls. Although we found no difference in performance of novice trainees with regard to basic anatomical identification or procedural tasks associated with ESS, the use of ESS simulators may improve time to completion.

Creation and validation of three-dimensional printed models for basic nasal endoscopic training

BACKGROUND

Three-dimensional (3D) printed models have been shown to be promising in surgical training in rhinology. The objectives of this study were to develop a set of 3D-printed models including the pediatric and adult nasal cavity, and the postsurgical paranasal sinuses, and to assess the face and content validity in endoscopic training.

METHODS

The computed tomography (CT) data of a pediatric patient without nasal disorders and an adult patient with nasal septal deviation were selected to produce the models of the pediatric and adult nasal cavity, and the CT data of an adult patient who underwent endoscopic sinus surgery 4 months ago was chosen to create the paranasal sinus model. After the models were printed by our desktop-level 3D printer, 5 rhinologists used the 5-point Likert scales to evaluate the fidelity and utility. Additionally, a group of prespecified tasks were completed by the rhinologists and 5 residents respectively for supplementary content validation. The difference of time used in completing each task was analyzed by Mann-Whitney U test.

RESULTS

All the models were prototyped in 24 hours, and the total cost for each model was less than 100 CNY (15 USD). The overall scores for fidelity and usefulness in endoscopic training were above 4.0. The experts accomplished all tasks using significantly less time than the residents (all p < 0.05).

CONCLUSION

The models of nasal cavities and paranasal sinuses made by our desktop-level 3D printer are high-fidelity, low-cost, and useful in training basic endoscopic skills.

Construct validity of a low-cost medium-fidelity endoscopic sinus surgery simulation model

OBJECTIVE

Assess construct validity of a low-cost medium-fidelity silicone injection molded model task trainer for endoscopic sinus surgery (ESS) training.

METHODS

Fellowship-trained rhinologists, otolaryngology attendings, and otolaryngology residents at various levels of training performed sinus endoscopy and seven procedures on the model. Construct validity was evaluated by comparing novice to various levels of experienced performance using a validated checklist.

RESULTS

Thirty-two subjects participated in this study. Otolaryngology attendings and postgraduate year (PGY) 3 to 5 otolaryngology residents significantly outperformed PGY 1 to 2 otolaryngology residents on most tasks in the task-specific checklist.

CONCLUSIONS

This study demonstrated the construct validity of the low-cost medium-fidelity ESS model.

LEVEL OF EVIDENCE

NA Laryngoscope, 129:1505-1509, 2019.

New frontiers and emerging applications of 3D printing in ENT surgery: a systematic review of the literature

3D printing systems have revolutionised prototyping in the industrial field by lowering production time from days to hours and costs from thousands to just a few dollars. Today, 3D printers are no more confined to prototyping, but are increasingly employed in medical disciplines with fascinating results, even in many aspects of otorhinolaryngology. All publications on ENT surgery, sourced through updated electronic databases (PubMed, MEDLINE, EMBASE) and published up to March 2017, were examined according to PRISMA guidelines. Overall, 121 studies fulfilled specific inclusion criteria and were included in our systematic review. Studies were classified according to the specific field of application (otologic, rhinologic, head and neck) and area of interest (surgical and preclinical education, customised surgical planning, tissue engineering and implantable prosthesis). Technological aspects, clinical implications and limits of 3D printing processes are discussed focusing on current benefits and future perspectives.

A low cost and stepwise training model for skull base repair using a suturing and knotting technique during endoscopic endonasal surgery

PURPOSE

Cerebrospinal fluid leakage is always the primary complication during the endoscopic endonasal skull base surgery. Dural suturing technique may supply a rescue method. However, suturing and knotting in such a deep and narrow space are difficult. Training in the model can improve skills and setting a stepwise curriculum can increase trainers' interest and confidence.

METHODS

We constructed an easy model using silicone and acrylic as sphenoid sinus and using the egg-shell membrane as skull base dura. The training is divided into three steps: Step 1: extracorporeal knot-tying suture on the silicone of sphenoid sinus, Step 2: intra-nasal knot-tying suture on the same silicone, and Step 3: intra-nasal egg-shell membrane knot-tying suture. Fifteen experienced microneurosurgical neurosurgeons (Group A) and ten inexperienced PGY residents (Group B) were recruited to perform the tasks. Performance measures were time, suturing and knotting errors, and needle and thread manipulations. The third step was assessed through the injection of full water into the other side of the egg to verify the watertight suture. The results were compared between two groups.

RESULTS

Group A finishes the first and second tasks in significantly less time (total time, 125.1 ± 10.8 vs 195.8 ± 15.9 min) and fewer error points (2.4 ± 1.3 vs 5.3 ± 1.0) than group B. There are five trainers in group A who passed the third step, this number in group B was only one.

CONCLUSIONS

This low cost and stepwise training model improved the suture and knot skills for skull base repair during endoscopic endonasal surgery. Experienced microneurosurgical neurosurgeons perform this technique more competent.

Intraoperative Functional Endoscopic Sinus Surgery Training: Efficient Teaching Techniques-A New Method

Introduction:

Functional endoscopic sinus surgery is a complex procedure used by otorhinolaryngologists to treat a host of nasal sinus pathologies. Due to the involved nasal anatomy and the nature of the procedure, teaching residents to use an endoscope is challenging. Simulation labs have been helpful but intraoperative instruction can still present difficulty in communication between resident and attending physicians during the teaching process. The purpose of this is to hypothesize a method of teaching intraoperatively that can be used supplemental to or independently of virtual reality teaching.

Method:

Literature review to determine current intraoperative verbal teaching methods used by surgeons was performed. Review was also performed on the effects of simulation techniques in preparing residents for the operating room. Although this was not a systematic review including statistical analysis, a gap was found in the literature on how residents can be efficiently taught intraoperatively to navigate an endoscope while maintaining patient safety. A novel and inexpensive method has been devised as a possible teaching method.

Conclusions:

Extensive literature is not available in intraoperative teaching techniques. It is therefore uncertain whether such a method has been used before. Further study, possibly in the form of surveys and intraoperative trials, must be done to determine the effectiveness of this mechanism.

Development and Validity of a Silicone Renal Tumor Model for Robotic Partial Nephrectomy Training

OBJECTIVE

To provide a training tool to address the technical challenges of robot-assisted laparoscopic partial nephrectomy, we created silicone renal tumor models using 3-dimensional printed molds of a patient's kidney with a mass. In this study, we assessed the face, content, and construct validity of these models.

MATERIALS AND METHODS

Surgeons of different training levels completed 4 simulations on silicone renal tumor models. Participants were surveyed on the usefulness and realism of the model as a training tool. Performance was measured using operation-specific metrics, self-reported operative demands (NASA Task Load Index [NASA TLX]), and blinded expert assessment (Global Evaluative Assessment of Robotic Surgeons [GEARS]).

RESULTS

Twenty-four participants included attending urologists, endourology fellows, urology residents, and medical students. Post-training surveys of expert participants yielded mean results of 79.2 on the realism of the model's overall feel and 90.2 on the model's overall usefulness for training. Renal artery clamp times and GEARS scores were significantly better in surgeons further in training (P ≤.005 and P ≤.025). Renal artery clamp times, preserved renal parenchyma, positive margins, NASA TLX, and GEARS scores were all found to improve across trials (P <.001, P = .025, P = .024, P ≤.020, and P ≤.006, respectively).

CONCLUSION

Face, content, and construct validity were demonstrated in the use of a silicone renal tumor model in a cohort of surgeons of different training levels. Expert participants deemed the model useful and realistic. Surgeons of higher training levels performed better than less experienced surgeons in various study metrics, and improvements within individuals were observed over sequential trials. Future studies should aim to assess model predictive validity, namely, the association between model performance improvements and improvements in live surgery.

A systematic review of validated sinus surgery simulators

BACKGROUND

Simulation provides a safe and effective opportunity to develop surgical skills. A variety of endoscopic sinus surgery (ESS) simulators has been described in the literature. Validation of these simulators allows for effective utilisation in training.

OBJECTIVE OF REVIEW

To conduct a systematic review of the published literature to analyse the evidence for validated ESS simulation.

SEARCH STRATEGY

Pubmed, Embase, Cochrane and Cinahl were searched from inception of the databases to 11 January 2017.

EVALUATION METHOD

Twelve thousand five hundred and sixteen articles were retrieved of which 10 112 were screened following the removal of duplicates. Thirty-eight full-text articles were reviewed after meeting search criteria. Evidence of face, content, construct, discriminant and predictive validity was extracted.

RESULTS

Twenty articles were included in the analysis describing 12 ESS simulators. Eleven of these simulators had undergone validation: 3 virtual reality, 7 physical bench models and 1 cadaveric simulator. Seven of the simulators were shown to have face validity, 7 had construct validity and 1 had predictive validity. None of the simulators demonstrated discriminate validity.

CONCLUSION

This systematic review demonstrates that a number of ESS simulators have been comprehensively validated. Many of the validation processes, however, lack standardisation in outcome reporting, thus limiting a meta-analysis comparison between simulators.

Development and validation of a 3D-printed model of the ostiomeatal complex and frontal sinus for endoscopic sinus surgery training

BACKGROUND

Endoscopic sinus surgery poses unique training challenges due to complex and variable anatomy, and the risk of major complications. We sought to create and provide validity evidence for a novel 3D-printed simulator of the nose and paranasal sinuses.

METHODS

Sinonasal computed tomography (CT) images of a patient were imported into 3D visualization software. Segmentation of bony and soft tissue structures was then performed. The model was printed using simulated bone and soft tissue materials. Rhinologists and otolaryngology residents completed 6 prespecified tasks including maxillary antrostomy and frontal recess dissection on the simulator. Participants evaluated the model using survey ratings based on a 5-point Likert scale. The average time to complete each task was calculated. Descriptive analysis was used to evaluate ratings, and thematic analysis was done for qualitative questions.

RESULTS

A total of 20 participants (10 rhinologists and 10 otolaryngology residents) tested the model and answered the survey. Overall the participants felt that the simulator would be useful as a training/educational tool (4.6/5), and that it should be integrated as part of the rhinology training curriculum (4.5/5). The following responses were obtained: visual appearance 4.25/5; realism of materials 3.8/5; and surgical experience 3.9/5. The average time to complete each task was lower for the rhinologist group than for the residents.

CONCLUSION

We describe the development and validation of a novel 3D-printed model for the training of endoscopic sinus surgery skills. Although participants found the simulator to be a useful training and educational tool, further model development could improve the outcome.