Innovating medical education: Development of an affordable, 3-D printed knot-tying simulator

BACKGROUND

Three-dimensional (3-D) printing offers an innovative option to produce clinical simulators because of its low production costs and widespread availability. We aimed to develop a low-cost, 3-D printed knot-tying simulator that overcomes the barriers students face in self-directed skills development.

APPROACH

Medical students completing a procedural residency preparation course (PRPC) completed a pre-survey with Likert scales and multiple choice questions to assess their perceptions of and barriers to self-directed knot-tying practice. Subsequently, a 3-D printed knot-tying simulator, which contains a progression of knot-tying challenges and a designated video curriculum, was designed. After utilising the simulator in a 1-hour, faculty-guided knot-tying session, PRPC students assessed the educational utility and usability of the simulator via a post-survey.

EVALUATION

The primary barriers students faced in engaging in self-directed knot-tying practice included limited accessibility to simulators and insufficient knowledge of knot-tying techniques. Many students (91.3%, n = 21) agreed that practicing with the simulator improved their knot-tying motor skills and was easy to use (100%, n = 23). Twenty-two (95.7%) students agreed that they would continue to use the simulator beyond the knot-tying session and PRPC.

IMPLICATIONS

We demonstrate the educational utility and usability of a novel 3-D printed knot-tying simulator for medical education. Enabling students to engage in self-directed technical skills development is critical in developing surgical skills that can translate to clinical environments. Our simulator highlights the benefits of 3-D printers as an innovative, inexpensive option to improve the availability and accessibility to medical education tools.

Non-high-density lipoprotein cholesterol and treatment targets in vascular surgery patients

INTRODUCTION

Low-density lipoprotein cholesterol (LDL) is a known contributing factor to atherosclerotic cardiovascular disease (ASCVD) and a primary therapeutic target for medical management of ASCVD. Non-high-density lipoprotein cholesterol (non-HDL) has recently been identified as a secondary therapeutic target but is not yet widely used in vascular surgery patients. We sought to assess if vascular surgery patients were undertreated per non-HDL therapeutic guidelines.

METHODS

This was an observational study that used a single-center database to identify a cohort of adult patients who received care from a vascular surgery provider from 01/2001 to 07/2021. ICD-9/10-CM codes were used to identify patients with a medical history of hyperlipidemia (HLD), coronary artery disease (CAD), cerebrovascular occlusive disease (CVOD), peripheral artery disease (PAD), hypertension (HTN), or diabetes mellitus (DM). Patient smoking status and medications were also identified. Lab values were obtained from the first and last patient encounter within our system. Primary outcomes were serum concentrations of LDL and non-HDL, with therapeutic thresholds defined as 70 mg/dL and 100 mg/dL, respectively.

RESULTS

The cohort included 2465 patients. At first encounter, average age was 59.3 years old, 21.4% were on statins, 8.4% were on a high-intensity statin, 25.7% were diagnosed with HLD, 5.2% with CAD, 15.3% with PAD, 26.3% with DM, 18.6% with HTN, and 2.1% with CVOD. At final encounter, mean age was 64.8 years, 23.5% were on statins with 10.1% on high-intensity statin. Diagnoses frequency did not change at final encounter. At first encounter, nearly two-thirds of patients were not at an LDL <70 mg/dL (62.3%) or non-HDL <100 mg/dL (66.0%) with improvement at final encounter to 45.2 and 40.5% of patients not at these LDL or non-HDL treatment thresholds, respectively. Patients on statins exhibited similar trends with 51.1 and 50.1% of patients not at LDL or non-HDL treatment thresholds at first encounter and 39.9 and 35.4% not at LDL or non-HDL treatment thresholds at last encounter. Importantly, 6.9% of patients were at LDL but not non-HDL treatment thresholds.

DISCUSSION

Among vascular surgery patients, over half did not meet non-HDL targets. These results suggest that we may be vastly under-performing adequate medical optimization with only about one-fourth of patients on a statin at their final encounter and approximately one-tenth of patients being treated with a high-intensity statin. With recent evidence supporting non-HDL as a valuable measurement for atherosclerotic risk, there is potential to optimize medical management beyond current high-intensity statin therapy. Further investigation is needed regarding the risk of adverse events between patients treated with these varied therapeutic targets.

Nodo-Tie: an innovative, 3-D printed simulator for surgical knot-tying skills development

Introduction

Clinical simulators are an important resource for medical students seeking to improve their fundamental surgical skills. Three-dimensional (3-D) printing offers an innovative method to create simulators due to its low production costs and reliable printing fidelity. We aimed to validate a 3-D printed knot-tying simulator named Nodo-Tie.

Methods

We designed a 3-D printed knot-tying simulator integrated with a series of knot-tying challenges and a designated video curriculum made accessible via a quick-response (QR) code. The Nodo-Tie, which costs less than $1 to print and assemble, was distributed to second-year medical students starting their surgical clerkship. Participants were asked to complete a survey gauging the simulator's usability and educational utility. The time between simulator distribution and survey completion was eight weeks.

Results

Students perceived the Nodo-Tie as easy-to-use (4.6 ± 0.8) and agreed it increased both their motor skills (4.5 ± 0.9) and confidence (4.5 ± 0.8) for tying surgical knots in the clinical setting. Many students agreed the Nodo-Tie provided a stable, durable surface for knot-tying practice (83.7%, n = 41) and that they would continue to use it beyond their participation in the study period (91.7%, n = 44).

Discussion

Medical students found this interactive, 3-D printed knot-tying simulator to be an effective tool to use for self-directed development of their knot-tying skills. Given the Nodo-Tie's low cost, students were able to keep the Nodo-Tie for use beyond the study period. This increases the opportunity for students to engage in the longitudinal practice necessary to master knot-tying as they progress through their medical education.

Key messages

Clinical simulators provide proactive learners with reliable, stress-free environments to engage in self-directed surgical skills development. The Nodo-Tie, a 3-D printed simulator, serves as a cost-effective, interactive tool for medical students to develop their knot-tying abilities beyond the clinical setting.

Adapting to the Times: Combining Microlearning Videos and Twitter to Teach Surgical Technique

OBJECTIVE

Surgical videos are commonly utilized by trainees to prepare for surgical cases. However, currently available videos tend to be of excessive length, variable quality, and exist behind paywalls or in other exclusive formats. Our objective was to create a series of videos that would address these shortcomings, and further allow for dynamic engagement between learners and experts.

DESIGN

Our group created surgical videos using principles of microlearning, an educational strategy which deconstructs content into small units and uses social media platforms where learners and educators may actively engage. We published a library of short (<3 min) videos covering various steps of abdominal transplantation operations on a YouTube channel. We leveraged Twitter to disseminate the content and engage with experts and learners from around the world.

SETTING

Multi-institutional.

RESULTS

Over the period from July 2020 to January 2021, 24 microlearning videos were created, stored on a YouTube channel, and posted to Twitter weekly using a newly created account. During that time period, the videos, averaging 124 seconds in length, were viewed 4393 times and watched for a total of 127 hours. The account gained 611 followers in 37 countries and 37 US states with 312,400 impressions (defined as tweet views). Twitter users who engaged with our microlearning content (favorite, retweet, or reply) included faculty (27%), residents (21%), fellows (8%), and medical students (11%).

CONCLUSIONS

Broad participation with the educational material and discussion on Twitter demonstrated the potential for the microlearning technique to provide educational benefit for learners internationally. The spread of the tweets shows an opportunity to augment traditional surgical education, and the willingness of faculty to discuss alternative techniques with their peers. Our group will continue to develop a library of microlearning videos for surgical operations and engage with other institutions for collaboration and expansion.

Optimizing Existing Mental Health Screening Methods in a Dementia Screening and Risk Factor App: Observational Machine Learning Study

Background

Mindstep is an app that aims to improve dementia screening by assessing cognition and risk factors. It considers important clinical risk factors, including prodromal symptoms, mental health disorders, and differential diagnoses of dementia. The 9-item Patient Health Questionnaire for depression (PHQ-9) and the 7-item Generalized Anxiety Disorder Scale (GAD-7) are widely validated and commonly used scales used in screening for depression and anxiety disorders, respectively. Shortened versions of both (PHQ-2/GAD-2) have been produced.

Objective

We sought to develop a method that maintained the brevity of these shorter questionnaires while maintaining the better precision of the original questionnaires.

Methods

Single questions were designed to encompass symptoms covered in the original questionnaires. Answers to these questions were combined with PHQ-2/GAD-2, and anonymized risk factors were collected by Mindset4Dementia from 2235 users. Machine learning models were trained to use these single questions in combination with data already collected by the app: age, response to a joke, and reporting of functional impairment to predict binary and continuous outcomes as measured using PHQ-9/GAD-7. Our model was developed with a training data set by using 10-fold cross-validation and a holdout testing data set and compared to results from using the shorter questionnaires (PHQ-2/GAD-2) alone to benchmark performance.

Results

We were able to achieve superior performance in predicting PHQ-9/GAD-7 screening cutoffs compared to PHQ-2 (difference in area under the curve 0.04, 95% CI 0.00-0.08, P=.02) but not GAD-2 (difference in area under the curve 0.00, 95% CI –0.02 to 0.03, P=.42). Regression models were able to accurately predict total questionnaire scores in PHQ-9 (R²=0.655, mean absolute error=2.267) and GAD-7 (R²=0.837, mean absolute error=1.780).

Conclusions

We app-adapted PHQ-4 by adding brief summary questions about factors normally covered in the longer questionnaires. We additionally trained machine learning models that used the wide range of additional information already collected in Mindstep to make a short app-based screening tool for affective disorders, which appears to have superior or equivalent performance to well-established methods.

Divergent effects of canonical and non-canonical TGF-β signalling on mixed contractile-synthetic smooth muscle cell phenotype in human Marfan syndrome aortic root aneurysms

Aortic root aneurysm formation is a cardinal feature of Marfan syndrome (MFS) and likely TGF‐β driven via Smad (canonical) and ERK (non‐canonical) signalling. The current study assesses human MFS vascular smooth muscle cell (SMC) phenotype, focusing on individual contributions by Smad and ERK, with Notch3 signalling identified as a novel compensatory mechanism against TGF‐β‐driven pathology. Although significant ERK activation and mixed contractile gene expression patterns were observed by traditional analysis, this did not directly correlate with the anatomic site of the aneurysm. Smooth muscle cell phenotypic changes were TGF‐β‐dependent and opposed by ERK in vitro, implicating the canonical Smad pathway. Bulk SMC RNA sequencing after ERK inhibition showed that ERK modulates cell proliferation, apoptosis, inflammation, and Notch signalling via Notch3 in MFS. Reversing Notch3 overexpression with siRNA demonstrated that Notch3 promotes several protective remodelling pathways, including increased SMC proliferation, decreased apoptosis and reduced matrix metalloproteinase activity, in vitro. In conclusion, in human MFS aortic SMCs: (a) ERK activation is enhanced but not specific to the site of aneurysm formation; (b) ERK opposes TGF‐β‐dependent negative effects on SMC phenotype; (c) multiple distinct SMC subtypes contribute to a ‘mixed’ contractile‐synthetic phenotype in MFS aortic aneurysm; and (d) ERK drives Notch3 overexpression, a potential pathway for tissue remodelling in response to aneurysm formation.

Statins Reduce Thoracic Aortic Aneurysm Growth in Marfan Syndrome Mice via Inhibition of the Ras-Induced ERK (Extracellular Signal-Regulated Kinase) Signaling Pathway

Background

Statins reduce aneurysm growth in mouse models of Marfan syndrome, although the mechanism is unknown. In addition to reducing cholesterol, statins block farnesylation and geranylgeranylation, which participate in membrane‐bound G‐protein signaling, including Ras. We dissected the prenylation pathway to define the effect of statins on aneurysm reduction.

Methods and Results

Fbn1^C1039G/+ mice were treated with (1) pravastatin (HMG‐CoA [3‐hydroxy‐3‐methylglutaryl coenzyme A] reductase inhibitor), (2) manumycin A (MA; FPT inhibitor), (3) perillyl alcohol (GGPT1 and ‐2 inhibitor), or (4) vehicle control from age 4 to 8 weeks and euthanized at 12 weeks. Histological characterization was performed. Protein analysis was completed on aortic specimens to measure ERK (extracellular signal‐regulated kinase) signaling. In vitro Fbn1^C1039G/+ aortic smooth muscle cells were utilized to measure Ras‐dependent ERK signaling and MMP (matrix metalloproteinase) activity. Pravastatin and MA significantly reduced aneurysm growth compared with vehicle control (n=8 per group). In contrast, PA did not significantly decrease aneurysm size. Histology illustrated reduced elastin breakdown in MA‐treated mice compared with vehicle control (n=5 per group). Although elevated in control Marfan mice, both phosphorylated c‐Raf and phosphorylated ERK1/2 were significantly reduced in MA‐treated mice (4–5 per group). In vitro smooth muscle cell studies confirmed phosphorylated cRaf and phosphorylated ERK1/2 signaling was elevated in Fbn1^C1039G/+ smooth muscle cells (n=5 per group). Fbn1^C1039G/+ smooth muscle cell Ras‐dependent ERK signaling and MMP activity were reduced following MA treatment (n=5 per group). Corroborating in vitro findings, MMP activity was also decreased in pravastatin‐treated mice.

Conclusions

Aneurysm reduction in Fbn1^C1039G/+ mice following pravastatin and MA treatment was associated with a decrease in Ras‐dependent ERK signaling. MMP activity can be reduced by diminishing Ras signaling.