533 The Use of Virtual Reality Simulation to Facilitate Surgical Ward-Based Learning in Medical Students During the Covid-19 Pandemic

Introduction

The Covid-19 pandemic quickly resulted in the removal of all non-essential personnel from surgical wards. It also resulted in suspending medical student placements which are heavily relied upon to provide the students with necessary “hands-on” experience. Virtual Reality (VR) simulation was employed in order to ensure that the students had a comparable experience.

Method

VR simulations were used to simulate the ward environments and the students were able to gain valuable experience with common scenarios encountered on surgical wards. Each student was allocated a 1-hour time slot per session with a debriefing session after each. The digital immersive environment allowed students to build upon their didactic preparation and previously acquired knowledge base.

Results

Feedback was given at the end of each simulation by the simulation facilitator. Using the technical proficiency that they had acquired in the first scenario; the students went on to employ these skills directly in their next scenarios thereby capitalising on the repetition of core skills to maximize their learning.

Conclusions

In this instance, VR was successfully used to enhance both knowledge acquisition and experience. Feedback from the participating students was overwhelmingly positive with many suggesting that they were more comfortable learning in a simulated environment.

Real-world bone turnover marker use: impact on treatment decisions and fracture

The use of bone turnover marker (BTM) testing for patients with osteoporosis in the USA has not been well characterized. This retrospective US-based real-world data study found BTM testing has some association with treatment decision-making and lower fracture risk in patients with presumed osteoporosis, supporting its use in clinical practice.

INTRODUCTION

The purpose of this study was to characterize bone turnover marker (BTM) testing patterns and estimate their clinical utility in treatment decision-making and fragility fracture risk in patients with osteoporosis using a retrospective claims database.

METHODS

Data from patients aged ≥ 50 years with newly diagnosed osteoporosis enrolled in the Truven MarketScan^® Commercial Claims and Encounters and Medicare Supplemental and Co-ordination of Benefits databases from January 2008 to June 2018 were included. Osteoporosis was ascertained by explicit claims, fragility fracture events associated with osteoporosis, or prescribed anti-resorptive or anabolic therapy. BTM-tested patients were 1:1 propensity score matched to those untested following diagnosis. Generalized estimating equation models were performed to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for testing versus no testing on both treatment decision-making and fragility fracture.

RESULTS

Of the 457,829 patients with osteoporosis, 6075 were identified with ≥ 1 BTM test following diagnosis; of these patients, 1345 had a unique treatment decision made ≤ 30 days from BTM testing. The percentage of patients receiving BTM tests increased significantly each year (average annual % change: + 8.1%; 95% CI: 5.6-9.0; p = 0.01). Patients tested were significantly more likely to have a treatment decision (OR: 1.14; 95% CI: 1.13-1.15), and testing was associated with lower odds of fracture versus those untested (OR: 0.87; 95% CI: 0.85-0.88).

CONCLUSION

In this large, heterogeneous population of patients with presumed osteoporosis, BTM testing was associated with treatment decision-making, likely leading to fragility fracture reduction following use.

Identification and diagnosis of Secondary Progressive Multiple Sclerosis during the clinical encounter: Results from a physician survey

BACKGROUND

It is difficult to characterize the transition from relapsing-remitting multiple sclerosis (RRMS) to secondary progressive MS (SPMS), due to symptomatic variability across patients. Diagnosis of SPMS is prolonged and often established retrospectively, as it is based on patient clinical history and symptoms. This cross-sectional study aimed to identify MS neurologist reported clinical indicators deemed important in diagnosing SPMS in clinical practice.

METHODS

A web-based quantitative survey was conducted among MS-treating neurologists across the United States in January 2019. The questionnaire comprised of 17 questions evaluating primary clinical indicators used by neurologists in assessing patient progression to SPMS. Treatment approach and factors influencing treatment decision-making following SPMS diagnosis were also analyzed in the survey.

RESULTS

Overall, 300 neurologists completed the survey; most of the respondents were general MS-treating neurologists (63%) and from private care setting (58%). The overall respondents as well as MS-focused neurologists ranked patient history (45% and 42%, respectively) and patients' neurological exam (39% and 44%, respectively) as -primary clinical indicators of SPMS diagnosis. 57% of neurologists always or mostly switched disease modifying therapies after progression to SPMS, and mostly considered 3-6 months' assessment interval to diagnose SPMS.

CONCLUSION

The survey indicated that neurologists are able to recognize signs of SPMS within six months of symptomatic assessment. The diagnosis is primarily based on patient history among MS-treating neurologists. Therefore, continued education to neurologists may facilitate early diagnosis and timely introduction of effective treatment to manage the progression of SPMS.

Direct-drive laser fusion: status, plans and future

Laser-direct drive (LDD), along with laser indirect (X-ray) drive (LID) and magnetic drive with pulsed power, is one of the three viable inertial confinement fusion approaches to achieving fusion ignition and gain in the laboratory. The LDD programme is primarily being executed at both the Omega Laser Facility at the Laboratory for Laser Energetics and at the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory. LDD research at Omega includes cryogenic implosions, fundamental physics including material properties, hydrodynamics and laser-plasma interaction physics. LDD research on the NIF is focused on energy coupling and laser-plasma interactions physics at ignition-scale plasmas. Limited implosions on the NIF in the 'polar-drive' configuration, where the irradiation geometry is configured for LID, are also a feature of LDD research. The ability to conduct research over a large range of energy, power and scale size using both Omega and the NIF is a major positive aspect of LDD research that reduces the risk in scaling from OMEGA to megajoule-class lasers. The paper will summarize the present status of LDD research and plans for the future with the goal of ultimately achieving a burning plasma in the laboratory. This article is part of a discussion meeting issue 'Prospects for high gain inertial fusion energy (part 2)'.

A Rare Case of Retroperitoneal Isolated Enteric Duplication Cyst with Malignant Transformation

Introduction/Objective

Isolated enteric duplication cysts (IEDC) are rare congenital abnormalities that do not have a communication with the normal intestinal lumen. They are usually recognized before the age of 2 years. They are rarely encountered in adults and very seldom undergo malignant change. These cysts are predominantly located within the abdominal cavity. They histologically demonstrate gastrointestinal mucosal lining and smooth muscle in the wall.

Methods

We report a case of a 45-year-old African American female who was evaluated for a pain in the left-sided abdomen and pelvis. Magnetic resonance imaging revealed a large multilocular cystic retroperitoneal mass, extending into the left iliac fossa and anteriorly displacing the colon. No other mass lesion was radiologically identified. The main radiologic impression was sarcoma. A biopsy was performed, and a pathologic diagnosis of adenocarcinoma was established with a consideration of primary retroperitoneal mucinous cystadenocarcinoma. An en bloc surgical resection of the retroperitoneal mass with adjacent segment of the descending colon was accomplished. Gross examination revealed an 11 x 5 x 4 cm cystic mass, containing a necrotic fluid and adherent to a 4 cm long segment of descending colon. Microscopically, the mass was lined by neoplastic cells arranged into tubules, villi and glands. Areas of necrosis were present. The wall of the cystic mass showed extensive hyalinized fibrosis and focal invasion. The neoplastic cells had positive immunoreactivity for CK7, CK20 and CDX2, but were negative for PAX8, PR and ER. Desmin immunostain and trichrome special stain highlighted a focus of smooth muscle bundle within the wall of the mass. These findings led to the pathologic diagnosis of adenocarcinoma arising in retroperitoneal IEDC.

Conclusion

In conclusion, we present this case because of its unusual presentation and location. Recognition of this entity and its rare malignant potential is important as it can pose a diagnostic challenge to pathologists.

Evaluation of Changes in Microbiology and Periodontal Parameters During and After Fixed Orthodontic Appliances

The objective of the study was to evaluate the changes in microbiology through quantitative analysis of aerobic and anaerobic colonies and periodontal measurements during and after 1 month of removal of fixed orthodontic appliances. This prospective study comprised 30 patients, aged 12-30 years seeking orthodontic treatment in the department of Orthodontics and Dentofacial Orthopaedics of People's College of Dental Sciences and Research Centre, Bhopal from May 2016 to November 2017. Microbiological samples (supra- and subgingival plaque) and periodontal measurements like bleeding on probing (BOP), periodontal pocket depth (PPD) with oral hygiene assessment indices {plaque index (PI), gingival index (GI)} were used at 2 time interval: when patient undergoing orthodontic treatment >12 month (baseline, T₁) and 1 month after the removal of appliance (T₂). Bacterial culture method used to detect aerobic and anaerobic colony forming units (CFU) and their ratio (aerobic/anaerobic). Data analyzed using paired t-test and chi-square test. There was a significant decrease in an aerobic and anaerobic CFU (both supra- and subgingivally) and increase in CFU ratio (relatively less anaerobes) (p≤0.05) at T₂. Supragingival plaque sampling showed greater diminution in the CFU count as compared to the subgingival CFU, as these sites are more accessible for maintaining hygiene. Also, periodontal measurements showed significant decrement (PI, GI, PPD and BOP) at T₂ (p≤0.05). Fixed orthodontic treatment has transient effect on periodontium as supra- and subgingival CFU count decreases and periodontal health was ameliorated after removal of appliances which was accompanied with periodontopathic bacteria and clinical periodontal signs of inflammation during treatment.

A multicentre randomised phase III trial comparing pembrolizumab versus single-agent chemotherapy for advanced pre-treated malignant pleural mesothelioma: the European Thoracic Oncology Platform (ETOP 9-15) PROMISE-meso trial

BACKGROUND

Malignant pleural mesothelioma (MPM) is an aggressive malignancy characterised by limited treatment options and a poor prognosis. At relapse after platinum-based chemotherapy, single-agent chemotherapy is commonly used and single-arm trials of immune-checkpoint inhibitors have demonstrated encouraging activity.

PATIENTS AND METHODS

PROMISE-meso is an open-label 1:1 randomised phase III trial investigating the efficacy of pembrolizumab (200 mg/Q3W) versus institutional choice single-agent chemotherapy (gemcitabine or vinorelbine) in relapsed MPM patients with progression after/on previous platinum-based chemotherapy. Patients were performance status 0-1 and unselected for programmed cell death ligand 1 (PD-L1) status. At progression, patients randomly assigned to receive chemotherapy were allowed to crossover to pembrolizumab. The primary end point was progression-free survival (PFS), assessed by blinded independent central review (BICR). Secondary end points were overall survival (OS), investigator-assessed PFS, objective response rate (ORR), and safety. Efficacy by PD-L1 status was investigated in exploratory analyses.

RESULTS

Between September 2017 and August 2018, 144 patients were randomly allocated (pembrolizumab: 73; chemotherapy: 71). At data cut-off [20 February 2019, median follow-up of 11.8 months (interquartile range: 9.9-14.5)], 118 BICR-PFS events were observed. No difference in BICR-PFS was detected [hazard ratio = 1.06, 95% confidence interval (CI): 0.73-1.53; P = 0.76], and median BICR-PFS (95% CI) for pembrolizumab was 2.5 (2.1-4.2), compared with 3.4 (2.2-4.3) months for chemotherapy. A difference in ORR for pembrolizumab was identified (22%, 95% CI: 13% to 33%), over chemotherapy (6%, 95% CI: 2% to 14%; P = 0.004). Forty-five patients (63%) assigned to chemotherapy received pembrolizumab at progression. With follow-up to 21 August 2019 [17.5 months: (14.8-19.7)], no difference in OS was detected between groups (HR = 1.12, 95% CI: 0.74-1.69; P = 0.59), even after adjusting for crossover. Pembrolizumab safety was consistent with previous observations. Exploratory efficacy analyses by PD-L1 status demonstrated no improvements in ORR/PFS/OS.

CONCLUSION

This is the first randomised trial evaluating the efficacy of pembrolizumab in MPM patients progressing after/on previous platinum-based chemotherapy. In biologically unselected patients, although associated with an improved ORR, pembrolizumab improves neither PFS nor OS over single-agent chemotherapy.

Retrospective analysis of EMR database to assess the effectiveness of Saccharomyces boulardii CNCM I-745 in children with acute diarrhoea during routine clinical practice

This study aimed to assess the efficacy of Saccharomyces boulardii, a yeast probiotic, in the management of acute diarrhoeal disorders in the paediatric population in outpatient settings. It was a multicentre retrospective analysis of medical records of children who were treated for acute diarrhoea by routine treatment (oral rehydration solution and zinc) with or without S. boulardii. Overall, 160 children presenting with acute diarrhoea at seven different outpatient paediatric settings were included in the study. Children were divided into two categories based on their treatment with S. boulardii (SB group) or without S. boulardii (Non-SB group). Baseline demographic, anthropometric and clinical variables were compared between the two groups. The median duration of diarrhoea post-treatment was significantly shorter in the S. boulardii group (3 days) than in the non-SB group (4 days). A significant reduction in the frequency of stools was observed post-treatment in the S. boulardii group (1.7 versus 2.5 in the non-SB group). There was a significant weight gain in the S. boulardii group post-treatment (300 g) in comparison with the non-SB group (mean loss of 400 g). This study established the positive role of S. boulardii in the management of acute diarrhoeal diseases in children. Moreover, the S. boulardii probiotic was seen to be effective in diarrhoeal diseases in children with dehydration.

Gastric point-of-care ultrasound (PoCUS) during pregnancy and the postpartum period: a systematic review

Personalised risk assessment of the likelihood of pulmonary aspiration is recommended for pregnant women undergoing general anaesthesia and gastric point-of-care ultrasound (PoCUS) may help to achieve this. Traditionally, risk assessment is based upon adherence to fasting times, but gastric emptying may vary during pregnancy and surgery often needs to be expedited. We systematically reviewed the evidence for gastric PoCUS up to August 2018 in pregnant and postpartum women to determine whether it can identify and quantify stomach contents, provide aspiration risk assessment via qualitative or quantitative means, and determine how gastric emptying is affected by pregnancy. Twenty-two articles comprising 1050 participants were included and studies were classified by qualitative or quantitative findings. The evidence suggests that gastric PoCUS is a reliable and feasible method of imaging the stomach in pregnancy in clinical practice. Qualitative assessment via the Perlas grading system can provide rapid assessment of gastric volume states. If fluid is visible, identification of patients at high risk of pulmonary aspiration requires measurement of antral cross-sectional area. Cut-off values of 608 mm² and 960 mm² are recommended in the semi-recumbent and right lateral semi-recumbent positions, respectively. Validated methods to quantify stomach volumes are available, however their usefulness is currently restricted to research. Gastric PoCUS also provides evidence that gastric emptying of ingested food is delayed by term pregnancy, labour and during the early postpartum period. However, the passage of fluids through the stomach appears unaffected throughout the peripartum period.

Search for Electron Antineutrino Appearance in a Long-Baseline Muon Antineutrino Beam

Electron antineutrino appearance is measured by the T2K experiment in an accelerator-produced antineutrino beam, using additional neutrino beam operation to constrain parameters of the Pontecorvo-Maki-Nakagawa-Sakata (PMNS) mixing matrix. T2K observes 15 candidate electron antineutrino events with a background expectation of 9.3 events. Including information from the kinematic distribution of observed events, the hypothesis of no electron antineutrino appearance is disfavored with a significance of 2.40σ and no discrepancy between data and PMNS predictions is found. A complementary analysis that introduces an additional free parameter which allows non-PMNS values of electron neutrino and antineutrino appearance also finds no discrepancy between data and PMNS predictions.

Are the tubular bones of the hand really the commonest site for an enchondroma?

AIM

To investigate whether the long-held view that the hand is the commonest site for an enchondroma is actually correct in light of more sensitive imaging techniques that are able to demonstrate small enchondromas at other skeletal sites.

MATERIALS AND METHODS

A two-part retrospective study was undertaken. Part 1 comprised a review of the hand radiographs obtained in two major teaching hospitals over a 10-year period to establish the incidence of enchondroma in the hand. Part 2 was a review of a series of enchondromas of the proximal humerus, distal femur, and proximal tibia <4 cm in length on magnetic resonance imaging (MRI) to see which cases were visible or not on corresponding radiographs.

RESULTS

Part 1: 84 enchondromas were identified on 116,354 trauma radiographs to give an incidence of 0.07%. Part 2: 157 patients with an enchondroma on MRI <4 cm were reviewed. Only 17% of lesions <2 cm in length were visible on the contemporaneous radiographs. In lesions that were 2-2.9 and 3-3.9 cm the percentage visible on the radiographs increased to 58 and 77%, respectively.

CONCLUSION

It is well recognised from existing studies that incidental enchondromas can be seen in approximately 2.5% of routine shoulder and knee MRI scans. This figure is 35 times higher than the incidence found in the series of hand trauma radiographs. This infers that the hand should no longer be considered as the commonest site for an enchondroma. This is because radiographs are relatively insensitive to the detection of small lesions in larger bones, such as the proximal humerus and around the knee, when compared with MRI.

Precision lattice parameter determination from transmission diffraction of thick specimens with irregular cross sections

Accurate determination of lattice parameters from X-ray diffraction requires that the diffraction angles be measured very precisely, and significant errors result if the sample–detector separation differs from that assumed. Transmission diffraction from bones, which have a complex cross section and must be left intact, is a situation where this separation is difficult to measure and it may differ from position to position across the specimen. This article describes a method for eliminating the effect of variable sample cross section. Diffraction patterns for each position on the specimen are collected before and after 180° rotation about an axis normal to the cross section of interest. This places the centroid of the diffracting mass at the center of rotation and provides the absolute lattice parameters from the average apparent lattice parameters at the two rotation angles. Diffraction patterns were collected across the cross section of three specimens: a 3D-printed elliptical cylinder of Hyperelastic Bone (HB), which is composed primarily of synthetic hydroxyapatite (hAp), a 3D-printed HB model of the second metacarpal bone (Mc2), and a modern human Mc2 containing nanocrystalline carbonated apatite (cAp). Rietveld refinement was used to determine precise unit-cell parameters a apparent and c apparent for each pattern of each scan, and these values determined the actual average 〈a〉 and 〈c〉 for each sample. The results indicate that the 0°/180° rotation method works well enough to uncover variations approaching 1 × 10−3 Å in cAp unit-cell parameters in intact bones with irregular cross sections.

Outcomes of Endoscopic Sphincteroplasty Using Large Balloon Dilatation for Difficult Common Bile Duct Stone Removal at Dhulikhel Hospital

Background Endoscopic sphincteroplasty (ESPT) using a large Controlled Radial Expansion (CRE) Wire guided balloon dilatation has gained acceptance in removing a difficult common bile duct (CBD) stones. Objective To evaluate effectiveness and complications of removing large and difficult bile duct stones with sphincterotomy combined with large balloon dilatation. Method A total of 132 patients, from February 2014 to June 2017, who had biliary ductal calculus which was either greater than 15 mm or difficult to remove with standard technique, underwent Endoscopic Retrograde Cholangiopancreaticography (ERCP) with Endoscopic sphincteroplasty using a large Controlled radial expansion wire guided balloon dilatation. The success rate of complete stone clearance and post Endoscopic Retrograde Cholangiopancreaticography complications were analyzed. Result There were 48 (36.4 %) male and 84 (63.6%) female patients with mean age of 55.48 ± 16.36 years. Stones were removed with sphincteroplasty in first attempt in 90 out of 132 (68.2%) patients, 26 out of 37 (70.27%) patients in second session and in all 7(100%) patients in third attempt. Five (11.90%) patients were lost to follow up and 4 were advised for surgery because of failure to remove stones by sphincteroplasty. Overall success of endoscopic sphincterotomy and large balloon dilatation in our study was 93.18%. Complications were seen in 17 (13.6%) patients; bleeding seen in 9 (6.8%) patients and mild pancreatitis in 8 (6.1%) patients. None of the patients had severe pancreatitis or perforation secondary to the procedure. Conclusion Endoscopic sphincteroplasty after sphincterotomy is an effective and safe technique for a difficult common bile duct stone removal.

Critical care usage after major gastrointestinal and liver surgery: a prospective, multicentre observational study

BACKGROUND

Patient selection for critical care admission must balance patient safety with optimal resource allocation. This study aimed to determine the relationship between critical care admission, and postoperative mortality after abdominal surgery.

METHODS

This prespecified secondary analysis of a multicentre, prospective, observational study included consecutive patients enrolled in the DISCOVER study from UK and Republic of Ireland undergoing major gastrointestinal and liver surgery between October and December 2014. The primary outcome was 30-day mortality. Multivariate logistic regression was used to explore associations between critical care admission (planned and unplanned) and mortality, and inter-centre variation in critical care admission after emergency laparotomy.

RESULTS

Of 4529 patients included, 37.8% (n=1713) underwent planned critical care admissions from theatre. Some 3.1% (n=86/2816) admitted to ward-level care subsequently underwent unplanned critical care admission. Overall 30-day mortality was 2.9% (n=133/4519), and the risk-adjusted association between 30-day mortality and critical care admission was higher in unplanned [odds ratio (OR): 8.65, 95% confidence interval (CI): 3.51-19.97) than planned admissions (OR: 2.32, 95% CI: 1.43-3.85). Some 26.7% of patients (n=1210/4529) underwent emergency laparotomies. After adjustment, 49.3% (95% CI: 46.8-51.9%, P<0.001) were predicted to have planned critical care admissions, with 7% (n=10/145) of centres outside the 95% CI.

CONCLUSIONS

After risk adjustment, no 30-day survival benefit was identified for either planned or unplanned postoperative admissions to critical care within this cohort. This likely represents appropriate admission of the highest-risk patients. Planned admissions in selected, intermediate-risk patients may present a strategy to mitigate the risk of unplanned admission. Substantial inter-centre variation exists in planned critical care admissions after emergency laparotomies.