Resilient design in nuclear energy: Critical lessons from a cross-disciplinary analysis of the Fukushima Dai-ichi nuclear accident

This paper presents a multidisciplinary analysis of the Fukushima Dai-ichi Nuclear Power Plant accident. Along with the latest observations and simulation studies, we synthesize the time-series and event progressions during the accident across multiple disciplines, including in-plant physics and engineering systems, operators' actions, emergency responses, meteorology, radionuclide release and transport, land contamination, and health impacts. We identify three key factors that exacerbated the consequences of the accident: (1) the failure of Unit 2 containment venting, (2) the insufficient integration of radiation measurements and meteorology data in the evacuation strategy, and (3) the limited risk assessment and emergency preparedness. We conclude with new research and development directions to improve the resilience of nuclear energy systems and communities, including (1) meteorology-informed proactive venting, (2) machine learning-enabled adaptive evacuation zones, and (3) comprehensive risk-informed emergency planning while leveraging the experience from responses to other disasters.

The surgery-first approach for orthognathic correction of maxillary deficiency-is it stable? Three-dimensional assessment of CBCT scans and digital dental models

The aim of this study was to determine the skeletal stability of Le Fort I maxillary advancement following the surgery-first approach, by three-dimensional (3D) assessment of cone beam computed tomography (CBCT) scans and digital dental models. CBCT scans of 25 class III patients obtained 1 week preoperatively (T0) and 1 week (T1) and 6 months (T2) postoperatively were superimposed to measure surgical movements (T0-T1) and skeletal relapse (T1-T2). The distorted dentition of the CBCT scans at T1 was replaced with 3D images of the dental models to assess the postoperative occlusion. Surgical movements of the maxilla (mean ± standard deviation values) were 6.79 ± 2.30 mm advancement, 1.28 ± 1.09 mm vertically, and 0.71 ± 0.79 mm mediolaterally. Horizontal rotation (yaw) was 1.56° ± 1.21°, vertical rotation (pitch) 1.86° ± 1.88°, and tilting (roll) 1.63° ± 1.54°. At T2, the posterior relapse was 0.72 ± 0.43 mm (P = 0.001) and relapse in pitch was 1.56° ± 1.42° (P = 0.007). There was no correlation between the size of the surgical movements and the amount of relapse. A weak correlation was noted between the number of teeth in occlusal contact immediately following surgery and relapse of maxillary roll (r = - 0.434, P = 0.030). The stability of maxillary advancement with the surgery-first approach was satisfactory and was not correlated with the quality of the immediate postoperative occlusion.

Outcome measures of the surgery first approach for orthognathic correction of dentofacial deformities

In the surgery-first approach (SFA), orthognathic surgery is performed without the need for presurgical orthodontic treatment. This study was aimed at assessing the treatment durations and occlusal outcomes for a consecutive cohort of patients, with a range of dentofacial deformities, who had completed orthognathic treatment using SFA. The duration of orthognathic treatment was measured. The overall change in occlusion, and the quality of the final occlusion, were evaluated using the patients' study casts. A single, independent, calibrated operator carried out the occlusal scores, using the validated Peer Assessment Rating (PAR) index. This was repeated to test intraoperator reliability. A total of 51 patients completed surgery-first treatment during the study period. The mean (range) age at surgery was 23.3 (15-47) years. The pre-treatment skeletal jaw relationship was Class III in 39 cases, and Class II in 12 cases. The mean (SD) overall treatment duration was 11.7 (5.7) months. The intraexaminer reliability of assessing the occlusion was high. The PAR scores confirmed a significant improvement in the quality of occlusion at the completion of treatment, which compares favourably with previous studies on the conventional orthodontics-first approach. The surgery first approach can be effective at correcting both Class II and Class III malocclusion types with reduced treatment times.

Nuclear waste Educator's workshop: What and how do we teach about nuclear waste?

A workshop was held at the Massachusetts Institute of Technology (MIT) on July 25th and 26th, 2022. The objective was to develop a blueprint for educating next-generation engineers and scientists about nuclear waste management and disposal, which requires knowledge from diverse disciplines, including nuclear, chemical, civil, environmental, and geological science and engineering. The 49 participants included university professors, researchers, industry experts, and government officials from different areas. First, we have developed a list of key fundamental knowledge on waste management and disposal across the nuclear fuel cycle. In addition, we discussed strategies on how to teach students with diverse backgrounds through innovative teaching strategies as well as how to attract students into this area. Through the workshop, we identified the critical needs to (1) develop community resources for nuclear waste education; (2) synthesize historical perspectives, including past contamination and the management of general hazardous waste; (3) emphasize a complete life-cycle perspective, including proper waste management as the key component for energy sustainability; (4) teach students how to communicate about the key facts and risks to technical and non-technical audiences; and (5) accelerate the use of the state-of-art-technologies to attract and retain a young workforce. Furthermore, we aim to build a diverse, inclusive community that supports students in developing their own narratives about nuclear waste, particularly in recognizing that antagonistic views have been important to improving safety and protecting public health and the environment.

Hospitalization and hospital mortality rates during the first and second waves of the COVID-19 pandemic in Quebec: interrupted time series and decomposition analysis

OBJECTIVES

We investigated hospitalization and hospital mortality rates by cause during the first year of the COVID-19 pandemic in Quebec, Canada.

STUDY DESIGN

Interrupted time series and decomposition analysis.

METHODS

We analyzed hospital mortality during the first (February 25-August 22, 2020) and second waves (August 23, 2020-March 31, 2021), compared with 2019. We identified the cause of death and examined trends using: 1) interrupted time series analysis; 2) log-binomial regression; and 3) decomposition of cause-specific mortality.

RESULTS

Hospitalization rates decreased; however, the proportion of deaths increased from 27.0 per 1000 in 2019 to 35.0 per 1000 in the first wave, for an excess of 8.0 deaths per 1000 admissions. COVID-19 was the cause of a third of excess deaths (2.6 per 1000). Other drivers of excess deaths included respiratory conditions (1.6 deaths per 1000), circulatory disorders (0.6 deaths per 1000), and cancer (0.9 deaths per 1000). COVID-19 was the cause of 58% of excess deaths in the second wave. Interrupted time series regression indicated that the proportion of deaths increased at the outset of the first wave but returned to prepandemic levels before increasing again in the second wave. Compared with 2019, the first wave was associated with 1.31 times (95% confidence interval [CI] 1.28-1.33) and the second wave with 1.17 times (95% CI 1.15-1.19) the risk of death during hospitalization.

CONCLUSIONS

The pandemic was associated with a greater risk of hospital mortality. Excess deaths were driven by COVID-19 but also other causes, including respiratory conditions, circulatory disorders, and cancer.

Multiorgan MRI findings after hospitalisation with COVID-19 in the UK (C-MORE): a prospective, multicentre, observational cohort study

INTRODUCTION

The multiorgan impact of moderate to severe coronavirus infections in the post-acute phase is still poorly understood. We aimed to evaluate the excess burden of multiorgan abnormalities after hospitalisation with COVID-19, evaluate their determinants, and explore associations with patient-related outcome measures.

METHODS

In a prospective, UK-wide, multicentre MRI follow-up study (C-MORE), adults (aged ≥18 years) discharged from hospital following COVID-19 who were included in Tier 2 of the Post-hospitalisation COVID-19 study (PHOSP-COVID) and contemporary controls with no evidence of previous COVID-19 (SARS-CoV-2 nucleocapsid antibody negative) underwent multiorgan MRI (lungs, heart, brain, liver, and kidneys) with quantitative and qualitative assessment of images and clinical adjudication when relevant. Individuals with end-stage renal failure or contraindications to MRI were excluded. Participants also underwent detailed recording of symptoms, and physiological and biochemical tests. The primary outcome was the excess burden of multiorgan abnormalities (two or more organs) relative to controls, with further adjustments for potential confounders. The C-MORE study is ongoing and is registered with ClinicalTrials.gov, NCT04510025.

FINDINGS

Of 2710 participants in Tier 2 of PHOSP-COVID, 531 were recruited across 13 UK-wide C-MORE sites. After exclusions, 259 C-MORE patients (mean age 57 years [SD 12]; 158 [61%] male and 101 [39%] female) who were discharged from hospital with PCR-confirmed or clinically diagnosed COVID-19 between March 1, 2020, and Nov 1, 2021, and 52 non-COVID-19 controls from the community (mean age 49 years [SD 14]; 30 [58%] male and 22 [42%] female) were included in the analysis. Patients were assessed at a median of 5·0 months (IQR 4·2-6·3) after hospital discharge. Compared with non-COVID-19 controls, patients were older, living with more obesity, and had more comorbidities. Multiorgan abnormalities on MRI were more frequent in patients than in controls (157 [61%] of 259 vs 14 [27%] of 52; p<0·0001) and independently associated with COVID-19 status (odds ratio [OR] 2·9 [95% CI 1·5-5·8]; padjusted=0·0023) after adjusting for relevant confounders. Compared with controls, patients were more likely to have MRI evidence of lung abnormalities (p=0·0001; parenchymal abnormalities), brain abnormalities (p<0·0001; more white matter hyperintensities and regional brain volume reduction), and kidney abnormalities (p=0·014; lower medullary T1 and loss of corticomedullary differentiation), whereas cardiac and liver MRI abnormalities were similar between patients and controls. Patients with multiorgan abnormalities were older (difference in mean age 7 years [95% CI 4-10]; mean age of 59·8 years [SD 11·7] with multiorgan abnormalities vs mean age of 52·8 years [11·9] without multiorgan abnormalities; p<0·0001), more likely to have three or more comorbidities (OR 2·47 [1·32-4·82]; padjusted=0·0059), and more likely to have a more severe acute infection (acute CRP >5mg/L, OR 3·55 [1·23-11·88]; padjusted=0·025) than those without multiorgan abnormalities. Presence of lung MRI abnormalities was associated with a two-fold higher risk of chest tightness, and multiorgan MRI abnormalities were associated with severe and very severe persistent physical and mental health impairment (PHOSP-COVID symptom clusters) after hospitalisation.

INTERPRETATION

After hospitalisation for COVID-19, people are at risk of multiorgan abnormalities in the medium term. Our findings emphasise the need for proactive multidisciplinary care pathways, with the potential for imaging to guide surveillance frequency and therapeutic stratification.

FUNDING

UK Research and Innovation and National Institute for Health Research.

Reproducibility and reliability of digital occlusal planning for orthognathic surgery

The digital articulation of dental models is gradually replacing the conventional physical approach for occlusal prediction planning. This study was performed to compare the accuracy and reproducibility of free-hand articulation of two groups of digital and physical dental models, 12 Class I (group 1) and 12 Class III (group 2). The models were scanned using an intraoral scanner. The physical and digital models were independently articulated 2 weeks apart by three orthodontists to achieve the maximum inter-digitation, with coincident midlines and a positive overjet and overbite. The occlusal contacts provided by the software color-coded maps were assessed and the differences in the pitch, roll, and yaw were measured. The reproducibility of the achieved occlusion of both the physical and digital articulation was excellent. The z-axis displayed the smallest absolute mean differences of 0.10 ± 0.08 mm and 0.27 ± 0.24 mm in the repeated physical and repeated digital articulations, respectively, both in group 2. The largest discrepancies between the two methods of articulation were in the y-axis (0.76 ± 0.60 mm, P = 0.010) and in roll (1.83° ± 1.72°, P = 0.005). The overall measured differences were< 0.8 mm and< 2°. Despite the steep learning curve, digital occlusal planning is accurate enough for clinical applications.

Impella in Acute Myocardial Infarction Complicated by Cardiogenic Shock: History and Current Controversies

In this review, the authors discuss a brief history of the Impella mechanical circulatory support device, a mechanistic role for the device in the context of the underlying pathophysiology of acute myocardial infarction cardiogenic shock (AMI-CS), the current body of literature evaluating its role in AMI-CS, and upcoming efforts to identify a role more clearly for the device in AMI-CS.

Clinical characteristics with inflammation profiling of long COVID and association with 1-year recovery following hospitalisation in the UK: a prospective observational study

BACKGROUND

No effective pharmacological or non-pharmacological interventions exist for patients with long COVID. We aimed to describe recovery 1 year after hospital discharge for COVID-19, identify factors associated with patient-perceived recovery, and identify potential therapeutic targets by describing the underlying inflammatory profiles of the previously described recovery clusters at 5 months after hospital discharge.

METHODS

The Post-hospitalisation COVID-19 study (PHOSP-COVID) is a prospective, longitudinal cohort study recruiting adults (aged ≥18 years) discharged from hospital with COVID-19 across the UK. Recovery was assessed using patient-reported outcome measures, physical performance, and organ function at 5 months and 1 year after hospital discharge, and stratified by both patient-perceived recovery and recovery cluster. Hierarchical logistic regression modelling was performed for patient-perceived recovery at 1 year. Cluster analysis was done using the clustering large applications k-medoids approach using clinical outcomes at 5 months. Inflammatory protein profiling was analysed from plasma at the 5-month visit. This study is registered on the ISRCTN Registry, ISRCTN10980107, and recruitment is ongoing.

FINDINGS

2320 participants discharged from hospital between March 7, 2020, and April 18, 2021, were assessed at 5 months after discharge and 807 (32·7%) participants completed both the 5-month and 1-year visits. 279 (35·6%) of these 807 patients were women and 505 (64·4%) were men, with a mean age of 58·7 (SD 12·5) years, and 224 (27·8%) had received invasive mechanical ventilation (WHO class 7-9). The proportion of patients reporting full recovery was unchanged between 5 months (501 [25·5%] of 1965) and 1 year (232 [28·9%] of 804). Factors associated with being less likely to report full recovery at 1 year were female sex (odds ratio 0·68 [95% CI 0·46-0·99]), obesity (0·50 [0·34-0·74]) and invasive mechanical ventilation (0·42 [0·23-0·76]). Cluster analysis (n=1636) corroborated the previously reported four clusters: very severe, severe, moderate with cognitive impairment, and mild, relating to the severity of physical health, mental health, and cognitive impairment at 5 months. We found increased inflammatory mediators of tissue damage and repair in both the very severe and the moderate with cognitive impairment clusters compared with the mild cluster, including IL-6 concentration, which was increased in both comparisons (n=626 participants). We found a substantial deficit in median EQ-5D-5L utility index from before COVID-19 (retrospective assessment; 0·88 [IQR 0·74-1·00]), at 5 months (0·74 [0·64-0·88]) to 1 year (0·75 [0·62-0·88]), with minimal improvements across all outcome measures at 1 year after discharge in the whole cohort and within each of the four clusters.

INTERPRETATION

The sequelae of a hospital admission with COVID-19 were substantial 1 year after discharge across a range of health domains, with the minority in our cohort feeling fully recovered. Patient-perceived health-related quality of life was reduced at 1 year compared with before hospital admission. Systematic inflammation and obesity are potential treatable traits that warrant further investigation in clinical trials.

FUNDING

UK Research and Innovation and National Institute for Health Research.

Exploring the performances of the vibrating barriers for the seismic protection of the Zoser pyramid

In this paper we aim to investigate the use of the Vibrating Barrier (ViBa) as a potential strategy to mitigate the effects of the seismic action on the Zoser Pyramid. The Vibrating Barrier is a structure buried in the soil that is able to absorb a significant portion of the dynamic energy arising from the ground motion. The working principle exploits the dynamic interaction among vibrating structures resting on a compliant semi-infinite space, namely the structure–soil–structure interaction. A reliable numerical simulation of the Zoser Pyramid and the surrounding soil undergoing stochastic ground motion excitations representing the seismicity in Saqqara is presented. Due to the unique structural form, the ViBa is herein optimized through an ad-hoc procedure to minimize a response strain energy spectral density used as a synthetic performance parameter. Various layouts of the ViBa have been considered and presented in the paper. The efficiency of the ViBa is assessed by numerical simulation of the finite element model of the ViBa-Soil-Pyramid system and by laboratory testing. Results from a pertinent Monte Carlo study show an evident reduction of the stresses in the Pyramid manifesting the feasibility of this novel strategy to protect historic structures from earthquake-induced ground motion. Experimental results on a 1:500 gelatine model of the pyramid and the surrounding area highlighted the efficiency and efficacy of the proposed approach.

Toward Brief Dual Antiplatelet Therapy and P2Y12 Inhibitors for Monotherapy After PCI

The optimal duration of dual antiplatelet therapy (DAPT) after percutaneous coronary intervention remains a controversial topic. The European Society of Cardiology and the American College of Cardiology/American Heart Association recommend at least 6 and 12 months of DAPT after PCI in patients with stable coronary artery disease or acute coronary syndrome, respectively. Although prolonging DAPT duration reduces ischemic events, it is associated with higher rates of bleeding and possible fatal outcomes. The DAPT score can be an important tool to identify patients who may still benefit from prolonged therapy. Nevertheless, several recent randomized controlled trials showed that shortening DAPT duration from 12 to 1-3 months reduces bleeding rates without significantly increasing ischemic event rates. These trials also suggested replacing acetylsalicylic acid (aspirin) with P2Y12 inhibitors after short-term DAPT. We review and compare past and present studies regarding DAPT and analyze the evidence favoring a short DAPT duration and the long-term single antiplatelet agent of choice.

Prognostic significance of ischemic electrocardiographic changes with regadenoson stress myocardial perfusion imaging

BACKGROUND

In patients undergoing regadenoson SPECT myocardial perfusion imaging (MPI), the prognostic value of ischemic ST-segment depression (ST↓) and the optimal ST↓ threshold have not been studied.

METHODS

A retrospective cohort study of consecutive patients referred for regadenoson stress MPI was conducted. Patients with uninterpretable ECG were excluded. Two diagnostic thresholds of horizontal or downsloping ST↓ were studied, ≥ 0.5 mm and ≥ 1.0 mm. The primary endpoint was the composite major adverse cardiac events (MACE) of cardiac death, myocardial infarction, or coronary revascularization.

RESULTS

Among 8615 subjects (mean age 62 ± 13 years; 55% women), 89 (1.0%) had ST↓ ≥ 1.0 mm and 133 (1.5%) had ST↓ ≥ 0.5 mm. Regadenoson-induced ST↓ was more common in women (P < .001). Mean follow-up was 2.5 ± 2.2 years. After multivariate adjustment, ST↓ ≥ 1.0 mm was associated with a non-significant increase in MACE risk (P = .069), irrespective to whether MPI was abnormal (P = .162) or normal (P = .214). Ischemic ST↓ ≥ 0.5 mm was independently associated with MACE in the entire cohort (HR 2.14; CI 1.38-3.32; P = .001), whether MPI is normal (HR 2.07; CI 1.07-4.04; P = .032) or abnormal (HR 2.24; CI 1.23-4.00; P = .007), after adjusting for clinical and imaging covariates. An ST↓ threshold of ≥ 0.5 mm provided greater incremental prognostic value beyond clinical and imaging parameters (Δχ2 = 12.78; P < .001) than ≥ 1.0 mm threshold (Δχ2 = 3.72; P = .093).

CONCLUSION

Regadenoson-induced ischemic ST↓ is more common in women and it provides a modest independent prognostic value beyond MPI and clinical parameters. ST↓ ≥ 0.5 mm is a better threshold than ≥ 1.0 mm to define ECG evidence for regadenoson-induced myocardial ischemia.

The current state of PEEK implant osseointegration and future perspectives: a systematic review

Polyetheretherketone (PEEK) has been considered as an alternative to replace surgical metal implants. Several medical applications, including dental and orthopaedic implants, need confirmed osseointegration before functional loading. The present study aims at providing a comprehensive systematic review of the evidence on PEEK implants' osseointegration. A systematic search was conducted using Cochrane library, MEDLINE (PubMed), Ovid MEDLINE, Web of Science and EMBASE databases. Publications were identified in accordance with specific inclusion and exclusion criteria. Eligibility screening, data extraction and quality assessment were performed. The review protocol was registered in PROSPERO (CRD42018116061). A total of 55 articles were reviewed and 29 of the most relevant that met the inclusion criteria were selected. Heterogeneity was identified among the included studies. Several approaches have been applied to enhance PEEK osseointegration, with most in vivo studies conducted on small-scale animal models but no study evaluating the osseointegration of PEEK under cyclic loading. However, PEEK modifications are demonstrated to enhance osseointegration preclinically. Collectively, the present review shows a shortage of evidence, including a lack of comprehensive assessment of osseointegration, the need for large-animal-model tests, the need to assess the effect of loading on the implants and the lack of randomised controlled clinical trials.

Prenatal Substance Use Disorders and Dental Caries in Children

Substance use is common in women of reproductive age, but limited data exist on the dental health of their children, including risk of caries. We conducted a longitudinal cohort study of 790,758 infants born between 2006 and 2016 in Quebec, Canada. We identified women with substance use disorders before or during pregnancy. The main outcome measure was hospitalization for dental caries in offspring up to 12 y after birth. We estimated hazard ratios (HRs) with 95% confidence intervals (CIs) for the association of maternal substance use with pediatric dental caries, adjusted for potential confounders. Children exposed to maternal substance use had a higher incidence of hospitalization for dental caries than unexposed children (105.2 vs. 27.0 per 10,000 person-years). Maternal substance use was associated with 1.96 times the risk of childhood dental caries (95% CI, 1.80-2.14), including a greater risk of caries of enamel, dentin, or cementum (HR, 2.00; 95% CI, 1.82-2.19) and dental pulp (HR, 2.36; 95% CI, 2.07-2.70), relative to no substance use. Associations were elevated for alcohol (HR, 2.31; 95% CI, 2.03-2.64) but were also present for cocaine, cannabis, opioids, and other substances. Substance use during pregnancy was more strongly associated with dental caries hospitalization than prepregnancy substance use. Associations were stronger in early childhood. Maternal substance use is associated with the future risk of dental caries hospitalization in children. Targeting substance use early in the lives of women may contribute to dental caries prevention in offspring.

Rate and impact of venous thromboembolism in patients with ST-segment elevation myocardial infarction: Analysis of the Nationwide Inpatient Sample database 2003–2013

Venous thromboembolism (VTE) and coronary artery disease are major health issues that cause substantial morbidity and mortality. New data have emerged suggesting that these two conditions could have a close relationship. Thus, we sought to determine the trends in annual rate of VTE occurrence in patients with ST-segment elevation myocardial infarction (STEMI) and measure its impact on in-hospital mortality, bleeding complications, and cost and length of hospitalization. We queried the 2003–2013 Nationwide Inpatient Sample databases to identify adults with primary diagnosis of STEMI. VTE events were then allocated. Inpatient outcomes of patients with VTE were compared to those without VTE. Out of 2,495,757 hospitalizations for STEMI, VTE was diagnosed in 25,149 (1%) hospitalizations. Patients who experienced VTE were older (mean age: 67.5 vs 64.8, p < 0.01) and had a higher proportion of black patients (10.1% vs 7.7%, p < 0.001) and females (40.1% vs 35%, p < 0.001) compared to patients without VTE. There was an increasing trend in the rate of VTE during the study period (2003: 0.8% vs 2013: 1.0%, p < 0.001). Patients with VTE had a prolonged hospitalization (median: 9 vs 3 days, p < 0.001), increased cost, higher risk of gastrointestinal bleeding (OR: 2.13, p < 0.001), intracranial hemorrhage (OR: 2.14, p < 0.001), blood transfusions (OR: 1.94, p < 0.001), and mortality (OR: 1.39, p < 0.001). The rate of VTE occurrence in patients with STEMI in our study was 10 per 1000 admissions. VTE was associated with more bleeding complications, longer hospital stays, higher costs, and mortality. These findings suggest that a more aggressive approach for VTE prophylaxis may be warranted in this population.

The effect of facial expression on facial symmetry in surgically managed unilateral cleft lip and palate patients (UCLP)

AIM

To evaluate the symmetry of facial expression in surgically managed UCLP patients.

MATERIALS AND METHODS

The study was conducted on 13 four-year-old children. Facial images were captured at rest and at maximum smile using stereophotogrammetry. A generic mesh, which is a mathematical facial mask consisting of a fixed number of indexed vertices, was utilised for the assessment of facial asymmetry. This was quantified by measuring the disparity between the left- and right-hand sides of the face after superimposing the original 3D images on their mirror copies.

RESULTS

Residual asymmetries at rest were identified at the vermillion of the upper lip and at the nares with a deviation of the philtrum towards the scar tissue. Vertical and anteroposterior asymmetries were identified on the cleft side. At maximum smile, the asymmetry increased noticeably at the vermillion of the upper lip and at the alar base. In the mediolateral direction, the philtrum deviated towards the cleft side with a significant increase of the asymmetry scores.

DISCUSSION

Asymmetry of the upper lip has significantly increased at maximum smile as a result of the upward forces of all perioral lifting muscles, which affected the lip directly.

CONCLUSIONS

The innovation of this study is the measurement of facial asymmetry for the objective outcome measure of the surgical repair of UCLP. The philtrum was the main site of residual asymmetry, which indicates the need for refining the primary repair of the cleft lip. Further corrective surgery may be required.

Assessing the outcome of orthognathic surgery by three-dimensional soft tissue analysis

Studies of orthognathic surgery often focus on pre-surgical versus post-surgical changes in facial shape. In contrast, this study provides an innovative comparison between post-surgical and control shape. Forty orthognathic surgery patients were included, who underwent three different types of surgical correction: Le Fort I maxillary advancement, bilateral sagittal split mandibular advancement, and bimaxillary advancement surgery. Control facial images were captured from volunteers from local communities in Glasgow, with patterns of age, sex, and ethnic background that matched those of the surgical patients. Facial models were fitted and Procrustes registration and principal components analysis used to allow quantitative analysis, including the comparison of group mean shape and mean asymmetry. The primary characteristic of the difference in shape was found to be residual mandibular prognathism in the group of female patients who underwent Le Fort I maxillary advancement. Individual cases were assessed against this type of shape difference, using a quantitative scale to aid clinical audit. Analysis of the combined surgical groups provided strong evidence that surgery reduces asymmetry in some parts of the face such as the upper lip region. No evidence was found that mean asymmetry in post-surgical patients is greater than that in controls.

Abstract 351: National Rates of Venous Thromboembolism in Patient with STEMI: Results from the National Inpatient Sample 2003-2013

Background: There is a growing body of evidence against the use of triple therapy (anticoagulation and dual antiplatelet) among patients with acute coronary syndrome. Venous thromboembolism (VTE) is another potential indication for triple therapy, but the magnitude of such problem is unknown. Therefore, we aimed to determine the trends of annual rate of immediate VTE occurrence in patients with ST-segment elevation myocardial infarction (STEMI) and measure its impact.

Methods: We queried the 2003-2013 Nationwide Inpatient Sample to identify adults with primary diagnosis of STEMI using ICD-9-CM codes. VTE, including limb vein thrombosis and pulmonary embolism, was allocated when present among the secondary discharge diagnosis. Demographics and inpatient outcomes were compared in the VTE and non-VTE group.

Results: From 2,495,757 hospitalizations for STEMI, 15,471 (0.6%) also experienced VTE. The group who experienced VTE was older (mean age: 68.44 vs 64.81, p<0.01) and had higher proportions of black patients (10.6% vs 7.7%, p<0.001) and females (42.1% vs 35%, p<0.001) compared to the non-VTE group. There was an increasing trend in the annual rate of VTE during the study period (2003: 0.3% vs 2013: 0.9%, p < 0.01). Patients with VTE had a prolonged hospitalization (12.8 vs 4.63 days, p <0.01), higher risk of gastrointestinal bleeding (OR:1.65; 95% CI 1.54-1.76, p<0.01) and intracranial hemorrhage(OR:1.52, 95% CI:1.23-1.87, P<0.01), needed more blood transfusions (OR:1.74; 95% CI:1.66-1.82, p<0.01) and had increased mortality (OR:1.53, 95%CI:1.46-1.6, p<0.01).

Conclusion: There is an increasing annual rate in immediate VTE occurrence in patients with STEMI. VTE is associated with more bleeding complications, longer hospital stay, and higher mortality. It is plausible that individualized or more aggressive protocols of VTE prophylaxis are needed in this population.

Abstract 715: Peripheral Artery Disease in Patients with End Stage Renal Disease: Nationwide Trends in Management and Outcomes

Background: Patients with end stage renal disease (ESRD) are at high risk for peripheral artery disease (PAD). We sought to determine the national prevalence of PAD, trends in management and outcomes among this high risk population.

Methods: We queried the 2003-2014 National Inpatient Sample databases to identify PAD related admissions (claudication and critical limb ischemia) among patients with ESRD using ICD-9 codes. Temporal trends in treatment options, and in-hospital mortality were analyzed. Multivariate logistic regression was used to assess predictors of major amputation.

Results: Among 9 million ESRD patient admissions, 357,949 (3.9%) had PAD related diagnosis. Patients were mainly white (39%), men (58%), with mean age of 65.6 years. The prevalence of PAD slightly decreased from 4.3% in 2003 to 3.9% in 2014 (P trend < 0.001). Utilization of percutaneous transluminal angioplasty (PTA) increased by 142% (10.6% to 25.7%), whereas, open bypass use decreased by 51% (14.1% to 6.9%) during the study period (P trend < 0.001). Moreover, the total number of major amputations was 65,669. There was a notable decline in its usage from 25.9% to 15.3% (adjusted odds ratio [OR] per year: 0.96; 95% confidence interval: 0.95-0.98, P<0.001). Revascularization appeared to reduce the risk of amputation (OR 0.49, P<0.001). On the contrary, hypertension (OR 2.5, P<0.001), heart failure (OR 1.5, P<0.001), and black race (OR 1.5, P<0.001) were independent predictors of amputation. Overall in-hospital mortality rate was 6.3%, with no statistically significant trend throughout the years.

Conclusion: PAD is a common disease in ESRD patients. Among therapeutic options, a significant increase in less invasive endovascular revascularization methods and a decline in open bypass surgeries were noted. Despite the significant drop in amputation rates, racial disparities persist, with black patients having higher odds of major amputation.

Abstract 726: Intermittent Pneumatic Compression during Hemodialysis to improve Quality of Life in Patients with Peripheral Artery Disease and End Stage Renal Disease

Peripheral artery disease (PAD) is a prevalent global problem with increased mortality. Affects about one in four patients with end stage renal disease (ESRD). Intermittent pneumatic compression (IPC) has shown improvement of lower extremity hemodynamics and symptoms and may be implemented during hemodialysis (HD).

We designed a trial to test the utility of IPC in the ESRD population by assessing improvement in quality of life (QOL) and functional limitation from PAD-related symptoms. We aim to present our design and initial results.

Methods: This is a prospective single cohort study for paired analysis undergoing recruitment of outpatients at the HD unit of John H. Stroger, Jr. Hospital of Cook County. A sample size of 78 yields a power of 80% and alpha of 0.05, assuming an average peak walking time of five minutes and 25% improvement after supervised exercise. PAD is confirmed by ankle-brachial index (ABI) and demographics collected. A baseline Six-minute Walk Test (6MWT), Peripheral Artery Questionnaire (PAQ) and Walking Impairment Questionnaire (WIQ) are administered and will be compared with their performance post intervention. The IPC device (Bio Arterial Plus) will be used for intervention during each HD for two months average. We present continuous variables as mean±SD and categorical variables as percentage.

Results: From 10 recruited patients in the first month, 60% are men, age 54.6±13.1 years, the majority Hispanic (80%). 70% of ABI were abnormal, all due to non-compressible PAD (1.44±0.20). All patients have HTN, 50% diabetes, 20% hyperlipidemia, 10% had a stroke and 10% revascularization for PAD. At baseline 6MWT, distance walked was 357.7±59.5 m, with 600±52.5 total steps and fatigue as main symptom (30%) and no typical claudication. QOL questionnaires showed WIQ walking distance 68.58±18.04, WIQ walking speed 72.5±26.36, and WIQ stair climbing 50.04±30.04 points; PAQ physical limitation 61±21.4, PAQ symptoms 62.79±18.7, PAQ satisfaction 68.67±27.9, PAQ quality of life 64±13.04, and PAQ social limitation 70±23.13 points.

Conclusion: Non-compressible PAD is prevalent in ESRD, and QOL seems significantly compromised from it. Our trial will provide insight of an alternative therapy, and optimize the time in HD even further.

Abstract 352: National Trends in Cancer-Associated Thrombosis Hospitalizations among Patients with Pancreatic, Gastric and Lung Primary: Results from Nationwide Inpatient Sample Database 2009-2014

Introduction: Venous thromboembolism ( VTE ) is a leading cause of morbidity and mortality in cancer; and its occurrence leads to an increased number of hospitalizations. Therefore, we aimed to determine the trends in the annual rate of cancer-associated thrombosis ( CAT ) hospitalizations and measure its impact in patients with highly thrombogenic tumor types, such as pancreas, stomach and lung.

Methods: We queried the 2009-2014 Nationwide Inpatient Sample database to identify adults with gastric, pancreatic or lung cancer. Hospitalizations in which VTE was among the top-three discharge diagnoses, were considered as CAT admissions. In-hospital outcomes of patients with VTE were compared to those without VTE. Using SPSS, version 24, we conducted a linear regression analysis for trend and binary logistic regression analysis to obtain adjusted odds ratios ( OR )

Results: From 3 million admissions, 149.577 (4.9%) were related to VTE. The patients were mainly white (68.9%) men (53.2%) with a median age of 69 (IQR:17) years; and the predominant tumor type was lung cancer (73.4%). Although the rate of CAT admissions remained steady during the study period (2009: 5.0% vs 2014: 4.9%, p <0.01), the inpatient mortality was higher among patients admitted with CAT (10.2% vs 9.3%, OR:1.11, CI: 1.08 - 1.13, p < 0.01). The negative effect of VTE on inpatient mortality persisted after adjusting for tumor type, metastatic disease and demographics (OR:1.11, CI: 1.08 - 1.13, p < 0.01). The median length of stay was 5 days in both groups (p<0.01), but the cost was significantly higher among those admitted with CAT (USD33,468 vs USD30,452, p <0.01). Figure 1 summarizes demographics ( A ) and trends ( B )

Conclusion: CAT admissions in patients with stomach, pancreas and lung cancer are associated with a higher inpatient mortality and its management is costly. Conceivably, risk stratification based on early mortality may assist in therapy and resources selection to improve outcomes and cost allocation.

Abstract 247: Is Oxygen Therapy Beneficial in Acute Myocardial Infarction? A Meta-Analysis

Background: Supplemental oxygen (O2) is beneficial in patients with acute myocardial infarction (AMI) who have hypoxemia. However in patients who have suspected AMI without hypoxemia, the benefit of O2 remains uncertain. We conducted a meta-analysis, including the recent landmark trials, to establish the efficacy and safety of O2 in AMI.

Methods: We searched Medline, Embase, and Ovid SP databases for randomized clinical trials that compared O2 with room air in suspected AMI without hypoxemia. Hypoxemia was defined as O2 saturation of <90%. The primary endpoint was all-cause mortality. Data were pooled by the random effects model and I2 was used to assess for the heterogeneity.

Results: A total of 6 studies including 8193 participants were included in the final analysis. On pooled analysis, there was no significant difference between the two arms in 30-day all-cause mortality (OR=1.10 [0.67, 1.80]; p=0.70), cardiogenic shock (OR=0.75 [0.49, 1.16]; p=0.19), recurrent myocardial infarction (OR=1.24 [0.46, 3.34]; p=0.67) and left ventricular ejection fraction (SMD= -1.95 [-4.76, 0.85]; p=0.17).

Conclusion: Contrary to the routine clinical practice, our analysis shows that O2 administration does not provide any benefit in AMI patients who have normal oxygen saturation. It is reasonable to reserve O2 only for patients with AMI and hypoxemia.

Assessment of facial asymmetry before and after the surgical repair of cleft lip in unilateral cleft lip and palate cases

This study was performed to assess facial asymmetry in patients with unilateral cleft lip and palate (UCLP) before and after primary lip repair. Three-dimensional facial images of 30 UCLP cases (mean age 3.7±0.8months) captured 1-2days before surgery and 4 months after surgery using stereophotogrammetry were analysed. A generic mesh - a mathematical facial mask consisting of thousands of points (vertices) - was conformed on the three-dimensional images. Average preoperative and postoperative conformed facial meshes were obtained and mirrored by reflecting on the lateral plane. Facial asymmetry was assessed by measuring the distances between the corresponding vertices of the superimposed facial meshes. Asymmetries were further examined in three directions: horizontal, vertical, and anteroposterior. Preoperatively, the philtrum and bridge of the nose were deviated towards the non-cleft side. The maximum vertical asymmetry was at the upper lip. The greatest anteroposterior asymmetry was at the alar base and in the paranasal area. The overall facial asymmetry improved markedly after surgery. Residual anteroposterior asymmetry was noted at the alar base, upper lip, and cheek on the cleft slide. In conclusion, dense correspondence analysis provided an insight into the anatomical reasons for the residual dysmorphology following the surgical repair of cleft lip for future surgical consideration.

The accuracy of three-dimensional prediction of soft tissue changes following the surgical correction of facial asymmetry: An innovative concept

The accuracy of three-dimensional (3D) predictions of soft tissue changes in the surgical correction of facial asymmetry was evaluated in this study. Preoperative (T1) and 6-12-month postoperative (T2) cone beam computed tomography scans of 13 patients were studied. All patients underwent surgical correction of facial asymmetry as part of a multidisciplinary treatment protocol. The magnitude of the surgical movement was measured; virtual surgery was performed on the preoperative scans using Maxilim software. The predicted soft tissue changes were compared to the actual postoperative appearance (T2). Mean (signed) distances and mean (absolute) distances between the predicted and actual 3D surface meshes for each region were calculated. The one-sample t-test was applied to test the alternative hypothesis that the mean absolute distances had a value of <2.0mm. A novel directional analysis was applied to analyse the accuracy of the prediction of soft tissue changes. The results showed that the distances between the predicted and actual postoperative soft tissue changes were less than 2.0mm in all regions. The predicted facial morphology was narrower than the actual surgical changes in the cheek regions. 3D soft tissue prediction using Maxilim software in patients undergoing the correction of facial asymmetry is clinically acceptable.

A Review of Water-Resistant Hemicellulose-Based Materials: Processing and Applications

Hemicelluloses, due to their hydrophilic nature, may tend to be overlooked as a component in water-resistant product applications. However, their domains of use can be greatly expanded by chemical derivatization. Research in which hydrophobic derivatives of hemicelluloses or combinations of hemicelluloses with hydrophobic materials are used with to prepare films and composites is considered herein. Isolation methods that have been used to separate hemicellulose from biomass are also reviewed. Finally, the most useful pathways to change the hydrophilic character of hemicelluloses to hydrophobic are reviewed. In this way, the water resistance can be increased and applications of targeted water-resistant hemicellulose developed. Several applications of these materials are discussed.

Neurosensory deficit following mandibular sagittal split osteotomy: A comparative study between positional screws and miniplates fixation

This retrospective study compared the incidence of long-term inferior alveolar nerve injury for positional screws and miniplate fixation of bilateral sagittal split osteotomies carried out in 2 hospitals in Scotland. The study involved a mixture of mandibular setback and advancement surgery. The outcome of neurosensory deficit (NSD) was solely based on subjective assessment by the surgeons and patients' reported alteration in sensation. Numbness, tingling and any alterations in sensation beyond 6 months were considered long-term inferior alveolar nerve injury. This study was conducted on 28 sagittal split osteotomies (group 1) which were fixed with three upper border fixation screws and 36 sagittal split osteotomies (group 2) which were fixed with upper border sliding plate. The reported and documented neurosensory deficits were analysed. The difference in the number of cases of long-term inferior alveolar nerve injury between the 2 methods was 10.3%; the 95% confidence interval for the difference was [-2.94 to 23.5], p = 0.1612. Upper border plate was associated with more long-term NSD but there is insufficient evidence to prove that one method was more superior to the other. The need for a prospective randomized trial was highlighted.

State-of-the-art three-dimensional analysis of soft tissue changes following Le Fort I maxillary advancement

We describe the comprehensive 3-dimensional analysis of facial changes after Le Fort I osteotomy and introduce a new tool for anthropometric analysis of the face. We studied the cone-beam computed tomograms of 33 patients taken one month before and 6-12 months after Le Fort I maxillary advancement with or without posterior vertical impaction. Use of a generic facial mesh for dense correspondence analysis of changes in the soft tissue showed a mean (SD) anteroposterior advancement of the maxilla of 5.9 (1.7) mm, and mean (SD) minimal anterior and posterior vertical maxillary impaction of 0.1 (1.7) mm and 0.6 (1.45) mm, respectively. It also showed distinctive forward and marked lateral expansion around the upper lip and nose, and pronounced upward movement of the alar curvature and columella. The nose was widened and the nostrils advanced. There was minimal forward change at the base of the nose (subnasale and alar base) but a noticeable upward movement at the nasal tip. Changes at the cheeks were minimal. Analysis showed widening of the midface and upper lip which, to our knowledge, has not been reported before. The nostrils were compressed and widened, and the lower lip shortened. Changes at the chin and lower lip were secondary to the limited maxillary impaction.

Efficacy of three-dimensional visualization in mobile apps for patient education regarding orthognathic surgery

'Sur-face' is an interactive mobile app illustrating different orthognathic surgeries and their potential complications. This study aimed to evaluate the efficacy of Sur-face by comparing two methods of delivering patient information on orthognathic surgeries and their related potential complications: a mobile app with interactive three-dimensional (3D) animations and a voice recording containing verbal instructions only. For each method, the participants' acquired knowledge was assessed using a custom-designed questionnaire. Participants in the 'app' group performed significantly better (P<0.0034) than those in the 'voice' group and retained more knowledge, suggesting that interactive visualizations play a key role in improving understanding of the orthognathic surgical procedure and its associated complications. This study emphasizes the impact of 3D visualizations in delivering information regarding orthognathic surgery and highlights the advantage of delivering validated patient information through mobile apps.

[Landmark-based statistical procrustes analysis in the examination of breast shape and symmetry]

AIM

The aim of this presentation is the explanation of a mathematical analysis of a landmark-based procrustes calculation. The various components of breast symmetry and their impact on breast reconstruction have been examined.

METHOD

In an objective breast shape analysis asymmetries are quantified as a measure of the difference between a 3D landmark configuration of a breast and its mirror image. 10 landmarks, 4 on each side and 2 for a definition of the midline were defined. For each landmark the 3D coordinates were calculated statistically with the help of the software Programme R. Over a midline from the jugulum to the manubrium sterni, a mirror image of the breast was constructed. The data for the breast to be reconstructed and the non-operated breast from 44 patients were investigated. The statistical differences of the Procrustes analysis were used for an asymmetry score and the proportions of the individual components were calculated. These included size, location and orientation of the breast as well as the individual inherent morphological surface form data of the breast.

RESULTS

All 44 patients exhibited breast asymmetries and the mean asymmetry score amounted to 0.52. A calculation of the proportions of the individual components making up the asymmetry score revealed that morphological surface data made the largest contribution to the asymmetry score, closely followed by location, i. e., positioning of the breast on the thoracic wall. In contrast, the size of the breast and its orientation were of lesser relevance.

CONCLUSION

When considering breast symmetry in plastic surgery, the form plays a more important role than the size as objectively calculated by the statistical procrustes analysis. Almost equally important as the form is the positioning of the breast on the thoracic wall which contributes significantly more to total breast symmetry than axial displacements.

[Obstructive sleep apnea syndrome in the elderly]

Obstructive sleep apnea/hypopnea syndrome (OSAHS) is a common disease in the general population. However, original works on the SAHS in the elderly are few and their results are discordant. Studies show an increased prevalence of OSAHS with age, and despite this high prevalence, it remains under-diagnosed due to lack of knowledge of geriatric features of this disease and the frequency of comorbidities that may worsen as a result of nocturnal breathing problems but can also mask the symptoms necessary for positive diagnosis. The functional symptoms are dominated by neurological signs such as daytime hypersomnia and cognitive impairment often reported by those around the patient. The treatment is based mainly on continuous positive airway pressure which tolerance in elderly patients suffering from sleep apnea is similar to that of younger patients. Mandibular implants can be discussed depending on the severity of the condition. Surgical treatment is not indicated because of the increased frequency of complications.