Does surgical companionship modify the learning curve for fenestrated and branched endovascular aortic repair?

OBJECTIVES: The goal of this study was to describe the learning curve of an operator trained in an aortic centre during the first years of performing fenestrated/branched endovascular aortic repairs independently. METHODS: Patients electively treated with fenestrated/branched stent grafts from January 2013 to March 2020 were included retrospectively. Groups were defined according to the treating operator: experienced operator (group 1), early-career operator (group 2) or both during a 14-month surgical companionship period (group 3). The early-career operator's learning curve was assessed using a cumulative sum analysis. A composite criterion including technical failure, death and/or any major adverse event was evaluated in a logistic regression model. RESULTS: Overall, 437 patients (93% male; median 69 (63, 77) years old) were included (group 1: n = 240; group 2: n = 173; group 3: n = 24). There were significantly more extended thoraco-abdominal aneurysms (extent I, II, III and V) in group 1 compared to group 2 [n = 68 (28%) vs 19 (11%), P<0.001]. The technical success rate was 94% (P=0.874). The 30-day mortality and/or major adverse event rates in juxta-/pararenal aneurysms or extent IV thoraco-abdominal aneurysms were 8.1% in group 1 and 9.7% in group 2 (P = 0.612), whereas they were 10% (group 1) and 0 (group 2) for extended thoraco-abdominal aneurysms (P=0.339). The adjusted cumulative sum analysis highlighted satisfactory results from the beginning of the experience. The operator's experience was not predictive of the composite criterion [adjusted OR 0.77; 95% (0.42, 1.40); P=0.40]. CONCLUSIONS: This study demonstrated favourable outcomes in patients treated with a fenestrated/branched aortic stent graft performed by an early-career operator trained in a high-volume centre from the beginning of independent practice.

Scientific report on the analysis of the 2-year compulsory intensified monitoring of atypical scrapie.

The European Commission asked EFSA whether the scientific data on the 2-year intensified monitoring in atypical scrapie (AS) outbreaks (2013-2020) provide any evidence on the contagiousness of AS, and whether they added any new knowledge on the epidemiology of AS. An ad hoc data set from intensified monitoring in 22 countries with index case/s of AS in sheep and/or goats (742 flocks from 20 countries, 76 herds from 11 countries) was analysed. No secondary cases were confirmed in goat herds, while 35 secondary cases were confirmed in 28 sheep flocks from eight countries. The results of the calculated design prevalence and of a model simulation indicated that the intensified monitoring had limited ability to detect AS, with no difference between countries with or without secondary cases. A regression model showed an increased, but not statistically significant, prevalence (adjusted by surveillance stream) of secondary cases in infected flocks compared with that of index cases in the non-infected flocks (general population). A simulation model of within-flock transmission, comparing a contagious (i.e. transmissible between animals under natural conditions) with a non-contagious scenario, produced a better fit of the observed data with the non-contagious scenario, in which each sheep in a flock had the same probability of developing AS in the first year of life. Based on the analyses performed, and considering uncertainties and data limitations, it was concluded that there is no new evidence that AS can be transmitted between animals under natural conditions, and it is considered more likely (subjective probability range 50-66%) that AS is a non-contagious, rather than a contagious disease. The analysis of the data of the EU intensified monitoring in atypical scrapie infected flocks/herds confirmed some of the known epidemiological features of AS but identified that major knowledge gaps still remain.

An International Comparison of the Management of Gastrointestinal Surgical Emergencies in Octogenarians-England Versus United States: A National Population-based Cohort Study.

OBJECTIVE: To compare the United States and England for the utilization of surgical intervention and in-hospital mortality from 5 gastrointestinal emergencies in octogenarians. BACKGROUND: The proportion of older adults is growing and will represent a substantial challenge to clinicians in the next decade. METHODS: Between 2006 and 2012, the rate of surgical intervention and in-hospital mortality for 5 index conditions for octogenarians were compared between the United States and England: appendicitis, incarcerated/strangulated abdominal hernia, perforation of esophagus, small or large bowel, and peptic ulcer. Univariate and multivariate analyses were performed to adjust for underlying differences in patient demographics. RESULTS: Thirty-two thousand one hundred fifty-one admissions of octogenarians in England for 5 index surgical emergencies were compared with 162,142 admissions in the USA.Surgical intervention was significantly more common in the USA than in England for all 5 conditions: appendicitis [odds ratio (OR) 4.63, 95% confidence interval (95% CI) 4.21-5.09], abdominal hernia (OR 2.06, 95% CI 1.97-2.15), perforated esophagus (OR 1.71, 95% CI 1.31-2.24), small and large bowel perforation (OR 4.33, 95% CI 4.12-4.56), and peptic ulcer perforation (OR 4.63, 95% CI 4.27-5.02). In-hospital mortality was significantly more common in England than in the USA for all 5 conditions: appendicitis (OR 3.22, 95% CI 2.73-3.78), abdominal hernia (OR 3.49, 95% CI 3.29-3.70), perforated esophagus (OR 4.06, 95% CI 3.03-5.44), small and large bowel perforation (OR 6.97, 95% CI 6.60-7.37), and peptic ulcer perforation (OR 3.67, 95% CI 3.40-3.96). CONCLUSION: Surgery is used less commonly in England for emergency gastrointestinal conditions in octogenarians, which may be associated with a high rate of in-hospital mortality from these conditions compared with the USA.

Tablet and web-based audiometry to screen for hearing loss in adults with cystic fibrosis.

INTRODUCTION: Individuals with chronic lung disease (eg, cystic fibrosis (CF)) often receive antimicrobial therapy including aminoglycosides resulting in ototoxicity. Extended high-frequency audiometry has increased sensitivity for ototoxicity detection, but diagnostic audiometry in a sound-booth is costly, time-consuming and requires a trained audiologist. This cross-sectional study analysed tablet-based audiometry (Shoebox MD) performed by non-audiologists in an outpatient setting, alongside home web-based audiometry (3D Tune-In) to screen for hearing loss in adults with CF. METHODS: Hearing was analysed in 126 CF adults using validated questionnaires, a web self-hearing test (0.5 to 4 kHz), tablet (0.25 to 12 kHz) and sound-booth audiometry (0.25 to 12 kHz). A threshold of ≥25 dB hearing loss at ≥1 audiometric frequency was considered abnormal. Demographics and mitochondrial DNA sequencing were used to analyse risk factors, and accuracy and usability of hearing tests determined. RESULTS: Prevalence of hearing loss within any frequency band tested was 48%. Multivariate analysis showed age (OR 1.127; (95% CI: 1.07 to 1.18; p value<0.0001) per year older) and total intravenous antibiotic days over 10 years (OR 1.006; (95% CI: 1.002 to 1.010; p value=0.004) per further intravenous day) were significantly associated with increased risk of hearing loss. Tablet audiometry had good usability, was 93% sensitive, 88% specific with 94% negative predictive value to screen for hearing loss compared with web self-test audiometry and questionnaires which had poor sensitivity (17% and 13%, respectively). Intraclass correlation (ICC) of tablet versus sound-booth audiometry showed high correlation (ICC >0.9) at all frequencies ≥4 kHz. CONCLUSIONS: Adults with CF have a high prevalence of drug-related hearing loss and tablet-based audiometry can be a practical, accurate screening tool within integrated ototoxicity monitoring programmes for early detection.

Editor's Choice - Assessment of Correlation Between Mean Size of Infrarenal Abdominal Aortic Aneurysm at Time of Intact Repair Against Repair and Rupture Rate in Nine Countries.

OBJECTIVE: This study aimed to analyse the mean abdominal aortic aneurysm (AAA) diameter for repair in nine countries, and to determine variation in mean AAA diameter for elective AAA repair and its relationship to rupture AAA repair rates and aneurysm related mortality in corresponding populations. METHODS: Data on intact (iAAA) and ruptured infrarenal AAA (rAAA) repair for the years 2010-2012 were collected from Denmark, England, Finland, Germany, Hungary, New Zealand, Norway, Sweden, and the USA. The rate of iAAA repair and rAAA per 100 000 inhabitants above 59 years old, mean AAA diameter for iAAA repair and rAAA repair, and the national rates of rAAA were assessed. National cause of death statistics were used to estimate aneurysm related mortality. Direct standardisation methods were applied to the national mortality data. Logistic regression and analysis of variance model adjustments were made for age groups, sex, and year. RESULTS: There was a variation in the mean diameter of iAAA repair (n = 34 566; range Germany = 57 mm, Denmark = 68 mm). The standardised iAAA repair rate per 100000 inhabitants varied from 10.4 (Hungary) to 66.5 (Norway), p<.01, and the standardised rAAA repair rate per 100 000 from 5.8 (USA) to 16.9 (England), p<.01. Overall, there was no significant correlation between mean diameter of iAAA repair and standardised iAAA rate (r2 = 0.04, p = .3). There was no significant correlation between rAAA repair rate (n = 12 628) with mean diameter of iAAA repair (r2 = 0.2, p = .1). CONCLUSION: Despite recommendations from learned society guidelines, data indicate variations in mean diameter for AAA repair. There was no significant correlation between mean diameter of AAA repair and rates of iAAA repair and rAAA repair. These analyses are subject to differences in disease prevalence, uncertainties in rupture rates, validations of vascular registries, causes of death and registrations.

An international comparison of the utilisation of and outcomes from minimal access surgery for the treatment of common abdominal surgical emergencies.

BACKGROUND: Minimal access surgery (MAS) has suggested improvements in clinical outcomes compared to open surgery in several abdominal elective and emergency surgeries. The aims of this study were to compare England with the United States in the utilisation of MAS and mortality from four common abdominal surgical emergencies. METHODS: Between 2006 and 2012, the rate of MAS and in-hospital mortality for appendicitis, incarcerated or strangulated abdominal hernia, small or large bowel and peptic ulcer perforation were compared between England and the United States. Univariate and multivariate analyses were performed to adjust for differences in baseline patient demographics. RESULTS: 132,364 admissions in England were compared to an estimated 1,811,136 admissions in the United States. Minimal access surgery was used less commonly in England for appendicitis (odds ratio (OR) 0.27, 95% CI 0.267-0.278), abdominal hernia (OR 0.16, 95% CI 0.15-0.17), small or large bowel perforation (OR 0.33, 95% CI 0.32-0.35) and peptic ulcer perforation (OR 0.93, 95% CI 0.87-0.99). In-hospital mortality was increased in England compared to the United States for all four conditions: appendicitis (OR 2.11, 95% CI 1.66-2.68), abdominal hernia (OR 3.25, 95% CI 3.10-3.40), small or large bowel perforation (OR 3.88, 95% CI 3.76-3.99) and peptic ulcer perforation (OR 3.09, 95% CI 2.94-3.25). In England, after adjustment for patient demographics, open surgery was associated with increased in-hospital mortality for abdominal hernia (OR 1.80, 95% CI 1.26-2.71), small or large bowel perforation (OR 1.59, 95% CI 1.37-1.87) and peptic ulcer perforation (OR 2.31, 95% CI 1.91-2.82). CONCLUSIONS: Minimal access surgery was performed less commonly and in-hospital mortality was increased in England compared to the United States for common abdominal surgical conditions. Therefore, strategies to enhance adoption of MAS in emergency conditions in England need to be optimised and include appropriate patient selection and improved surgeon MAS training.

Reintervention After Antireflux Surgery for Gastroesophageal Reflux Disease in England.

BACKGROUND: After antireflux surgery, highly variable rates of recurrent gastroesophageal reflux disease (GERD) have been reported. OBJECTIVE: To identify the occurrence and risk factors of recurrent GERD requiring surgical reintervention or medication. METHODS: The Hospital Episode Statistics database was used to identify adults in England receiving primary antireflux surgery for GERD in 2000 to 2012 with follow-up through 2014, and the outcome was surgical reintervention. In a subset of participants, the Clinical Practice Research Datalink was additionally used to assess proton pump inhibitor therapy for at least 6 months (medical reintervention). Risk factors were assessed using multivariable Cox regression providing adjusted hazard ratios (HRs) with 95% confidence intervals (95% CIs). RESULTS: Among 22,377 patients who underwent primary antireflux surgery in the Hospital Episode Statistics dataset, 811 (3.6%) had surgical reintervention, with risk factors being age 41 to 60 years (HR = 1.22, 95% CI 1.03-1.44), female sex (HR = 1.5; 95% CI 1.3-1.74), white ethnicity (HR = 1.71, 95% CI 1.06-2.77), and low hospital annual volume of antireflux surgery (HR = 1.32, 95% CI 1.04-1.67). Among 2005 patients who underwent primary antireflux surgery in the Clinical Practice Research Datalink dataset, 189 (9.4%) had surgical reintervention and 1192 (59.5%) used proton pump inhibitor therapy, with risk factors for the combined outcome being age >60 years (HR = 2.38, 95% CI 1.81-3.13) and preoperative psychiatric morbidity (HR = 1.58, 95% CI 1.25-1.99). CONCLUSION: At least 3.6% of patients may require surgical reintervention and 59.5% medical therapy following antireflux surgery in England. The influence of patient characteristics and hospital volume highlights the need for patient selection and surgical experience in successful antireflux surgery.

Comparison of Surgical Intervention and Mortality for Seven Surgical Emergencies in England and the United States.

OBJECTIVE: To examine differences between England and the USA in the rate of surgical intervention and in-hospital mortality for 7 index surgical emergencies. BACKGROUND: Considerable international variation exists in the configuration, provision, and outcomes of emergency healthcare. METHODS: Patients aged <80 years hospitalized with 1 of 7 surgical emergencies (ruptured abdominal aortic aneurysm, aortic dissection, appendicitis, perforated esophagus, peptic ulcer, small bowel or large bowel, and incarcerated or strangulated hernias) were identified from English Hospital Episode Statistics and the USA Nationwide Inpatient Sample (2006-2012) and classified by whether they received a corrective surgical intervention. The rates of surgical intervention and population mortality were compared between England and the USA after adjustment for patient demographic factors. RESULTS: From 2006 to 2012, there were 136,047 admissions in English hospitals and 1,863,626 admissions in US hospitals due to the index surgical emergencies.Proportion of patients receiving no surgical intervention, for all 7 conditions was greater in the England (OR 4.25, 1.55, 8.53, 1.92, 2.06, 2.42, 1.75) and population in-hospital mortality was greater in England (OR 1.34, 1.67, 2.22, 1.65, 2.7, 4.46, 3.22) for ruptured abdominal aortic aneurysm, aortic dissection, appendicitis, perforated esophagus, peptic ulcer, small bowel or large bowel, and incarcerated or strangulated hernias respectively.In England (where follow-up was available), lack of utilization of surgery was also associated with increased in-hospital and long-term mortality for all conditions. CONCLUSION: England and US hospitals differ in the threshold for surgical intervention, which may be associated with increases in mortality in England for these 7 general surgical emergencies.

A new renal inpatient nutrition screening tool (Renal iNUT): a multicenter validation study.

BACKGROUND: Screening of patients with renal disease for malnutrition risk on hospital admission provides an opportunity to improve prognosis. This study aimed to assess the validity and reliability of the Renal iNUT, a novel renal-specific inpatient nutrition screening tool. METHODS: Adult inpatient admissions to three renal units were screened using the Renal Inpatient Nutrition Screening Tool (iNUT) and the generic Malnutrition Universal Screening Tool (MUST) and compared against nutritional status using Subjective Global Assessment (SGA) as the standard. Construct validity was assessed by Handgrip Strength (HGS), reliability by repeated iNUT administration and nurse opinion by questionnaire. RESULTS: Of 141 admissions, 45% were malnourished (SGA score B or C). Using iNUT, 49% patients had increased malnutrition risk (score ≥1), 35.5% requiring dietetic referral (score ≥2). MUST indicated 20% at increased malnutrition risk and dietetic referral in 7%. iNUT was more sensitive than MUST in identifying increased malnutrition risk (92.1% vs 44.4%) and dietetic referral (69.8% vs 15.9%). Specificity of iNUT for increased risk was 82.1% and 92.3% for dietetic referral. 47% patients had sarcopenic-range HGS, with significant difference between iNUT score ≥2 and 0 (p < 0.001). iNUT reliability assessed by kappa was 0.74 (95% CI, 0.58 to 0.9), indicating substantial agreement. Nurse evaluation (n = 71) was highly favorable. CONCLUSIONS: The Renal iNUT is a valid and reliable nutrition screening tool when used by nurses admitting patients to specialist renal wards. In comparison with MUST, use of iNUT is likely to improve the identification of malnourished patients for nutritional intervention and dietetic referral.

A population-based cohort study examining the risk of abdominal cancer after endovascular abdominal aortic aneurysm repair.

OBJECTIVE: Endovascular aneurysm repair (EVAR) has increasingly been used as the primary treatment approach for abdominal aortic aneurysm (AAA). This study examined the hypothesis that EVAR leads to an increased risk of abdominal cancer within the radiation field compared with open AAA repair. METHODS: The nationwide English Hospital Episode Statistics database was used to identify all patients older than 50 years who received an AAA repair in 2005 to 2013. EVAR and open AAA repair groups were compared for the incidence of postoperative cancer using inverse probability weights and G-computation formula to adjust for selection bias and confounding. RESULTS: Among 14,150 patients who underwent EVAR and 24,645 patients who underwent open AAA repair, follow-up was up to 7 years. EVAR was associated with an increased risk of postoperative abdominal cancer (hazard ratio [HR], 1.14; 95% confidence interval [CI], 1.03-1.27) and all cancers (HR, 1.09; 95% CI, 1.02-1.17). However, there was no difference between the groups in the risk of lung cancer (HR, 1.04; 95% CI, 0.92-1.18) or obesity-related nonabdominal cancer (HR, 1.12; 95% CI, 0.69-1.83). Within the EVAR group, use of computed tomography surveillance was not associated with any increased risk of abdominal cancer (HR, 0.94; 95% CI, 0.71-1.23) or all cancers (HR, 0.97; 95% CI, 0.81-1.17). CONCLUSIONS: This study suggests an increased risk of abdominal cancer after EVAR compared with open AAA repair. The differential cancer risk should be further explored in alternative national populations, and radiation exposure during EVAR should be measured as a quality metric in the assessment of EVAR centers.

The Influence of Antireflux Surgery on Esophageal Cancer Risk in England: National Population-based Cohort Study.

OBJECTIVE: To evaluate how antireflux surgery influences the risk of esophageal cancer in patients with gastroesophageal reflux disease (GERD) and Barrett esophagus. BACKGROUND: GERD is a major risk factor for esophageal adenocarcinoma, and the United Kingdom has the highest incidence of esophageal adenocarcinoma globally. METHODS: Hospital Episode Statistics database was used to identify all patients in England aged over 18 years diagnosed with GERD with or without Barrett Esophagus from 2000 to 2012, with antireflux surgery being the exposure investigated. The Clinical Practice Research Datalink (CPRD) was used to provide a sensitivity analysis comparing proton pump inhibitor therapy and antireflux surgery. Hazard ratios (HR) with 95% confidence intervals (CI) were calculated using Cox proportional hazards model with inverse probability weights based on the probability of having surgery to adjust for selection bias and confounding factors. RESULTS: (i) Hospital Episode Statistics analysis; among 838,755 included patients with GERD and 28,372 with Barrett esophagus, 22,231 and 737 underwent antireflux surgery, respectively. In GERD patients, antireflux surgery reduced the risk of esophageal cancer (HR = 0.64; 95% CI 0.52-0.78). In Barrett esophagus patients, the corresponding HR was (HR = 0.47; 95% CI 0.12-1.90).(ii) CPRD analysis; antireflux surgery was associated with decreased point estimates of esophageal adenocarcinoma in patients with GERD (0% vs. 0.2%; P = 0.16) and Barrett esophagus (HR = 0.75; 95% CI 0.21-2.63), but these were not statistically significant. CONCLUSION: Antireflux surgery may be associated with a reduced risk of esophageal cancer risk, however it remains primarily an operation for symptomatic relief.

Thresholds for Abdominal Aortic Aneurysm Repair in England and the United States.

BACKGROUND: Thresholds for repair of abdominal aortic aneurysms vary considerably among countries. METHODS: We examined differences between England and the United States in the frequency of aneurysm repair, the mean aneurysm diameter at the time of the procedure, and rates of aneurysm rupture and aneurysm-related death. Data on the frequency of repair of intact (nonruptured) abdominal aortic aneurysms, in-hospital mortality among patients who had undergone aneurysm repair, and rates of aneurysm rupture during the period from 2005 through 2012 were extracted from the Hospital Episode Statistics database in England and the U.S. Nationwide Inpatient Sample. Data on the aneurysm diameter at the time of repair were extracted from the U.K. National Vascular Registry (2014 data) and from the U.S. National Surgical Quality Improvement Program (2013 data). Aneurysm-related mortality during the period from 2005 through 2012 was determined from data obtained from the Centers for Disease Control and Prevention and the U.K. Office of National Statistics. Data were adjusted with the use of direct standardization or conditional logistic regression for differences between England and the United States with respect to population age and sex. RESULTS: During the period from 2005 through 2012, a total of 29,300 patients in England and 278,921 patients in the United States underwent repair of intact abdominal aortic aneurysms. Aneurysm repair was less common in England than in the United States (odds ratio, 0.49; 95% confidence interval [CI], 0.48 to 0.49; P<0.001), and aneurysm-related death was more common in England than in the United States (odds ratio, 3.60; 95% CI, 3.55 to 3.64; P<0.001). Hospitalization due to an aneurysm rupture occurred more frequently in England than in the United States (odds ratio, 2.23; 95% CI, 2.19 to 2.27; P<0.001), and the mean aneurysm diameter at the time of repair was larger in England (63.7 mm vs. 58.3 mm, P<0.001). CONCLUSIONS: We found a lower rate of repair of abdominal aortic aneurysms and a larger mean aneurysm diameter at the time of repair in England than in the United States and lower rates of aneurysm rupture and aneurysm-related death in the United States than in England. (Funded by the Circulation Foundation and others.).

The impact of endovascular aneurysm repair on mortality for elective abdominal aortic aneurysm repair in England and the United States.

BACKGROUND: Procedural mortality is of paramount importance for patients undergoing elective abdominal aortic aneurysm (AAA) repair. Previous comparative studies have demonstrated international differences in the care of ruptured AAA. This study compared the use of endovascular aneurysm repair (EVAR) and in-hospital mortality for elective AAA repair in England and the United States. METHODS: The English Hospital Episode Statistics and the U.S. Nationwide Inpatient Sample (NIS) were interrogated for elective AAA repair from 2005 to 2010. In-hospital mortality and the use of EVAR were analyzed separately for each health care system, after within-country risk adjustment for age, gender, year, and an accepted national comorbidity index. RESULTS: The study included 21,272 patients with AAA in England, of whom 86.61% were male, with median (interquartile range) age of 74 (69-79) years. There were 196,113 AAA patients in the United States, of whom 76.14% were male, with median (interquartile range) age of 73 (67-78) years. In-hospital mortality was greater in England (4.09% vs 1.96 %; P < .01) and EVAR less common (37.33% vs 64.36%; P < .01). These observations persisted in age- and gender-matched comparison. In both countries, lower mortality and greater use of EVAR were seen in centers performing greater numbers of AAA repairs per annum. In England, lower mortality and greater use of EVAR were seen in teaching hospitals with larger bed capacity. CONCLUSIONS: In-hospital survival and the uptake of EVAR are lower in England than in the United States. In both countries, mortality was lowest in high-caseload centers performing a greater proportion of cases with endovascular repair. These common factors suggest strategies for improving outcomes for patients requiring elective AAA repair.

Predicting Mid-term All-cause Mortality in Patients Undergoing Elective Endovascular Repair of a Descending Thoracic Aortic Aneurysm.

INTRODUCTION: All-cause mortality in patients after repair of aortic aneurysms of the descending thoracic aorta thoracic endovascular aortic repair (TEVAR) is relatively high at mid-term follow-up. The aim of this study was to derive and validate a system that could predict all-cause mortality after TEVAR to aid with patient selection. METHODS: The MOTHER database contained 625 patients that underwent elective surgery for descending thoracic aortic aneurysms. Univariate analysis identified preoperative factors associated with mid-term all-cause mortality, and a Cox proportional hazards model was developed. The model was internally validated using Kaplan-Meier comparison of observed vs predicted mortality. External validation was performed using a data set from the University of Florida College of Medicine. RESULTS: There were 625 patients that underwent TEVAR for descending thoracic aortic aneurysm in the MOTHER database and 231 in the University of Florida College of Medicine validation set. The mid-term mortality rate at 6 years of follow-up was 34.4% and 34%, respectively. The all-cause mortality risk score was calculated using 0.0398 × (age) + 0.516 × (renal insufficiency) + 0.46 × (previous cerebrovascular disease) + 0.352 × (prior tobacco use) + 0.376 × (number of devices >2) + 0.016 × (maximum aneurysm diameter). Using this score, low-, medium-, and high-risk groups were defined, with predicted survival at 5 years of 80%, 60%, and 40%. Patients at high risk of mid-term all-cause death were identified in the validation cohort using the prediction rule. CONCLUSIONS: Identifying patients with a limited life expectancy after TEVAR is possible using a preoperative risk-stratification system. This information can be used to inform decision making regarding when and whether to proceed with TEVAR.

An Artificial Neural Network Stratifies the Risks of Reintervention and Mortality after Endovascular Aneurysm Repair; a Retrospective Observational study.

BACKGROUND: Lifelong surveillance after endovascular repair (EVAR) of abdominal aortic aneurysms (AAA) is considered mandatory to detect potentially life-threatening endograft complications. A minority of patients require reintervention but cannot be predictively identified by existing methods. This study aimed to improve the prediction of endograft complications and mortality, through the application of machine-learning techniques. METHODS: Patients undergoing EVAR at 2 centres were studied from 2004-2010. Pre-operative aneurysm morphology was quantified and endograft complications were recorded up to 5 years following surgery. An artificial neural networks (ANN) approach was used to predict whether patients would be at low- or high-risk of endograft complications (aortic/limb) or mortality. Centre 1 data were used for training and centre 2 data for validation. ANN performance was assessed by Kaplan-Meier analysis to compare the incidence of aortic complications, limb complications, and mortality; in patients predicted to be low-risk, versus those predicted to be high-risk. RESULTS: 761 patients aged 75 +/- 7 years underwent EVAR. Mean follow-up was 36+/- 20 months. An ANN was created from morphological features including angulation/length/areas/diameters/volume/tortuosity of the aneurysm neck/sac/iliac segments. ANN models predicted endograft complications and mortality with excellent discrimination between a low-risk and high-risk group. In external validation, the 5-year rates of freedom from aortic complications, limb complications and mortality were 95.9% vs 67.9%; 99.3% vs 92.0%; and 87.9% vs 79.3% respectively (p<0.001). CONCLUSION: This study presents ANN models that stratify the 5-year risk of endograft complications or mortality using routinely available pre-operative data.

Comparison of aortic diameter and area after endovascular treatment of aortic dissection.

BACKGROUND: Different methods have been used to assess remodeling of the thoracic aorta after endovascular treatment of Stanford type B aortic dissections. Changes in morphology may be described using diameter, area, or volume. The aim of this study was to determine if aortic diameter measurements could be used to approximate aortic area in order to refine reporting standards. METHODS: The study population encompassed 100 patients enrolled in the VIRTUE registry (designed to assess thoracic endografting with the Valiant Stent Graft System [Medtronic, Minneapolis, MN] for the treatment of type B aortic dissections). Diameter and area measurements of the true lumen, false lumen, and whole aorta were made using three-dimensional computed tomographic (3D CT) workstations, at different anatomic locations. Measurements included preoperative, postoperative, and follow-up scans. The Pearson test was used to determine general correlation between diameter and volume at each location. Scatter plots were drawn and linear regression models were used to draw a line of best fit. Comparison of these with nonlinear models was performed. RESULTS: Aortic true and false lumen diameter and area showed good correlation (p < 0.001) in the majority of anatomic locations. This relationship was present preoperatively and during follow-up (p < 0.001). The linear regression models fit well with high R(2) values. At very large aortic sizes nonlinear models were a slightly better fit, but this was not significant. CONCLUSIONS: Aortic diameter measurements correlate with luminal areas in patients with type B aortic dissection. This implies area increases proportionately with diameter over time. Therefore, diameter measurements using multiplanar reconstructions based on a central luminal line appear to be adequate when assessing aortic remodeling after endovascular treatment of aortic dissection.

Impact of processing on the bioavailability and vascular effects of blueberry (poly)phenols.

SCOPE: Blueberries are a rich source of flavonoids and phenolic acids. Currently, little information is available regarding the impact of processing on the bioavailability and the bioactivity of blueberry (poly)phenols. METHODS AND RESULTS: In a randomized, controlled crossover trial, ten healthy volunteers consumed (a) blueberry-containing baked products, (b) an unprocessed blueberry drink containing the same amount of freeze-dried blueberry powder as used in the baked products, and (c) matched control baked products. Endothelial function was measured as flow-mediated dilation (FMD) and plasma samples taken at baseline and at 1, 2, 4, and 6 h postconsumption. Although processing did not significantly change the total (poly)phenolic amount, the processed products contained significantly less anthocyanins (-42%), more chlorogenic acid (23%), no flavanol nonamers or decamers, and significantly more flavanol dimers and trimers (36% and 28%, respectively). FMD increased after 1, 2, and 6 h consumption of the baked products to a similar degree as the unprocessed blueberries, despite significant differences in the levels of individual plasma metabolites. No changes were observed after the consumption of the control product. CONCLUSION: Careful processing can preserve important biological activities of blueberries despite changing the blueberry (poly)phenol composition and plasma metabolite profile.

Mortality from ruptured abdominal aortic aneurysms: clinical lessons from a comparison of outcomes in England and the USA.

BACKGROUND: The outcome of patients with ruptured abdominal aortic aneurysm (rAAA) varies by country. Study of practice differences might allow the formulation of pathways to improve care. METHODS: We compared data from the Hospital Episode Statistics for England and the Nationwide Inpatient Sample for the USA for patients admitted to hospital with rAAA from 2005 to 2010. Primary outcomes were in-hospital mortality, mortality after intervention, and decision to follow non-corrective treatment. In-hospital mortality and the rate of non-corrective treatment were analysed by binary logistic regression for each health-care system, after adjustment for age, sex, year, and Charlson comorbidity index. FINDINGS: The study included 11,799 patients with rAAA in England and 23,838 patients with rAAA in the USA. In-hospital mortality was lower in the USA than in England (53·05% [95% CI 51·26-54·85] vs 65·90%; p<0·0001). Intervention (open or endovascular repair) was offered to a greater proportion of cases in the USA than in England (19,174 [80·43%] vs 6897 [58·45%]; p<0·0001) and endovascular repair was more common in the USA than in England (4003 [20·88%] vs 589 [8·54%]; p<0·0001). Postintervention mortality was similar in both countries (41·77% for England and 41·65% for USA). These observations persisted in age-matched and sex-matched comparisons. In both countries, reduced mortality was associated with increased use of endovascular repair, increased hospital caseload (volume) for rAAA, high hospital bed capacity, hospitals with teaching status, and admission on a weekday. INTERPRETATION: In-hospital survival from rAAA, intervention rates, and uptake of endovascular repair are lower in England than in the USA. In England and the USA, the lowest mortality for rAAA was seen in teaching hospitals with larger bed capacities and doing a greater proportion of cases with endovascular repair. These common factors suggest strategies for improving outcomes for patients with rAAA. FUNDING: None.

A generalization of Chao's estimator for covariate information.

This note generalizes Chao's estimator of population size for closed capture-recapture studies if covariates are available. Chao's estimator was developed under unobserved heterogeneity in which case it represents a lower bound of the population size. If observed heterogeneity is available in form of covariates we show how this information can be used to reduce the bias of Chao's estimator. The key element in this development is the understanding and placement of Chao's estimator in a truncated Poisson likelihood. It is shown that a truncated Poisson likelihood (with log-link) with all counts truncated besides ones and twos is equivalent to a binomial likelihood (with logit-link). This enables the development of a generalized Chao estimator as the estimated, expected value of the frequency of zero counts under a truncated (all counts truncated except ones and twos) Poisson regression model. If the regression model accounts for the heterogeneity entirely, the generalized Chao estimator is asymptotically unbiased. A simulation study illustrates the potential in gain of bias reduction. Comparisons of the generalized Chao estimator with the homogeneous zero-truncated Poisson regression approach are supplied as well. The method is applied to a surveillance study on the completeness of farm submissions in Great Britain.