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The Sinha laboratory has developed protocols for differentiating human pluripotent stem cells (hPSCs) into vascular smooth muscle cells along developmental lineage-specific pathways. In development, paraxial mesoderm (PM), lateral plate mesoderm (LM) and neural crest (NC) linages each give rise to smooth muscle cells significant in a location-specific manner. Induced PSCs derived from patients enduring disease provide a platform from which disease-relevant cell models can be established in the laboratory. Here we describe a robust protocol for differentiating hPSCs into vascular smooth muscle cells via a neural crest lineage and the control steps required to ensure consistently high-quality differentiated cells.

Objectives A short-stay endovascular aneurysm repair (SS-EVAR) pathway for infrarenal abdominal aortic aneurysms offers the potential to improve service efficiency and patient satisfaction by reducing the hospital length of stay. This study aimed to determine whether the implementation of a novel set of patient selection criteria for a theoretical SS-EVAR pathway could facilitate an expansion of the proportion of suitable patients, whilst maintaining patient safety and limiting unplanned emergency readmissions. Methods Two SS-EVAR selection criteria (low and high risk) were generated based upon patient pre-operative comorbidities. The low risk criteria essentially selected fit and healthy individuals, whereas the high risk criteria included patients with a range of comorbidities that could still theoretically enable enrolment onto a SS-EVAR pathway. A retrospective analysis, whereby both criteria were applied to all elective EVARs recorded in the National Vascular Registry between 2013 and 2016 at a single tertiary vascular unit was performed. Rates and timings of postoperative complications, reinterventions and unplanned readmissions for patients meeting each criteria were assessed. Results In total, 188 patients were included (92% male, mean age 75.4 ± 7.2 years). Twenty-nine patients (15%) met the low risk criteria. Two (7%) of these experienced an inpatient complication which were both detected within 24 h of operation (including one who required reintervention), and no patients in this group had an unplanned readmission within 30 days. One-hundred and ten patients (59%) met our high risk criteria and 19 (17%) experienced an inpatient complication, with 4 (4%) of these occurring beyond 24 h post-EVAR (three urinary problems and one acute on chronic kidney injury). Six (6%) of these patients required a reintervention; however, all of these complications were detected within 24 h. Two (2%) high risk cohort patients required unplanned readmission within 30 days for a femoral pseudoaneurysm and musculoskeletal back pain. Conclusions With high risk patient selection criteria and appropriate post-operative safeguards, up to 60% of infrarenal abdominal aortic aneurysms patients could be safely enrolled onto a next-day discharge SS-EVAR pathway with minimal readmissions, thus allowing more effective resource utilisation.

Background The treatment of juxtarenal abdominal aortic aneurysms is challenging. Open surgical repair is not a viable option for many patients. The use of endovascular aneurysm sealing (EVAS) with chimney grafts (Ch-EVAS) has been proposed as an immediately available, off-the-shelf option for individuals with juxtarenal aneurysms who require urgent treatment or are unsuitable for fenestrated or branched devices. This study reports the outcomes from our first patients to undergo this procedure. Methods Data were collected prospectively for 62 consecutive patients undergoing Ch-EVAS at our institution. The procedures were undertaken for intact juxtarenal or suprarenal aneurysms in patients who were unfit for open repair or needed urgent treatment or when the aneurysm morphology was unsuitable for treatment with fenestrated or branched endografts. Results Between July 2013 and June 2016, there were 62 patients who were treated with Ch-EVAS; 77.4% were male, and the mean age was 73.9 years. Median aneurysm diameter was 64.5 mm. Eight suprarenal aneurysms were treated, with three chimney grafts. Of 54 juxtarenal aneurysms treated, 21 cases used two chimney grafts and 33 cases used one chimney graft. Median follow-up was 407 days. Eleven patients underwent reintervention. There were five type IA endoleaks, all successfully treated. One type IB and one type II endoleak occurred, neither requiring treatment. There were four minor strokes. Chimney patency is 97%. Conclusions These results in a group of high-risk patients suggest that Ch-EVAS is a viable alternative to custom-made devices in patients who are unfit for open surgery. Longer term follow-up and data from the international registry will determine the widespread applicability and durability of this technique.

Background Aortitis is a heterogeneous rare condition causing aortic inflammation, often due to infectious or autoimmune aetiology. Its presentation, diagnosis and optimal management remain poorly understood, often requiring multidisciplinary input. With the advent of improved imaging techniques, an increasing number of radiology reports are identifying features of vasculitis necessitating clinical investigation. We investigated how cases identified on imaging with features of aortitis reflected clinical diagnosis and treatment. We further examined whether radiological detection of aortitis enables more rapid management decisions to improve outcomes. Methods A search was conducted of all radiology reports from St George’s Hospital between 2008 and 2018 for key words indicating “aortitis”, including ‘hyperintense vessel uptake’ and ‘periaortic inflammation.’ From 15,963 initial results, 80 reports were identified with radiological suspicion of aortitis. Results Of 80 cases, 36/80 were diagnosed with autoimmune or idiopathic inflammatory pathology: 9 retroperitoneal fibrosis, 8 idiopathic, 7 Takayasu’s, 4 giant cell arteritis, 2 inflammatory aneurysms, 2 Behçet's, 2 IgG4 disease, 1 lupus, 1 granulomatosis with polyangiitis. Diagnosis of autoimmune or idiopathic aortitis was based on symptomatology, imaging, serology, vessel biopsy, and treatment response. 14/80 had infective aortitis: 11 had positive microbiology and 3 demonstrated empirical antibiotic response. Table 1 shows demographics. 12/80 had atheromatous disease. 18/80 were not further investigated due to comorbidity, lack of correlation with symptoms, or absence of follow-up. Initial imaging modalities with the highest yield were computed tomography (CTs) with aorta protocols and CTs of thorax/abdomen/pelvis. The most useful radiology report terms included: aortitis, periaortic inflammation, Takayasu’s, and hyperintense vessel uptake. Conclusion Our study is the first retrospective case analysis, to our knowledge, of more than 15,000 radiology reports used as a starting point to evaluate for aortitis, identifying a large dataset with a broad case-mix. It contrasts with current literature identifying cases histologically and post-operatively. We found that radiology can be a useful early alert for possible diagnoses which require further assessment. Consequently, we developed an alerting system within our radiology department based on the search terms and imaging modalities identified. This links to a multidisciplinary meeting including vascular and rheumatology, so highlighted cases are discussed early. Disclosures K. Townsend: None. G. Cattini: None. K. Moss: None. K. Stenson: None. P. Holt: None. R. Morgan: None. N. Sofat: None.

Background Duplex ultrasonography (DUS) currently has limited applicability in the diagnosis and surveillance of thoracic aortic pathologies because of associated limitations. This study investigates the feasibility of using an optimised DUS protocol to detect descending thoracic aortic pathology. Methods This was a prospective, case control cohort study. Patients with computed tomography (CT) confirmed thoracic aortic pathology underwent DUS of the thoracic aorta. A control group known to have no thoracic pathology also underwent DUS. The sonographer performing DUS was blinded to the CT findings, and recorded the presence of pathology or any dilated aortic segment where visualised. Diameter cutoff points of 35 mm and 40 mm were compared. Results Forty patients were scanned (20 cases and 20 controls). All patients but one had a technically adequate assessment of the thoracic aorta (at least one view of the descending thoracic aorta). Using a size threshold of 40 mm, 16 out of 19 cases and two out of 20 control patients would have been recommended for definitive imaging. Using a cutoff of 35 mm, this became 18 out of 19 cases and six of 20 controls. Sensitivity and specificity were 100% and 70% for a threshold of 35 mm, and 84% and 90% for a threshold of 40 mm. Conclusions DUS has the potential to be used as a diagnostic modality for thoracic aortic pathology, and may have a role in surveillance for some patients for whom CT scanning is contraindicated. Further validation and refinements to this technique are required. However, this study provides proof of concept.

Background: Current surveillance protocols after endovascular aneurysm repair (EVAR) are ineffective and costly. Stratifying surveillance by individual risk of reintervention requires an understanding of the factors involved in developing post-EVAR complications. This systematic review assessed risk factors for reintervention after EVAR and proposals for stratified surveillance. Methods: A systematic search according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines was performed using EMBASE and MEDLINE databases to identify studies reporting on risk factors predicting reintervention after EVAR and proposals for stratified surveillance. Results: Twenty-nine studies reporting on 39 898 patients met the primary inclusion criteria for reporting predictors of reintervention or aortic complications with or without suggestions for stratified surveillance. Five secondary studies described external validation of risk scores for reintervention or aortic complications. There was great heterogeneity in reporting risk factors identified at the pre-EVAR, intraoperative, and post-EVAR stages of treatment, although large preoperative abdominal aortic aneurysm diameter was the most commonly observed risk factor for reintervention after EVAR. Conclusion: Existing data on predictors of post-EVAR complications are generally of poor quality and largely derived from retrospective studies. Few studies describing suggestions for stratified surveillance have been subjected to external validation. There is a need to refine risk prediction for EVAR failure and to conduct prospective comparative studies of personalized surveillance with standard practice.

This review analyzed the incidence, mechanisms, and risk factors of aortic-related reintervention after endovascular repair of chronic dissections. The systematic review identified 28 studies describing 1,249 patients at median 27 months follow-up (range, 10.3 to 64.4). There were six reinterventions, 0.7 ruptures, and 1.2 surgical conversions per 100 patient-years of follow-up. Stent-related reinterventions were more frequent than nonstent related (80.2% vs 19.8%). Distal false lumen perfusion was the most common complication (40.5%). No individual risk factor-treatment timing, disease extent, covered aorta length, or remodelling-was associated with reintervention. Further investigation based on consistent reporting standards is required.

Elective repair of thoracic aortic aneurysms is a prophylactic procedure performed when the risk of aneurysm rupture is judged to outweigh perioperative risk. It has been demonstrated that mortality because of any cause in the 5 years after repair in frail surgical candidates is high, despite the fact that perioperative mortality is relatively favorable and aortic-related death is reduced.1,2 Patient selection, therefore, is vital if survival gains are to be achieved through elective repair of thoracic aneurysms. Preoperative factors are known to affect life expectancy after surgery, but the effect of perioperative complications on subsequent survival has not been reported. Patients undergoing elective thoracic aneurysm repair for thoracic aortic aneurysm from the updated MOTHER (Medtronic Thoracic Endovascular Registry) were studied, which comprises 7 clinical trials and 1 institutional series.3 Subjects with aneurysmal chronic aortic dissection were excluded. Perioperative complications were classified as neurological, cardiac, renal, respiratory, or access vessel-related. For all clinical trials, adverse events were reported via the trial data-collection process and were adjudicated by a review panel according to trial protocol. For the St George’s Vascular Institute cohort, all adverse events were reviewed …

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

Background Emergency abdominal surgery is associated with poor patient outcomes. We studied the effectiveness of a national quality improvement (QI) programme to implement a care pathway to improve survival for these patients. Objectives The objectives were to assess whether or not the QI programme improves 90-day survival after emergency abdominal surgery; to assess effects on 180-day survival, hospital stay and hospital readmission; and to better understand these findings through an integrated process evaluation, ethnographic study and cost-effectiveness analysis. Design This was a stepped-wedge cluster randomised trial. Hospitals were organised into 15 geographical clusters, and commenced the QI programme in random order over 85 weeks. Analyses were performed on an intention-to-treat basis. The primary outcome was analysed using a mixed-effects parametric survival model, adjusting for time-related effects. Ethnographic and economics data were collected in six hospitals. The process evaluation included all hospitals. Setting The trial was set in acute surgical services of 93 NHS hospitals. Participants Patients aged ≥ 40 years who were undergoing emergency abdominal surgery were eligible. Intervention The intervention was a QI programme to implement an evidence-based care pathway. Main outcome measures The primary outcome measure was mortality within 90 days of surgery. Secondary outcomes were mortality within 180 days, length of hospital stay and hospital readmission within 180 days. The main economic measure was the quality-adjusted life-years. Data sources Data were obtained from the National Emergency Laparotomy Audit database; qualitative interviews and ethnographic observations; quality-of-life and NHS resource use data were collected via questionnaires. Results Of 15,873 eligible patients from 93 NHS hospitals, primary outcome data were analysed for 8482 participants in the usual care group and 7374 in the QI group. The primary outcome occurred in 1393 participants in the usual care group (16%), compared with 1210 patients in the QI group (16%) [QI vs. usual care hazard ratio (HR) 1.11, 95% confidence interval (CI) 0.96 to 1.28]. No differences were found in mortality at 180 days or hospital readmission; there was a small increase in hospital stay in the QI group (HR for discharge 0.90, 95% CI 0.83 to 0.97). There were only modest improvements in care processes following QI implementation. The ethnographic study revealed good QI engagement, but limited time and resources to implement change, affecting which processes teams addressed, the rate of change and eventual success. In some sites, there were challenges around prioritising the intervention in busy environments and in obtaining senior engagement. The intervention is unlikely to be cost-effective at standard cost-effectiveness thresholds, but may be cost-effective over the lifetime horizon. Limitations Substantial delays were encountered in securing data access to national registries. Fewer patients than expected underwent surgery and the mortality rate was lower than anticipated. Conclusions There was no survival benefit from a QI programme to implement a care pathway for patients undergoing emergency abdominal surgery. The modest impact of the intervention on process measures, despite good clinician engagement, may have been limited by the time and resources needed to improve patient care. Future work Future QI programmes must balance intervention complexity with the practical realities of NHS services to ensure that such programmes can be delivered with the resources available. Trial registration Current Controlled Trials ISRCTN80682973 and The Lancet protocol 13PRT/7655. Funding This project was funded by the National Institute for Health Research (NIHR) Health Services and Delivery Research programme and will be published in full in Health Services and Delivery Research; Vol. 7, No. 32. See the NIHR Journals Library website for further project information.

INTRODUCTION Short stay endovascular aneurysm repair pathways (SS-EVAR) provide potential advantages to both healthcare providers and patients. However, these benefits must be carefully balanced against the inherent risks to patient safety and tariff penalties associated with unplanned readmissions. EVIDENCE ACQUISITION A literature review was performed using the databases MEDLINE, Embase and Cochrane Library up until March 2019. Search terms used included "endovascular aneurysm repair," "aneurysm repair," "EVAR," "abdominal aortic aneurysm," "day case," "short stay," "fast track," and "ambulatory." EVIDENCE SYNTHESIS Nine relevant articles (including one prior review on the topic) were identified. This early data suggests that SS-EVAR is associated with good patient satisfaction and modest cost savings for healthcare providers. Patient selection, preoperative preparation and supported discharge with early follow-up are essential components of a SS-EVAR pathway. Increasingly, SS-EVAR tends to be delivered via bilateral percutaneous access and loco-regional anesthesia. Over 70% of patients enrolled onto SS-EVAR pathways successfully complete them. Long procedures with excessive blood loss are associated with pathway non-completion. All serious complications occur within 6 hours of the procedure and the mortality (0-1%), morbidity (8-58%) and readmission rates (0-6%) associated with SS-EVAR remains acceptably low. SS-EVAR pathways can be safely and effectively implemented in both teaching and non-teaching hospitals. CONCLUSIONS Short-stay EVAR pathways are safe and acceptable to patients. With appropriate selection of motivated patients, successful expedited discharge can be achieved with limited readmissions, thus facilitating increased resource efficiency and cost savings for healthcare providers.

To compare the United States and England for the utilization of surgical intervention and in-hospital mortality from 5 gastrointestinal emergencies in octogenarians.The proportion of older adults is growing and will represent a substantial challenge to clinicians in the next decade.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.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).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.

OBJECTIVE: Surveillance imaging is considered mandatory after endovascular aneurysm repair (EVAR), but many patients are lost to follow up and the impact of this is poorly understood. This study aimed to examine compliance with post-operative surveillance in the UK and the impact of mal-/non-compliance on endograft re-interventions and survival. METHODS: EVAR-SCREEN centres reported EVAR for intact infrarenal abdominal aortic aneurysms (AAA) from 1 January 2007 to 31 December 2010, with follow up included up to 31 July 2014. Non-compliance was defined by the presence of a single 18 month period in which no surveillance imaging was performed. The outcomes were reported in compliant and non-compliant groups with survival analysis. RESULTS: EVAR was performed in 1414 patients in 10 UK centres. At the end of the study period there were 378 patients with five years of follow up available for analysis. Compliance with surveillance was 66% (61-68%). Compliance varied widely, from 9% to 88% between centres. Age (hazard ratio [HR] 1.03, 95% confidence interval [CI] 1.01-1.05; p = .02) and distance from hospital (HR 1.01, 95% CI 1.00-1.01; p

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.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.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 (rDespite 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.

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

Background Surveillance is mandatory for all patients with a thoracic aortic aneurysm (TAA). The frequency of surveillance imaging, however, is not evidence-based, as few data exist regarding TAA growth rates. This study aimed to determine the rate of TAA expansion and to inform surveillance intervals based on TAA diameter. Methods Patients with a TAA for whom morphological data were available from serial CT scans were studied. Annualized growth rates based on diameter at presentation and time taken to reach a theoretical intervention threshold of 55 mm were calculated. The number of patients who would have achieved the threshold undetected was determined based on simulated imaging intervals of 6 months, 1, 2 and 3 years. Results A total of 2916 scans from 995 patients were analysed. The mean aortic expansion rate was 2·76 mm per year for all patients, with an exponential increase observed at sizes above 45 mm. Only 3·9 per cent of patients with a starting diameter of 30–39 mm and 5·3 per cent of those with a diameter of 40–44 mm achieved threshold size within 2 years. Conversely, the probability of expansion to more than 55 mm was 74·5 per cent in 2 years for patients with a starting diameter of 50–54 mm, rising to 85·7 per cent at 3 years. Conclusion Based on a threshold of 55 mm for intervention, most patients with a maximum aortic diameter below 40 mm could safely undergo surveillance at 2-yearly intervals. Above 45 mm, annual surveillance is recommended. Patients with a diameter greater than 50 mm could be optimized for possible repair, if this is clinically appropriate.

Background Perioperative mortality is low for patients undergoing abdominal aortic aneurysm (AAA) repair, but long-term survival remains poor. Although patients diagnosed with AAA have a significant burden of cardiovascular disease and associated risk factors, there is limited understanding of the contribution of cardiovascular risk management to long-term survival. Methods General practice records within The Health Improvement Network (THIN) were examined. Patients with a diagnosis of AAA and at least 1 year of registered medical history were identified from 2000 to 2012. Medical therapies for cardiovascular risk were classified as antiplatelet, statin or antihypertensive agents. Progression to death was investigated using the G-computation formula with time-dependent co-variables to account for differences in exposure to cardiovascular risk-modifying treatments and the confounding between exposure, co-morbidities and death. Results Some 12 485 patients had a recorded diagnosis of AAA. From 2000 to 2012, prescription of medications that modify cardiovascular risk increased: from 26·6 to 76·7 per cent for statins, from 56·5 to 73·9 per cent for antiplatelet agents and from 75·3 to 84·0 per cent for antihypertensive drugs. Adjusted Kaplan–Meier curves demonstrated a better 5-year survival rate in patients receiving statins (68·4 versus 42·2 per cent), antiplatelet agents (63·6 versus 39·7 per cent) or antihypertensive agents (61·5 versus 39·1 per cent), compared with rates in patients not receiving each therapy. Conclusion Appropriate risk factor modification could significantly reduce long-term mortality in patients with AAA. In the UK, up to 30 per cent of patients are not currently receiving these medications.

Background The respective place of endovascular repair (ER) versus open surgery (OS) in thoracic dissecting aneurysm treatment remains debatable. This comprehensive review seeks to compare the outcomes of ER versus OS in chronic type B aortic dissection treatment. Methods Embase and Medline searches (2000 to 2017) were performed following PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analyses) guidelines. Outcomes data extracted comprised (1) early mortality and major complications: stroke, spinal cord ischemia (SCI), dialysis, and respiratory complications; and (2) late survival and reinterventions. Reintervention causes were divided into proximal, adjacent, and distal. Comparative studies allowed comparative meta-analysis. Noncomparative studies were analyzed in pooled proportion meta-analyses for each group. Results A total of 39 studies were identified after exclusions, of which 4 were comparative. Comparative meta-analysis demonstrated lower early mortality for ER (odds ratio [OR], 4.13; 95% confidence interval [CI], 1.10 to 15.4), stroke (OR, 4.33; 95% CI, 1.02 to 18.35), SCI (OR, 3.3; 95% CI, 0.97 to 11.25), and respiratory complications (OR, 6.88; 95% CI,1.52 to 31.02), but higher reintervention rate (OR, 0.34; 95% CI, 0.16 to 0.69). Midterm survival was similar (OR, 1.19; 95% CI, 0.42 to 3.32). Noncomparative studies demonstrated that most reinterventions were related to the aortic segment distal to primary intervention in both groups (OS 73%, ER 59%). Reintervention procedures were mainly surgical for OS (85%), mainly endovascular for ER (75%). Rupture rates were 1.2% (OS) and 3% (ER). Conclusions Endovascular repair is associated with significant early benefits, but this is not sustained at midterm. Reintervention is more frequent, but the OS is not exempt from reintervention or late rupture. Both techniques have their place, but patient selection is key.

Background Endovascular aneurysm sealing (EVAS) is a disruptive technology to treat abdominal aortic aneurysm (AAA). The use of sac filling rather than endograft fixation was designed to treat aortic aneurysms in a wide range of morphologic appearances and to reduce endoleaks. There are few data reporting outcomes beyond postoperative follow-up. This study reports outcomes up to 5 years for Nellix (Endologix, Irvine, Calif) EVAS. Methods Data were prospectively collected for EVAS patients from the time of adoption of EVAS in 2013. All patients treated with the Nellix device are included in this study, and as such, it reports on infrarenal, ruptured, and iliac aneurysms as well as the Nellix-in-Nellix application. Juxtarenal and suprarenal aneurysms were treated using the EVAS system with parallel grafts into the visceral vessels and are included. Therapeutic failure, a composite outcome of migration, sac expansion >5 mm, type Ia and type Ib endoleak, and secondary aortic rupture, was the primary outcome along with all-cause mortality, aneurysm-related mortality, and reintervention rates. Results There were 295 EVAS cases undertaken between March 2013 and July 2018. Indications for treatment were infrarenal (n = 185), juxtarenal and suprarenal (n = 73), ruptured (n = 18), and iliac (n = 13) aneurysms. There were 15 reinterventions using the Nellix-in-Nellix application. In some cases, EVAS was used to salvage failing endovascular or open aneurysm repairs. Median follow-up was 2.42 years (interquartile range, 1.07-3.57 years). Therapeutic failure was observed in 98 of the 295 cases (33.2%) overall and exceeded 50% in some subgroups. In 71 cases (24.1%), reintervention was performed, with reasons for no reintervention being mainly physiologic. Complications leading to therapeutic failure were most commonly seen beyond 2 years of follow-up. There were 15 secondary ruptures (5.36%), and 9 EVAS devices required explantation either electively or for aortic rupture. Conclusions EVAS with the Nellix device has not met expectations, and early encouraging results have been eroded. The incidence of therapeutic failure has been high, occurring 2 years and beyond after implantation. The Nellix system has been voluntarily recalled by Endologix, and the CE mark has subsequently been suspended. The adoption of EVAS as a disruptive technology highlights the need for cautious adoption of novel technologies and the strict governance around such arrangements.

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.

Objective Reducing length of stay (LOS) following surgery offers the potential to improve resource utilisation. Endovascular aneurysm repair (EVAR) is now delivered with a low level of morbidity and as such may be deliverable as a “23 hour stay” intervention. This systematic review aims to assess safety, feasibility and cost effectiveness of a short stay EVAR pathway. Methods A database search of Ovid MEDLINE (1996 – April 2018) and Embase (1974 – April 2018) was completed. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were used. A Newcastle–Ottawa Scale was applied to assess study bias. Results In total, 570 papers were identified through the literature search, of which 32 abstracts were screened. This led to nine papers being assessed for eligibility. From five suitable studies, 450 (75%) patients were successfully discharged the same or next day after EVAR. Complications most often occurred within 3 hours of surgery, and major complications requiring intensive treatment unit admission occurred within 6 hours. Readmission rates were 0–5% for those discharged early, with no difference in 30 day readmission. Early discharge led to a statistically significant cost saving of £13,360 (LOS four days) to £9844 (LOS one day). Conclusion Selected patients can safely undergo EVAR using a short stay pathway. A period of monitoring 6 h post-operatively for low risk patients would be sufficient. Reducing length of stay after EVAR in the UK from the current median of three days to 1.5 days would free 4361 bed days and lead to a saving of approximately £1,800,000 annually.

Annual procedural mortality reports have become mandatory for vascular surgery in England, reflecting a more widespread appetite for transparency and accountability across the National Health Service (NHS) [BMJ 2013;346:f854]. The outcomes of abdominal aortic aneurysm (AAA) repair, in particular, have attracted considerable commentary: from 1999 to 2006, postoperative mortality was higher in England than in many other countries (7.9 vs. 1.9-4.5%) [European Society for Vascular Surgery. 2nd Vascunet Report. 2008]. This stimulated considerable service reconfiguration (centralization), quality improvement initiatives, the uptake of endovascular technology, and the examination of institution-level mortality data [http://www.vascularsociety.org.uk/library/quality-improvement.html], which resulted in a fall in elective AAA mortality to 1.8% by 2012 [http://www.hqip.org.uk/assets/NCAPOP-Library/NCAPOP-2013-2014/Outcomes-after-Elective-Repair-of-Infra-renal-Abdominal-Aortic-Aneurysm.pdf (February 2015)]. Despite improvements at a national level, the outcomes of AAA repair vary considerably between different hospitals in the NHS [Circ Cardiovasc Qual Outcomes 2014;7:131-141], analogous to interprovider variation that has been reported across a range of emergency medical and surgical conditions [BMC Health Serv Res 2014;14:270]. This suggests that underlying institution structures and processes contribute independently to patients' outcomes. There is also considerable evidence that the outcomes of AAA repair vary in different healthcare systems, both in the elective European Society for Vascular Surgery, 2008 and emergency settings. A consideration of the role of structures and processes in influencing outcomes for AAA repair can be conducted across different institutions or even different healthcare systems. This can help identify which factors are consistently associated with the best outcomes, informing efforts to better organize and deliver services for patients requiring vascular surgery.

Purpose: To perform an evidence synthesis study to assess outcomes of endovascular repair of popliteal artery aneurysms (PAAs) using the Hemobahn or Viabahn stent-graft. Methods: A systematic literature review was conducted conforming to established standards to identify articles published between 1996 (the date of introduction of the Hemobahn stent-graft) and 2013 reporting stent-graft repair of PAAs in at least 10 patients. The data were pooled for Kaplan-Meier analysis of primary and secondary patency rates [presented with 95% confidence intervals (CIs)] as the primary outcomes. Random effects meta-analysis was performed for secondary outcomes that included rates of reintervention, endoleak, stent-graft fracture, and limb salvage. Results: Fourteen studies reported outcomes for 514 PAAs. There was considerable heterogeneity in reporting standards among studies. Pooled primary and secondary patency rates were 69.4% (95% CI 63.3% to 76.2%) and 77.4% (95% CI 70.1% to 85.3%), respectively, at 5 years. Five studies (including only one randomized controlled trial) compared surgical to endovascular repair; no difference was found in primary patency on evidence synthesis (hazard ratio 1.30, 95% CI 0.79 to 12.14, p=0.189). Conclusion: Stent-graft repair provides a feasible treatment option for anatomically suitable PAAs. Further studies are required to optimize both patient selection and follow-up protocols.

Background There is significant variation in the mortality rates of patients with a ruptured abdominal aortic aneurysm (rAAA) admitted to hospital in England. This study sought to investigate whether modifiable differences in hospital structures and processes were associated with differences in patient outcome. Methods Patients diagnosed with rAAA between 2005 and 2010 were extracted from the Hospital Episode Statistics database. After risk adjustment, hospitals were grouped into low-mortality outlier, expected mortality and high-mortality outlier categories. Hospital Trust-level structure and process variables were compared between categories, and tested for an association with risk-adjusted 90-day mortality and non-corrective treatment (palliation) rate using binary logistic regression models. Results There were 9877 patients admitted to 153 English NHS Trusts with an rAAA during the study. The overall combined (operative and non-operative) mortality rate was 67·5 per cent (palliation rate 41·6 per cent). Seven hospital Trusts (4·6 per cent) were high-mortality and 15 (9·8 per cent) were low-mortality outliers. Low-mortality outliers used significantly greater mean resources per bed (doctors: 0·922 versus 0·513, P < 0·001; consultant doctors: 0·316 versus 0·168, P < 0·001; nurses: 2·341 versus 1·770, P < 0·001; critical care beds: 0·045 versus 0·019, P < 0·001; operating theatres: 0·027 versus 0·019, P = 0·002) and performed more fluoroscopies (mean 12·6 versus 9·2 per bed; P = 0·046) than high-mortality outlier hospital Trusts. On multivariable analysis, greater numbers of consultants, nurses and fluoroscopies, teaching status, weekday admission and rAAA volume were independent predictors of lower mortality and, excluding rAAA volume, a lower rate of palliation. Conclusion The variability in rAAA outcome in English National Health Service hospital Trusts is associated with modifiable hospital resources. Such information should be used to inform any proposed quality improvement programme surrounding rAAA.

Background Lifelong surveillance is considered mandatory after endovascular repair (EVAR) of abdominal aortic aneurysms to detect endograft complications and prevent aneurysm rupture. Current protocols are not cost-effective or clinically effective. The international validity of the St George's Vascular Institute (SGVI) score for EVAR complications was examined. Methods The ENGAGE registry recruited patients undergoing EVAR at 79 centres in 30 countries. Reinterventions and endograft complications were recorded for up to 3 years after surgery. Preoperative aneurysm morphology was extracted from the registry database, and used to predict whether patients would be at low or high risk of complications after EVAR based on the SGVI score. Kaplan–Meier analysis was used to compare the incidence of endograft complications and reinterventions in patients predicted to be at low risk compared with those predicted to be at high risk. Results Some 1207 patients underwent EVAR, with follow-up of up to 3 years. The SGVI score accurately discriminated freedom from reinterventions (90·5 versus 79·3 per cent in low- versus high-risk patients; P < 0·001), freedom from endograft complications (77·9 versus 69·6 per cent in low- versus high-risk patients; P = 0·012), and freedom from a composite outcome measure of reinterventions or endograft complications (75·0 versus 66·1 per cent in low- versus high-risk patients; P = 0·006) during mid-term follow-up. Conclusion This study has provided international validation of a morphological risk score that predicts mid-term reinterventions and endograft complications. The results may enable risk-stratified surveillance after EVAR.

To review the trends in patient selection and early death rate for patients undergoing elective endovascular repair of infrarenal abdominal aortic aneurysms (EVAR) in 3 countries. For this study, audit data from 4,163 patients who had undergone elective infrarenal EVAR were amalgamated. The data originated from Australia, Canada (Ontario), and England (London, Cambridge, and Leicester).Statistical analyses were undertaken to determine whether patient characteristics and early death rate varied between and within study groups and over time. The study design was retrospective analysis of data collected prospectively between 1999 and 2012.One-year survival improved over time (P = 0.0013). Canadian patients were sicker than those in Australia or England (P0.001). American Society of Anesthesiologists classification (ASA) increased over time across all countries although more significantly in Canada. Age at operation remained constant, although older patients were treated more recently in London (P0.001). English centers treated larger aneurysms compared with Australia and Canada (P0.001). Australian centers treated a much larger proportion of aneurysms that were55 mm than other countries. Preoperative creatinine levels decreased over time for all countries and centers (P0.001). Infrarenal neck angles have significantly decreased over time (P0.001). Recent data from London (UK) showed that operations were performed on longer (P0.001) and wider (P0.001) infrarenal necks than elsewhere.In this international comparison, several trends were noted including improved 1-year survival despite declining patient health (as measured by increasing ASA status). This may reflect greater knowledge regarding EVAR that centers from different countries have gained over the last decade and improved medical management of patients with aneurysmal disease.

Background There is substantial international variation in mortality after abdominal aortic aneurysm (AAA) repair; many non‐operative factors influence risk‐adjusted outcomes. This study compared 90‐day and 5‐year mortality for patients undergoing elective AAA repair in England and Sweden. Methods Patients were identified from English Hospital Episode Statistics and the Swedish Vascular Registry between 2003 and 2012. Ninety‐day mortality and 5‐year survival were compared after adjustment for age and sex. Separate within‐country analyses were performed to examine the impact of co‐morbidity, hospital teaching status and hospital annual caseload. Results The study included 36 249 patients who had AAA treatment in England, with a median age of 74 (i.q.r. 69–79) years, of whom 87·2 per cent were men. There were 7806 patients treated for AAA in Sweden, with a median of age 73 (68–78) years, of whom 82·9 per cent were men. Ninety‐day mortality rates were poorer in England than in Sweden (5·0 versus 3·9 per cent respectively; P, Improving in England

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.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.Aortic true and false lumen diameter and area showed good correlation (p0.001) in the majority of anatomic locations. This relationship was present preoperatively and during follow-up (p0.001). 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.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.

Background Feature selection (FS) process is essential in the medical area as it reduces the effort and time needed for physicians to measure unnecessary features. Choosing useful variables is a difficult task with the presence of censoring which is the unique characteristic in survival analysis. Most survival FS methods depend on Cox’s proportional hazard model; however, machine learning techniques (MLT) are preferred but not commonly used due to censoring. Techniques that have been proposed to adopt MLT to perform FS with survival data cannot be used with the high level of censoring. The researcher’s previous publications proposed a technique to deal with the high level of censoring. It also used existing FS techniques to reduce dataset dimension. However, in this paper a new FS technique was proposed and combined with feature transformation and the proposed uncensoring approaches to select a reduced set of features and produce a stable predictive model. Methods In this paper, a FS technique based on artificial neural network (ANN) MLT is proposed to deal with highly censored Endovascular Aortic Repair (EVAR). Survival data EVAR datasets were collected during 2004 to 2010 from two vascular centers in order to produce a final stable model. They contain almost 91% of censored patients. The proposed approach used a wrapper FS method with ANN to select a reduced subset of features that predict the risk of EVAR re-intervention after 5 years to patients from two different centers located in the United Kingdom, to allow it to be potentially applied to cross-centers predictions. The proposed model is compared with the two popular FS techniques; Akaike and Bayesian information criteria (AIC, BIC) that are used with Cox’s model. Results The final model outperforms other methods in distinguishing the high and low risk groups; as they both have concordance index and estimated AUC better than the Cox’s model based on AIC, BIC, Lasso, and SCAD approaches. These models have p-values lower than 0.05, meaning that patients with different risk groups can be separated significantly and those who would need re-intervention can be correctly predicted. Conclusion The proposed approach will save time and effort made by physicians to collect unnecessary variables. The final reduced model was able to predict the long-term risk of aortic complications after EVAR. This predictive model can help clinicians decide patients’ future observation plan. Electronic supplementary material The online version of this article (doi:10.1186/s12911-017-0508-3) contains supplementary material, which is available to authorized users.

Approximately 40–50% of patients undergoing thoracic endovascular aortic repair require left subclavian artery coverage for adequate proximal landing zone. Many of these patients undergo left subclavian artery revascularisation. However, outcomes data for left subclavian artery revascularisation in the context of thoracic endovascular aortic repair remain limited. In this study, 70 left subclavian artery revascularisation procedures, performed on thoracic endovascular aortic repair patients at a tertiary hospital, were retrospectively reviewed. Particular emphasis was placed on revascularisation-related outcomes during staging interval between revascularisation and thoracic endovascular aortic repair. Forty-six (66%) carotid-subclavian bypass, 17 (24%) carotid-carotid-subclavian bypass and 7 (10%) aorto-inominate-carotid-subclavian bypass procedures were performed. There were no strokes or mortalities following left subclavian artery revascularisation procedures alone. Three (10%) minor complications occurred including a seroma, a haematoma and a temporary neuropraxia. Separation of complications following left subclavian artery revascularisation from those of the associated thoracic endovascular aortic repair can be difficult. Early outcomes data from patients who underwent left subclavian artery revascularisation in isolation indicate that the procedure is safe with low complication rates.

To provide data regarding the etiology and timing of retrograde type A aortic dissection (RTAD) after thoracic endovascular aortic repair (TEVAR).Details of patients who had RTAD after TEVAR were obtained from the MOTHER Registry supplemented by data from a systematic review of the literature. Univariate analysis and binary logistic regression analysis of patient or technical factors was performed.In MOTHER, RTAD developed in 16 of the 1010 patients (1.6%). Binary logistic regression demonstrated that an indication of TEVAR for aortic dissection (acute P = 0.000212; chronic P = 0.006) and device oversizing (OR 1.14 per 1% increase in oversizing above 9%, P0.0001) were significantly more frequent in patients with RTAD. Data from the systematic review was pooled with MOTHER data and demonstrated that RTAD occurred in 1.7% (168/9894). Most of RTAD occurred in the immediate postoperative (58%) period and was associated with a high mortality rate (33.6%). The odds ratio of RTAD for an acute aortic dissection was 10.0 (CI: 4.7-21.9) and 3.4 (CI: 1.3-8.8) for chronic aortic dissection. The incidence of RTAD was not significantly different for endografts with proximal bare stent (2.8%) or nonbare stent (1.9%) (P = 0.1298).Although RTAD after TEVAR is an uncommon complication, it has a high mortality rate. RTAD is significantly more frequent in patients treated for acute and chronic type B dissection, and when the endograft is significantly oversized. The proximal endograft configuration was not associated with any difference in the incidence of RTAD.

Lifelong surveillance is not cost-effective after endovascular aneurysm repair (EVAR), but is required to detect aortic complications which are fatal if untreated (type 1/3 endoleak, sac expansion, device migration). Aneurysm morphology determines the probability of aortic complications and therefore the need for surveillance, but existing analyses have proven incapable of identifying patients at sufficiently low risk to justify abandoning surveillance. This study aimed to improve the prediction of aortic complications, through the application of machine-learning techniques. Patients undergoing EVAR at 2 centres were studied from 2004–2010. Aneurysm morphology had previously been studied to derive the SGVI Score for predicting aortic complications. Bayesian Neural Networks were designed using the same data, to dichotomise patients into groups at low- or high-risk of aortic complications. Network training was performed only on patients treated at centre 1. External validation was performed by assessing network performance independently of network training, on patients treated at centre 2. Discrimination was assessed by Kaplan-Meier analysis to compare aortic complications in predicted low-risk versus predicted high-risk patients. 761 patients aged 75 +/− 7 years underwent EVAR in 2 centres. Mean follow-up was 36+/− 20 months. Neural networks were created incorporating neck angu- lation/length/diameter/volume; AAA diameter/area/volume/length/tortuosity; and common iliac tortuosity/diameter. A 19-feature network predicted aor- tic complications with excellent discrimination and external validation (5-year freedom from aortic complications in predicted low-risk vs predicted high-risk patients: 97.9% vs. 63%; p < 0.0001). A Bayesian Neural-Network algorithm can identify patients in whom it may be safe to abandon surveillance after EVAR. This proposal requires prospective study.

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

Background Endovascular treatments of Stanford type B aortic dissection may help to promote aortic remodeling and reduce the incidence of aortic-related complications. The aim of this study was to review published literature describing aortic remodeling after endovascular treatment of aortic dissection. Methods A systematic review of the literature was performed which was compliant with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The type of aortic morphology measurements made and the methods used to make them were characterized. The endpoints of interest were the change in these measurements over time. Results After initial screening, 77 articles were identified; 16 of which met the inclusion criteria. Few studies used three-dimensional reconstruction software and none had validated their measurement protocol. True lumen (TL) and false lumen (FL) diameters, areas, and in some cases volumes were measured. Studies assessed the aorta at a variety of different levels and over different periods of follow-up. Acute dissection patients displayed more consistent degree of remodeling (thoracic FL thrombosis in 80% to 90%) than chronic dissection patients (38% to 91%). Less remodeling was seen below the diaphragm in both groups. Conclusions Aortic remodeling after treatment for dissection is described in a highly heterogeneous manner. Despite this there appears to be a greater degree of complete FL resolution in patients with acute dissection than chronic. Factors such as length of aortic coverage and timing of treatment may explain the variation seen in the chronic dissection group. Consensus-based reporting standards are required to synthesize evidence and inform clinical decisions regarding patient selection and operative timing.

Purpose: To report the application of the Nellix endovascular aneurysm sealing (EVAS) device, including two chimney grafts, to successfully treat a type Ia endoleak. Case Report: An 87-year-old man had an asymptomatic 7.6-cm infrarenal abdominal aortic aneurysm (AAA) and a 4.5-cm right internal iliac artery aneurysm treated using an aortouni-iliac stent-graft. Two years after the index endovascular repair, an asymptomatic type Ia endoleak was detected on duplex ultrasound; the computed tomographic angiogram (CTA) demonstrated significant sac enlargement and stent-graft migration. Initial attempts to treat the leak with 2 aortic cuffs only reduced the size of the endoleak. Another procedure was undertaken using the Nellix device with chimney grafts to increase the proximal sealing zone above the existing stent-graft. Imaging postoperatively demonstrated successful resolution of the endoleak and continuing patency of both renal artery chimney stent-grafts. CTA at 6 months demonstrated persistent sealing of the endoleak. Conclusion: The use of the EVAS system may represent another endovascular solution that can be added to the clinician’s repertoire for treating type Ia endoleak after conventional endovascular repair of infrarenal AAA.

Background Lifelong surveillance is standard after endovascular repair of abdominal aortic aneurysm (EVAR), but remains costly, heterogeneous and poorly calibrated. This study aimed to develop and validate a scoring system for aortic complications after EVAR, informing rationalized surveillance. Methods Patients undergoing EVAR at two centres were studied from 2004 to 2010. Preoperative morphology was quantified using three-dimensional computed tomography according to a validated protocol, by investigators blinded to outcomes. Proportional hazards modelling was used to identify factors predicting aortic complications at the first centre, and thereby derive a risk score. Sidak tests between risk quartiles dichotomized patients to low- or high-risk groups. Aortic complications were reported by Kaplan–Meier analysis and risk groups were compared by log rank test. External validation was by comparison of aortic complications between risk groups at the second centre. Results Some 761 patients, with a median age of 75 (interquartile range 70–80) years, underwent EVAR. Median follow-up was 36 (range 11–94) months. Physiological variables were not associated with aortic complications. A morphological risk score incorporating maximum aneurysm diameter (P < 0·001) and largest common iliac diameter (measured 10 mm from the internal iliac origin; P = 0·004) allocated 75 per cent of patients to a low-risk group, with excellent discrimination between 5-year rates of aortic complication in low- and high-risk groups at both centres (centre 1: 12 versus 31 per cent, P < 0·001; centre 2: 12 versus 45 per cent, P = 0·002). Conclusion The risk score uses commonly available morphological data to stratify the rate of complications after EVAR. The proposals for rationalized surveillance could provide clinical and economic benefits.

Background: Surveillance is considered mandatory after endovascular repair (EVR), but its impact on imaging services remains unreported. This study reports the effect of EVR surveillance on imaging resources. Methods: A single-center’s duplex database was interrogated from January 1, 2004 to January 1, 2012. All examinations requested by a vascular surgeon were reported, including preoperative abdominal aortic aneurysms, surveillance after EVR, lower limb arterial and venous duplex, and arteriovenous fistulae. Results: A total of 24 309 patients underwent duplex. The EVR surveillance increased from 192 scans in 2004 to 1325 scans in 2011, 9.5% (192 of 2030) and 34.4% (1325 of 3850) of each year’s examinations. By 2011, EVR surveillance was the most common indication for duplex. Conclusion: Lifelong EVR surveillance creates a rapidly increasing workload for imaging services. Further research should aim to reduce the burden of EVR surveillance. Targeting surveillance to the minority of patients at greatest risk of endograft failure might optimize the usage of imaging resources.

Background— Endovascular repair of the thoracic aorta has become an increasingly utilized therapy. Although the short-term mortality advantage over open surgery is well documented, late mortality and the impact of presenting pathology on long-term outcomes remain poorly reported. Methods and Results— A database was built from 5 prospective studies and a single institutional series. Rates of perioperative adverse events were calculated, as were midterm death and reintervention rates. Multivariate analysis was performed with the use of logistic regression modeling. Kaplan-Meier survival curves were drawn for midterm outcomes. The database contained 1010 patients: 670 patients with thoracic aortic aneurysm, 195 with chronic type B aortic dissection, and 114 with acute type B aortic dissection. Lower elective mortality was observed in patients with chronic dissections (3%) compared with patients with aneurysms (5%). Multivariate analysis identified age, mode of admission, American Society of Anesthesiologists grade, and pathology as independent predictors of 30-day death ( P < 0.05). In the midterm, the all-cause mortality rate was 8, 4.9, and 3.2 deaths per 100 patient-years for thoracic aortic aneurysm, acute type B aortic dissection, and chronic type B aortic dissection, respectively. The rates of aortic-related death were 0.6, 1.2, and 0.4 deaths per 100 patient-years for thoracic aortic aneurysm, acute type B aortic dissection, and chronic type B aortic dissection, respectively. Conclusions— This study indicated that the midterm outcomes of endovascular repair of the thoracic aorta are defined by presenting pathology, associated comorbidities, and mode of admission. Nonaortic mortality is high in the midterm for patients with thoracic aortic aneurysm, and managing modifiable risk factors appears vital. Endovascular repair of the thoracic aorta results in excellent midterm protection from aortic-related mortality, regardless of presenting pathology.

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.