Comparative analysis of the outcomes of elective abdominal aortic aneurysm repair in England and Sweden.

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 < 0·001), but were not significantly different after 2007. Five-year survival was poorer in England (70·5 versus 72·8 per cent; P < 0·001). Use of EVAR was initially lower in England, but surpassed that in Sweden after 2010. In both countries, poor outcome was associated with increased age. In England, institutions with higher operative annual volume had lower mortality rates. CONCLUSION: Mortality for elective AAA repair was initially poorer in England than Sweden, but improved over time alongside greater uptake of EVAR, and now there is no difference. Centres performing a greater proportion of EVAR procedures achieved better results in England.

Value of risk scores in the decision to palliate patients with ruptured abdominal aortic aneurysm.

BACKGROUND: The aim of this study was to develop a 48-h mortality risk score, which included morphology data, for patients with ruptured abdominal aortic aneurysm presenting to an emergency department, and to assess its predictive accuracy and clinical effectiveness in triaging patients to immediate aneurysm repair, transfer or palliative care. METHODS: Data from patients in the IMPROVE (Immediate Management of the Patient With Ruptured Aneurysm: Open Versus Endovascular Repair) randomized trial were used to develop the risk score. Variables considered included age, sex, haemodynamic markers and aortic morphology. Backwards selection was used to identify relevant predictors. Predictive performance was assessed using calibration plots and the C-statistic. Validation of the newly developed and other previously published scores was conducted in four external populations. The net benefit of treating patients based on a risk threshold compared with treating none was quantified. RESULTS: Data from 536 patients in the IMPROVE trial were included. The final variables retained were age, sex, haemoglobin level, serum creatinine level, systolic BP, aortic neck length and angle, and acute myocardial ischaemia. The discrimination of the score for 48-h mortality in the IMPROVE data was reasonable (C-statistic 0·710, 95 per cent c.i. 0·659 to 0·760), but varied in external populations (from 0·652 to 0·761). The new score outperformed other published risk scores in some, but not all, populations. An 8 (95 per cent c.i. 5 to 11) per cent improvement in the C-statistic was estimated compared with using age alone. CONCLUSION: The assessed risk scores did not have sufficient accuracy to enable potentially life-saving decisions to be made regarding intervention. Focus should therefore shift to offering repair to more patients and reducing non-intervention rates, while respecting the wishes of the patient and family.

Quality of life, symptoms and treatment satisfaction in patients with aortic aneurysm using new abdominal aortic aneurysm-specific patient-reported outcome measures.

BACKGROUND: The aim of this study was to present preliminary data on quality of life (QoL), symptoms and treatment satisfaction gathered using three new abdominal aortic aneurysm (AAA)-specific patient-reported outcome measures (PROMs). METHODS: Patients with AAA were recruited from five National Health Service Trusts to complete the three new PROMs: the AneurysmDQoL, AneurysmSRQ and AneurysmTSQ. Patients were either under surveillance or had undergone AAA repair (open or endovascular) during the preceding 24 months. Data were initially collected as part of a study assessing the psychometric properties of the new measures, before being used in the observational analysis of outcomes presented here. RESULTS: Results, although largely non-significant, showed interesting trends. The impact of AAA repair on QoL appeared to worsen progressively after open repair (OR) and improve progressively after endovascular aneurysm repair (EVAR). Conversely, symptoms seemed to become progressively worse after EVAR and progressively better after OR. Information and understanding were key sources of dissatisfaction before the intervention, whereas postoperative dissatisfaction was related to bother from symptoms, follow-up and feedback about scan results. CONCLUSION: Although a larger, prospective data set is necessary to explore outcomes more fully with the new AAA-specific PROMs, the observational data presented here suggest there may be clinically important differences in the symptoms, impact on QoL and treatment satisfaction associated with OR and EVAR.

Preoperative morphology influences thoracic aortic aneurysm sac expansion after endovascular repair.

BACKGROUND: The fate of the aneurysm sac after thoracic endovascular aortic repair (TEVAR) remains poorly defined. The aim of this study was to characterize the incidence of aneurysm sac expansion after TEVAR, and to determine the effect of aneurysm morphology on postoperative sac behaviour. METHODS: Preoperative and postoperative CT angiography (CTA) images were analysed from a proprietary database (M2S). TEVARs undertaken for thoracic aortic aneurysms from 2004 to 2013 were included. Preoperative aortic morphology was available for each patient. Post-TEVAR sac expansion was defined as an increase in aortic diameter of at least 5 mm. The influence of aortic morphological variables on sac expansion was assessed using Cox regression and Kaplan-Meier analysis. RESULTS: CTA images were available for 899 patients who underwent TEVAR. Median follow-up was 2·1 (i.q.r. 1·7-2·4) years. Some 46·0 per cent had a maximum aneurysm diameter of 55 mm or more at the time of repair. The 5-year rate of freedom from sac expansion of at least 5 mm was 60·9 per cent. The sac expansion rate after 3 years was higher when the proximal sealing zone was over 38 mm in diameter (freedom from expansion 51·2 per cent versus 76·6 per cent for diameter 38 mm or less; P < 0·001), or 20 mm or less in length (freedom from expansion 67·3 per cent versus 77·1 per cent for length exceeding 20 mm; P = 0·022). Findings for the distal sealing zone were similar. The risk of sac expansion increased according to the number of adverse morphological risk factors (freedom from expansion rate 79·1 per cent at 3 years in patients with 2 or fewer risk factors versus 45·7 per cent in those with more than 2; P < 0·001). CONCLUSION: Sac expansion was common in this cohort of patients undergoing TEVAR for thoracic aortic aneurysm. Aneurysm sac expansion was significantly influenced by adverse morphological features in the aortic stent-graft sealing zones.

Design of new patient-reported outcome measures to assess quality of life, symptoms and treatment satisfaction in patients with abdominal aortic aneurysm.

BACKGROUND: No condition-specific patient-reported outcome measures exist for patients with abdominal aortic aneurysm (AAA). The aim of this work was to develop three questionnaires to assess quality of life (QoL), symptoms and treatment satisfaction in patients with AAA. METHODS: Semistructured interview techniques were used to explore patients' experiences of having an AAA in a series of focus groups and in-depth interviews. The information gathered was used to inform design and selection of items for the new tools; the overall structure of the new questionnaires was based on tools developed previously for patients with diabetes and other conditions. RESULTS: Fifty-four patients (51 men, 3 women; mean age 71·9 years) were recruited from four NHS Trusts to participate in focus groups or interviews, either while under surveillance, or following AAA repair (using open or endovascular techniques). The Aneurysm-Dependent Quality of Life Questionnaire (AneurysmDQoL) is an individualized measure of the impact of AAA on patients' QoL. Twenty-three domains were chosen specifically for their relevance to patients with AAA, with a further two overview items to assess overall QoL and the impact of AAA on QoL. The Aneurysm Symptom Rating Questionnaire (AneurysmSRQ) is a 44-item measure assessing physical and psychological symptoms reported by patients with AAA. The Aneurysm Treatment Satisfaction Questionnaire (AneurysmTSQ) contains 11 items, suitable for patients before and after surgical intervention. CONCLUSION: The iterative development process reported here has confirmed that these three new tools have good face and content validity for patients with AAA.

Expansion rate of descending thoracic aortic aneurysms.

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.

Comparison of long-term mortality after ruptured abdominal aortic aneurysm in England and Sweden.

BACKGROUND: Concern has been raised regarding international discrepancies in perioperative mortality after repair of ruptured abdominal aortic aneurysm (rAAA). The variation in in-hospital mortality is difficult to interpret, owing to international differences in discharge strategies. This study compared 90-day and 5-year mortality in patients who had a rAAA in England and Sweden. METHODS: Patients undergoing rAAA repair were identified from English Hospital Episode Statistics and the Swedish Vascular Registry (Swedvasc) between 2003 and 2012. Ninety-day and 5-year mortality were compared after matching for age and sex. Within-country analyses examined the impact of co-morbidity, teaching hospital status or hospital annual caseload, adjusted with causal inference techniques. RESULTS: Some 12 467 patients underwent rAAA repair in England, of whom 83.2 per cent were men; the median (i.q.r.) age was 75 (70-80) years. A total of 2829 Swedish patients underwent rAAA repair, of whom 81.3 per cent were men; their median (i.q.r.) age was 75 (69-80) years. The 90-day mortality rate was worse in England (44.0 per cent versus 33.4 per cent in Sweden; P < 0.001), as was 5-year mortality (freedom from mortality 38.6 versus 46.3 per cent respectively; P < 0.001). In England, lower mortality was seen in teaching hospitals with larger bed capacity, higher annual caseloads and greater use of endovascular aneurysm repair (EVAR). In Sweden, lower mortality was associated with EVAR, high annual caseload, or surgery on weekdays compared with weekends. CONCLUSION: Short- and long-term mortality after rAAA repair was higher in England. In both countries, mortality was lowest in centres performing greater numbers of AAA repairs per annum, and more EVAR procedures.

Cardiovascular risk prevention and all-cause mortality in primary care patients with an abdominal aortic aneurysm.

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.

Systematic Review of the Growth Rates and Influencing Factors in Thoracic Aortic Aneurysms.

OBJECTIVE/BACKGROUND: The growth rates of thoracic aortic aneurysms (TAAs) and factors influencing their expansion are poorly understood. This study aimed to review systematically published literature describing TAA expansion and examine factors that may be associated with this. METHODS: A comprehensive search of MEDLINE and Embase databases was performed until 30 April 2015. Studies describing rates of TAA growth were identified and systematically reviewed. Outcomes of interest were TAA growth rates and associated factors. Study quality was assessed using Scottish Intercollegiate Guidelines Network quality checklists for cohort studies. RESULTS: Eleven publications, involving 1383 patients, met the eligibility criteria and were included in the review. Included studies were generally low in quality. Aneurysm measurement and growth-rate estimation techniques were inconsistently reported. Mean growth rates for all TAAs ranged from 0.2 to 4.2 mm/year. Mean growth rates for ascending and aortic arch aneurysms ranged from 0.2 to 2.8 mm/year, while those for descending and thoracoabdominal aneurysms ranged from 1.9 to 3.4 mm/year in studies reporting according to anatomical location. Large aneurysm size, distal aneurysm locations, presence of Marfan's syndrome, and bicuspid aortic valve were consistently associated with accelerated TAA growth. Presence of chronic dissection and chronic obstructive pulmonary disorder were also implicated as risk factors for faster TAA growth. Associations between medical comorbidity and aneurysm expansion were conflicting. Previous aortic surgery and anticoagulants were reported to have a protective effect on aneurysm growth in two studies. CONCLUSION: There is a shortfall in the understanding of TAA expansion rates. Existing studies are heterogeneous in methodology and reported outcomes. Identified unifying themes suggest that TAAs grow at a slow rate with large presenting diameter, distal aneurysm, and history of bicuspid aortic valve or Marfan's syndrome serving as main risk factors for accelerated aneurysm growth. High-quality studies with a standardised approach to TAA growth assessment are required.

The Endovascular Sealing Device in Combination with Parallel Grafts for Treatment of Juxta/Suprarenal Abdominal Aortic Aneurysms: Short-term Results of a Novel Alternative.

BACKGROUND: The chimney technique using parallel grafts offers an alternative to fenestrated or branched endovascular solutions for juxtarenal and suprarenal aneurysms. Endograft deployment proximal to the renal or visceral ostia is combined with parallel stents to the aortic side branches. Application of the chimney technique using the Nellix device (Ch-EVAS) may offer some potential advantages with respect to the seal between the endograft and the parallel grafts. This study aimed to investigate the feasibility and efficacy of the Nellix endovascular aneurysm sealing (EVAS) system in conjunction with parallel grafts for the treatment of juxtarenal and suprarenal aneurysms. METHODS: A prospective evaluation of patients treated for juxtarenal and suprarenal non-ruptured aortic aneurysms using Ch-EVAS was undertaken in a single vascular unit. Patients were treated with this technique if they were unsuitable for either open repair or a custom-made complex branched/fenestrated endograft. Procedural, postoperative morbidity, and mortality data were recorded. RESULTS: Between March 2013 and April 2015, 28 patients were treated with Ch-EVAS. The median age was 75 years (range 60-87 years) and the median aneurysm diameter 66 mm (IQR 60-73 mm). Eight patients underwent suprarenal aneurysm repair including parallel grafts in the superior mesenteric artery and renal arteries. Five patients had a double chimney configuration; all the other patients were treated with a single chimney configuration. There was one 30-day or in-hospital mortality in a patient with a symptomatic aneurysm (4%) and three further deaths within 1 year of follow-up. One proximal type I endoleak and one type II endoleak occurred. Four patients underwent a reintervention. One patient experienced a transient ischemic attack and two patients suffered from a minor stroke (7%), therefore the total number of cerebrovascular complications was 11%. No patient required postoperative renal replacement therapy. CONCLUSIONS: Ch-EVAS appears to offer a feasible solution for juxtarenal and suprarenal aneurysms with adverse morphology. In this short-term follow-up endoleak rates were low and re-intervention rates were acceptable. Outcomes over extended follow-up will determine the application of this novel technique and better define which patients and aneurysm morphology can be treated effectively.

Mortality of emergency general surgical patients and associations with hospital structures and processes.

BACKGROUND: Variations in patient outcomes between providers have been described for emergency admissions, including general surgery. The aim of this study was to investigate whether differences in modifiable hospital structures and processes were associated with variance in mortality, amongst patients admitted for emergency colorectal laparotomy, peptic ulcer surgery, appendicectomy, hernia repair and pancreatitis. METHODS: Adult emergency admissions in the English NHS were extracted from the Hospital Episode Statistics between April 2005 and March 2010. The association between mortality and structure and process measures including medical and nursing staffing levels, critical care and operating theatre availability, radiology utilization, teaching hospital status and weekend admissions were investigated. RESULTS: There were 294 602 emergency admissions to 156 NHS Trusts (hospital systems) with a 30-day mortality of 4.2%. Trust-level mortality rates for this cohort ranged from 1.6 to 8.0%. The lowest mortality rates were observed in Trusts with higher levels of medical and nursing staffing, and a greater number of operating theatres and critical care beds relative to provider size. Higher mortality rates were seen in patients admitted to hospital at weekends [OR 1.11 (95% CI 1.06-1.17) P<0.0001], in Trusts with fewer general surgical doctors [1.07 (1.01-1.13) P=0.019] and with lower nursing staff ratios [1.07 (1.01-1.13) P=0.024]. CONCLUSIONS: Significant differences between Trusts were identified in staffing and other infrastructure resources for patients admitted with an emergency general surgical diagnosis. Associations between these factors and mortality rates suggest that potentially modifiable factors exist that relate to patient outcomes, and warrant further investigation.

Association of hospital structures with mortality from ruptured abdominal aortic aneurysm.

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.

International validation of a risk score for complications and reinterventions after endovascular aneurysm repair.

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.

Systematic Review and Meta-analysis of Long-term survival After Elective Infrarenal Abdominal Aortic Aneurysm Repair 1969-2011: 5 Year Survival Remains Poor Despite Advances in Medical Care and Treatment Strategies.

BACKGROUND: Improved critical care, pre-operative optimization, and the advent of endovascular surgery (EVAR) have improved 30 day mortality for elective abdominal aortic aneurysm (AAA) repair. It remains unknown whether this has translated into improvements in long-term survival, particularly because these factors have also encouraged the treatment of older patients with greater comorbidity. The aim of this study was to quantify how 5 year survival after elective AAA repair has changed over time. METHODS: A systematic review was performed identifying studies reporting 5 year survival after elective infrarenal AAA repair. An electronic search of the Embase and Medline databases was conducted to January 2014. Thirty-six studies, 60 study arms, and 107,814 patients were identified. Meta-analyses were conducted to determine 5 year survival and to report whether 5 year survival changed over time. RESULTS: Five-year survival was 69% (95% CI 67 to 71%, I(2) = 87%). Meta-regression on study midpoint showed no improvement in 5 year survival over the period 1969-2011 (log OR -0.001, 95% CI -0.014-0.012). Larger average aneurysm diameter was associated with poorer 5 year survival (adjusted log OR -0.058, 95% CI -0.095 to -0.021, I(2) = 85%). Older average patient age at surgery was associated with poorer 5 year survival (adjusted log OR -0.118, 95% CI -0.142 to -0.094, I(2) = 70%). After adjusting for average patient age, an improvement in 5 year survival over the period that these data spanned was obtained (adjusted log OR 0.027, 95% CI 0.012 to 0.042). CONCLUSION: Five-year survival remains poor after elective AAA repair despite advances in short-term outcomes and is associated with AAA diameter and patient age at the time of surgery. Age-adjusted survival appears to have improved; however, this cohort as a whole continues to have poor long-term survival. Research in this field should attempt to improve the life expectancy of patients with repaired AAA and to optimise patient selection.

Endovascular aneurysm sealing for infrarenal abdominal aortic aneurysms: 30-day outcomes of 105 patients in a single centre.

OBJECTIVE: Endovascular aneurysm sealing (EVAS) has been proposed as a novel alternative to endovascular aneurysm repair (EVAR) in patients with infrarenal abdominal aortic aneurysms (AAA). The early clinical experience, technical refinements, and learning curve of EVAS in the treatment of AAA at a single institution are presented. METHODS: One-hundred and five patients were treated with EVAS between March 2013 and November 2014. Prospective data were recorded on consecutive patients receiving EVAS. Data included demographics, preoperative aneurysm morphology, and 30-day outcomes, including rates of endoleak, limb occlusion, reintervention, and death. Postoperative imaging consisted of duplex ultrasound and computed tomographic angiography. RESULTS: The mean age of the cohort was 76 ± 8 years and 12% were female. Adverse neck morphology was present in 72 (69%) patients, including aneurysm neck length <10 mm (20%), neck diameter >32 mm (18%), ß-angulation >60° (21%), and conical aneurysm neck (51%). There was one death within 30 days. The incidence of Type 1 endoleak within 30 days was 4% (n = 4); all were treated successfully with transcatheter embolisation. All four proximal endoleaks were associated with technical issues that resulted in procedure refinement, and all were in patients with adverse proximal aortic necks. The persistent Type 1 endoleak rate at 30 days was 0% and there were no Type 2 or Type 3 endoleaks. Angioplasty and adjunctive stenting were performed for postoperative limb stenosis in three patients (3%). CONCLUSIONS: EVAS appears to be associated with reasonable 30-day outcomes despite the necessity of procedural evolution in the early adoption of this technique. EVAS appears to be applicable to patients with challenging aortic morphology and endoleak rates should reduce with procedural experience. The utility of EVAS will be defined by the durability of the device in long-term follow-up, although the absence of Type 2 endoleaks is encouraging.

Failure-to-rescue and interprovider comparisons after elective abdominal aortic aneurysm repair.

BACKGROUND: The use of postoperative complication rates to derive metrics such as failure-to-rescue (FTR) is of increasing interest in assessing the quality of care. The aim of this study was to quantify FTR rates for elective abdominal aortic aneurysm (AAA) repair in England using administrative data, and to examine its validity against case-note review. METHODS: A retrospective observational study using Hospital Episode Statistics (HES) data was combined with a multicentre audit of data quality. All elective AAA repairs done in England between 2005 and 2010 were identified. Postoperative complications were extracted, FTR rates quantified, and differences in FTR and in-hospital death rates established. A multicentre case-note review was performed to establish the accuracy of coding of complications, and the impact of inaccuracies on FTR rates derived from HES data. RESULTS: A total of 19 638 elective AAA repairs were identified from HES; the overall mortality rate was 4·6 per cent. Patients with complications (19·2 per cent) were more likely to die than those without complications (odds ratio 12·22, 95 per cent c.i. 10·51 to 14·21; P < 0·001) and had longer hospital stays (P < 0·001). FTR rates correlated strongly with death rates, whereas complication rates did not. On case-note review (661 procedures), 41·5 per cent of patients had a complication recorded in the case notes. There was evidence of systematic under-reporting of complications in HES, leading to an overall misclassification rate of 36·3 (95 per cent c.i. 33·7 to 39·2) per cent (P < 0·001), which was less pronounced for surgical complications (12·6 (11·1 to 13·9) per cent; P <0·001). Despite this, the majority of FTR rates derived from HES were not significantly different from those derived from case-note data. CONCLUSION: Postoperative complication and FTR rates after elective AAA repair can be derived from HES data. However, use of the metric for interprovider comparisons should be done cautiously, and only with concurrent case-note validation given the degree of miscoding identified.

Observations from the IMPROVE trial concerning the clinical care of patients with ruptured abdominal aortic aneurysm.

BACKGROUND: Single-centre series of the management of patients with ruptured abdominal aortic aneurysm (AAA) are usually too small to identify clinical factors that could improve patient outcomes. METHODS: IMPROVE is a pragmatic, multicentre randomized clinical trial in which eligible patients with a clinical diagnosis of ruptured aneurysm were allocated to a strategy of endovascular aneurysm repair (EVAR) or to open repair. The influences of time and manner of hospital presentation, fluid volume status, type of anaesthesia, type of endovascular repair and time to aneurysm repair on 30-day mortality were investigated according to a prespecified plan, for the subgroup of patients with a proven diagnosis of ruptured or symptomatic AAA. Adjustment was made for potential confounding factors. RESULTS: Some 558 of 613 randomized patients had a symptomatic or ruptured aneurysm: diagnostic accuracy was 91·0 per cent. Patients randomized outside routine working hours had higher operative mortality (adjusted odds ratio (OR) 1·47, 95 per cent confidence interval 1·00 to 2·17). Mortality rates after primary and secondary presentation were similar. Lowest systolic blood pressure was strongly and independently associated with 30-day mortality (51 per cent among those with pressure below 70 mmHg). Patients who received EVAR under local anaesthesia alone had greatly reduced 30-day mortality compared with those who had general anaesthesia (adjusted OR 0·27, 0·10 to 0·70). CONCLUSION: These findings suggest that the outcome of ruptured AAA might be improved by wider use of local anaesthesia for EVAR and that a minimum blood pressure of 70 mmHg is too low a threshold for permissive hypotension.

Endoscopic vein harvesting in lower extremity arterial bypass: a systematic review.

OBJECTIVE: Endoscopic vein harvesting (EVH) for arterial bypass surgery may be associated with lower wound complication rates than open vein harvesting (OVH), but other long-term outcomes remain controversial, and there are concerns that graft patency may be poorer after EVH compared with OVH. We conducted a systematic review of all available evidence for EVH in lower extremity arterial bypass (LEAB). METHODS: A literature search of Medline, Embase, Ovid and Cochrane databases between 1996 and 2013 was performed using the terms "endoscopic vein harvesting", "minimally invasive vein harvest", "peripheral bypass surgery", and "lower extremity bypass surgery", and detailed in line with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. Primary outcomes were graft patency and overall wound complication rates. Secondary outcomes were wound infection, length of hospital stay, and cost-effectiveness. Summary estimates were calculated by random effects meta-analysis if sufficient data were available. RESULTS: We identified 18 cohort studies and case series, with considerable clinical heterogeneity, including 2,343 patients. Meta-analysis of six studies revealed a significantly reduced rate of primary patency after EVH (hazard ratio 1.29, 95% confidence interval [CI] 1.03-1.63), with no significant difference between EVH and OVH with respect to wound infection in 12 studies (odds ratio 0.81, 95% CI 0.61-1.08). There was a lack of strong evidence to support the secondary outcomes of EVH. CONCLUSION: EVH reduces primary patency rates after LEAB, but does not demonstrate an advantage with respect to postoperative wound complications. However, the available data are heterogeneous, and uncertainty is introduced by both evolution in technology and increasing technical experience. EVH should be used with caution and in the context of formal research.

Predicting aortic complications after endovascular aneurysm repair.

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.

Population-based screening for the prevention of lower extremity complications in diabetes.

Diabetes-related foot disease is a major health problem leading to significant morbidity and cost. If high-risk populations could be identified and treated before they develop complications, a significant reduction in the burden of foot disease and number of amputations might be expected. We examined the evidence to support population-based screening programs. MEDLINE and EMBASE databases were searched from January 1970 to February 2012 to identify studies assessing the impact of screening on lower limb complications in diabetes. Foot screening was defined as combined risk stratification and intervention to prevent foot complications in a population of people with diabetes mellitus. Articles reporting singularly on stratification of risk factors to predict subsequent complications but not reporting effect on minor, major and/or combined major and minor (total) amputation were excluded. Two randomized control trials were identified. These demonstrated patient benefit from screening in the setting of a general secondary care diabetes clinic and renal dialysis unit. Four before and after studies suggested benefit from primary care or regional screening. One study tried to address confounding from general improvements in the provision of diabetes foot care separately from screening. All the observational studies were prone to confounding. The evidence base for formal national primary care-based foot screening of all patients with diabetes is weak. Focused research is needed to confirm that general population-based screening in the community is effective and cost-effective. Limited evidence suggests that screening of high-risk populations of patients may be justified.