Risk stratification by pre-operative cardiopulmonary exercise testing improves outcomes following elective abdominal aortic aneurysm surgery : a cohort study

Background: In 2009, the NHS evidence adoption center and National Institute for Health and Care Excellence (NICE) published a review of the use of endovascular aneurysm repair (EVAR) of abdominal aortic aneurysms (AAAs). They recommended the development of a risk-assessment tool to help identify AAA patients with greater or lesser risk of operative mortality and to contribute to mortality prediction. A low anaerobic threshold (AT), which is a reliable, objective measure of pre-operative cardiorespiratory fitness, as determined by pre-operative cardiopulmonary exercise testing (CPET) is associated with poor surgical outcomes for major abdominal surgery. We aimed to assess the impact of a CPET-based risk-stratification strategy upon perioperative mortality, length of stay and non-operative costs for elective (open and endovascular) infra-renal AAA patients. Methods: A retrospective cohort study was undertaken. Pre-operative CPET-based selection for elective surgical intervention was introduced in 2007. An anonymized cohort of 230 consecutive infra-renal AAA patients (2007 to 2011) was studied. A historical control group of 128 consecutive infra-renal AAA patients (2003 to 2007) was identified for comparison. Comparative analysis of demographic and outcome data for CPET-pass (AT ≥ 11 ml/kg/min), CPET-fail (AT < 11 ml/kg/min) and CPET-submaximal (no AT generated) subgroups with control subjects was performed. Primary outcomes included 30-day mortality, survival and length of stay (LOS); secondary outcomes were non-operative inpatient costs. Results: Of 230 subjects, 188 underwent CPET: CPET-pass n = 131, CPET-fail n = 35 and CPET-submaximal n = 22. When compared to the controls, CPET-pass patients exhibited reduced median total LOS (10 vs 13 days for open surgery, n = 74, P < 0.01 and 4 vs 6 days for EVAR, n = 29, P < 0.05), intensive therapy unit requirement (3 vs 4 days for open repair only, P < 0.001), non-operative costs (£5,387 vs £9,634 for open repair, P < 0.001) and perioperative mortality (2.7% vs 12.6% (odds ratio: 0.19) for open repair only, P < 0.05). CPET-stratified (open/endovascular) patients exhibited a mid-term survival benefit (P < 0.05). Conclusion: In this retrospective cohort study, a pre-operative AT > 11 ml/kg/min was associated with reduced perioperative mortality (open cases only), LOS, survival and inpatient costs (open and endovascular repair) for elective infra-renal AAA surgery

Limited Feasibility in Endovascular Aneurysm Repair Using Currently Available Graft in Korea

Despite the wide acceptance of endovascular aneurysmal repair in patients with abdominal aortic aneurysm (EVAR), stringent morphologic criteria recommended by manufacturers may preclude this treatment in patients with AAA. The purpose of this study was to investigate how many patients are feasible by Zenith and Excluder stent graft system, which are available in Korea. Eighty-two AAA patients (71 men, mean age 70 yr) who had been treated surgically or medically from January 2005 to December 2006 were included. Criteria for morphologic suitability (MS) were examined to focus on characteristics of aneurysm; proximal and distal landing zone; angulation and involvement of both iliac artery aneurysms. Twenty-eight patients (34.1%) were feasible in Zenith stent graft and 31 patients (37.8%) were feasible in Excluder. The patients who were excluded EVAR had an average of 1.61 exclusion criteria. The main reasons for exclusion were an unfavorable proximal neck (n=34, 41.5%) and problem of distal landing zone (n=25, 30.5%). There was no statistical significance among gender, age or aneurysm size in terms of MS. Only 32 patients (39%) who had AAA were estimated to be suitable for two currently approved grafts by strict criteria. However, even unfavorable AAA patients who have severe co-mobidities will be included in EVAR in the near future. Therefore, more efforts including fine skill and anatomical understanding will be needed to meet these challenging cases

The UK EndoVascular Aneurysm Repair (EVAR) randomised controlled trials: long-term follow-up and cost-effectiveness analysis.

BACKGROUND: Short-term survival benefits of endovascular aneurysm repair (EVAR) compared with open repair (OR) of intact abdominal aortic aneurysms have been shown in randomised trials, but this early survival benefit is soon lost. Survival benefit of EVAR was unclear at follow-up to 10 years. OBJECTIVE: To assess the long-term efficacy of EVAR against OR in patients deemed fit and suitable for both procedures (EVAR trial 1; EVAR-1); and against no intervention in patients unfit for OR (EVAR trial 2; EVAR-2). To appraise the long-term significance of type II endoleak and define criteria for intervention. DESIGN: Two national, multicentre randomised controlled trials: EVAR-1 and EVAR-2. SETTING: Patients were recruited from 37 hospitals in the UK between 1 September 1999 and 31 August 2004. PARTICIPANTS: Men and women aged ≥ 60 years with an aneurysm of ≥ 5.5 cm (as identified by computed tomography scanning), anatomically suitable and fit for OR were randomly assigned 1 : 1 to either EVAR (n = 626) or OR (n = 626) in EVAR-1 using computer-generated sequences at the trial hub. Patients considered unfit were randomly assigned to EVAR (n = 197) or no intervention (n = 207) in EVAR-2. There was no blinding. INTERVENTIONS: EVAR, OR or no intervention. MAIN OUTCOME MEASURES: The primary end points were total and aneurysm-related mortality until mid-2015 for both trials. Secondary outcomes for EVAR-1 were reinterventions, costs and cost-effectiveness. RESULTS: In EVAR-1, over a mean of 12.7 years (standard deviation 1.5 years; maximum 15.8 years), we recorded 9.3 deaths per 100 person-years in the EVAR group and 8.9 deaths per 100 person-years in the OR group [adjusted hazard ratio (HR) 1.11, 95% confidence interval (CI) 0.97 to 1.27;p = 0.14]. At 0-6 months after randomisation, patients in the EVAR group had a lower mortality (adjusted HR 0.61, 95% CI 0.37 to 1.02 for total mortality; HR 0.47, 95% CI 0.23 to 0.93 for aneurysm-related mortality;p = 0.031), but beyond 8 years of follow-up patients in the OR group had a significantly lower mortality (adjusted HR 1.25, 95% CI 1.00 to 1.56,p = 0.048 for total mortality; HR 5.82, 95% CI 1.64 to 20.65,p = 0.0064 for aneurysm-related mortality). The increased aneurysm-related mortality in the EVAR group after 8 years was mainly attributable to secondary aneurysm sac rupture, with increased cancer mortality also observed in the EVAR group. Overall, aneurysm reintervention rates were higher in the EVAR group than in the OR group, 4.1 and 1.7 per 100 person-years, respectively (p < 0.001), with reinterventions occurring throughout follow-up. The mean difference in costs over 14 years was £3798 (95% CI £2338 to £5258). Economic modelling based on the outcomes of the EVAR-1 trial showed that the cost per quality-adjusted life-year gained over the patient's lifetime exceeds conventional thresholds used in the UK. In EVAR-2, patients died at the same rate in both groups, but there was suggestion of lower aneurysm mortality in those who actually underwent EVAR. Type II endoleak itself is not associated with a higher rate of mortality. LIMITATIONS: Devices used were implanted between 1999 and 2004. Newer devices might have better results. Later follow-up imaging declined, particularly for OR patients. Methodology to capture reinterventions changed mainly to record linkage through the Hospital Episode Statistics administrative data set from 2009. CONCLUSIONS: EVAR has an early survival benefit but an inferior late survival benefit compared with OR, which needs to be addressed by lifelong surveillance of EVAR and reintervention if necessary. EVAR does not prolong life in patients unfit for OR. Type II endoleak alone is relatively benign. FUTURE WORK: To find easier ways to monitor sac expansion to trigger timely reintervention. TRIAL REGISTRATION: Current Controlled Trials ISRCTN55703451. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and the results will be published in full inHealth Technology Assessment; Vol. 22, No. 5. See the NIHR Journals Library website for further project information.Funding for this study was provided by the Health Technology Assessment programme of the National Institute for Health Research

Fenofibrate in the management of AbdoMinal aortic anEurysm (FAME): Study protocol for a randomised controlled trial

Background: Abdominal aortic aneurysm (AAA) is a slowly progressive destructive process of the main abdominal artery. Experimental studies indicate that fibrates exert beneficial effects on AAAs by mechanisms involving both serum lipid modification and favourable changes to the AAA wall. Methods/design: Fenofibrate in the management of AbdoMinal aortic anEurysm (FAME) is a multicentre, randomised, double-blind, placebo-controlled clinical trial to assess the effect of orally administered therapy with fenofibrate on key pathological markers of AAA in patients undergoing open AAA repair. A total of 42 participants scheduled for an elective open AAA repair will be randomly assigned to either 145 mg of fenofibrate per day or identical placebo for a minimum period of 2 weeks prior to surgery. Primary outcome measures will be macrophage number and osteopontin (OPN) concentration within the AAA wall as well as serum concentrations of OPN. Secondary outcome measures will include levels of matrix metalloproteinases and proinflammatory cytokines within the AAA wall, periaortic fat and intramural thrombus and circulating concentrations of AAA biomarkers. Discussion: At present, there is no recognised medical therapy to limit AAA progression. The FAME trial aims to assess the ability of fenofibrate to alter tissue markers of AAA pathology. Trial registration: Australian New Zealand Clinical Trials Registry, ACTRN12612001226897. Registered on 20 November 2012. © 2017 The Author(s)

Predictors of adverse events after endovascular abdominal aortic aneurysm repair: A meta-analysis of case reports

Introduction: Endovascular abdominal aortic aneurysm repair is a life-saving intervention. Nevertheless, complications have a major impact. We review the evidence from case reports for risk factors of complications after endovascular abdominal aortic aneurysm repair. Case presentation: We selected case reports from PubMed reporting original data on adverse events after endovascular abdominal aortic aneurysm repair. Extracted risk factors were: age, sex, aneurysm diameter, comorbidities, re-interventions, at least one follow-up visit being missed or refusal of a re-intervention by the patient. Extracted outcomes were: death, rupture and (non-)device-related complications. In total 113 relevant articles were selected. These reported on 173 patients. A fatal outcome was reported in 15% (N = 26) of which 50% came after an aneurysm rupture (N = 13). Non-fatal aneurysm rupture occurred in 15% (N = 25). Endoleaks were reported in 52% of the patients (N = 90). In half of the patients with a rupture no prior endoleak was discovered during follow-up. In 83% of the patients one or more re-interventions were performed (N = 143). Mortality was higher among women (risk ratio 2.9; 95% confidence interval 1.4 to 6.0), while the presence of comorbidities was strongly associated with both ruptures (risk ratio 1.6; 95% confidence interval 0.9 to 2.9) and mortality (risk ratio 2.1; 95% confidence interval 1.0 to 4.7). Missing one or more follow-up visits (≥1) or refusal of a re-intervention by the patient was strongly related to both ruptures (risk ratio 4.7; 95% confidence interval 3.1 to 7.0) and mortality (risk ratio 3.8; 95% confidence interval 1.7 to 8.3). Conclusion: Female gender, the presence of comorbidities and at least one follow-up visit being missed or refusal of a re-intervention by the patient appear to increase the risk for mortality after endovascular abdominal aortic aneurysm repair. Larger aneurysm diameter, higher age and multimorbidity at the time of surgery appear to increase the risk for rupture and other complications after endovascular abdominal aortic aneurysm repair. These risk factors deserve further attention in future studies