AAA Repair Research Articles

Top 10 candidate aortic disease trials.

Aortic pathologies such as aneurysm, dissection and trauma are relatively common and potentially fatal diseases. Over the past two decades, we have experienced unprecedented technical and medical developments in the field. Despite this, there is a great need, and great opportunities, to further explore the area. In this review, we have identified important areas that need to be further studied and selected priority aortic disease trials. There is a pressing need to update the AAA natural history and the role for endovascular AAA repair as well as to define biomarkers and genetic risk factors as well as influence of gender for development and progression of aortic disease. A key limitation of contemporary treatment strategies of AAA is the lack of therapy directed at small AAA, to prevent AAA expansion and need for surgical repair, as well as to reduce the risk for aortic rupture. Currently, the most promising potential drug candidate to slow AAA growth is metformin, and RCTs to verify or reject this hypothesis are warranted. In addition, the role of endovascular treatment for ascending pathologies and for uncomplicated type B aortic dissection needs to be clarified.

Long-Term Outcomes of Endovascular vs Open Surgical Repair for Abdominal Aortic Aneurysms: A Meta-Analysis of Randomized Trials

ObjectiveThe aim of this meta-analysis was to investigate whether Endovascular abdominal aortic aneurysm repair (EVAR) is inferior to open surgical repair in terms of adverse events during late follow up, defined as >8 years after the procedure. BackgroundEVAR is associated with reduced morbidity and mortality compared to open surgery in the early perioperative period. However, it is unknown whether this pattern remains during long-term follow up >8 years. MethodsA meta-analysis was conducted with the use of random effects modeling. Hazard ratios were calculated for mortality at different time intervals, and risk ratios were calculated in cases where the total number of events was available. ResultsThere was no difference in all-cause mortality during follow up of each study (HR: 1.04; 95%CI: 0.93–1.17; I2 = 16.0%). Subgroup analyses for all-cause mortality at 4 to 8 years of follow up (HR: 1.13; 95%CI: 0.94–1.35; I2 = 0.0%) and all-cause mortality at follow up >8 years (HR: 1.07; 95%CI: 0.89–0.28; I2 = 36.6%) also did not show any significant difference between the two approaches. The risks of aneurysm-related mortality and aneurysm rupture were similar during follow-up. However, the cumulative risk for reintervention during follow up was greater in the EVAR group (RR: 2.18; 95%CI: 1.50–3.17; I2 = 76.1%) and occurred in 29% vs 15% of patients in the EVAR vs surgery groups respectively. ConclusionsEVAR and open surgical repair of AAA are equally safe and have no difference in all-cause mortality. However, endovascular repair is associated with an increased need for re-intervention. Emerging technology in endovascular devices will likely further improve the outcomes of EVAR.Subject codes: Meta-analysis; aneurysm; atherosclerosis; complications.

Systematic Review and Meta: Analysis of Aortic Graft Infections following Abdominal Aortic Aneurysm Repair.

Introduction. Aortic graft infection (AGI) is a rare complication following AAA repair and is associated with high morbidity and mortality. Management is variable, and there are no evidence-based guidelines. The aim of this study was to systematically review and analyse management options for AGI. Methods Data was collected between July and August 2018. A full HDAS search was conducted on the following databases: MEDLINE, EMBASE, CINAHL, and PUBMED. Meta-analysis was conducted using RevMan 5 software. Results 1,365 patient outcomes were assessed (10 cohort studies and 12 comparative studies). The most common treatment was in situ replacement of the graft (ISR) followed by extra-anatomical replacement (EAR). Various grafts were used for ISR, such as fresh/cryopreserved allograft, venous graft, and prosthetic grafts. No graft material was shown to be superior. Axillobifemoral graft was the commonest type of EAR used. In the majority of cohort studies, ISR was the main treatment for AGI. There was no significant difference in the overall mortality rate (ISR n = 70/176 vs. EAR n = 70/176 vs. EAR P = 0.87). Graft occlusion rate was significantly lower in the ISR group vs. the EAR group (n = 70/176 vs. EAR n = 70/176 vs. EAR P = 0.87). Graft occlusion rate was significantly lower in the ISR group vs. the EAR group (n = 70/176 vs. EAR n = 70/176 vs. EAR P = 0.87). Graft occlusion rate was significantly lower in the ISR group vs. the EAR group (Discussion. In situ replacement is the preferred method of treatment as it had lower rates of occlusion. Further strong evidence is required, such as a multicentre trial to establish a management pathway for the condition.

Editor's Choice – Short Term and Long Term Outcomes After Endovascular or Open Repair for Ruptured Infrarenal Abdominal Aortic Aneurysms in the Vascular Quality Initiative

Repair of ruptured infrarenal abdominal aortic aneurysms (rAAA) has shifted from open surgical (OAR) to endovascular (EVAR) over the last decade. However, the long term impact of EVAR vs. OAR for rAAA has not been well described. Prospectively collected registry data (Vascular Quality Initiative [VQI]) were analysed retrospectively to identify patients who underwent EVAR or OAR for rAAA (2004-2018). The primary outcome was death (in hospital and overall post-discharge). Inverse probability weighting (IPW) was used to adjust for treatment selection. Poisson regression assessed the number of one year post-discharge re-interventions. In total, 4257 patients receiving EVAR (n=2389 [56%]) or OAR (n=1868 [44%]) for rAAA were identified. Patients were predominantly male (n=3310 [77.8%]) with a mean±standard deviation age of 72.7±9.6 years; most (n=2449 [59.4%]) presented with haemodynamic instability. Use of EVAR for rAAA increased from 7.8% in 2004 to 67.2% in 2018. After IPW, OAR was associated with a higher odds of in hospital mortality (odds ratio [OR] 1.76, 95% confidence interval [CI] 1.54-2.01; p<.001), which was confirmed after multivariable logistic regression (OR 2.08, 95% CI 1.76-2.45; p<.001). Multivariable Cox proportional hazards showed that OAR was also associated with increased overall post-discharge mortality among all patients (hazard ratio 1.36, 95% CI 1.23-1.51; p<.001). Within weighted treatment groups, five year survival was significantly different (55% for EVAR vs. 46% for OAR; p<.001). OAR showed a significantly higher risk of one year post-discharge re-interventions (incidence rate ratio 2.10, 95% CI 1.52-2.89; p<.001). Within the VQI, EVAR for rAAA repair has been increasingly adopted with favourable short term outcomes in terms of morbidity and mortality, as compared with OAR. Unlike elective AAA repair, survival rates between EVAR and OAR do not converge in long term follow up for patients who survived the index hospitalisation.

Assessment of the Risk Analysis Index for Prediction of Mortality, Major Complications, and Length of Stay in Patients who Underwent Vascular Surgery

Frailty is a risk factor for adverse postoperative outcomes. We aimed to test the performance of a prospectively validated frailty measure, the Risk Analysis Index (RAI) in patients who underwent vascular surgery and delineate the additive impact of procedure complexity on surgical outcomes. We queried the 2007-2013 American College of Surgeons National Surgical Quality Improvement Program database to identify 6 major elective vascular procedure categories (carotid revascularization, abdominal aortic aneurysm [AAA] repair, suprainguinal revascularization, infrainguinal revascularization, thoracic aortic aneurysm [TAA] repair, and thoracoabdominal aortic aneurysm [TAAA] repair). We trained and tested logistic regression models for 30-day mortality, major complications, and prolonged length of stay (LOS). The first model, "RAI," used the RAI alone; "RAI-Procedure (RAI-P)" included procedure category (e.g., AAA repair) and procedure approach (e.g., endovascular); "RAI-Procedure Complexity (RAI-PC)" added outpatient versus inpatient surgery, general anesthesia use, work relative value units (RVUs), and operative time. The RAI model was a good predictor of mortality for vascular procedures overall (C-statistic: 0.72). The C-statistic increased with the RAI-P (0.78), which further improved minimally, with the RAI-PC (0.79). When stratified by procedure category, the RAI predicted mortality well for infrainguinal (0.79) and suprainguinal (0.74) procedures, moderately well for AAA repairs (0.69) and carotid revascularizations (0.70), and poorly for TAAs (0.62) and TAAAs (0.54). For carotid, infrainguinal, and suprainguinal procedures, procedure complexity (RAI-PC) had little impact on model discrimination for mortality, did improve discrimination for AAAs (0.84), TAAs (0.73), and TAAAs (0.80). Although the RAI model was not a good predictor for major complications or LOS, discrimination improved for both with the RAI-PC model. Frailty as measured by the RAI was a good predictor of mortality overall after vascular surgery procedures. Although the RAI was not a strong predictor of major complications or prolonged LOS, the models improved with the addition of procedure characteristics like procedure category and approach.

Fenestrated Endograft Repair Is Associated With Improved Perioperative Outcomes but Absence of Hospital Volume Relationship in Comparison to Open Surgical Repair of Complex Abdominal Aortic Aneurysms

Complex abdominal aortic aneurysms (cAAAs) have traditionally been treated with an open surgical repair (OSR). During the past decade, fenestrated endovascular aneurysm repair (FEVAR) has emerged as a viable option. During this time, the hospital procedural volume to outcome relationship for OSR of cAAAs has been well established, but the impact of procedural volume on FEVAR outcomes remains undefined. This study investigated the outcomes of OSR and FEVAR for the treatment of cAAAs and examined the hospital volume-outcome relationship for these procedures. A retrospective review of a statewide vascular surgery registry was queried for all patients between 2012 and 2018 who underwent elective repair of a juxtarenal AAA with FEVAR or OSR. The primary outcomes were 30-day mortality, myocardial infarction, and new dialysis. Secondary end points included postoperative pneumonia, renal dysfunction (creatine concentration increase of >2 mg/dL from preoperative baseline), major bleeding, early procedural complications, length of stay, and need for reintervention. To evaluate procedural volume-outcome relationships, hospitals were stratified into low- and high-volume aortic centers on the basis of an annual procedural volume of four juxtarenal AAA repairs per year. To account for baseline differences, we calculated propensity scores and employed probability weighting. A total of 590 patients underwent FEVAR (n = 187) or OSR (n = 403) for cAAAs. After adjustment, OSR was associated with higher rates of 30-day mortality (10.6% vs 3.2%; P = .001), myocardial infarction (3.9% vs 0.81%; P = .29), and need for dialysis (13.5% vs 3.7%; P = .001). Postoperative pneumonia (6.8% vs 0.44%; P = .001) and need for transfusion (35.3% vs 9.6%; P = .001) were also significantly higher in the OSR cohort. The median length of stay for OSR and FEVAR was 9 days and 3 days, respectively. For those who underwent FEVAR, endoleaks were present in 11.6% of patients at 30 days and 5.4% of patients at 1 year, with the majority being type II. One percent of FEVAR patients required a secondary procedure with a median follow-up period of 331 days (229-378 days), and there were no FEVAR conversions to an open aortic repair during this period. Hospitals were divided into low- and high-volume aortic centers on the basis of their annual FEVAR cAAA volume. After adjustment, hospital FEVAR procedural volume was not associated with 30-day mortality or myocardial infarction. FEVAR was associated with lower perioperative morbidity and mortality compared with OSR for the management of complex AAAs. Procedural FEVAR volume-outcome analysis suggests no difference in 30-day morbidity or mortality between low- and high-volume centers, although long-term durability warrants further research.

Effect of Abdominal Aortic Aneurysm Repair (Arterial Stiffening) on Pulse Wave Velocity and its Impact on Cardiovascular Hemodynamics

Introduction: Aortic grafting and endografting has been reported to affect pulse wave velocity (PWV) and is considered a surrogate of arterial stiffness as well as a prognostic factor of cardiovascular morbidity. We aim to study potential correlations of PWV alterations post AAA repair using common aortic grafts with cardiovascular events, hypertension and kidney injury. Methods: Fifty-seven consecutive AAA patients from a single center were initially enrolled for a PWV analysis (Complior SP/ Analyze). Measurements were obtained pre-operatively, 1 week and 6 months post-operatively. Systolic blood pressure, carotid-radial (cr) PWV (central aortic stiffness), carotid-femoral (cf) PWV (peripheral aortic stiffness), cardiac events, medication adjustments and renal failure were recorded. Results: Ten open (6 Dacron, 4 ePTFE grafts) and 47 endovascular (OVATION stent-grafts), 49 elective and 8 urgent, AAA repairs were fully followed-up. Patient demographics included (mean values): age 69 years, aortic diameter 5.6 cm, BMI 27,6 kg/m2. All patients were men, 51 (92%) were smokers, 47 (83%) had hypertension, 15 (27%) Coronary Artery Disease, 6 (11%) diabetes mellitus, 33 (60%) dyslipidemia, 26 (47%) chronic obstructive pulmonary disease, 10 (18%) peripheral artery disease. We noticed an increase in c-f PWV (central aortic stiffness) (10.4,12.3,11.6; @preop, 1W and 6M postop, respectively, p< 0,001) and a decrease in c-r PWV (peripheral stiffness) (9.2,8.5,8.4, p< 0,01; respectively). 55% presented a rise greater than 10% of cf-PWV and 46% a decrease greater than 10% of cr-PWV. During the first 6 postoperative months, 3 (5%) needed adjustment of antihypertensive medical treatment presenting a greater than 20% rise of cf-PWV. 5 (8%) presented acute cardiovascular syndromes: 2 acute pulmonary oedema (greater than 20% rise of cf-PWV), 1 acute coronary syndrome (greater than 40% rise of cf-PWV), 1 aortic dissection (greater than 40% decrease of cr-PWV), 1 stroke (greater than 130% increase of cr-PWV). Five patients presented an acute kidney injury of which 3 presented a decrease of cf-PWV instead of an expected increase. Conclusion: PWV is an easy, reproducible and low cost examination, that can estimate modifications of aortic stiffness after AAA repair, either open or endovascular. This seems to have a subsequent effect on hypertension and major cardiovascular events. Current guidelines do not discriminate high risk subgroups for extensive cardiac follow up but thorough cardiac and renal consultation and lifetime follow may be crucial after AAA repair. More compliant new generation aortic grafts and endografts may decrease this effect. More studies are required to clarify the significance of PWV for AAA patients. Disclosure: Nothing to disclose

The Influence of Gender on Outcomes Following Elective Repair of Asymptomatic Large Abdominal Aortic Aneurysms

Introduction: Vascular Services Quality Improvement Program (VSQIP) was introduced in the United Kingdom in order to reduce mortality from elective repair of AAA. Prior to introduction of VSQIP women had lower survival rates from AAA repair (1). This study examines the influence of gender on perioperative outcome and post operative survival following elective repair of AAAs in the 10 years after implementation of the (VSQIP) in a regional vascular surgery center in the United Kingdom. Methods: Patients who underwent elective repair of AAA in a specialist vascular center between 1st January 2008 and 31st March 2018 were included. All patients were assessed using the nationally agreed Vascular Services Quality Improvement Programme care pathway for AAAs. The VSQIP pathway involved anesthetic assessment prior to intervention which included cardiopulmonary exercise testing as well as contrast enhanced CT scan of aorta. This was followed by multidisciplinary assessment to plan each patient's treatment. Each CT scan was examined to assess the morphology of AAA. Patients were stratified by age, gender, AAA morphology and preoperative anaerobic threshold. Postoperative survival was assessed using Kaplan-Meier analysis. Multivariate logistic regression analysis was used to determine predictors of perioperative mortality. Results: A total of 702 patients underwent elective repair of AAA of whom 632 were men and 70 were women. The mean age of study cohort was 73.5 years (std. dev: 7.3) and mean AAA diameter was 62 mm (std. dev.: 9.9). Two hundred and forty four patients underwent open repair, 402 underwent standard infra renal EVAR and 56 underwent complex EVAR with perioperative and 30 day mortality of 1.13%. Anaerobic threshold< 8 (HR: 95%CI: 2.01 (1.09-3.32)), complex aneurysm morphology [HR (95%CI): 4.55 (1.51-7.33)] were independent risk factor for perioperative mortality, whilst female gender [(HR (95%CI): 0.98 (092-1.68)] was not. There was no difference in post-operative survival between men and women who underwent elective repair of AAA (Log rank: 1.82 P=NS) Conclusion: Following the implementation of VSQIP female gender is no longer a significant risk factor for perioperative mortality or postoperative reduced survival following elective repair of large asymptomatic AAA. Disclosure: Nothing to disclose

Systematic Review and Meta-analysis of Aortic Graft Infections Following AAA Repair

Systematic Review and Meta-analysis of Aortic Graft Infections Following AAA Repair

Five-Year Natural History of Screening Detected Sub-Aneurysms and Abdominal Aortic Aneurysms in 70-Year-Old Women and Systematic Review of Repair Rate in Women

Introduction - The aim of this study was to report on the natural history of a population-based cohort of 70-year old women with screening-detected infra-renal abdominal aortic aneurysms or sub-aneurysms as well as to systematically review publications reporting the rate of infra-renal intact aneurysm repair in women. Methods - In a previous study1, 5140 (74%) of 6925 invited women attended an ultrasound (US) examination of the abdominal aorta at age 70 years. All 52 women with screening detected sub-aneurysms (SA, diameter 25-29mm) and abdominal aortic aneurysms (AAA, diameter ≥30mm), were followed for 5 years with ultrasound. Infrarenal aortic diameters, AAA repair, all-cause and AAA-specific mortality, and risk factors were recorded. In addition, a systematic review of the rate of infra-renal intact aneurysm repair in women was conducted. Results - Sub-aneurysm A total of 33 (0.6%) women had a SA at the age of 70 and after five years follow-up two (6%) declined follow-up, five (15%) had died, and 26 were re-examined at age 75. 12/26 (46%) had progressed to AAAs from SAs and one woman was directly qualified for surgery. Smoking (p=0.010) and aortic diameter (p=0.040) were associated with progression to AAA. Aortic Abdominal Aneurysm A total of 19 (0.4%) women had an AAA at the age 70. After 5 years follow-up two (11%) had died, six (32%) had been electively repaired with no 30-day mortality, and 11 (58%) had an AAA still under surveillance at age 75 years. Systematic review In the systematic search four studies2-5 were identified and data on natural history was extracted and reviewed. A total of 842 women, with a mean aortic diameter of 26-39 mm at start of surveillance, were identified with a mean age of 70-75 years. After a follow-up of 2.5-10 years the elective repair rate was 3-25%. Data on rupture rate and all-cause mortality was scarce. Conclusion - Screening-detected AAAs and sub-aneurysms are clinically relevant in women. Within five years of detection a high proportion of AAAs require elective surgery, and a high proportion of sub-aneurysms progress to AAAs. Consequently, surveillance of sub-aneurysms in women with reasonable life-expectancy can be considered. Publications on repair-rate in women with intact AAAs are scarce and heterogeneous.

Contemporary Analysis of Intact Abdominal Aortic Aneurysm Repair by Treatment Method

Introduction: The long-term results of the landmark randomised trials comparing EVAR and open aneurysm repair (OAR) were challenged when recent recommendations of abdominal aortic aneurysm management were being based on them. In the last two decades since those trials were conducted, improvement in perioperative medicine, refined patient selection and advances in graft technology resulted in lower operative mortality. However, the impact of EVAR and OAR on long-term patient survival has been controversial (1, 2). The aim of this study was to compare the outcomes of OAR and EVAR in the recent era. Methods: This was an observational study. Both national administrative and clinical vascular databases were interrogated to capture all patients that underwent a planned AAA repair from the 1st of January 2010 until the 31st of December 2014. The data was matched by using unique patient identifying numbers, and death dates were obtained from national mortality database. Open repair and EVAR using 2nd 3rd generation endografts were included, trial devices and fenestrated/branched configuration were excluded. Logistic regression models were used to determine predictors of 30-day mortality, and Cox proportional hazards model was used to determine predictors of survival. The censoring date for survival analysis was the 31st of January 2018. The national ethics committee approved this study. Results: Overall, 1220 patients underwent aneurysm repair, of which 62 patients were excluded. The mean age was 74 years and 218 (18.2%) patients were females. There were 615 (53.1%) patients on whom an EVAR was performed and the median (interquartile range) AAA diameter was 61 (55-70)mm. The 30-day mortality after OAR and EVAR was 3.5% and 0.7% respectively (adjusted OR: 5.5 [95%CI:1.8-16.4]). The median and maximum follow-up was 4.5 and 8 years respectively. The crude survival curves crossed at 18 months and after adjusting for confounders, EVAR was associated with a HR 1.5 (95%CI:1.2-1.9). Patients who underwent an EVAR had a higher aneurysm-related mortality. Other prognostic factors that were also associated with a lower survival rate were: increased age, being female, and having renal impairment and ischaemic heart disease. Conclusion: In this real world setting using the current endografts devices and technology, patients who underwent EVAR enjoyed a lower short mortality but this benefit disappeared at 2 years follow-up. OAR had a higher survival rate in the long term. Disclosure: Nothing to disclose

Preliminary Results of the Evar 30-D SACVA Registry. The First and Largest Multicentric Registry in Southern Spain of Evar for Abdominal Aortic Aneurysms

Introduction: EVAR has been adopted worldwide as a standard approach for AAA in high risk patients unfit for open repair (OR), but also offered to no high-risk patients with no friendly anatomy for EVAR, based in the lower short-term morbidity of the endovascular approach. But published data are still controversial about the benefits of this approach in patients fit for surgery or with hostile aortic anatomies. Methods: Consecutive cases included from January 2016 to December 2017 in a collaboration between 10 Vascular Surgery departments and the Sociedad Andaluza de Angiología y C Vascular(SACVA). Retrospective multicentre data collected through specific designed formularies analyzed by the statistical department FIBAO(CHU Jaen). Initial descriptive analysis are presented in this paper. Results: 372 cases were collected from 10 centers, range cases/center (74-3). Elective EVAR 306(82%) and emergent EVAR 66 cases(18%). Epidemiological data: 357(96%) males and 15(4%) females, mean age of 73,69y.o. for no emergent EVAR VS 75y.o. for emergent EVAR. Tobacco use(89%) followed by arterial hypertension(80%) are the most prevalent cardiovascular risk factors. Based on AAA anatomy 76% were aortic aneurysms, 21% aorto-iliac and just 3% isolated iliac aneurysms. Mean of the AAA max diameter was 60.44mm for elective VS 75.54mm for emergent/ruptured cases. Mean neck diameter at renal arteries level was 24,3mm for elective VS 24.9mm for emergencies, and 2cm lower to renal was 26.57mm for elective vs 27.99mm for emergent. Anaesthetic risk 57.4% of the patients were ASA III and 25.7% ASA IV. Percutaneous access in 41.8% of the elective and 27.3% of the emergent cases. 29.7% of the cases where considered hostile neck anatomies, with 18.8% treated out of the instructions of use(IFU's) of the stentgraft. Stentgraft devices: 45.9 % with infrarenal fixation versus 54.1% suprarenal fixation. Technical success for EVAR achieved in 97.8%, with a conversion to OpenRepair rate inferior to 1.3%. 30-D endoleaks in 17.5% of the cases, from those 6% classed as type I. Hospital stay for elective EVAR was 4.85 days VS 8.44 for emergencies. Post-Implant syndrome in 17.4% patients. 30-D mortality for the 62 emergent cases was 22.2% VS 0.7% for the 312 elective. No major 30-D complications reported after EVAR in 85% of the elective cases versus 57.1% of the emergencies. Conclusion: The results of this multicentric registry, the largest with these characteristics performed in Spain shows similar 30-D results compared with other international registries and trials published in the literature, with a global decrease in 30-D mortality, lower than 1.5% for elective AAA repair and close to 20% for ruptured AAA, and reported technical success of superior to 98%. But the elevate number of cases included in this registry performed in hostile necks and out of the stentgrafts IFU's should be clearly remarked. Although it seems not to be relevant at the initial presented 30-D data after EVAR there is a need of close follow-up of these patients and it is mandatory to report the mid and long-term results of these patients over the next years. Disclosure: Nothing to disclose

Procedure Choice by Applying Cardio-pulmonary Exercise Test (CPET)-Based Stratification can Nullify Early Mortality Differences Between Elective Open Surgical and Endovascular Aneurysm Repair.

Introduction: The Endovascular Aneurysm Repair (EVAR) 1 trial concluded that EVAR offers a clear operative mortality benefit over open surgical repair (OSR) in patients fit for both procedures. Cardiopulmonary exercise testing (CPET) has been shown to be a reliable tool to measure fitness for major operations. This study aims to assess the impact of a CPET-based patient selection (open/endovascular) strategy upon perioperative mortality for elective AAA repair. The hypothesis of the study was that using a CPET-based stratification approach would enable higher risk patients as defined by anaerobic threshold/maximal oxygen uptake (AT/VO2max) to be channelled towards a lower risk procedure therefore nullifying the potential mortality risk difference across both groups. Methods: Between December 2009- January 2017, 247 patients from a single centre identified with a large (≥5.5cm) AAA anatomically suitable for either EVAR or OSR underwent preoperative CPET. Based on prescribed thresholds for the purpose of this study, patients were stratified to undergo OSR if designated ‘pass’ (AT≥11ml/kg/min, VO2max≥13L/min, nominated as Group 1) or EVAR when designated ‘fail’ (AT<11ml/kg/min, VO2max <13L/min, nominated as Group 2). Patients who underwent fenestrated/chimney EVAR were excluded, as were patients who crossed over for any reason. A retrospective analysis of prospectively collected data was undertaken. Primary parameters analysed included: BMI, age, length of stay (LOS) in intensive care or in total and 30-day mortality rate (30dMR). Statistical and numerical analyses were conducted within Microsoft Excel. Results: 247 AAA patients underwent CPET testing preoperatively over Nov 2009- Jan 2017. 133 patients were excluded (1 EVAR converted to OSR, 28 referred for FEVAR, 33 not operated upon at closure of the study, 3 CPET results unavailable or incomplete, 4 turned down, 2 refused surgery, 62 crossed over between groups) resulting in 114 available for analysis. There were 48 patients in group 1 who underwent OSR; 66 patients in group 2 underwent EVAR. Age was lower in Group 1 (median 68 years, CI 66.3 to 69.7) compared to Group 2 (median 75.5 years, 95% CI 73.96 to 77; p<0.05); BMI was similar across both groups (Group 1: median 27.35, 95% CI 26.2 to 28.4); group 2: median 28.8, 95% CI 25.5 to 28.8; p= 0.41). AT was higher in Group 1 (median 12 ml/kg/min, 95% CI 11.31 to 12.69) compared to group 2 (median 9 ml/kg/min, 95% CI 8.64 to9.36; p < 0.05, t-test). Similarly, VO2max was significantly higher in group 1 (median 18.5L/min, 95% CI 17.5 to 19.5) compared to group 2 (median 12L/min, 95% CI 11.27 to 12.73; p<0.05, t-test). None of the patients in group 2 needed ITU stay (median 0, 95% CI -0.2 to 0.2), whilst average ITU LOS for group 1 was 2 nights (median 2, 95% CI 1.26 to 2.73; p<0.05, two-sample t-test assuming unequal variances). This was mirrored in total LOS (group 1: median 7 days, 95% CI 4.2 to 9.8, group 2: median 2 days, 95% CI 1.8 to 4.2; p<0.05). 30dMR showed no statistical difference between the 2 groups (group 1: 30dMR= 4.2%, group 2: 30dMR = 0; p=0.09, chi-squared test), supporting our hypothesis. Conclusion: Older patients tended to ‘fail’ their CPET using the given parameters, but may have benefited in then being opted in for EVAR. A CPET-based stratification approach equalises the potential mortality differences between EVAR and OSR, supporting decision-making in terms of individualised procedure choice. Stratification to EVAR also leads to reduced LOS and ITU stay.

Fenestrated and Branched Endografting After Previous Open Infra-renal Aortic Aneurysm Repair

Introduction - Proximal para-anastomotic aneurysms, or aneurysmal degenerations of the native aorta above a previous infra-renal aortic open repair (P-AAAs), are not rare challenging scenarios. The aim of this study was to report the early and mid-term outcomes following endovascular repair of P-AAAs with fenestrated and branched endografts (FB-EVAR) Methods - From 2006 to 2017, we prospectively collected and retrospectively analyzed pre, intra and postoperative data of patients undergoing FB-EVAR for P-AAAs at two European vascular surgery units. Early outcomes were: technical success (target visceral vessels cannulation and stenting, absence of Type I-III endoleak, iliac limb occlusion and 24-h mortality), spinal cord ischemia (SCI), and 30-day mortality. Mid-term outcomes were: survival, target visceral vessels (TVV) patency, and freedom from re-interventions. Fisher’s exact test, Kaplan Mayer and Log rank were used for the statistical analysis Results - During the study period, 108 patients (M:94%; age:71±4years; ASA 3-4:74%>26%) were enrolled. The previous aortic OR was a tubular aorto-aortic 63(58%), a bifurcated aorto bi-iliac 37(34%) or an aorto bi-femoral 8(8%) bypass. The OR was performed 10±2years prior to the FB-EVAR. A previous TEVAR had also been performed in 7 patients (6%). The aortic lesions at the time of FB-EVAR was a type I-III 69(64%) or type IV 39(36%) thoracoabdominal aneurysm according to the Crawford’s classification. The mean aneurysm diameter was 64±6mm. Overall, 390 TVVs (3.6±1 TVV/case) were perfused by endograft fenestrations (63;58%), branches (26;24%) or both fenestrations and branches (19;18%). Tubular, tri-modular or aorto-monoiliac implants were planned in 68 (63%), 38 (35%) and 2 (2%) patients, respectively. Proximal TEVAR, carotid-subclavian bypass and iliac branch devices were planned adjunctive procedures in 41 (38%), 5 (5%) and 3 (3%) cases, respectively. Technical success was 93%. Technical failures included 5 TVV-loss (celiac trunk:1; renal arteries:4) and 3 deaths within 24 hours (cardiac aetiology). Post-operative SCI was diagnosed in 7 patients (7%), including 4 (4%) permanent. Type I-III TAAAs (p .04) and endograft incorporating both fenestrations and branches (p .04) were associated with SCI. Cardiac and pulmonary morbidity was 9% and 10%, respectively. Post-operative renal failure (GFR reduction >30% of baseline) was diagnosed in 22 patients (20%). Bowel ischemia was depicted in 3 (3%) patients. The 30-day mortality was 4%. Preoperative chronic renal failure (p .03), post-operative cardiac morbidity (p .04), and bowel ischemia (p .003) were associated with 30-day mortality. The mean follow-up was 38±18 months. Survival at 1, 3 and 5 years was 82%, 64% and 54%, respectively. There was no late aneurysm-related mortality. Survival during follow-up was significantly impacted by pre-operative chronic renal failure (p .005), post-operative cardiac morbidity (p .04), and SCI (p .04). Target visceral patency at 1, 3 and 5 years was 93%, 91% and 91%, respectively. New onset of hemodialysis was required in 4 patients (4%). Aneurysm enlargement (>5mm) was detected in 6 (5.5%) cases. Freedom from re-interventions at 1, 3 and 5 years was 89%, 77% and 74%, respectively Conclusion - Endovascular treatment of aortic aneurysmal evolution above a prior open AAA repair with FB-EVAR is safe and effective. If those promising results are confirmed during late follow-up, FB-EVAR should be considered as a therapeutic option, especially in high-risk patients

Survival After Elective Endovascular or Open AAA Repair: A Systematic Review and Meta-analysis

Introduction - Endovascular aneurysm repair (EVAR) has become the preferred strategy for elective AAA repair. However, superiority of EVAR has recently been challenged by reports of impaired longevity in patients who underwent elective endovascular repair. (1, 2) In this context we considered a systematic review and meta-analysis of the available survival data relevant. Possible confounding by age differences between patients receiving EVAR or open surgical repair (OSR) was addressed by estimating relative survival. Methods - A search using PubMed, Embase, Web of Science and Cochrane for the 1993-2018 interval identified 53 eligible papers that reported short-term and/or long-term mortality of EVAR and OSR. Identified studies included 4 randomized controlled trials (RCTs), 20 reports based on administrative registries, and 29 cohort studies. Pooled overall survival estimates (Hazard ratios with corresponding 95% CIs for EVAR versus OSR) were calculated using a random-effects model. For each study expected survival was calculated based on the matched (age, sex, year of operation and country) general population. Relative survival was consequently calculated as the ratio between observed and expected survival, according to EVAR or OSR. (3, 4) Results - The analysis includes data of 189.022 patients: 102.053 EVARs and 86.969 OSRs. Pooled 30-day mortality for EVAR was 1.16% (95% CIs 0.92 – 1.39) and 3.27% (95% CIs: 2.71 – 3.83) for OSR. Combined (overall) 3, 5, and 10-year survival rates were similar for EVAR and OSR. However, data from cohort studies indicated superior survival after OSR at 3 years and a trend towards superior survival at 5 and 10 years. Yet, EVAR patients included in these cohort studies were older (73.7 years) compared to OSR patients (71.4 years). Correction of age inequality through relative survival analysis showed comparable 3, 5, and 10 years survival for EVAR and OSR among all types of studies. Conclusion - Pooled data confirm superior 30-day survival of EVAR over OSR, but long-term survival up to 10 years is equivalent, when corrected for age inequality. Asymmetrical medical decision making with regard to EVAR and OSR may result in confounding by indication in the cohort and registry studies. Although relative survival estimates reduce the impact of age differences, it is plausible that fitter patients or patients with more complex AAA morphologies are more likely to receive OSR. Published data do not allow for extension beyond the 10-year survival window or for analysis of specific subgroups (women, young patients).

Ensuring Competency in Simulated Open Aortic Aneurysm Repair Using a Newly Developed Procedure-specific Assessment Tool- A Reliable Tool with Credible Pass-fail Standard for Assessment During Training, Testing and Certification

Introduction: There is an increasing need to establish structured simulation-based training programs in open repair of infrarenal aortic aneurysms (AAA) to address the current challenges such as work hour restrictions and decreasing frequency of open surgical repairs with the widespread shift to endovascular treatment (1,2). Simulation-based training programs for open AAA repair require a dedicated assessment tool with a credible pass-fail score to ensure minimum competences before apprenticeship on patients. Previous studies have used existing surgical assessment tools (3,4), however an up-to-date, and procedure-specific tool covering all steps of open AAA repair has yet to be developed and validated using a contemporary framework. The aims of the study were to develop a procedure-specific assessment tool for simulated open AAA repair, gather validity evidence for the tool, and establish a pass/fail standard for assessment. Methods: Validity evidence was explored using the contemporary framework by Messick (5). Three vascular surgeons with expertise in open AAA repair, and a professor in medical education with expertise in assessment and validation, developed the OPEn aortic aneurysm Repair Assessment of Technical Expertise (OPERATE) to ensure content evidence. Vascular surgical trainees with varying experience were invited to perform an open AAA repair on an abdominal model for open aortic surgery with pulsatile flow. All participants received e-learning materials prior to the operations. To ensure the quality and integrity of data, all procedures were performed in a standardized simulation-based environment with the presence of a supervisor who provided guidance when needed. The procedures were video recorded, anonymised, and scored independently by three expert vascular surgeons in a mutual blinded setup. The Angoff standard setting method was used to establish a credible pass-fail standard to determine consequences of testing. Results: A total of 16 novices and nine experienced open vascular surgeons participated in the study. The OPERATE consists of twelve items including four global scores (Figure 1). A high internal consistency for all items (Cronbach's alpha .92) and a high inter-rater reliability (Cronbach's alpha .94) were achieved. The novices performed significantly inferior from the experienced group with mean OPERATE scores of 15.1 and 25.6 (p=0.01), respectively (Figure 2). The pass/fail standard based on the Angoff method was 27.7. One novice passed the test while six experienced failed to achieve the pass-fail score. Conclusion: Strong validity evidence with a credible pass-fail standard was established for the newly developed procedure-specific assessment tool OPERATE, demonstrating its reliable use for structured formative assessment during training and summative assessment during testing or certification. The OPERATE has high discriminatory abilities and a high pass-fail standard emphasising the need for novice vascular surgeons to train in a simulation-based environment to achieve the minimum competences and skillsets before apprenticeship training on patients. The low scores in the experienced group underlines that familiarisation with the simulation equipment must be ensured before performance is assessed.Figure 2Box and whiskers plot showing the scores of the two groups.View Large Image Figure ViewerDownload Hi-res image Download (PPT) Disclosure: Nothing to disclose

MCAM/CD146 Which is Differentially Expressed in Vascular Diseases, is a Potential Biomarker in Abdominal Aortic Aneurysm

Introduction - AAA is characterized by chronic inflammation, apoptosis of vascular smooth muscle cells (VSMC), angiogenesis, extracellular matrix degradation, microcalcification and oxidative stress, processes that lead to the aorta degeneration. The role of VSMCs during the development and progression of AAA is not yet defined but their apoptosis results in the loss of the cells primarily responsible for the synthesis of extracellular matrix proteins. Cell adhesion molecules have been reported to be involved in the progression of atherosclerosis and plaque vulnerability. CD146 is an adhesion molecule located essentially in the vascular system and also present as a soluble form (sCD146) in the bloodstream. Although CD146/sCD146 has been previously associated with cardiovascular diseases, its potential role in AAA has not been addressed. Because of its role in angiogenesis, lymphocyte activation, tissue regeneration, inflammatory response and cellular senescence regulation, processes modulated in AAA, we hypothesized that CD146/sCD146 could play a role in AAA pathogenesis. Therefore, we investigated CD146 expression in AAA and its potential as a biomarker for AAA. Methods - We analyzed aortic samples from patients undergoing AAA repair in comparison with those from healthy multiorgan donors and femoral samples from atherosclerotic disease (AD) patients. Vascular tissue samples were studied using real-time PCR, immunohistochemistry and Western Blot. CD146, VSMC cell marker and endothelial cell marker genes transcript levels were determined relative to b-actin. Plasma levels of sCD146 were quantified by ELISA. Results - CD146 mRNA transcript levels were significantly lower in AAA (n=89) than in control aortas (n=17; p<0.001) and AD patients (n=15; p<0.001). Plasma levels of sCD146 were lower in AAA than in control and AD (AAA, 273.87±14.20, controls, 385.75±13.57; AD, 323.18±11.73 pg/ml; mean ± SEM) being differences statistically significants. When AAA patients were stratified according to maximum aortic diameter in: £55 mm, 55–69.9 mm and ≥70 mm, the expression of CD146 mRNA and sCD146 was already decreseased in the £55 mm group. Immunohistochemistry showed that CD146 was expressed mainly in the medial layer and endothelial cells from the microvasculature of the tissues. VSMC mRNA cell markers display the same expression profile than CD146 mRNA, in contrast to endothelial cell markers, wich were higher in AAA and AD than in controls. A positive correlation between CD146 mRNA and both cell markers was found in AAA but not in controls. In the experimental AngII induced AAA mouse model CD146 aortic mRNA levels were also decreased in AAA mice compared with control mice. Conclusion - We showed that CD146/sCD146 expression was significantly lower in AAA patients when compared with healthy individuals and, more importantly, with patients having atherosclerotic pathology without AAA and that mRNA levels correlates with VSMC markers genes in AAA. As VSMC apoptosis is revealed by downregulation of VSMC marker genes, CD146 could be a marker of VSMC loss, but this fact still remains uncertain. As CD146 is differently expressed in AD and AAA, CD146 could be a putative new marker for AAA. Further investigations will be needed to evaluate the role of CD146 in AAA pathology.

Redefining the “Honor Roll:” do hospital rankings predict surgical outcomes or receipt of quality surgical care?

BackgroundHospital ranking systems are often used by individuals to inform choice around which healthcare system may be best equipped to manage their care. MethodsThe 2013–2015 100% Medicare Inpatient and Outpatient SAFs was utilized to identify patients who underwent surgery (AAA repair, CABG, THA, TKA and lung resection) at one of the top-20 hospitals ranked by USNWR. ResultsOn multivariable linear regression analysis, after controlling for clinical and hospital level factors, rank position among the top 20 USNWR hospitals was not associated with the proportion of patients who experienced a complication (β = 0.167), failure-to-rescue (β = 0.277), 90-day readmission (β = 0.186) and 90-day mortality (β = 0.033)(all p > 0.05). Similar trends were observed among each surgical procedure type, as well as even among all top 50 USNWR ranked hospitals (all p > 0.05). ConclusionRank position among hospitals within the USNWR "honor roll" was not associated with differences in patient outcomes following surgical intervention. Patients and hospitals need to exercise caution when placing weight on rank-position among hospitals as a means to discriminate clinical outcomes and quality of actual patient care.

Percutaneous endovascular abdominal aneurysm repair: State-of-the art.

Endovascular repair of abdominal aortic aneurysms emerged initially as an alternative treatment strategy for patients considered to be inoperable or high risk for surgery. The evolution of endovascular techniques has made this technology a safe and less invasive alternative to open surgery for patients with suitable aortic anatomy. This manuscript reviews the current state of the art for endovascular AAA repair techniques, clinical outcomes, guideline recommendations, and future applications.

The impact of combined iliac occlusive disease and aortic aneurysm on open surgical repair

ObjectiveSevere aortoiliac occlusive disease is a relative contraindication for endovascular aneurysm repair, owing to an association with high stent graft-related complication and reintervention rates in this population. Open AAA repair requiring aortofemoral bypass (AFB), however, may represent a unique population with differing outcomes from standard open repair. We sought to compare the demographic and procedural characteristics, as well as outcomes of patients undergoing standard intra-abdominal repairs (STD) versus those requiring AFB. MethodsUsing a prospectively maintained database, we retrospectively identified patients who underwent open AAA repair from 1994 to 2017. A total of 1087 consecutive cases were performed consisting of 981 STD (681 tube graft, 300 aortoiliac) and 106 AFB cases. Demographics, procedural data, postoperative complications, and long-term survival were analyzed. ResultsThe AFB cohort had more women (39.0 vs 22.8%; P = .001) and higher rates of hypertension (81.1 vs 69.8%; P = .015), chronic obstructive pulmonary disease (28.3 vs 17.4%; P = .006), and smoking (50.9 vs 36%; P = .002). The AFB group had smaller mean aortic (5.22 vs 5.77 cm; P = .001) and graft (17.08 vs 18.2 mm; P = .001) diameters. Proximal clamp position and blood loss were equivalent, although total anesthesia time was longer (295 vs 234 minutes; P = .001) in the AFB cohort. Overall 30-day postoperative morbidity (38.7 vs 24.8%; P = .002) was higher in the AFB group. Specifically, postoperative renal insufficiency (8.2 vs 3.4%; P = .032), wound infection (5.7 vs 1.2%; P = .005), and hematoma/seroma (5.7 vs 1.2%; P = .003) were more likely. Hospital length of stay was longer for AFB (11.9 vs 9.9 days; P = .007). The 30-day mortality (0.9% AFB vs 1.8% STD; P = .50) and major morbidity (17 vs 11.5%; P = .10) did not differ. Reintervention rate within 30 days of the initial surgery (12.3 vs 4.6; P = .001) and overall (33 vs 18.9%; P = .001) was higher in the AFB group. Long-term survival was lower in the AFB group (5-year survival: 63.1% AFB vs 71.9% STD; hazard ratio 0.76, log-rank P = .047). Multivariate regression analysis identified age, comorbid conditions, and aneurysm characteristics—rather than repair type—as independent predictors of 30-day reintervention and mortality at 5 years. ConclusionsPatients requiring AFB for AAA owing to associated iliac occlusive disease have more preoperative comorbidities, postoperative complications, a longer length of stay, reintervention rates and shorter 5-year survival. Patient and aneurysm characteristics rather than surgical repair type appear to be responsible for these differences. Nevertheless, 30-day mortality and major morbidity were comparable, making AFB an attractive alternative to endovascular aneurysm repair in patients with advanced iliac occlusive disease.