Abdominal Aortic Aneurysm Surveillance Research Articles

Thirty-Nine Percent of Patients with a Ruptured Abdominal Aortic Aneurysm (AAA) Have an Incidentally Detected AAA Prior to Rupture

IntroductionAbdominal aortic aneurysm (AAA) screening has been offered to 65-year-old men living in Oslo, Norway, since May 2011. A significant number of AAA-related deaths occurred in individuals who are not eligible for screening. The primary aim of this study was to describe the group of patients admitted to Oslo University Hospital with a ruptured AAA after the implementation of the local AAA screening project. The following parameters were investigated: AAA detection prior to rupture, surveillance status, eligibility for screening and comorbidities. We also sought to compare outcomes (repair rates and 30-day mortality) between patients with and without an AAA detected prior to rupture. MethodsThis cohort study included patients admitted acutely to Oslo University Hospital due to a symptomatic or ruptured AAA in the period January 2011 to December 2022. Data on demographics, prior AAA detection, surveillance status, treatment and mortality were collected retrospectively through electronic medical records. ResultsWe identified 200 patients with a symptomatic or ruptured AAA, among which 79 (40%) had an AAA detected prior to rupture – one (1%) through screening and 78 (39%) incidentally. Up to 30% of the incidentally detected AAAs were not under any surveillance. Six patients were found eligible for screening: one had attended, three were non-attenders and two had not been invited. Patients with an incidentally detected AAA prior to rupture had a more advanced age and a significantly higher degree of comorbidities than patients without a previously detected AAA, and the repair rates in these groups were 56% and 84% respectively (p < 0.001). Adjusted for comorbidities and risk factors, the odds ratio for repair among patients with incidentally detected AAA was 0.56 (p = 0.292). The 30-day mortality was not significantly different between the two groups (p = 0.097). ConclusionMost patients with a ruptured AAA were not eligible for screening, but 39% of the patients had an incidentally detected AAA prior to rupture. Standardized reporting and follow-up of incidentally detected AAAs is thus identified as an additional measure to organized screening in the effort to reduce AAA-related mortality.

Patient Perceptions of Surveillance of Small Abdominal Aortic Aneurysms in the Over 85s

Recently instigated local practice for patients with small abdominal aortic aneurysms (AAAs) involves contacting all patients, aged ≥85 years, to discuss with them the advantages and disadvantages of removal from surveillance. However, reasons why patients opt to remain on, or come off, surveillance, are currently unknown. The present study's objective is to explore patient perception of surveillance decision-making. A mixed-methods exploratory evaluation was undertaken using patient feedback obtained from a telephone survey. All patients aged ≥85 years, who had a consultation regarding ongoing surveillance of small AAAs (30-49 mm), and consented, were contacted by researchers, who conducted semi-structured interviews concerning factors influencing decision-making. A total of 24 patients (20 male; mean age = 86.9 years) were interviewed; 16 of 24 (66%) had opted to remain on surveillance, with no age difference between those opting in or out. Most felt surveillance was important (91%), and that it made them feel safer (73%). The majority (73%) thought they knew what happened when their AAA reached threshold (5.5 cm), what happened when a threshold AAA is not fixed (64%), and how major AAA surgery is (59%). However, actual knowledge was poor: most (91%) correctly understood surgery was major, but 56% thought that threshold AAA meant certain death or rupture; and 38% thought immediate surgery was required. Thematic analysis expounded patients' beliefs regarding surveillance, which were summarized in 3 distinct subgroups: reliance on professionals' opinions, needing peace of mind, and poor understanding. While most patients find surveillance reassuring, patient knowledge of AAA management at threshold is poor, potentially impacting surveillance decision-making. Elderly patients, with small AAAs contemplating ongoing surveillance, need to be better informed about AAA management at threshold to support shared decision-making.

O62: Five year followup of the abdominal aortic aneurysm Get Fit Trial: a randomised controlled trial of exercise to improve fitness in patients with AAA

Abstract Aims Improved fitness of patients on Abdominal Aortic Aneurysm(AAA) surveillance is predicted to reduce cardiovascular events and improve perioperative morbidity and mortality. The AAA GetFit Trial was a randomised control trial comparing community exercise programme(CEP) with standard care which demonstrated improved CardioPulmonary Exercise Test-related fitness in AAA patients to inform a definitive RCT. This study aims to investigate longer-term five-year clinical outcomes of these individuals. Methods The AAA GetFit trial recruited participants from Greater Manchester’s AAA Surveillance programme, and randomly assigned participants to either i)24-week CEP with choice of gym or home exercises, or ii) standard clinical care. We performed a retrospective analysis of clinical outcomes from this trial over five-year follow-up reviewing whether they underwent operative repair, 30-day postoperative morbidity, cardiovascular event, and mortality. We defined 30-day post-operative morbidity using Clavien-Dindo classification≥3. Results In total, 56 participants were recruited, 28 were randomised to CEP group, 86% were males. Mean age at time of enrolment was 72.8(SD5.7) years. At five-year follow-up, mortality in control and CEP were 60%(n=6) and 40%(n=4). In each group, 36%(n=20) underwent operative repair. There was no perioperative mortality. One perioperative morbidity occurred in control subject. Cardiovascular events(n=8) occurred in 7% and 21% control and CEP, respectively. Mean diameter of aneurysm increased in both CEPvsControl(0.89vs0.82cm). Conclusions The AAA GetFit trial showed significant benefits in cardiovascular fitness through community-based exercise. Clinical outcomes thus far were similar in both groups, there is an indication CEP improves perioperative outcomes.

Influence of cardiometabolic medications on abdominal aortic aneurysm growth in the UK Aneurysm Growth Study: metformin and angiotensin-converting enzyme inhibitors associated with slower aneurysm growth.

There is a clinical need for treatments that can slow or prevent the growth of an abdominal aortic aneurysm, not only to reduce the need for surgery, but to provide a means to treat those who cannot undergo surgery. Analysis of the UK Aneurysm Growth Study (UKAGS) prospective cohort was conducted to test for an association between cardiometabolic medications and the growth of an abdominal aortic aneurysm above 30 mm in diameter, using linear mixed-effect models. A total of 3670 male participants with data available on abdominal aortic aneurysm growth, smoking status, co-morbidities, and medication history were included. The mean age at recruitment was 69.5 years, the median number of surveillance scans was 6, and the mean(s.e.) unadjusted abdominal aortic aneurysm growth rate was 1.75(0.03) mm/year. In a multivariate linear mixed-effect model, smoking (mean(s.e.) +0.305(0.07) mm/year, P = 0.00003) and antiplatelet use (mean(s.e.) +0.235(0.06) mm/year, P = 0.00018) were found to be associated with more rapid abdominal aortic aneurysm growth, whilst metformin was strongly associated with slower abdominal aortic aneurysm growth (mean(s.e.) -0.38(0.1) mm/year, P = 0.00019), as were angiotensin-converting enzyme inhibitors (mean(s.e.) -0.243(0.07) mm/year, P = 0.0004), angiotensin II receptor antagonists (mean(s.e.) -0.253(0.08) mm/year, P = 0.00255), and thiazides/related diuretics (mean(s.e.) -0.307(0.09) mm/year, P = 0.00078). The strong association of metformin with slower abdominal aortic aneurysm growth highlights the importance of the ongoing clinical trials assessing the effectiveness of metformin with regard to the prevention of abdominal aortic aneurysm growth and/or rupture. The association of angiotensin-converting enzyme inhibitors, angiotensin II receptor antagonists, and diuretics with slower abdominal aortic aneurysm growth points to the possibility that optimization of cardiovascular risk management as part of abdominal aortic aneurysm surveillance may have the secondary benefit of also reducing abdominal aortic aneurysm growth rates.

Evaluation of outcomes and utility of abdominal aortic aneurysm surveillance in octogenarians and nonagenarians.

The aim of this study was to evaluate the utility of our regional abdominal aortic aneurysm (AAA) screening programme in octogenarians and nonagenarians. This was to help decide whether discontinuation might be appropriate in certain instances. Primary outcomes were the number of patients who reached threshold (5.5cm) and the number where intervention was offered. Secondary outcome was cost effectiveness. A retrospective review of a regional AAA surveillance database was carried out to evaluate outcomes. Data collected included patient age, sex, date of first and last scan, initial and latest size of aneurysm, outcome, time under surveillance and total number of scans. Patients were divided into three groups (80-84 years, 85-89 years and 90+ years). The number of patients in this age group was 354. Only 2.0% (n=7) of patients underwent intervention. Threshold size was achieved in 8.3% (n=18), 14.8% (n=18) and 26.7% (n=4), in the age groups 80-84 years, 85-89 years and 90+ years, respectively. Of these patients, operative intervention was possible in 2.8% (n=6), 0.8% (n=1) and 0% (n=0), respectively. A relatively small number of octogenarians and nonagenarians reach the threshold size during surveillance. An even smaller proportion require repair of their aneurysm. While there may be a role for AAA surveillance in octogenarians in highly selected groups, these data should inform the discussions made with individual patients. It should also inform future evaluation of such surveillance.

Incidental Cardiovascular Abnormalities in the Abdominal Aortic Aneurysm (AAA) Surveillance Population During the AAA Get Fit Trial: A Case Series and Review of the Literature.

Background The prevalence of cardiovascular disease and incidence of major adverse cardiovascular events (MACEs) is very high among the abdominal aortic aneurysm (AAA) surveillance population. Formal assessments of and interventions to reduce cardiovascular risk are not a routine part of the surveillance programme at present. However, its potential importance is highlighted by incidental findings during the AAA Get Fit Trial, a randomised controlled trial which included baseline cardiopulmonary exercise testing (CPET). We speculate that CPET can act as an opportunistic screening programme to identify cardiovascular disease in AAA surveillance patients. Methods The AAA Get Fit Trial was a prospective, randomised controlled trial at a tertiary vascular centre, Manchester University NHS Foundation Trust, conducted between November 2017 and August 2019. Patients underwent CPET at baseline, 8, 16, 24 and 36 weeks as well as clinical history and examination and blood tests. We report on incidental cardiovascular abnormalities diagnosed during the trial. Results Of the 59 participants in the trial, four (6.8%) were identified to have abnormal findings suggestive of unstable cardiovascular disease. On subsequent further investigation, two patients were diagnosed and treated for severe coronary artery disease after abnormal ECG findings were noted during CPET. One patient was diagnosed with unstable angina after obtaining a detailed history on baseline assessment which was treated medically before going on to have a successful elective AAA repair. Conclusions There is a high incidence of MACEs among this high-risk population both pre and perioperatively. Identifying and treating cardiovascular disease among the AAA surveillance population must be a focus of the future AAA screening programme.

Current Imaging Strategies in Patients with Abdominal Aortic Aneurysms.

An abdominal aortic aneurysm (AAA) is defined as a localized dilatation of the abdominal aorta of ≥ 3 cm. With a prevalence of 4-8 %, AAA is one of the most common vascular diseases in Western society. Radiological imaging is an elementary component in the diagnosis, monitoring, and treatment planning of AAA patients. This is a narrative review article on preoperative imaging strategies of AAA, incorporating expert opinions based on the current literature and standard-of-care practices from our own center. Examples are provided to illustrate clinical cases from our institution. Radiological imaging plays a pivotal role in the initial diagnosis and monitoring of patients with AAA. Ultrasound is the mainstay imaging modality for AAA screening and surveillance. Contrast-enhanced CT angiography is currently considered the gold standard for preoperative imaging and image-based treatment planning in AAA repair. New non-contrast MR angiography techniques are robustly applicable and allow precise determination of aortic diameters, which is of critical importance, particularly with regard to current diameter-based surgical treatment guidelines. 3D imaging with multiplanar reformation and automatic centerline positioning enables more accurate assessment of the maximum aortic diameter. Modern imaging techniques such as 4D flow MRI have the potential to further improve individualized risk stratification in patients with AAA. · Ultrasound is the mainstay imaging modality for AAA screening and monitoring. · Contrast-enhanced CT angiography is the gold standard for preoperative imaging in AAA repair. · Non-contrast MR angiography allows for accurate monitoring of aortic diameters in AAA patients. · Measurement of aortic diameters is more accurate with 3D-CT/MRI compared to ultrasound. · Research seeks new quantitative imaging biomarkers for AAA risk stratification, e. g., using 4D flow MRI.

600 Long-Term Clinical Outcomes of the Abdominal Aortic Aneurysm Get Fit Trial: A Randomised Controlled Trial of Exercise to Improve Fitness in Patients with Abdominal Aortic Aneurysm

Abstract Aim Improved fitness of patients on Abdominal Aortic Aneurysm (AAA) surveillance is predicted to reduce cardiovascular events and improve perioperative morbidity and mortality. The AAA GetFit Trial was a randomised control trial comparing community exercise programme (CEP) with standard care which demonstrated improved CardioPulmonary Exercise Test-related fitness in AAA patients to inform a definitive RCT. This study aims to investigate longer-term four-year clinical outcomes of these individuals. Method The AAA GetFit trial recruited participants from Greater Manchester's AAA Surveillance programme, and randomly assigned participants to either i)24-week CEP with choice of gym or home exercises, or ii) standard clinical care. We performed a retrospective analysis of prospective clinical outcomes from this trial over four-year follow-up reviewing whether they underwent operative repair, 30-day postoperative morbidity, cardiovascular event, and mortality with four-year followup. We defined 30-day post-operative morbidity using Clavien-Dindo classification≥3. Results In total,56 participants recruited, 28 were randomised to CEP group, 86% were males. Mean age at time of enrolment was 72.8(SD5.7) years. At four-year follow-up, mortality in CEP and control were both 14%(n = 4). In each group, 25%(n = 7) underwent operative repair. There was no perioperative mortality.Perioperative morbidity(n = 2) was 29% in CEP and 0% in control.Cardiovascular events(n = 9) was 7% in CEP and 25% in control.Mean diameter of aneurysm increased slower in CEPvsControl(0.84vs0.93cm). Conclusions The AAA GetFit trial showed significant benefits in cardiovascular fitness through community-based exercise. Although clinical outcomes thus far were similar in both groups, there is a suggestion of reduced cardiovascular events in the CEP group.

Understanding and Improving Risk Assessment of Abdominal Aortic Aneurysm Growth Using Statistical Shape Modeling of the Infrarenal Aorta

Maximum diameter of the aneurysmal sac remains the primary method for defining surveillance intervals and the timing for surgical intervention. Recent studies have attempted to expand on this one-dimensional metric by incorporating additional descriptors of the aneurysmal sac such as undulation, curvature and tortuosity. However, these metrics are often biased and may overlook certain anatomical abnormalities, limiting predictive potential. This study aimed to identify novel three-dimensional shape features of the aneurysmal flow lumen and outer wall structure (OWS, with or without intraluminal thrombus) to predict aneurysmal growth. A cohort of 192 patients (median age, 72 [range, 62-79]; 99% male) with infrarenal abdominal aortic aneurysms (AAAs) (initial max diameter, 50.3 ± 4.2 mm) and serial computed tomography images obtained during AAA surveillance (median follow-up, 2.0 years [range, 1.0-5.3 years]) were retrospectively considered for this study. Estimated annual AAA growth was the clinical end point and was used to classify patients into slow (first quintile, <2.5 mm/year) and fast (fifth quintile, >5.0 mm/year) cohorts. A previously validated pipeline was implemented to automatically segment computed tomography images. Three-dimensional statistical shape models of the aneurysmal flow lumen and OWS were used to identify three-dimensional patterns involved in AAA growth. Undulation index and radius of curvature of the AAA, previously suggested to be predictive of AAA growth, were also calculated. Model training with derived shape features was performed using iterated 10-fold optimization with shuffling (100 iterations). C-statistics for each feature combination was used to evaluate performance. Integrating the lumen and OWS as unique components within the three-dimensional statistical shape model captured the lumen-thrombus interface. These features proved to be superior to max diameter, undulation index, and radius of curvature in prediction of AAA growth phenotype (P < .001). Corresponding median C-statistics for predicting slow and fast growth are highlighted in the Figure. Integrated models outperformed individual components in prediction of both slow and fast AAA growth (P < .001). Standardized feature extraction from both the aneurysmal flow lumen and the OWS, enabled by a fully automated pipeline, can characterize the evolving lumen-thrombus interface, and improves AAA growth prediction. Future work is focused on validating this statistical shape-based model on larger cohorts that also include smaller AAAs.

MetAAA trial patients show superior quality of life compared to patients under regular surveillance for small AAA - A single-center retrospective cohort study.

Abdominal aortic aneurysm (AAA) is a multifactorial vascular disease associated with high morbidity and mortality. Currently, surgical intervention is the only treatment option and there is no drug therapy available for AAA. Hence, surveillance of AAA until indication for surgery may impact patient quality of life (QoL). There is a paucity of high-quality observational data on health status and QoL, particularly among AAA patients participating in randomized controlled trials. The objective of this study was to compare QoL scores of AAA patients on surveillance to those of AAA patients enrolled in the MetAAA trial. Overall, 54 MetAAA trial patients and 23 AAA patients under regular surveillance for small AAA (of a longitudinal monitoring study) were asked to complete three established and validated (in total 561 longitudinally collected) QoL questionnaires: 1) the 36-Item Short Form Health Survey (SF-36), 2) the Aneurysm Symptom Rating Questionnaire (ASRQ), and 3) the Aneurysm-Dependent Quality of Life questionnaire (ADQoL). A superior health status and QoL was found in AAA patients participating in the MetAAA trial compared to AAA patients under regular surveillance. In detail, MetAAA trial patients showed superior general health perception (P=0.012), higher energy level (P=0.036) as well as enhanced emotional well-being (P=0.044) and fewer limitations due to general malaise (P=0.021), which was subsequently reflected in an overall superior current QoL score (P=0.039) compared to AAA patients under regular surveillance. AAA patients enrolled in the MetAAA trial showed superior health status and QoL compared to AAA patients under regular surveillance.

The Impact of Abdominal Aortic Aneurysm Surveillance on Octogenarians in Regional Vascular Center

The Impact of Abdominal Aortic Aneurysm Surveillance on Octogenarians in Regional Vascular Center

Anticoagulants and reduced thrombus load in abdominal aortic aneurysms assessed with three-dimensional contrast-enhanced ultrasound examination.

The relationship between intraluminal thrombus (ILT) and abdominal aortic aneurysm (AAA) growth and rupture risk remains ambiguous. Studies have shown a limited effect of antiplatelet therapy on ILT size, whereas the impact of anticoagulant therapy on ILT is unresolved. This study aims to evaluate an association between antithrombotic therapy and ILT size assessed with three-dimensional contrast-enhanced ultrasound (3D-CEUS) examination in a cohort of patients with AAA. In a cross-sectional study, 309 patients with small AAAs were examined with 3D-CEUS. Patients were divided into three groups based on prescribed antithrombotic therapy: anticoagulant (n= 36), antiplatelet (n= 222), and no antithrombotic therapy (n= 51). Patient ILT size was calculated in volume and thickness and compared between the three groups. Patients on anticoagulants had a significantly lower estimated marginal mean ILT volume of 16mL (standard error [SE],±3.2) compared with 28mL (SE,±2.7) in the no antithrombotic group and 30mL (SE,±1.3) in the antiplatelet group when adjusting for AAA volume (P< .001) and comorbidities (P< .001). In addition, patients on anticoagulant therapy had significantly lower estimated marginal mean ILT thickness of 10mm (SE,±1.1) compared with 13mm (SE,±0.9) in the no antithrombotic group of and 13mm (SE,±0.4) in the antiplatelet group when adjusting for AAA diameter (P= .03) and comorbidities (P= .035). A 3D-CEUS examination is applicable for ILT assessment and demonstrates that patients with AAA on anticoagulant therapy have lower ILT thickness and volume than patients with AAA on antiplatelet therapy and those without antithrombotic therapy. Causality between anticoagulants and ILT size, and extrapolation to AAA growth and rupture risk, is unknown and merits further investigations, to further nuance US-based AAA surveillance strategy.

The Abdominal Aortic Aneurysm Get Fit Trial: A Randomised Controlled Trial of Exercise to Improve Fitness in Patients with Abdominal Aortic Aneurysm

Ruptured abdominal aortic aneurysm (AAA) carries a mortality rate of up to 80%. Elective repair prevents rupture, but peri-operative mortality remains at 2% – 3%. This mortality rate and long term survival rate are associated with impaired peak oxygen uptake (peak VO2), oxygen uptake at anaerobic threshold (AT) and ventilatory equivalent for CO2 (VECO2) at AT on cardiopulmonary exercise testing (CPET). Improving fitness to optimise these variables could improve peri-operative and long term survival, but the required exercise training suitable for patients with AAA has yet to be established. This randomised controlled trial aimed to evaluate the effectiveness of 24 week, patient directed, community based exercise on CPET measured fitness in AAA surveillance patients. This was a prospective randomised controlled trial in a tertiary UK vascular centre conducted using CONSORT guidelines. Patients on AAA surveillance (n = 56) were randomly assigned to either (1) a 24 week community exercise programme (CEP) with choice of gym or home exercises, or (2) standard clinical care including advice on weight loss and exercise. The primary outcome was change in peak VO2 at 24 weeks, with secondary outcomes including AT, VECO2, cardiovascular biomarkers (lipid profile, pro-B-type natriuretic peptide, and high sensitivity C reactive protein, body mass index, and HRQoL. Follow up was at eight, 16, 24, and 36 weeks to evaluate duration of benefit. All analyses were performed on an intention to treat basis. CEP patients (n = 28) achieved mean (95% confidence interval [CI]) improvements from baseline in peak VO2 of 1.5 (95% CI 0.5 – 2.5), 2.1 (95% CI 1.1 – 3.2), 2.3 (95% CI 1.2 – 3.3), and 2.2 (95% CI 1.1, 3.3) mL/kg/min at 8, 16, 24, and 36 weeks, respectively. These changes in CEP patients were significantly greater than those seen in control patients at 16 (p = .002), 24 (p = .031), and 36 weeks (p < .001). There were also significant improvements in AT, triglyceride levels, and HRQoL in CEP patients. This CEP significantly improved those CPET parameters associated with impaired peri-operative and long term survival in patients following AAA repair. These improvements were maintained at 12 weeks following the end of the programme.

Analyzing Sex Differences in Intensity of Cardiovascular Disease Prevention Medications in Patients With Abdominal Aortic Aneurysms—A Single-Center Cross-Sectional Study

Patients with abdominal aortic aneurysm (AAA) are at a significant risk of cardiovascular events, similar to that of patients who have already experienced a major cardiac event. The European Society for Vascular Society AAA guidelines suggest that antiplatelet therapy and lipid-lowering therapy (LLT) should be considered in all patients with AAA. This study explores the overall prevalence and intensity of antithrombotic therapy and LLT, and lipid profile monitoring in a single center AAA surveillance cohort alongside any sex differences. This was a retrospective, single center, cross-sectional study of 614 patients enrolled in the AAA surveillance program of a tertiary vascular surgery unit. All patients undergoing at least 1 surveillance scan from January 1, 2018, to December 31, 2020, were assessed. Electronic hospital records linked to real-time primary care records were interrogated for data on demographics, comorbidities, antiplatelet and LLT prescriptions, and serum cholesterol laboratory results. An analysis of covariance test was used to account for the effects of confounding comorbidities. Twenty-one percent of patients were not on antithrombotic therapy, and 20% of patients were not on LLT which reflects a group of patients receiving sub-optimal clinical care. In total, 47% of the cohort were on low/moderate intensity statin therapy which reflects a group of patients where care can be improved upon. Female sex was independently associated with a reduced likelihood of being prescribed LLT (P=0.008, eta squared (ηp2)=0.012, small effect size) but not antithrombotic therapy (P=0.202). Fewer women underwent low-density lipoprotein cholesterol (LDL-C) monitoring (mean difference 9%, P=0.040) and achieved the European Society of Cardiology-European Atherosclerosis Society- LDL-C target of <1.4mmol/L (mean difference 9%, P=0.040). Overall, there is room for improvement in these aspects of cardiovascular risk prevention for both sexes. Sex differences in the prescription of LLT, the prevalence of lipid profile monitoring, and likelihood of achieving LDL-C targets exist among patients with AAA, with a lower prevalence in women.

Reliability of the modified Frailty Index (mFI) for intervention and continued surveillance in elective infrarenal abdominal aortic aneurysm (AAA)

IntroductionFrailty has been proven to lead to higher morbidity and mortality rates in surgical patients, independent of age. The modified Frailty Index (mFI) is a validated means of assessing for frailty. Aim of studyThe aim of this study is to ascertain if the mFI correlates with clinician experience in turning down patients for abdominal aortic aneurysm (AAA) surgery and/or AAA surveillance. MethodsA contemporaneously recorded database of all AAA patients treated during 2017 at a large University Hospital was reviewed. Patients were categorised into the following groups; continued surveillance, turned down for surveillance, patient declined surveillance, patient offered surgery, patient turned down for surgery and patient declined surgery. ResultsOne hundred and forty two patients were included. Twenty-eight patients <5.5 cm were turned down for surveillance with a mFI of 0.27. Forty-one patients <5.5 cm continued with surveillance, with a mFI of 0.09 (p < 0.0001). Eighteen patients >5.5 cm were turned down for surgical intervention with a median mFI of 0.36. Forty-two patients were offered surgical intervention had a median mFI of 0.09 (p < 0.0001). ConclusionFrailty is associated with higher morbidity and mortality amongst frail patient cohorts. mFI is a valid and easy to use tool to predict perioperative outcomes in AAA intervention. It correlates well with senior, experienced clinicians’ decision-making in relation to who should and who should not undergo elective AAA surgery and those patients who should have ongoing aneurysm surveillance.

The correlation between different ultrasound planes and computed tomography measures of abdominal aortic aneurysms.

Ultrasound measurements of the aorta are typically taken in the axial plane, with the transducer perpendicular to the aorta, and diameter measurements are obtained by placing the callipers from the anterior to the posterior wall and the transverse right to the left side of the aorta. While the 'conventional' anteroposterior walls in both sagittal and transverse plains may be suitable for aneurysms with less complicated geometry, there is controversy regarding the suitability of this approach for complicated, particularly tortuous aneurysms, as they may offer a more challenging situation. Previous work undertaken within our research group found that when training inexperienced users of ultrasound, they demonstrated more optimal calliper placement to the abdominal aorta when approached from a decubitus window to obtain a coronal image compared to the traditional ultrasound approach. To observe the level of agreement in real-world reporting between computed tomography (CT) and ultrasound measurements in three standard planes; transverse AP, sagittal AP and coronal (left to right) infra-renal abdominal aortic aneurysm (AAA) diameter. This is a retrospective review of the Otago Vascular Diagnostics database for AAA, where ultrasound and CT diameter data, available within 90 days of each other, were compared. In addition to patient demographics, the infrarenal aorta ultrasound diameter measurements in transverse AP and sagittal AP, along with a coronal decubitus image of the aorta was collected. No transverse measurement was performed from the left to the right of the aorta. Three hundred twenty-five participants (238 males, mean age 76.4 ± 7.5) were included. Mean ultrasound outer to the outer wall, transverse AP and sagittal AP diameters were 48.7 ± 10.5 mm and 48.9 ± 9.9 mm, respectively. The coronal diameter measurement of the aorta from left to right was 53.9 ± 12.8 mm in the left decubitus window. The mean ultrasound max was 54.3 ± 12.6 mm. The mean CT diameter measurement was 55.6 ± 12.7 mm. Correlation between the CT max and ultrasound max was r 2 = 0.90, and CT with the coronal measurement r 2 = 0.90, CT and AP transverse was r2=0.80, and CT with AP sagittal measurement was r 2 = 0.77. The decubitus ultrasound window of the abdominal aorta, with measurement of the coronal plane, is highly correlated and in agreement with CT scanning. This window may offer an alternative approach to measuring the infrarenal abdominal aortic aneurysm and should be considered when performing surveillance of all infra-renal AAA.

Editor's Choice – The Abdominal Aortic Aneurysm Get Fit Trial: A Randomised Controlled Trial of Exercise to Improve Fitness in Patients with Abdominal Aortic Aneurysm

Ruptured abdominal aortic aneurysm (AAA) carries a mortality rate of up to 80%. Elective repair prevents rupture, but peri-operative mortality remains at 2% - 3%. This mortality rate and long term survival rate are associated with impaired peak oxygen uptake (peak VO2), oxygen uptake at anaerobic threshold (AT) and ventilatory equivalent for CO2 (VECO2) at AT on cardiopulmonary exercise testing (CPET). Improving fitness to optimise these variables could improve peri-operative and long term survival, but the required exercise training suitable for patients with AAA has yet to be established. This randomised controlled trial aimed to evaluate the effectiveness of 24 week, patient directed, community based exercise on CPET measured fitness in AAA surveillance patients. This was a prospective randomised controlled trial in a tertiary UK vascular centre conducted using CONSORT guidelines. Patients on AAA surveillance (n= 56) were randomly assigned to either (1) a 24 week community exercise programme (CEP) with choice of gym or home exercises, or (2) standard clinical care including advice on weight loss and exercise. The primary outcome was change in peak VO2 at 24 weeks, with secondary outcomes including AT, VECO2, cardiovascular biomarkers (lipid profile, pro-B-type natriuretic peptide, and high sensitivity C reactive protein, body mass index, and HRQoL. Follow up was at eight, 16, 24, and 36 weeks to evaluate duration of benefit. All analyses were performed on an intention to treat basis. CEP patients (n= 28) achieved mean (95% confidence interval [CI]) improvements from baseline in peak VO2 of 1.5 (95% CI 0.5 - 2.5), 2.1 (95% CI 1.1 - 3.2), 2.3 (95% CI 1.2 - 3.3), and 2.2 (95% CI 1.1, 3.3) mL/kg/min at 8, 16, 24, and 36 weeks, respectively. These changes in CEP patients were significantly greater than those seen in control patients at 16 (p= .002), 24 (p= .031), and 36 weeks (p < .001). There were also significant improvements in AT, triglyceride levels, and HRQoL in CEP patients. This CEP significantly improved those CPET parameters associated with impaired peri-operative and long term survival in patients following AAA repair. These improvements were maintained at 12 weeks following the end of the programme.

Aneurysm Geometry Analyzed by the Novel Three-Dimensional Tomographic Ultrasound Relates to Abdominal Aortic Aneurysm Growth

Abdominal aortic aneurysms (AAAs) are increasingly screen-detected and many small aneurysms enter surveillance. Computed tomography identifies characteristics that can predict subsequent AAA growth but ionizing radiation and nephrotoxic contrast disadvantage its use in surveillance. We investigated whether duplex and 3-dimensional tomographic ultrasound identified features associated with AAA growth in patients on AAA surveillance. Duplex and three-dimensional tomographic ultrasound imaging was performed independently by 2 vascular scientists in 128 AAA surveillance patients who all had AAA growth measured over at least 2 years. Diameter, cross-sectional area, length, volume, wall thickness/volume, and intraluminal thrombus were measured. Pulsatility using maximum systolic and minimum diastolic diameters corrected for diameter and distensibility (consisting of strain and stiffness) were also calculated. AAA growth rate correlated with AAA diameter (r 0.43), volume (r 0.46), and cross-sectional area (r 0.42) (P < 0.01). Measuring wall thickness was inaccurate, but wall volume (corrected for AAA volume) inversely related to growth rate (r -0.43, P < 0.01). On a multivariate analysis, diameter and wall volume (r2adjusted 0.22, P < 0.01) improved prediction of growth rate compared with diameter alone (r2adjusted 0.18, P<0.01). Intraluminal thrombus volume, strain distensibility, and elastic distensibility were not significantly associated with AAA growth. AAA growth most strongly related to AAA volume and inversely to wall volume. AAA volume and wall volume may prove useful in the prediction of AAA growth rates.

A Population-Based Approach to Abdominal Aortic Aneurysm Surveillance Is Associated With Guideline Concordant Care

Most abdominal aortic aneurysms (AAAs) detected incidentally or through targeted screening are small and require surveillance. However, larger AAAs can require vascular surgery (VS) evaluation and intervention. However, prior studies have reported poor follow-up for AAA patients, especially those with small AAAs, and largescale surveillance program outcomes are unreported in U.S.-based healthcare systems. In this study, we have described an established AAA surveillance program and examined its impact on concordance with surveillance guidelines.

Establishment of a clinical nurse specialist-led, virtual aneurysm surveillance clinic.

The COVID-19 pandemic has necessitated significant changes to the manner in which healthcare is delivered. Chief among these has been the need to rapidly adopt virtual, or telephone clinics as a means of reducing unnecessary patient exposure to hospitals and clinical care settings. We were greatly aided in our adoption of virtual clinics by our experience in the establishment and maintenance of a Clinical Nurse Specialist-led, virtual clinic for both abdominal aortic (AAA) and extra-aortic aneurysm (EAA) surveillance within our department since 2016. Patients undergoing surveillance for abdominal aortic aneurysm (AAA) require frequent and lifelong clinical review. Previous studies have shown that post-operative surveillance in particular is critical in prolonging survival in AAA patients and in the early detection of late complications particularly following endovascular repair (EVAR). Poor compliance with EVAR surveillance has been shown to result in worse outcomes. The aim of this study was to evaluate the success of a nurse-led virtual clinic programme in terms of the safe management of patients undergoing AAA surveillance in a nurse-led virtual clinic. Over the course of the 4-year period from 2016 to 2019, 1352 patients were enrolled in the virtual aneurysm surveillance clinic. The majority of patients each year were male, ranging from 78.2% in 2016 to 85.2% in 2017. The majority of patients encountered the service owing to pre-operative surveillance of an AAA, with this group comprising at least 65% of the total cohort of patients each year.Over the course of the 4-year period of the virtual clinic there were 1466 patient encounters. Each ambulatory day care centre (ADCC) attendance normally costs the hospital €149. Therefore, a total saving of €218,434 resulted from this initiative alone. No patient presented as an emergency with a ruptured aneurysm during the time period studied. Patients with AAA can be safely kept under surveillance in a nurse-led virtual clinic. Our experience with this model of care proved to be particularly advantageous during the period of the early COVID-19 pandemic.