Lessons learned about prevalence and growth rates of abdominal aortic aneurysms from a 25-year ultrasound population screening programme.

BACKGROUND: This study aimed to assess how the prevalence and growth rates of small and medium abdominal aortic aneurysms (AAAs) (3·0-5·4 cm) have changed over time in men aged 65 years, and to evaluate long-term outcomes in men whose aortic diameter is 2·6-2·9 cm (subaneurysmal), and below the standard threshold for most surveillance programmes. METHODS: The Gloucestershire Aneurysm Screening Programme (GASP) started in 1990. Men aged 65 years with an aortic diameter of 2·6-5·4 cm, measured by ultrasonography using the inner to inner wall method, were included in surveillance. Aortic diameter growth rates were estimated separately for men who initially had a subaneurysmal aorta, and those who had a small or medium AAA, using mixed-effects models. RESULTS: Since 1990, 81 150 men had ultrasound screening for AAA (uptake 80·7 per cent), of whom 2795 had an aortic diameter of 2·6-5·4 cm. The prevalence of screen-detected AAA of 3·0 cm or larger decreased from 5·0 per cent in 1991 to 1·3 per cent in 2015. There was no evidence of a change in AAA growth rates during this time. Of men who initially had a subaneurysmal aorta, 57·6 (95 per cent c.i. 54·4 to 60·7) per cent were estimated to develop an AAA of 3·0 cm or larger within 5 years of the initial scan, and 28·0 (24·2 to 31·8) per cent to develop a large AAA (at least 5·5 cm) within 15 years. CONCLUSION: The prevalence of screen-detected small and medium AAAs has decreased over the past 25 years, but growth rates have remained similar. Men with a subaneurysmal aorta at age 65 years have a substantial risk of developing a large AAA by the age of 80 years.

Editor's Choice - Inequalities in Abdominal Aortic Aneurysm Screening in England: Effects of Social Deprivation and Ethnicity.

OBJECTIVE: Population screening for abdominal aortic aneurysm (AAA) in men is currently ongoing in several countries. The aim was to examine the effects of deprivation and ethnicity on uptake of screening for abdominal aortic aneurysm (AAA) and prevalence of AAA. METHODS: This was a review of outcomes from a population screening programme using data collected contemporaneously on a bespoke national database. Men aged 65 in two annual cohorts (2013/14 and 2014/15) were invited for AAA screening. Attendance and prevalence of AAA (aortic diameter >2.9 cm) were recorded. Results were compared according to measures of social deprivation and recorded ethnicity. RESULTS: Some 593,032 men were invited and 461,898 attended for ultrasound screening; uptake 77.9%. Uptake was related to social deprivation: 65.1% in the most deprived decile, 84.1% in the least deprived: OR for least deprived 2.84, 95% CI 2.76-2.92, p<.0001. Men in deprived areas were more likely to actively decline screening: 6% versus 3.8% in the least deprived decile. AAA were twice as common in the most deprived compared with the least deprived decile: OR 2.1, 95% CI 1.77-2.27, p<.0001. AAA were more common in white British men than in black (OR 0.46, 95% CI 0.31-0.71) or Asian (OR 0.18, 95% CI 0.13-0.26) men. There was considerable local variation in all findings. CONCLUSIONS: Social deprivation affects uptake of AAA screening in 65 year old men. Local factors are the most important determinants of uptake, so solutions to improve uptake must be designed at local, not national level.

Impact of the first 5 years of a national abdominal aortic aneurysm screening programme.

BACKGROUND: The Abdominal Aortic Aneurysm (AAA) Screening Programme was introduced by the National Health Service (NHS) in England to reduce the rate of death from ruptured AAA in men. The programme commenced in 2009 and was implemented completely across the country in April 2013. The aim was to review the first 5 years of the programme, looking specifically at compliance and early outcome. METHODS: Men aged 65 years were invited for a single abdominal ultrasound scan. Data were entered into a bespoke database (AAA SMaRT). This was a planned analysis after the first 5 years of the programme. RESULTS: The summation analysis involved the first 700 000 men screened, and the first 1000 men with a large AAA referred for possible treatment. The prevalence of AAA (aortic diameter larger than 2·9 cm) in 65-year-old men was 1·34 per cent. Mean uptake was 78·1 per cent, but varied from 61·7 to 85·8 per cent across the country. Based on the Index of Multiple Deprivation, uptake was 65·1 per cent in the most deprived versus 84·1 per cent in the least deprived areas. Of the first 1000 men referred for possible treatment of a large AAA (greater than 5·4 cm), the false-positive rate was 3·2 per cent. Some 870 men underwent a planned AAA intervention (non-intervention rate 9·2 per cent), with seven deaths (perioperative mortality rate 0·8 per cent). CONCLUSION: The processes in the NHS AAA Screening Programme are effective in detecting and treating men with AAA.

Outcome in Men with a Screen-detected Abdominal Aortic Aneurysm Who are not Fit for Intervention.

OBJECTIVE/BACKGROUND: Abdominal aortic aneurysm (AAA) screening in Gloucestershire has been ongoing for 25 years. The aim of this study was to review the outcome of a cohort of men with a large (> 5.4 cm) screen-detected AAA who did not have early intervention for their AAA. METHODS: A prospectively maintained database was interrogated for a 10-year interval from 2001 to 2011. Men who did not have their large AAA repaired within 3 months of the diagnosis were identified. The reasons for initial nonintervention and subsequent outcomes were identified from a combination of hospital case notes and general practitioner records. RESULTS: Of 334 men referred, 59 (median age 71 years, range 62-83 years) did not have intervention within 3 months (initial nonintervention rate 17.6%). The reasons included placed back on surveillance after assessment (n = 34); immediately discharged (n = 12); required further investigations (n = 5); died before complete assessment (n = 3); and incomplete follow-up (n = 5). Sixteen men had delayed AAA repair with no perioperative mortality. Overall mortality in the study was 14/34 (nine from ruptured AAA, the rest from medical conditions). Two further men survived repair of a ruptured AAA. The overall rate of ruptured AAA was 11/59 (18.6%). CONCLUSION: Information from studies such as these can be used to help plan treatment of men with a large AAA and to compare performance of vascular units.

International variations in AAA screening.

INTRODUCTION: Abdominal aortic aneurysm (AAA) screening programmes reduce AAA-related mortality and are cost-effective. This study aims to assess the state and variability of AAA screening programmes worldwide. METHODS: Data were obtained from an international expert group convened at the 34th Charing Cross Symposium as well as government websites and published reports on screening programmes. RESULTS: Six countries are in the process of implementing national AAA screening programmes, with Italy still performing screening trials. There is wide variability in inclusion criteria between countries with the majority screening only men in their 65th year, however 3 programmes include women, 2 programmes only include patients with high cardiovascular risk, and 2 trials are also screening for hypertension and lower limb atherosclerosis. Surveillance intervals vary between screening programmes, with the most common regimen being to vary the surveillance interval depending upon aneurysm size, however the optimum surveillance interval in terms of decreasing mortality and cost effectiveness remains uncertain. DISCUSSION: International dissemination of current AAA screening programme outcomes is required to inform developing programmes about optimum screening intervals, benefits of surveillance of the subaneurysmal aorta, and screening for other cardiovascular disease.

A multicentre observational study of the outcomes of screening detected sub-aneurysmal aortic dilatation.

OBJECTIVES: Currently most abdominal aortic aneurysm screening programmes discharge patients with aortic diameter of less than 30 mm. However, sub-aneurysmal aortic dilatation (25 mm-29 mm) does not represent a normal aortic diameter. This observational study aimed to determine the outcomes of patients with screening detected sub aneurysmal aortic dilatation. DESIGN AND METHODS: Individual patient data was obtained from 8 screening programmes that had performed long term follow up of patients with sub aneurysmal aortic dilatation. Outcome measures recorded were the progression to true aneurysmal dilatation (aortic diameter 30 mm or greater), progression to size threshold for surgical intervention (55 mm) and aneurysm rupture. RESULTS: Aortic measurements for 1696 men and women (median age 66 years at initial scan) with sub-aneurysmal aortae were obtained, median period of follow up was 4.0 years (range 0.1-19.0 years). Following Kaplan Meier and life table analysis 67.7% of patients with 5 complete years of surveillance reached an aortic diameter of 30 mm or greater however 0.9% had an aortic diameter of 54 mm. A total of 26.2% of patients with 10 complete years of follow up had an AAA of greater that 54 mm. CONCLUSION: Patients with sub-aneurysmal aortic dilatation are likely to progress and develop an AAA, although few will rupture or require surgical intervention.

Remodelling of vascular (surgical) services in the UK.

The last few years have seen major changes in the delivery of vascular services in the UK. An increasingly elderly population with greater expectations from their medical services has challenged established methods. It also became apparent that outcomes for low volume, high risk index vascular interventions such as abdominal aortic aneurysm repair were poor in the UK compared to the rest of Europe. Other ongoing challenges were the introduction of a national aortic aneurysm screening programme and the development of vascular surgery as a separate speciality. This article details the approach taken to modernise vascular services in the UK, using a quality framework agreed by vascular specialists, which drove the structural change to move vascular interventions into fewer, higher volume centres. The introduction of modern networks is designed to maintain services in surrounding hospitals without on site vascular inpatient services. The initial effects of this service remodelling are positive, with elective aortic aneurysm mortality rates falling nationally from 7.5 to 2.4 per cent.

Triumphs and tribulations in a new national screening programme for abdominal aortic aneurysm.

A nationally funded aortic aneurysm screening programme for 65 year old men commenced in 2009 in England. The aim is to implement screening by commissioning local programmes covering populations of over 800,000 to a national standard. By April 2012 approximately 80 per cent of England will be covered, with the aim to complete roll out by 2013. So far, almost 100,000 65 year old men have been screened, and over 1000 abdominal aortic aneurysms detected. The incidence rate of 1.7 per cent is lower than expected, but updated calculations suggest that the programme remains cost effective. Other issues under discussion are the method of measurement of aortic diameter, and a quality assurance programme to guarantee the national standard. The key to a successful long-term programme will be its ability to remain flexible and responsive to emerging data.

A potential pathway for managing diabetic patients with arterial emboli detected by retinal screening.

OBJECTIVE: The aim was to review a pathway of care for diabetic patients found to have retinal artery emboli detected by retinal screening. DESIGN: This was a retrospective review of a pathway agreed in 2001 by a multidisciplinary team. MATERIALS AND METHODS: The prospectively collected Gloucestershire Diabetic Retinal Screening Programme database was reviewed; patients sent for carotid duplex imaging underwent review of their scan results and their casenotes. RESULTS: The prevalence of retinal emboli was 214 out of 25,299 diabetic patients who had retinal screening (0.85%). Some 200 diabetic patients underwent carotid duplex imaging; 23 had ipsilateral and 2 had contralateral carotid stenosis > 70%. Of these, ten patients underwent carotid endarterectomy without any major morbidity. CONCLUSIONS: [corrected] A pathway was established for the small number of patients with retinal emboli, and could be tested in other populations.

Reprinted article "Neovascularisation is the principal cause of varicose vein recurrence: results of a randomised trial of stripping the long saphenous vein".

OBJECTIVES: To determine whether routine stripping of the long saphenous vein reduces recurrence after varicose vein surgery. DESIGN: Randomised controlled trial. All operations done by a consultant vascular surgeon. Two year follow-up. MATERIALS AND METHODS: One hundred patients with primary long saphenous varicose veins (133 legs) were randomised. Two year follow-up in 81 patients (113 legs) with questionnaire, clinical examination and Duplex scanning. RESULTS: Some 89% remained satisfied with the results of their surgery, though 35% had recurrent veins on clinical examination. Recurrence was reduced from 43 to 25% in patients who had their long saphenous vein stripped (p = 0.04, χ(2)). Neovascularisation (serpentine tributaries arising from the ligated saphenofemoral junction) was detected in 52% of limbs and was the commonest cause of recurrence. Most tributaries were less than 3 mm in diameter and only caused recurrence if the long saphenous vein or a major thigh vein was intact. Twelve patients had tributaries greater than 3 mm diameter and all had recurrent varicose veins. CONCLUSIONS: Recurrence is common after varicose vein surgery and in this study was caused principally by neovascularisation at the ligated saphenofemoral junction. Clinical recurrence is reduced by routine stripping of the long saphenous vein.

Ultrasound measurement of aortic diameter in a national screening programme.

OBJECTIVE: Currently there is no universally accepted standard for ultrasound measurement of abdominal aortic aneurysm (AAA). The aim was to investigate the reliability and reproducibility of inner to inner (ITI) versus outer to outer (OTO) ultrasound measurement of AAA diameter. METHODS: A prospective study design was used to collect 60 random images of aorta (1.4-7.1 cm). Inner and outer wall diameter measurements were then performed by 13 qualified AAA screening technicians and 11 vascular sonographers. RESULTS: The mean (range) diameter for all 60 aortas by ITI was 3.91 cm (1.39-6.80) and by OTO was 4.18 cm (1.63-7.09), a significant mean difference of 0.27 cm (95% CI: 0.23-0.32 cm). The reproducibility coefficients for differences between technicians were 0.30 cm (95% CI: 0.24-0.36) for ITI and 0.42 cm (95% CI: 0.35-0.49) for OTO indicating significantly better repeatability using ITI. Finally, 15 images were measured twice in random order by all screeners and sonographers. For AAAs > 5 cm, repeatability was significantly better with ITI than OTO (0.14 vs. 0.21; p = 0.016). CONCLUSION: There was the expected difference in AAA diameter between the two methods (0.27 cm). However, ITI wall method was measurably more reproducible.