Influence of screening on the incidence of ruptured abdominal aortic aneurysm: 5-year results of a randomized controlled study

Abstract

From family medical practices 15775 men and women of men). Aortic surgery was offered to the screened group aged 65-80 years were identified and randomized into two if certain criteria were met and no patient died from groups: one group was invited for ultrasonographic rupture who was fit for operation and accepted elective screening for abdominal aortic aneurysm (AAA), and the treatment. The incidence of rupture was reduced by 55 other acted as age-and sex-matched controls. Of the 7887 per cent in men in the group invited for screening, invited for screening 5394 (68.4 per cent) accepted. AAA compared with controls. The incidence of rupture in was detected in 218 (4.0 per cent overall and 7-6 per cent women was low in both groups. Patients and methodsMen and women aged 65-80 years were identified for each general practice in this district from a combination of the practice register and Family Health Service lists. The patients in each practice were then randomized by computer to 'control' and 'screening' groups. Patients randomized to screening were invited for abdominal ultrasonographic scanning by letter from their family practice; one reminder was sent if there was no reply. Maximum aortic diameter in the anteroposterior and transverse planes was measured as previously described". A diameter of 3 cm or more was considered aneurysmal. Patients with an aneurysm of 3.0-4.4 cm diameter were rescanned annually and those with an aneurysm of 45-59 cm diameter were rescanned at intervals of 3 months. This protocol was continued for the duration of the study to February 1994 or until the patient either died, underwent surgical intervention or declined further followup. The criteria for considering surgical repair were applied prospectively: an aortic diameter of 6 cm or more, an increase of diameter of 1 cm or more per year, or the development of symptoms attributable to the aneurysm. Abnormal scans and batches of normal scans were reviewed by a consultant radiologist for quality control. Patients were assessed in outpatient clinics at their third scan or if an abnormality was detected; a further confirmatory scan was Paper accepted 3 March 1995 1066 performed by the consultant vascular surgeon at this visit. Patients who fulfilled the criteria for surgery were assessed and elective aneurysm repair planned if they were deemed fit and consented to operation. If patients were unfit or declined surgery, ultrasonographic surveillance was continued. Criteria for fitness for surgery were based on those of Bernstein and Chan".Mortality data were obtained weekly from the Registrar of Births and Deaths in Chichester district before coding was undertaken, and those labelled as aortic aneurysm were checked by a clinician. The causes of death for the study population were noted, including ruptured AAA. Details of those dying outside the district but who lived locally were included. Details of operative mortality and morbidity were obtained from a prospective study started in 19814. Results Population screened and acceptance rate...

The Evidence for Management of Abdominal Aortic Aneurysms: Lessons Learned from Randomised Controlled Trials

“…Despite these criticisms the Chichester study remains a land mark as it demonstrated the feasibility of US screening for AAA and its potential value and remains a blue print for other aneurysm screening studies. This study identified a low but none the less troubling rate of AAA rupture in patients who had a non aneurysmal aorta on the first screening study 2 . A population based screening study in Gloucester demonstrated that 2.2-percent of men aged 65-73 years have a maximal aortic diameter of 2.5 to 2.9 mm and suggested that this group of patients should undergo repeat US scanning at 5 yearly intervals 10 .…”

“…This has led to the concept of its use for screening of at risk populations. In the last 20 years there have been four population based randomised controlled trials which have assessed the value of targeted screening in reducing mortality from abdominal aortic aneurysms in the unselected elderly male population [2][3][4][5] . These trials which have been undertaken in Chichester (England) 2 , England (MASS trial) 3 , Viborg County (Denmark) 4 and the city of Perth and suburbs (Western Australia) 5 have together recruited over 120,000 subjects.…”

“…It was also unique as it included women as well as men. It identified all men and women aged between 65 and 80 years of age from 9 general practices in the catchment area of St Richard's hospital in Chichester between 1988 and 1991 2,8,9 . The subjects were randomised to undergo a single screening ultrasound (US) or a control group who were followed up.…”

Towards patient-specific risk assessment of abdominal aortic aneurysm

“…For example, a stenosis (narrowing) of a blood vessel is usually quantified by relating the lumen (blood) diameter or cross-sectional area at the location of the stenosis to the lumen diameter/area at a reference location without stenosis [1]. Similarly, a vascular aneurysm (dilatation) is characterized primarily by its diameter [37]. Treatment of a particular vascular disease is usually considered if the geometrical parameter that characterizes the severity of the disease exceeds a threshold.…”

Routine Screening for Asymptomatic Abdominal Aortic Aneurysm in High‐risk Patients Is Not Recommended in Emergency Departments That Are Frequently Crowded

“…The most significant risk factors for AAA are male sex, older age, a history of smoking, a family history of AAA, and atherosclerosis. [1][2][3][4][5][6][7][8][9][10][11][12] The prevalence of AAA is highest among men between the ages of 50 and 79 years (3%-8%) and is the 14th leading cause of death for men aged 55 years and older. 13 AAAs that rupture are associated with a high mortality rate (>50%).…”