Screening for abdominal aortic aneurysm in a geographically isolated area

BACKGROUND: Screening for abdominal aortic aneurysm has been shown to reduce aneurysm-related mortality, but the applicability of the results to the whole of the UK has been questioned. This study examined screening in a remote and rural area. METHODS: Over 3 years, men aged 65-74 years were offered screening in the community by ultrasonography, usually in general practitioner surgeries. Men with an aneurysm were rescanned at intervals or assessed for surgery. The screening and hospital costs of the programme were calculated. RESULTS: Some 9323 men were offered screening of whom 8355 (89.6 per cent) attended. Uptake was high in all areas. A total of 430 scans (5.1 per cent) were abnormal; 40 men had an aneurysm greater than 55 mm in diameter. Twenty further men had an aorta that enlarged to greater than 55 mm during follow-up. A total of 54 men had elective repair with one death (mortality rate 2 per cent). The cost of screening alone was 16 pound per invitation and the overall cost of the programme, including surgery, was 58 pound per invitation. CONCLUSION: Screening for abdominal aortic aneurysm can be carried out in a remote and rural area with high uptake, acceptable clinical results and at no greater cost than in more densely populated areas.     

Distribution of aortic diameter in a screened male population.

Between September 1990 and August 1991, 2291 men aged 65 years were invited for ultrasonographic screening of the aorta in the Gloucestershire aneurysm screening programme; 1748 (76.3 per cent) attended. An aortic diameter less than or equal to 2.5 cm was found in 1547 (88.5 per cent); 174 (10.0 per cent) had diameters in the range 2.6-4.0 cm, and 26 (1.5 per cent) had diameters greater than 4.0 cm. The mean(s.d.) aortic diameter was 2.1(0.55) cm and 97.5 per cent of patients had a diameter less than or equal to 3.3 cm. Any man over the age of 65 years with an aortic diameter greater than 3.3 cm has an aortic aneurysm.     

Abdominal pain: a surgical audit of 1190 emergency admissions

In an audit of 1190 emergency admissions with abdominal pain (1166 patients) in a general surgical unit, the diagnosis was non-specific abdominal pain (NSAP) in 415 (35 per cent), acute appendicitis in 200 (17 per cent) and intestinal obstruction in 176 (15 per cent). The largest number of admissions occurred in the age groups 10-29 years (31 per cent) and 60-79 years (29 per cent). Surgical operations were performed in 551 patients (47 per cent) and there was a 16 per cent incidence of unnecessary appendicectomy (22 per cent in the age group 20-29 years). Fifty-one deaths resulted in a 30-day hospital mortality rate of 4.4 per cent and a perioperative mortality rate of 8 per cent. The mortality rate increased significantly in patients aged greater than or equal to 60 years, and patients aged 80-89 years had a perioperative mortality rate of 20 per cent. The causes of perioperative death included laparotomy for inoperable disease (28 per cent), ruptured abdominal aortic aneurysm (23 per cent), perforated peptic ulcer (16 per cent) and colonic resections (14 per cent). The perioperative mortality rates for ruptured aneurysm and perforated ulcer were 71 and 23 per cent respectively. The duration of inpatient stay increased significantly with the age of the patients, including those with NSAP. The results of the study indicate a need to review the methods of management of ruptured aortic aneurysm and perforated peptic ulcer, the methods of diagnosis of appendicitis, particularly in young females, and the factors that determine the duration of stay of patients suffering from NSAP.     

Prevalence of abdominal aortic aneurysm in patients with occlusive peripheral vascular disease

Over a 1-year period, 242 patients with peripheral vascular disease underwent abdominal ultrasonography to detect the presence of an abdominal aortic aneurysm. In 34 (14 per cent) an abdominal aortic aneurysm was found; half of these aneurysms were greater than 4 cm in diameter. In addition, 16 patients had ectatic aortas. Abdominal aortic aneurysms were more common in men than in women (17 versus 8 per cent). Patients with claudication were as likely to have an abdominal aortic aneurysm as those with rest pain or gangrene. The presence of aortoiliac occlusive disease increased the chance of an aneurysm being present (P less than 0.02). Patients with occlusive peripheral vascular disease are a high-risk group with regard to the development of an abdominal aortic aneurysm. Patients with proximal occlusive disease represent a subgroup at even higher risk.     

Abdominal aortic aneurysm: incidence in a population at risk

One hundred twenty patients aged fifty years and over underwent screening by ultrasound for abdominal aortic aneurysms as part of their routine follow-up visit to a cardiologist. The overall incidence of aneurysm greater than or equal to 4 centimeters in diameter was 5%. In the 84 men with aortas less than 4 centimeters, the average aorta size was 2.4 centimeters. In the 30 women with aortas less than 4 centimeters, the average aorta size was significantly smaller, 1.9 centimeters (p less than .001). It was discovered that men who smoke and have hypertension have a statistically significant increase in aorta size compared to those men without these risk factors (less than .05). The results indicate that the incidence of abdominal aortic aneurysm is probably high enough in this population to justify screening by ultrasound.     

Influence of sex on expansion rate of abdominal aortic aneurysms

BACKGROUND: The UK Small Aneurysm Trial suggested that female sex is an independent risk factor for rupture of abdominal aortic aneurysm (AAA). This study assessed the effect of sex on the growth rate of AAA. METHODS: Between January 1985 and August 2005 all patients who were referred to the Royal Infirmary of Edinburgh with an AAA who were not considered for early aneurysm repair were assessed by serial abdominal ultrasonography. Maximum anteroposterior and transverse diameters of the AAAs were measured. RESULTS: A total of 1255 patients (824 men and 431 women) were followed up for a median of 30 (range 6-185) months. A median of six examinations (range 2-37) was performed for each patient. Median diameter on initial examination was 41 (range 25-83) mm. Median growth rate overall was 2.79 (range - 4.80-37.02) mm per year. Median growth rate of AAA was significantly greater in women than men (3.67 (range - 1.2-37.02) versus 2.03 (range - 4.80-21.00) mm per year; P < 0.01). Weighted linear regression analysis revealed that large initial anteroposterior AAA diameter and female sex were significant predictors of faster aneurysm growth rate (P < 0.001 and P = 0.006 respectively). CONCLUSION: The growth rate of AAA was significantly greater in women than in men. This may have implications for the frequency of follow-up and timing of repair of AAA in women.     

General practice-based population screening for abdominal aortic aneurysms: a pilot study

All 1195 male patients aged between 65 and 74 years on the Family Practitioner Committee register for the four group practices in Stroud, UK were invited for a health screening check. The examinations included abdominal ultrasonography to measure maximum aortic diameter, measurement of blood pressure and recording of smoking habits. An attendance rate of 76 per cent was achieved (906 patients). Seventy-one patients (7.8 per cent) were found to have aortic diameters greater than 2.5 cm and 14 (1.5 per cent) had aortic diameters greater than 4.0 cm. Aneurysms were more common in smokers and in hypertensive patients. However, restriction of screening to patients with these risk factors would have led to a number of aneurysms remaining undiscovered. We recommend therefore that ultrasound screening for abdominal aortic aneurysms should be offered to all men between the ages of 65 and 74 years.     

Screening for abdominal aortic aneurysms during a basic medical checkup in residents of a Japanese rural community

To determine the prevalence of abdominal aortic aneurysms (AAA) and the size distribution of the abdominal aortic diameter in the Japanese population, 1591 residents of a farming community were screened by ultrasonography during the annual basic medical checkup arranged by the town. The mean diameter of the abdominal aorta was 17.2 ± 2.2 mm and four AAAs were found (0.3%), all in men aged 60 years or older, three of whom were hypertensive. The mean diameter of the common iliac artery was 10.2 ± 5.1 mm and five iliac arterial aneurysms were found (0.3%). One man had both aortic and iliac arterial aneurysms. The iliac arterial aneurysms were also found in men, four of whom were aged 60 years or older and had a smoking habit. We were able to keep the cost of screening low by combining the program with an annual basic medical checkup. These findings indicate that it is important to examine the iliac artery as well as the abdominal aorta because the incidence of aneurysm is similar in both. Screening for AAAs using ultrasonography is accurate enough to detect them before rupture, and can be effectively performed in men aged 60 years or older during their annual basic medical checkup. Received: May 14, 1999 / Accepted: March 24, 2000     

Quantifying the risks of hypertension, age, sex and smoking in patients with abdominal aortic aneurysm

BACKGROUND: The prevalence of abdominal aortic aneurysm (AAA) in a community-based sample of men and women aged 65-79 years was correlated with known risk factors. In addition, the effect of high blood pressure and the use of antihypertensive medication on growth of AAAs were studied. METHODS: Aortic diameter was assessed by ultrasonography and data on risk factors were collected by self-administered questionnaire for 5356 men and women as part of a randomized controlled trial. RESULTS: Current hypertension increased the risk of having an aortic aneurysm by 30-40 per cent while use of antihypertensive medication increased the risk by 70-80 per cent, adjusting for current blood pressure. There was no clear relationship between hypertension and growth rates of existing aneurysms in this study, although these results were largely from data on small aneurysms. Men were nearly six times more likely to develop an AAA than women; the risk increased by 40 per cent every 5 years after the age of 65 years. Smoking was an independent risk factor for AAA, with level of exposure being more significant than duration. CONCLUSION: Male sex, smoking and hypertension are strong risk factors for the development of AAA. In this study hypertension did not significantly increase the growth rate of existing aneurysms. Smoking remains the most important avoidable risk factor for AAA. The analyses presented here suggest that selection for screening, other than by age and sex, is not worthwhile.     

Screening of abdominal aortic aneurysm: a pragmatic approach

In order to evaluate the feasibility of a selective screening programme for abdominal aortic aneurysm (AAA) within an urban setting and assess its impact on the expected increase in workload for the local hospital(s), a population based, prospective study was performed. A total of 4823 men aged 65 years were invited for ultrasound examination of the abdominal aorta between January 1993 and April 1997 as part of a general practice-based aneurysm screening programme covering two districts with a general hospital each. All examinations were carried out by senior radiographers using a portable B mode grey scale machine and a 3.5 MHz curvi-linear array probe. Patients with a maximum aortic diameter of over 3 cm were annually recalled, those with over 4 cm were referred to hospital for an out-patient's appointment. Those with AAA greater than 5 cm were considered for surgery. Of those approached, 3497 (72.5%) took part in the study, 1206 (25%) did not attend and 120 (2.5%) were excluded by their general practitioners (GPs) on medical grounds. Of the men taking part, 3130 (89.5%) had an aortic diameter equal to or less than 2.5 cm, 196 (5.6%) between 2.6 and 3.0 cm, and 171 (4.9%) had aortic diameters greater than 3 cm--29 of whom had AAA greater than 5 cm with a mean diameter of 6.0 cm (range 5.1-9.0 cm). Of 127 men with an initial diameter of 3.1-4.0 cm (mean progression in size of 2.3 mm/year), 22 enlarged to > 4 cm and 3 to > 5 cm. Of 24 men with an initial diameter of 4.1-5.0 cm, 6 enlarged to > 5 cm. Some 69 (2%) patients were referred to hospital requiring a total of 125 consultations (1.8 consultations per patient); 21 underwent surgery and one died from rupture whilst awaiting surgery. Five patients refused their operation and two failed to attend the clinic (all > 5 cm) but remain well to date. No patient died following surgery. We conclude that, screening for AAA in men at age 65 years within an urban setting is feasible and well received by patients and GPs. Screening does not lead to a huge increase in terms of outpatient appointments and operations for AAA.     

Abdominal aortic aneurysm rupture rates: A 7-year follow-up of the entire abdominal aortic aneurysm population detected by screening

Purpose: The goal of the current study was to identify the risk of rupture in the entire abdominal aortic aneurysm (AAA) population detected through screening and to review strategies for surgical intervention in light of this information. Methods: Two hundred eighteen AAAs were detected through ultrasound screening of a family practice population of 5394 men and women aged 65 to 80 years. Subjects with an AAA of less than 6.0 cm in diameter were followed prospectively with the use of ultrasound, according to our protocol, for 7 years. Patients were offered surgery if symptomatic, if the aneurysm expanded more than 1.0 cm per year, or if aortic diameter reached 6.0 cm. Results: The maximum potential rupture rate (actual rupture rate plus elective surgery rate) for small AAAs (3.0 to 4.4 cm) was 2.1% per year, which is less than most reported operative mortality rates. The equivalent rate for aneurysms of 4.5 to 5.9 cm was 10.2% per year. The actual rupture rate for aneurysms up to 5.9 cm using our criteria for surgery was 0.8% per year Conclusion: In centers with an operative mortality rate of greater than 2%, (1) surgical intervention is not indicated for asymptomatic AAAs of less than 4.5 cm in diameter, and (2) elective surgery should be considered only for patients with aneurysms between 4.5 and 6 cm in diameter that are expanding by more than 1 cm per year or for patients in whom symptoms develop. In centers with elective mortality rates of greater than 10% for abdominal aortic aneurysm (AAA) repair, the benefit to the patient of any surgical intervention for an asymptomatic AAA of less than 6.0 cm in diameter is questionable. (J Vasc Surg 1998;28:124-8.)     

Prevalence of abdominal aortic aneurysm in the offspring of patients dying from aneurysm rupture.

The prevalence of abdominal aortic aneurysm (AAA) is high in the brothers of patients with aneurysm. A genetic component in the development of AAA has, therefore, been postulated. In this study the offspring of patients who had died from AAA rupture were invited to undergo ultrasonography of the abdominal aorta. The attendance rate was 69 per cent. Thirty-nine sons of median age 60 (range 45-75) years and 23 daughters of median age 62 (range 42-80) years were examined. Abdominal aortic dilatation was found in eight men and one woman. The presence of aortic dilatation in these nine cases was not related to age, hypertension, smoking or symptoms of occlusive arterial disease. It is concluded that the sons of those who have died from ruptured AAA constitute a high-risk group for the development of this condition and should be considered for further screening.     

Recommendations for screening intervals for small aortic aneurysms

BACKGROUND: The aim was to determine the optimum rescreening interval for small abdominal aortic aneurysms (AAAs). METHODS: Data from 12 years of population screening of 65-year-old men were analysed and 1121 small AAAs (less than 4.0 cm in initial diameter) were divided into groups: group 1 (2.6-2.9 cm; n = 625), group 2 (3.0-3.4 cm; n = 330) and group 3 (3.5-3.9 cm; n = 166). Expansion rate and the cumulative proportions to expand to over 5.5 cm, or require surgery, or rupture were calculated. RESULTS: Expansion rate was related to initial aortic diameter: 0.09 cm per year in group 1, 0.16 cm per year in group 2 and 0.32 cm per year in group 3 (P < 0.001). Aneurysms in 2.4 per cent of patients in group 1 exceeded a diameter of 5.5 cm or required surgery within 5 years; there were no ruptures. In group 2, no aorta exceeded 5.5 cm but at 3 years 2.1 per cent had reached 5.5 cm and 2.9 per cent had required surgery. The rupture rate at 3 years was zero. In group 3, the aneurysm diameter exceeded 5.5 cm in 1.2 per cent of patients, but no patient required surgery or experienced rupture within 1 year; at 2 years 10.5 per cent of aneurysms had exceeded 5.5 cm in diameter or required surgery and 1.4 per cent had ruptured. CONCLUSION: The appropriate rescreening interval can be determined by initial aortic diameter in screened 65-year-old men. AAAs of initial diameter 2.6-2.9 cm should be rescanned at 5 years, those of 3.0-3.4 cm at 3 years and those of 3.5-3.9 cm at 1 year.     

Risk of aortic aneurysm surgery as assessed by preoperative gated heart pool scan

Gated heart pool scan measuring left ventricular ejection fraction (LVEF) was performed preoperatively in 72 patients presenting for elective repair of abdominal aortic aneurysm. Patients with a positive cardiac history were more likely to have a LVEF of less than or equal to 45 per cent (P less than 0.001). The operative mortality rate was 4 per cent. Each of three patients who died had a LVEF less than or equal to 35 per cent and developed cardiac failure which led to renal failure. Five other patients developed cardiac failure manifested by acute pulmonary oedema during the early postoperative period. There was no statistically significant association between a positive cardiac history and the occurrence of postoperative cardiac failure or death. However, patients with a LVEF of less than or equal to 45 per cent were more likely to develop postoperative cardiac failure (P = 0.004) while patients with a LVEF of less than or equal to 35 per cent had a greater chance of dying (P less than 0.001). No patient died with a LVEF greater than 35 per cent. Preoperative evaluation of LVEF can select patients at high risk of cardiac death from repair of abdominal aortic aneurysm. Such patients could be followed conservatively if they remain asymptomatic and the aneurysm does not enlarge. If operation is considered mandatory, patients with a low LVEF should receive intensive perioperative monitoring with enhancement of ventricular performance.     

Ultrasound screening of first-degree relatives of patients with an abdominal aortic aneurysm

The pedigrees were constructed of 43 patients (probands) who underwent resection of an abdominal aortic aneurysm. Seven probands (16.2%) had a first-degree relative (parent, sibling, child) known to have had an abdominal aortic aneurysm (multiplex family). To determine the prevalence of undiagnosed abdominal aortic aneurysm, ultrasound screening of first-degree relatives over age 40 years was undertaken. Of 202 eligible relatives, 103 (51.0%) were screened. An occult abdominal aortic aneurysm was defined as an infrarenal aortic diameter greater than 3.0 cm or an infrarenal/suprarenal aortic diameter ratio of greater than 1.5. An incipient abdominal aortic aneurysm was defined as a clear focal bulge of the infrarenal aorta, which was less than 3.0 cm in greatest diameter. Four of 103 relatives (3.9%) were found to have an occult abdominal aortic aneurysm (age/sex: 57M, 60M, 62F, 65M), and three (2.9%) were found with an incipient abdominal aortic aneurysm (age/sex: 56M, 60M, 67F). These smaller abdominal aortic aneurysms were in patients younger than the operated probands (average age men, 67 years; women, 69 years). Six of seven individuals were in families previously considered simplex, increasing the actual multiplex family frequency from 16.2% to 27.9%. All seven new abdominal aortic aneurysms were found in the 49 siblings age 55 years or older. There were no abdominal aortic aneurysms found in the 39 relatives under age 55 years, in 14 children ages 50 to 59 years or in one parent. Therefore of the siblings age 55 years or older, 5/20 men (25.0%) and 2/29 women (6.9%) were found to have a previously undiagnosed abdominal aortic aneurysm.(ABSTRACT TRUNCATED AT 250 WORDS)     

Ruptured abdominal aortic aneurysm: factors influencing operative mortality

Of fifty-eight consecutive patients surgically treated for aneurysm of the abdominal aorta, twenty were emergency cases following the rupture. Associated diseases were found in 85 per cent of patients; hypertension being the most common. Fifty per cent of patients were in shock on admission. The duration between rupture and operation was three hrs to two weeks with the average of 115.5 hrs. In six patients, the diagnosis of abdominal aortic aneurysm was known for over six months. The operative mortality rate in case of ruptured abdominal aortic aneurysm was 45 per cent. The most important determinants of survival were the incidence of shock on admission, the incidence of associated disease, the known duration of the aneurysm, and the time interval from rupture to admission. The intraoperative factors most influencing survival were the type of rupture, intraoperative hypotension, and total blood loss. Comparison of the mortality rate in elective surgery of abdominal aortic aneurysms (5.3 per cent) with that in ruptured aneurysms (45.0 per cent) suggests the necessity for early elective operations whenever abdominal aortic aneurysms are diagnosed.     

A community screening programme for abdominal aortic aneurysms

Three-hundred and sixty-nine unselected men aged 65-79 years were invited for screening for abdominal aortic aneurysm. One hundred and forty-one men were examined and 4 aneurysms detected. 43.2% of men aged 65-74 attended for examination in response to a single unsolicited letter of explanation with the date of an appointment, but only 29.1% of those aged 75-79 years. It is suggested that community mortality from ruptured aortic aneurysm could be reduced by ultrasound screening of the aorta in men aged 65-74 years and early selective aneurysm surgery.     

Late results concerning feasibility and compliance from a randomized trial of ultrasonographic screening for abdominal aortic aneurysm

BACKGROUND: The study was an update at 10 years of a randomized trial of the efficacy of screening for abdominal aortic aneurysm (AAA). The extent of benefit, feasibility and compliance were examined, and reasons why this intervention may fail a proportion of those screened were identified. METHODS: A total of 6058 men aged 65 years and over were randomized to a group invited to attend ultrasonographic screening or to a control group. The mortality rate from AAA in the two arms of the trial was compared using a Poisson model. Analyses were by intention to treat. RESULTS: There was a 21 per cent reduction in mortality rate from AAA over the 10-year follow-up (relative risk 0.79 (95 per cent confidence interval 0.53 to 1.40)). The observed relative mortality reduction peaked at 4 years with a 52 per cent reduction in the study group. Eighteen of 24 AAA deaths in the study group were among those who did not attend the first screen, or failed to comply with the follow-up protocol. CONCLUSION: A greater awareness of the benefits of full participation in a screening programme could provide a larger and sustained mortality reduction.     

A single normal ultrasonographic scan at age 65 years rules out significant aneurysm disease for life in men.

BACKGROUND: Screening for abdominal aortic aneurysm (AAA) has been carried out in Gloucestershire since 1990. All men in the county are offered aortic ultrasonography in their 65th year. Men with an aortic diameter of less than 26 mm are considered 'normal' and no follow-up is arranged. The aim of this study was to ascertain if men with 'normal' aortic diameters at age 65 years ever develop a clinically significant aneurysm. METHODS: A cohort study was performed on 223 65-year-old men who had an aorta of less than 26 mm in diameter in 1988. These men had repeat ultrasonography in 1993 and 2000. The causes of death in men who died during this interval were investigated. RESULTS: Eight men were lost to follow-up. As far as it was possible to ascertain, none of the 86 men who died over the 12-year interval did so from ruptured AAA. There was no clinically significant increase in mean aortic diameter in the remaining 129 men who had three serial ultrasonographic scans over the 12-year interval. CONCLUSION: A single, 'normal' ultrasound scan at age 65 years effectively rules out the risk of clinically significant aneurysm disease for life in men.     

A 14-year experience with 6 cm as a criterion for surgical treatment of abdominal aortic aneurysm.

BACKGROUND: It remains unclear when to recommend operation for an asymptomatic abdominal aortic aneurysm (AAA). This study examined a prospective series of patients for whom standard criteria were applied. METHODS: Some 584 consecutive patients with an AAA of diameter 3 cm or greater detected by ultrasonographic screening have been observed for up to 14 years. Repeat ultrasonographic examinations have been performed at intervals. Surgery was not considered unless the aneurysm measured 6 cm in diameter, expanded at a rate equivalent to at least 1 cm per year, caused the patient symptoms, or an iliac aneurysm was present that required treatment. RESULTS: Operation was performed on 127 patients; the majority (80; 63 per cent) had an aneurysm that reached 6 cm in diameter. Use of the above criteria prevented rupture in all but 24 (4 per cent) of the 584 patients over the 14-year interval. Of these 24 patients, 11 were unfit for planned surgery and eight declined operation or follow-up. Rupture in the five remaining patients (1 per cent) who were available for treatment compared favourably with the reported 30-day mortality rate for elective surgical treatment of 1.4-12 per cent. CONCLUSION: Repeated observation is preferable to surgical intervention until an aortic aneurysm measures 6 cm in diameter, expands by 1 cm per annum or causes symptoms. Presented as a poster to the 52nd Annual Meeting of the Society for Vascular Surgery, San Diego, California, USA, June 1998