Ultrasonographic screening for abdominal aortic aneurysm.

OBJECTIVE--To assess the prevalence of abdominal aortic aneurysm in a selected group of men over the age of 60, and define main risk factors. DESIGN--Population based screening study. SETTING--Private Norwegian health maintenance organisation. SUBJECTS--500 men over the age of 60 years. INTERVENTIONS--General examination by a general practitioner, together with measurements of blood glucose and serum cholesterol concentrations. Abdominal scan with a B-mode ultrasound imager. MAIN OUTCOME MEASURES--An increase in the diameter of the aorta of more than 150% over the diameter at the origin of the superior mesenteric artery, or maximum diameter of more than 29 mm. Correlation with history of smoking, serum cholesterol concentration, and general health. RESULTS--29 patients (5.8%) had small, and 12 (2.4%) had large, abdominal aortic aneurysms. There was a significant association between aortic aneurysm and history of smoking (p < 0.01), poor health (defined as coexistent hypertension, cardiovascular disease, or diabetes mellitus) (p < 0.01), and increasing age (p = 0.025). There was no association with hypercholesterolaemia. CONCLUSION--Ultrasonic screening of groups at risk followed by elective operation may reduce mortality of abdominal aortic aneurysm.     

Ultrasonographic screening of the abdominal aorta among siblings of patients with abdominal aortic aneurysms

To evaluate the prevalence of abdominal aortic dilatations among asymptomatic brothers and sisters of patients with abdominal aortic aneurysms (AAAs), an ultrasonographic screening study was performed. One hundred and two siblings of patients operated on for AAAs at two Swedish hospitals were invited to attend, and 87 of them (35 men and 52 women) from 32 different families, accepted the invitation. Their median age was 63 years (range 39-82 years). Aortic dilatation was diagnosed in ten of the brothers (29 per cent) and three of the sisters (6 per cent). In ten cases (eight men and two women) there was a localized dilatation caudal to the coeliac axis, and in three a general dilatation of the abdominal aorta with the diameter at the coeliac axis greater than 29 mm. None of the aortic dilatations had been known before this study was performed. The conclusion is that the prevalence of asymptomatic aortic dilatations among brothers of patients with AAAs seems to be high and that this group should be selected for further screening studies.     

The value of abdominal examination in the diagnosis of abdominal aortic aneurysm.

BACKGROUND: There is considerable variability in the reported value of clinical examination in the diagnosis of abdominal aortic aneurysms (AAA). This study aims to assess accuracy of abdominal examination by a doctor, a nurse and the patient in the diagnosis of AAA and whether this accuracy is related to the size of the aneurysm and/or the BMI of the patient. METHODS: 164 patients, 138 men and 26 women, median age 71 years, consented to participate in this prospective, single blind, controlled study. Thirty-nine patients attending for carotid duplex were used as controls. Abdominal examination was performed by a doctor and a nurse. Patients then performed self-examination. RESULTS: Examination by a doctor, a nurse and the patient were similar in accuracy in diagnosing/excluding AAA which was directly related to AAA size and patient BMI. The Negative Predicted Value of abdominal examination exceeds 0.9 with AAA diameters > or =4 cm and the Positive Predictive Value exceeds 0.8 with AAA diameters > or =5 cm. CONCLUSIONS: Abdominal examination by a doctor, a nurse and the patient is of value in the exclusion and diagnosis of significant AAA. It should be promoted and may represent a useful adjunct to population screening with ultrasound.     

The case for expanding abdominal aortic aneurysm screening

Both the U.S. Preventive Services Task Force and the UK National Institute for Health and Care Excellence are re-evaluating their screening paradigms for abdominal aortic aneurysms (AAAs). Currently, most countries that screen for AAA do so only in male ever-smokers between the ages of 65 and 75 years and in patients with a family history of AAA. However, these recommendations are based primarily on screening trials predating the endovascular era. The wider applicability of endovascular aneurysm repair and its safety profile, especially in the elderly, have changed the risk-benefit of repair and, by extension, screening. This is despite the decreasing prevalence of AAA thanks to improved medical therapies and lower smoking rates. This evidence summary critically examines the evidence behind screening and the potential for expanded screening.     

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)     

Advantages and pitfalls of abdominal aortic aneurysm screening in high-risk patients

Screening for abdominal aortic aneurysm (AAA) has been suggested for older men. Our aim was to determine the effect of participant selection on prevalence and treatment suitability. Men aged 65 to 75 years attending cardiology clinics composed the high-risk group; the control group was from the community. AAA screening was performed, with follow-up or surgery arranged. Four hundred eight of 651 (62.7%) high-risk men and 109 of 908 (45.0%; p< .0001) men attended from the community. In the high-risk patients, 40 AAAs were diagnosed, with a mean diameter of 41.4 mm (+/-10.4 mm). In the control group, 22 new AAAs were found, with an average size of 40.9 mm (+/-10.4 mm). Higher polypharmacy existed in the high-risk group (4.6+/-2.2 vs 2.3+/-2.0; p< .0001). More aneurysm patients were on dual-antiplatelet therapy (32.5% vs 15.4%; p= .048) compared with the overall high-risk group. In this group, three underwent surgery; one was anatomically unsuitable for endovascular repair and medically unfit for open repair. Two in the control group had surgery. A higher prevalence of AAA is encountered in high-risk men. Most aneurysms are small; however, a significant proportion of the aneurysms detected were of a size that would warrant repair. The decision to perform surgical repair is likely to be influenced by the comorbid medical conditions, which placed the patients in the high-risk category.     

Management of cholelithiasis in patients with abdominal aortic aneurysm.

Gallstones were detected in 42 of 865 patients with abdominal aortic aneurysm (4.9%). Eighteen patients underwent concomitant aneurysm resection and cholecystectomy. Eleven patients had aneurysmectomy without cholecystectomy. Thirteen patients underwent cholecystectomy alone. There were no significant increases in operative mortality, duration of operation, or length of hospital stay when cholecystectomy was added to aneurysm resection. However, there was one instance of prosthetic infection which occurred in a patient who did not have his graft retroperitonealized prior to cholecystectomy, and who also underwent gastrostomy and drainage of the liver bed. There have been no graft complications in the remaining 17 consecutive patients who had their graft retroperitonealized prior to cholecystectomy. Nine of 11 patients who underwent aneurysmectomy without cholecystectomy experienced an episode of acute cholecystitis during a mean follow-up period of 2.9 years. Two of these episodes occurred in the immediate postoperative period and one patient died of biliary sepsis. On the basis of these findings, concomitant aneurysmectomy and cholecystectomy is advised in those patients with cholelithiasis undergoing aortic aneurysm resection providing no contraindications exist.     

Hypotensive resuscitation in patients with ruptured abdominal aortic aneurysm.

BACKGROUND: The technique of hypotensive resuscitation in haemorrhagic shock involves resuscitation to below normotensive blood pressures achieving the minimum perfusion pressure that will adequately perfuse vital organs until definitive arrest of haemorrhage. AIM: To summarise the evidence for the use of hypotensive resuscitation in patients with uncontrolled haemorrhagic shock and ruptured abdominal aortic aneurysm (AAA). METHODS: A MEDLINE (1966-2004) and Cochrane library search for articles relating to hypotensive resuscitation was undertaken; see text for further details. RESULTS: Several animal studies exist using an abdominal aortotomy model of ruptured AAA. These have demonstrated improved tissue perfusion, decreased blood loss and improved survival associated with hypotensive resuscitation compared with aggressive resuscitation. There are several human studies advocating delayed rather than immediate resuscitation in trauma patients but careful review of the literature reveals no prospective studies of hypotensive resuscitation in patients with ruptured AAA. CONCLUSIONS: Animal studies demonstrate superiority of hypotensive resuscitation over aggressive resuscitation but further research is required to assess its efficacy in patients with ruptured AAA.     

The place of screening in the management of abdominal aortic aneurysm

The present method of management of Abdominal Aortic Aneurysms (AAA) is ineffective in preventing AAA rupture. 5000 people still die of AAA in the UK each year. Improvements in surgery can only reduce the mortality in the minority who reach hospital following chance detection, and then only by a few percent. Screening, with detection in the community and planned treatment can reduce the mortality of the disease by 58%. Screening programmes for AAA have recently been approved for men aged 65 years, in both the UK and the USA. The proposed UK National Screening Programme is outlined briefly. CONCLUSION: If the aim of treatment is to reduce the mortality of the disease as a whole, resources would be better spent on screening programmes for AAA, rather than developing increasingly sophisticated operative techniques that could only reduce the overall death from AAA by a few percent.     

Cost-effectiveness of screening women for abdominal aortic aneurysm

BACKGROUND: Women are usually not considered for abdominal aortic aneurysm (AAA) screening because of their lower prevalence of disease. This position may, however, be questioned given the higher risk of rupture and the longer life expectancy among women. The purpose of this study was to assess the cost-effectiveness of screening 65-year-old women for AAA. METHODS: A systematic review of the literature was conducted to obtain data of importance to evaluate the effectiveness of screening women for AAA. Data were entered into a Markov simulation cohort model. RESULTS: The review suggested some main assumptions for women with AAA. Prevalence is 1.1%. In 6.8%, the AAA is of a size that merits surgery, and the patients are fit for a procedure. For patients with an AAA, the yearly risk for elective surgery and the rupture incidence was 3.1% and 2.4%, respectively, in the invited group and 1.1% and 5.7% in the noninvited group. The operative mortality for elective surgery was 3.5%, and the total mortality for ruptured AAA was 86.3%. The long-term mortality for AAA patients was 3.6 times higher than for an age-matched healthy population. Screening reduced the AAA rupture incidence by 33% and the AAA-related death rate by 35%. The cost per life year gained was estimated at $5911. CONCLUSION: The incremental cost-effectiveness ratio was similar to that found for screening men, which reflects the fact that the lower AAA prevalence in women is balanced by a higher rupture rate. Screening women for AAA may be cost-effective, and future evaluations on screening for AAA should include women.     

Renal function in patients with abdominal aortic aneurysm. Comparison with hypertensive patients

AIMS: Renal dysfunction occurs occasionally after the repair of abdominal aortic aneurysm (AAA), and preoperative renal function is considered as one of the potential causes. The present study was designed to evaluate and compare renal function and risk factors of AAA patients with those of hypertensive patients. METHODS: We prospectively examined 95 patients with AAA and 72 patients with essential hypertension (HT) without other cardiovascular diseases (CVD). Renal function, urinary albumin excretion (UAE) and renal scintigraphy were compared. Kidney size was calculated using ultrasonography. RESULTS: Serum creatinine and creatinine clearance in AAA patients was worse than in HT patients. Smoking status was more apparent in AAA patients. Renal artery stenosis occurred in 8 patients with AAA. Renal scintigraphy showed normal function in 19%, hypofunction in 69% and severe dysfunction in 12% of the AAA patients, and normal function in 42% and hypofunction in 58% of the HT patients (p < 0.0001). Multivariate linear regression analysis showed that renal function was related to age, UAE, CVD, smoking status and kidney size for all patients, UAE, CVD, smoking status and kidney size for AAA patients, and age and kidney size for HT patients. CONCLUSION: Renal function of AAA patients was worse than HT patients without other CVD. The risk factors for renal dysfunction were different between AAA and HT patients. These preoperative conditions may relate to the postoperative renal dysfunction seen in AAA patients.     

Natural history of patients with abdominal aortic aneurysm

Factors determining the outcome for patients with abdominal aortic aneurysm (AAA) were analysed in a retrospective population-based study of 187 consecutively diagnosed AAAs at one hospital during a 9-year period. All aneurysms were diagnosed by ultrasound, and those cases that were not primarily operated upon, were followed by repeat ultrasound examinations. An expansion rate of more than 0.4 cm/year was seen in 27% of the aneurysms and a tendency towards a higher rate of expansion could be seen with larger lesions. The overall cumulative rupture rate was 12% at 5 years. For patients with small (less than 5 cm) aneurysms it was 2.5% at 7 years, and no aneurysm could definitively be shown to be smaller than 5 cm at the time of rupture. The rupture risk was significantly higher (28% at 3 years) for larger aneurysms (greater than or equal to 5 cm). The only reliable predictor for rupture was aneurysm size. The overall cumulative survival was 51% at 5 years. Patients with large aneurysms did not have a significantly shorter survival although a tendency for this to be the case was found. There was a significant difference between the proportion of deaths caused by aneurysm rupture in patients with small aneurysms when compared to those with large aneurysms, 5.5 and 53%, respectively. The expansion rate for AAA was highly individual and aneurysm diameter was the only recognisable predictor of rupture. The rupture rate for AAAs smaller than 5 cm was lower than previously reported.