Screening for Aortic Aneurysms

Did you know, the United Kingdom, Sweden, the United States of America, and Canada all offer one-off screening ultrasound scans to detect abdominal aortic aneurysms (AAA) in men aged 65 years? Although our cardiologists believe New Zealand should be offering our residents this test also, we currently have no government funded AAA screening program.



AAAs usually have no symptoms and are present in up to 10 percent of older men and 1-2 percent of older women. The majority of AAAs do not rupture but if they do, up to 80% of patients will die. The aim of screening is to detect, monitor and repair AAAs before they rupture.



The clinical bottom line is one-time AAA screening with a simple ultrasound in asymptomatic men aged 65 years and older compared to no screening, significantly reduces the rate of AAA related death by 43% (at 3-5 years follow up) and 34% (at 13-15 years follow-up).


Screening also reduces AAA rupture rate by 48% and 35% respectively.


And finally, screening decreases the number of emergency AAA related surgeries performed by 50% (at 3-5 years follow up) and 48% (at 13-15 years follow-up) .


Essentially, by age 80 years (at 13-15 year follow up) 1 in 311 screened men will be saved. In NZ, these numbers may be even greater as our literature suggests at risk populations extend beyond men aged 65 and over to include:




1) Males aged 65 years and over.


2) Females aged 65 years and over - with cardiovascular disease, a Cardiovascular Risk > 10%, or a family history of AAA.


3) Males aged 50 years and over – with cardiovascular disease, a Cardiovascular Risk >10%, a family history of AAA, or are current or past smokers.


4) Maori males and females aged 50 years and over.




Note: Cardiovascular Risk is the estimated risk of having a cardiovascular event, such as a heart attack, stroke, angina or peripheral arterial disease in the next 5 years. Your doctor or nurse can calculate this using several factors such as your age, gender, smoking history, diabetes status, cholesterol ratio, blood pressure and family history.




As primary care health professionals, we at Sumner Health Centre aim to improve access to health care, promote health, and prevent diseases at an individual, family and community level. In order to help achieve this, we would like all the above four groups to consider AAA ultrasounds.




Abdominal ultrasounds are an effective, highly sensitive and non-invasive test. Sadly, because they are not yet funded, you will need to pay around $150 for the test and you will need to see your doctor prior for a radiology request form.


The ultrasound will measure the diameter of your aorta (the main blood vessel below your heart in your abdomen). After the screening, your doctor will interpret the results and depending on the diameter of your aorta you may require either no further screening, ongoing monitoring, or a referral to a specialist for treatment. These options will then be eligible for public funding.




We do acknowledge that screening tests can be a source of anxiety. If screening reveals a mildly or moderately enlarged aorta we will be monitoring this to ensure it does not worsen. Some people may feel like they are living with a “ticking time bomb”. In countries that routinely screen, psychological and quality of life effects have been discussed in literature, and we can reassure you that despite there being evidence of a small deterioration of quality of life (due to worry) after diagnosis, this is short-term and usually returns to normal levels by 12 months (7, 8).




If you have any questions or believe you may fit one of the four at risk groups for screening, please call the clinic and make an appointment to discuss this with your doctor.




Questions and Answers




1) What is an abdominal aortic aneurysm (AAA)?


In some people, the wall of the aorta in the abdomen can become weak and stretch to form an aneurysm. When this happens, there is a risk that the aorta may rupture leading to serous and often fatal blood loss. If the rupture happens the blood loss is usually so fast that the chances of getting to hospital on time are poor.


2) What is an AAA screening ultrasound?


The most effective way to screen for a AAA is to have an ultrasound scan. This is pain free, quick and easy. The screener will put some gel on your abdomen and pass an ultrasound probe over it to see your aorta. You will be able to see the image on a screen also. They will measure the diameter of your aorta and this measurement is used to determine if you have an aneurysm. In Christchurch you will likely have this done at a Pacific Radiology Clinic. The procedure will only take a few minutes.


3) When will I get the results?


The results will be sent electronically to your doctor within a few days. The doctor or nurse will contact you then.


4) What do the results mean?


There are 3 possible outcomes:


*Normal sized aortas measuring <29mm require no further follow up. This will include about 95% of people.


*Small to moderate aneurysms with aorta diameter 30mm - 49mm will require monitoring with surveillance scanning. The frequency will range from 6 monthly to once every 10 years depending on your gender, age, ethnicity and aorta diameter.


*Large aneurysms with an aorta diameter of >50mm for female and Maori or >55mm for other males over 65 years will be referred to the hospital for possible surgical repair.


5) Does the Canterbury area have the capacity to deal with the increased screening and possible surgical interventions?


Yes, at a recent Canterbury Initiative education day, the topic was discussed and it is believed our health system can handle this increased work load.




Author:  Rachel McDonald, practice nurse



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