In health care, an abdominal aortic aneurysm is "an abnormal balloon- or sac-like dilatation in the wall of the abdominal aorta which gives rise to the visceral, the parietal, and the terminal (iliac) branches below the aortic hiatus at the diaphragm."[1]
The largest of the randomized controlled trials on which this guideline was based studied a screening program that consisted of[6]:
Screening men ages 65-74 years (not restricted to ever smokers). 'Men in whom abdominal aortic aneurysms (> or =3 cm in diameter) were detected were followed-up... Patients with an aortic diameter of 3·0–4·4 cm were rescanned at yearly intervals, whereas those with an aortic diameter of 4·5–5·4 cm were rescanned at 3-monthly intervals ... Surgery was considered on specific criteria (diameter > or =5.5 cm, expansion > or =1 cm per year, symptoms)'.
This trial reported significant short[6] ( number needed to screen after 4 years of approximately 590 to prevent nonfatal ruptured AAA plus AAA-related deaths[7]) and long term[8] ( number needed to screen after 7 years of approximately 280 to prevent nonfatal ruptured AAA plus AAA-related deaths) benefit and cost effectiveness.[9] Subsequent randomized controlled trials also found benefit:
Effective January 1, 2007, provisions of the SAAAVE Act (Screening Abdominal Aortic Aneurysm Very Efficiently) now provide a free, one-time, ultrasound AAA screening benefit for those qualified seniors. Men who have smoked at least 100 cigarettes during their life, and men and women with a family history of AAA qualify for the one-time ultrasound screening.
Enrollees must visit their healthcare professional for their Welcome to Medicare physical within six months of enrollment in order to qualify for the free screening.
The Welcome to Medicare Physical Exam must be completed within the first six months of Medicare eligibility, but there is no published time limit thereafter for completion of the AAA screening. Providers who perform the physical and order the AAA screening need to document the AAA risk factors.[13]
Repair should be considered for symptomatic aneurysms or those larger than 5.5 cm according to a systematic review[15] of randomized controlled trials.[16]>[17]
Aneurysms > 5.5 cm Mean age 77 Unfit for open repair
Endovascular
None
Mortality at 3 yrs
Endo=74% None=77%
Endovascular repair of abdominal aortic aneurysm.
Endovascular repair (i.e., inserting a stent or patch) is a less invasive procedure that may be used when the renal arteries are not part of the aneurysm.[21] Endovascular repair has improved short term outcomes.[22] However, it has similar outcomes as compared to open surgery at two years[23] and six years[20].
In a cohort study, endovascular repair may have improved outcomes as compared to open repair.[21]
↑ 6.06.1Ashton HA, Buxton MJ, Day NE, et al (2002). "The Multicentre Aneurysm Screening Study (MASS) into the effect of abdominal aortic aneurysm screening on mortality in men: a randomised controlled trial". Lancet360 (9345): 1531-9. PMID 12443589. [e]ACP Journal Club
↑Cina CS (2003). "Screening for abdominal aortic aneurysm reduced death from AAA in older men". ACP J. Club138 (3): 66. PMID 12725621. [e]
↑Kim LG, P Scott RA, Ashton HA, Thompson SG (2007). "A sustained mortality benefit from screening for abdominal aortic aneurysm". Ann. Intern. Med.146 (10): 699-706. PMID 17502630. [e]
↑Multicentre Aneurysm Screening Study Group (2002). "Multicentre aneurysm screening study (MASS): cost effectiveness analysis of screening for abdominal aortic aneurysms based on four year results from randomized controlled trial". BMJ325 (7373): 1135. PMID 12433761. [e]ACP Journal Club
↑Ashton HA, Gao L, Kim LG, Druce PS, Thompson SG, Scott RA (2007). "Fifteen-year follow-up of a randomized clinical trial of ultrasonographic screening for abdominal aortic aneurysms". The British journal of surgery94 (6): 696-701. DOI:10.1002/bjs.5780. PMID 17514666. Research Blogging.
↑Lederle FA, Kane RL, MacDonald R, Wilt TJ. Systematic review: repair of unruptured abdominal aortic aneurysm. Ann Intern Med. 2007 May 15;146(10):735-41. PMID 17502634