emrapidbombs.supercast.com<\/strong><\/a><\/p>\nAuthor: Blake Briggs, MD<\/p>\n
Peer Reviewer: Iltifat Husain, MD<\/p>\n
Introduction<\/strong><\/p>\nNothing strikes more fear and suspense in healthcare than when discussing \u201cabdominal aortic aneurysms\u201d (AAA). Perhaps it is due to their utterly silent growth and potential for catastrophic rupture. AAA is the most common \u201ctrue\u201d aneurysm in the human body.1\u00a0In developed countries, the prevalence is estimated between 2-8%, with men nearly twice as affected.2\u00a0From screening, it is estimated nearly 1,000,000 people in the US alone have a AAA.3\u00a0Since the 1990\u2019s, mortality from AAA has dramatically decreased by ~50%, likely secondary to rates of smoking cessation, more awareness and screening, and improved vascular surgery techniques. It continues to remain a very difficult diagnosis due to its ability to remain virtually silent until rupture. This review will focus on the risk factors, screening definitions, presentation and diagnosis of a patient with a AAA. The techniques of AAA bedside ultrasound are outside the scope of this review.<\/p>\n
Anatomy and definitions<\/strong><\/p>\nThe mighty abdominal aorta is a retroperitoneal structure. It begins at the diaphragm and extends to its bifurcation into the right and left common iliac arteries in the lower abdomen (usually below the umbilicus, L4 level).<\/p>\n
In adults, >3.0 cm diameter at any location along the abdominal aorta is an aneurysm.<\/p>\n
The most common location for a AAA is the segment between the renal and inferior mesenteric arteries.4<\/p>\n
Small aneurysms <4.0 cm<\/p>\n
Medium aneurysms 4.0-5.5 cm<\/p>\n
Large >5.5 cm<\/p>\n
Risk Factors<\/strong><\/p>\nThe most important factor for aneurysm expansion is ongoing smoking.5<\/p>\n
Other risks include: older age, Caucasian race, hypertension, family history of AAA, presence of other aneurysms in the body, and atherosclerosis (#obviously).2<\/p>\n