Abdominal Aortic Aneurysm

Question
What is the official measurement for an abdominal aortic aneurysm to be declared a medical emergency—5 or 6 cm?

Answer
Five to 6 cm is considered the range in which risk of rupture begins to increase substantially, so that intervention (surgery or endograft) is usually desirable. Zwiebel's Introduction to Vascular Ultrasonography says 5 to 5.5 cm, and adds this: "Symptomatic aneurysms may result in abdominal, flank, or back pain; embolization, thrombosis; or rupture. The latter complication is usually fatal" (5th edition, p 381).

Of course, "medical emergency" might not apply to an aneurysm that hasn't ruptured yet; that description might be reserved for a ruptured AAA. The outlook is dismal for those folks, as mentioned in Zwiebel. Rutherford's Vascular Surgery is more specific: "The mortality rate for ruptured aneurysms has not changed significantly and continues to be 40% to 70%. In fact, the true mortality for ruptured aneurysms is much closer to 80% to 90% if deaths occurring before patients reach the hospital are included" (5th edition, p 1299).


Uncle Don is Donald Ridgway, RVT, author of Introduction to Vascular Scanning: A Guide for the Complete Beginner, editor of Vascular Technology Review and CD-ROM Mock Exam in Vascular Technology, and coeditor of Vascular Physics Review. He is a practicing vascular technologist and an instructor in the vascular technology program at Grossmont College in California, where he was responsible for seeing that program become the first vascular technology curriculum to receive American Medical Association accreditation.

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