Missed Aortic Aneurysm Diagnosis: Building the Malpractice Case
An abdominal aortic aneurysm (AAA) is a bulge in the wall of the aorta, the body's largest artery, as it runs through the abdomen. Many aneurysms grow slowly without symptoms for years. The danger comes when one starts expanding quickly or ruptures. A ruptured AAA causes massive internal bleeding and is often fatal, even with emergency surgery.
That's what makes missed AAA cases so serious. When an aneurysm is caught before rupture, it can usually be repaired. When it's missed, the next sign is often a catastrophe. These cases tend to involve one of two failures: a symptomatic aneurysm missed in the emergency department, or an aneurysm seen on earlier imaging that was never followed up.
Why AAAs Get Missed in the ER
The classic signs of a ruptured or leaking AAA are abdominal or back pain, low blood pressure, and a pulsating mass in the abdomen. In practice, many patients don't show all three, and the pain can look like something far more common.
Frequent misdiagnoses include:
Kidney stones. Flank pain radiating toward the groin can look a lot like renal colic.
Musculoskeletal back pain. Especially in patients with a history of back problems.
Diverticulitis or other abdominal conditions.
Fainting or dizziness attributed to dehydration or a cardiac cause.
The misdiagnosis that comes up most in litigation is kidney stone. An older patient with flank pain gets treated for a stone without imaging that would show the aorta, and goes home. Hours or days later, the aneurysm ruptures.
Who's at Risk
Risk factors matter because they shape what a reasonable provider should have considered. Common ones include:
Older age, especially over 65
Male sex
Smoking history
High blood pressure
Atherosclerosis or other vascular disease
Family history of aneurysm
An expert will often argue that a patient with several of these factors and unexplained abdominal, back, or flank pain should have had AAA on the differential diagnosis, and that ruling it out was part of the standard of care.
What the Standard of Care Usually Requires
Considering the diagnosis. For a patient with risk factors and compatible symptoms, AAA should be considered and either confirmed or ruled out.
Bedside ultrasound. Many emergency physicians use point-of-care ultrasound to quickly look at the aorta. It can identify an aneurysm in minutes, though it can't always confirm whether it's leaking.
CT angiography. In a stable patient, CT imaging with contrast is commonly used to evaluate the aneurysm and look for rupture or leakage.
Urgent vascular surgery consult. A symptomatic aneurysm, even one that hasn't ruptured, generally calls for urgent evaluation by a vascular surgeon. A rupture calls for emergency surgery. Delays in getting the surgeon involved, or in transferring the patient to a facility that can do the repair, are a common source of liability.
Reading the imaging correctly. Some cases involve imaging that showed the aneurysm, but the finding was missed, misread, or not communicated to the treating physician.
Missed Incidental Findings
The second major category doesn't involve the ER at all. Many aneurysms are first seen by accident on imaging done for something else, like a CT for kidney stones or back pain.
When a radiologist notes an aneurysm on a report, the finding needs to reach someone who will act on it. Failures can happen at several points:
The radiologist doesn't mention the aneurysm or buries it in the report.
The ordering physician doesn't read or act on the finding.
No one tells the patient or arranges follow-up imaging.
The patient is never referred to a vascular surgeon.
These cases can be strong because the aneurysm was documented in the patient's own record, sometimes years before it ruptured. They often involve multiple defendants, including radiologists, ER physicians, primary care physicians, and the systems responsible for tracking results.
Screening
The U.S. Preventive Services Task Force recommends a one-time screening ultrasound for AAA in men ages 65 to 75 who have ever smoked. Failure-to-screen claims against primary care physicians are possible, but they generally depend on the patient's age, sex, smoking history, and the specific guidelines in effect at the time of care.
Causation and Survival
Causation is usually the main fight in a missed AAA case. Ruptured aneurysms have a high death rate even with prompt surgery, and the defense will argue the patient likely would have died anyway.
Key questions include:
Was the aneurysm intact, leaking, or ruptured at the first visit? An intact or contained aneurysm is far more survivable than a free rupture.
How large was it? Size helps establish risk and the urgency of repair.
How long was the delay? Hours can matter.
Was the patient a surgical candidate? The defense may argue the patient's health made repair too risky.
Some states allow recovery under a "loss of chance" doctrine, where a delay reduced the patient's chance of survival even if survival wasn't more likely than not. Others don't. How your jurisdiction handles this can shape the whole case.
Which Experts You Need
Emergency medicine physician. Addresses whether AAA should have been considered, what workup was required, and whether discharge was appropriate.
Vascular surgeon. Usually the central causation expert. Explains when repair was needed, whether open repair or endovascular repair (EVAR) was appropriate, and how survival odds changed with the delay.
Radiologist. Essential when imaging was misread, or when an incidental finding was not reported clearly.
Primary care physician. Relevant in screening cases and when an incidental finding was never followed up.
Damages experts. In wrongful death cases, economists may be needed for lost earnings and household services. In survival cases, life care planners may address ongoing care after repair.
Common Defense Arguments
Atypical presentation. Symptoms pointed to kidney stones or back pain.
Rupture was sudden. The aneurysm was stable at the visit and ruptured afterward without warning.
Not survivable. Even with immediate surgery, the patient likely would not have survived.
Not a surgical candidate. The patient's health made repair too risky.
Proper communication. The radiology finding was reported, and follow-up was the patient's responsibility.
Missed AAA cases are built on timing, risk factors, and the record. When the aneurysm was documented, the patient had risk factors, or the presentation fit, those facts usually form the core of the claim.