Symptoms of Abdominal Aortic Aneurysm
Most abdominal aortic aneurysms remain completely asymptomatic until rupture and are typically discovered incidentally on imaging performed for unrelated reasons. 1, 2
Asymptomatic Presentation (Most Common)
- Approximately two-thirds of AAAs produce no symptoms whatsoever and are detected as incidental findings on ultrasound, CT, or other abdominal imaging studies 2
- Large unruptured aneurysms are quite often asymptomatic and may only be found incidentally on physical examination or imaging 3
- Patients are generally asymptomatic, with diagnosis made during imaging studies for other reasons or for screening purposes 4
Symptomatic AAA (Indicates Impending Rupture)
When symptoms develop, they signal a medical emergency requiring immediate evaluation:
Cardinal Warning Symptoms
- Acute abdominal pain is the most common presenting symptom of impending rupture 5, 2
- Back pain occurs in 65-90% of cases of ruptured AAA and is a critical warning sign 5, 6
- Flank pain may indicate impending rupture and warrants immediate ICU admission 5
- Pain may be described as "sharp" or "stabbing" rather than the classic "tearing" or "ripping" quality 2
Physical Examination Findings
- Pulsatile abdominal mass is present in only 47.1% of cases (low sensitivity) 1, 6, 7
- The classic triad of hypotension, back pain, and pulsatile abdominal mass is present in only 50% of ruptured AAAs 3
- Hypotension has a pooled sensitivity of only 30.9% for ruptured AAA 6
Less Common Presentations
- Unilateral lower limb swelling can occur due to compression of the inferior vena cava 8
- Shortness of breath may result from associated pulmonary embolism secondary to caval thrombosis 8
- Fever is present in ≥70% of cases of ruptured AAA 5
- Syncope occurs in 27.8% of ruptured AAA cases 6
Critical Clinical Pitfalls
The absence of classic symptoms does not rule out AAA or impending rupture. 6 Classic clinical symptoms have poor sensitivity:
- Abdominal pain: only 61.7% sensitive 6
- Back pain: only 53.6% sensitive 6
- Syncope: only 27.8% sensitive 6
Any patient with a known AAA presenting with acute abdominal, back, or flank pain should be presumed to have impending rupture and requires immediate ICU admission with urgent repair within 24-48 hours 5
When to Suspect AAA
Maintain high clinical suspicion in patients with:
- Age >60 years with risk factors (smoking, male sex, family history) 9, 7
- New onset abdominal or back pain with atherosclerotic risk factors 5, 2
- Unexplained hypotension with abdominal symptoms 7
Recurrent or refractory pain identifies patients at highest risk of progression to complete rupture, regardless of aneurysm size on imaging 5