What is the best management for an elderly male patient with hypertension and a history of heavy smoking who has a 4.5 cm abdominal aortic aneurysm?

Management of 4.5 cm Abdominal Aortic Aneurysm

The best management for this patient is regular follow-up with ultrasound every 6 months (Option C), as this 4.5 cm AAA falls below the 5.5 cm threshold for elective repair, and surveillance offers comparable mortality benefit to immediate surgery with fewer operative complications. 1, 2

Rationale for Surveillance Over Surgery

• Elective repair is reserved for AAAs ≥5.5 cm in diameter, as aneurysms below this threshold have substantially lower rupture risk 3, 1, 2
• The 1-year rupture risk for AAAs of 5.5-5.9 cm is 9%, but this risk decreases significantly for smaller aneurysms like this 4.5 cm lesion 3
• For intermediate-sized AAAs (4.0-5.4 cm), periodic surveillance provides comparable mortality benefit to routine elective surgery, with the advantage of avoiding unnecessary operations 3, 1

Specific Surveillance Protocol

• Follow-up ultrasound imaging every 6 months is specifically recommended for aneurysms measuring 4.5-5.4 cm in diameter 3, 1, 2
• Ultrasound remains the preferred modality due to its high sensitivity (95%) and near 100% specificity, with no radiation exposure 3, 4
• CT angiography may be considered before continued surveillance to better characterize aneurysm morphology, particularly to identify saccular features that increase rupture risk even below the 5.5 cm threshold 3, 1

Indications for Surgical Intervention

• Surgery becomes indicated if the aneurysm grows to ≥5.5 cm or expands rapidly (>1.0 cm/year) 3, 1, 2
• The most recent European guidelines (2024) confirm surgical thresholds at 5.5 cm for men 3

Critical Risk Factor Management (Must Be Addressed Immediately)

This patient's heavy smoking and hypertension are particularly concerning modifiable risk factors:

• Smoking cessation is the single most important intervention, as smoking is the strongest modifiable risk factor for AAA expansion and rupture 3, 1, 2
• Optimal blood pressure control is essential, as hypertension accelerates aneurysm growth rates 3, 1, 2
• Statin therapy should be initiated for cardiovascular risk reduction in all patients with atherosclerotic peripheral arterial and aortic disease 3, 1

Why Other Options Are Incorrect

Reassurance (Option A) is inappropriate because this patient requires active surveillance and aggressive risk factor modification—not passive observation 1, 2

Urgent surgery (Option B) is not indicated because:

• Open repair is reserved for AAAs ≥5.5 cm in good surgical candidates 1, 2
• Endovascular repair is typically for aneurysms ≥5.5 cm or those with rapid expansion 1, 2
• Premature surgery exposes the patient to unnecessary operative mortality (4.7% for open repair, 1.0% for endovascular) without survival benefit 5

Aneurysm endarterectomy (Option D) is not a recognized treatment for AAA—this appears to be a distractor option, as AAA treatment involves either open surgical repair or endovascular aneurysm repair (EVAR), not endarterectomy 1

Common Pitfalls to Avoid

• Do not provide false reassurance—the success of watchful waiting depends entirely on patient compliance with surveillance and risk factor modification 2
• Do not delay smoking cessation counseling—this must be addressed at the initial visit, as continued smoking dramatically increases rupture risk 3, 1, 2
• Do not forget to screen for other vascular disease—patients with AAA have high rates of coronary artery disease and other peripheral arterial disease that require evaluation 3, 4