General Surgery · Year 3 · from General Surgery

Case 2: Abdominal Aortic Aneurysm

Patient Demographics

  • Age: 68 years
  • Sex: Male
  • Occupation: Retired truck driver

Chief Complaint

"My doctor found an enlarged blood vessel in my belly on an ultrasound."

History of Present Illness

The patient underwent an abdominal ultrasound for unrelated kidney symptoms, which incidentally revealed an abdominal aortic aneurysm. He is asymptomatic from a vascular standpoint - no abdominal pain, no back pain, and no symptoms of rupture. He has a history of smoking and was previously told he had "hardening of the arteries."

Past Medical History

  • Hypertension (20 years)
  • Hyperlipidemia
  • COPD (mild, on inhalers)
  • Coronary artery disease (MI 5 years ago, medically managed)
  • Peripheral artery disease (claudication at 2 blocks)
  • Former smoker (60 pack-years, quit 3 years ago)

Family History

  • Father died of "burst aorta" at age 65
  • Brother has AAA under surveillance

Medications

  • Aspirin 81 mg daily
  • Atorvastatin 80 mg daily
  • Lisinopril 20 mg daily
  • Metoprolol 50 mg BID
  • Albuterol inhaler PRN

Physical Examination

  • Vitals: BP 148/82, HR 68, BMI 28
  • Cardiovascular: Regular rhythm, no murmurs
  • Abdomen: Pulsatile mass palpated in periumbilical region, non-tender
  • Lower extremities: Diminished but palpable pulses bilaterally, no ulcers

Initial Imaging

Screening Ultrasound:

  • Infrarenal AAA: 5.2 cm maximum diameter

Additional Imaging for Surgical Planning

CT Angiography (Abdomen and Pelvis):

  • Infrarenal AAA: 5.4 cm maximum diameter
  • Adequate infrarenal neck: 2.0 cm length, 24 mm diameter
  • Neck angle: 30 degrees
  • Minimal thrombus in aneurysm sac
  • Iliac arteries: Common iliacs 1.4 cm bilaterally (ectatic but not aneurysmal)
  • No iliac occlusive disease
  • Suitable anatomy for endovascular repair (EVAR)

Risk Stratification for Rupture

  • Size: 5.4 cm (threshold for repair typically 5.5 cm in men)
  • Growth rate: Unknown (first detection)
  • Risk factors: Male, smoker, family history, hypertension
  • Estimated annual rupture risk: 3-5%

Society Guidelines

  • Repair recommended for:
  • AAA ≥5.5 cm in men, ≥5.0 cm in women
  • Rapid growth (>0.5 cm in 6 months)
  • Symptomatic AAA (any size)
  • This patient: 5.4 cm - close to threshold

Multidisciplinary Discussion

Given:

  • Size approaching repair threshold
  • Strong family history of rupture
  • Suitable EVAR anatomy
  • Patient preference after discussion

Decision: Proceed with elective EVAR

Preoperative Optimization

  • Cardiology clearance (stress test negative for ischemia)
  • Pulmonary function testing (moderate COPD, optimized)
  • Smoking cessation maintained
  • Blood pressure optimization

Operative Procedure

Endovascular Aneurysm Repair (EVAR):

  • Bilateral femoral artery cutdowns
  • Bifurcated modular stent graft deployed
  • Main body: Infrarenal fixation
  • Bilateral iliac limbs placed
  • Completion angiogram: No endoleak, excellent positioning
  • Aneurysm sac excluded

Postoperative Course

  • Monitored overnight in step-down unit
  • Pedal pulses intact
  • No groin complications
  • Discharged POD 1

Surveillance Protocol

  • CT angiography at 1 month, 6 months, then annually
  • Monitor for:
  • Endoleak (persistent blood flow into aneurysm sac)
  • Sac expansion
  • Graft migration
  • Limb occlusion

1-Month CT Follow-up

  • No endoleak
  • Aneurysm sac stable
  • Graft in good position

Teaching Points

  1. AAA often asymptomatic - screening important in high-risk patients
  2. US Preventive Services Task Force recommends one-time screening for men 65-75 who have ever smoked
  3. Size is primary determinant of rupture risk
  4. EVAR vs. open repair: Similar long-term outcomes, EVAR has lower perioperative mortality but requires lifelong surveillance
  5. Anatomic suitability determines EVAR candidacy
  6. Medical optimization essential (statins, blood pressure, smoking cessation)
  7. Family history increases risk and may lower treatment threshold

Clinical Image

Image Description: CT angiography demonstrating an infrarenal abdominal aortic aneurysm with mural thrombus. The maximum diameter exceeds 5 cm, approaching the threshold for elective repair. Note the relationship to the renal arteries and iliac bifurcation.

Attribution: Image from Wikimedia Commons, Category:CT images of abdominal aortic aneurysms. Source: https://commons.wikimedia.org/wiki/Category:CT_images_of_abdominal_aortic_aneurysms

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