Patient presentation
A 68-year-old man with hypertension and a significant smoking history presents to the emergency department with the abrupt onset of severe abdominal and back pain. On examination he has a tender, pulsatile abdominal mass.
The combination of his risk factors, presentation, and physical findings raises immediate concern for a symptomatic abdominal aortic aneurysm, which may represent impending or actual rupture. You must rapidly determine his hemodynamic status and decide between resuscitation, expedited imaging, and emergent operative repair.
Aneurysm is defined as focal arterial dilatation to at least 1.5 times normal diameter; for the infrarenal aorta, 3 cm or greater is aneurysmal. The classic triad of pain, hypotension, and a pulsatile mass mandates an emergent surgical evaluation.
What you'll be asked — and what a strong resident discusses
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What is your initial assessment and management priority for this patient?
Expected answer
Treat this as a possible ruptured AAA until proven otherwise. Begin with ABCs, place two large-bore IVs, type and cross, send labs, and place on a monitor. Most importantly, assess hemodynamic stability. If unstable, the patient goes directly to the OR with the vascular team and blood mobilized — do not delay for imaging. If stable, obtain emergent CT angiography to confirm rupture and delineate anatomy for repair planning.
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How does hemodynamic stability change your management pathway?
Expected answer
An unstable patient with the classic triad does not need confirmatory imaging — proceed immediately to the OR for emergent repair, employing permissive hypotension (target SBP ~70-90 mmHg, a 'talking patient') to avoid disrupting clot and worsening hemorrhage. A stable patient can undergo CTA to confirm diagnosis and assess suitability for EVAR versus open repair. Sending an unstable patient to CT is a potentially fatal error.
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What is permissive hypotension and why is it used here?
Expected answer
In contained or ruptured AAA, aggressive fluid resuscitation raises blood pressure and can dislodge the tamponading clot/retroperitoneal hematoma, precipitating uncontrolled hemorrhage. Permissive (hypotensive) resuscitation maintains just enough perfusion — typically a patient who is awake and talking, SBP roughly 70-90 — until proximal vascular control is obtained in the OR.
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What imaging do you use to diagnose and to plan repair, and why the difference?
Expected answer
Duplex ultrasound is used for screening and surveillance because it is non-invasive, low-risk, and bedside-available — useful in the unstable patient to quickly confirm an aneurysm. CT angiography provides far more accurate measurements and delineates the proximal neck, landing zones, access vessels, and iliac anatomy needed for operative planning and EVAR feasibility, so it is obtained preoperatively in a stable patient.
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What determines whether this patient is a candidate for EVAR versus open repair?
Expected answer
The proximal aortic neck anatomy is the key determinant: adequate neck length, acceptable angulation, diameter, and shape are required to obtain a proximal seal. Suitable iliofemoral access vessels are also needed. If landing zones and access are favorable, EVAR is preferred (especially in the emergent setting if available). If anatomy is hostile, open surgical repair is performed. Long-term mortality is equivalent between the two, but EVAR has lower perioperative mortality.
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What are the standard size thresholds and indications for elective AAA repair?
Expected answer
Repair is indicated in patients with a reasonable life expectancy when the AAA is greater than 5.5 cm, when it expands 1 cm or more in a year, or when it becomes symptomatic. USPSTF recommends one-time screening ultrasound for men aged 65-75 who have ever smoked. Below threshold, asymptomatic aneurysms are surveilled with serial ultrasound.
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What are the major postoperative complications you watch for after AAA repair?
Expected answer
Cardiac ischemia (the leading cause of perioperative death), renal failure (contrast/ischemia/suprarenal clamp), ischemic colitis of the sigmoid colon (from IMA/hypogastric compromise), lower extremity ischemia, and spinal cord ischemia. After EVAR specifically, endoleaks. Vigilant monitoring of urine output, lower extremity pulses, neuro exam, and bowel function is essential.
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The patient develops bloody diarrhea and abdominal distension on POD 2. What is your concern and management?
Expected answer
This is ischemic colitis of the sigmoid colon, often from interruption of IMA/collateral flow. It can present with bloody diarrhea, abdominal pain, distension, fever, leukocytosis, or metabolic acidosis. Obtain flexible sigmoidoscopy to assess mucosal viability. Mucosal/partial-thickness ischemia is managed nonoperatively with bowel rest, IV fluids, and antibiotics. Transmural necrosis, peritonitis, or worsening acidosis mandates exploration and colon resection, typically with end colostomy.
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Describe the types of endoleaks and which require intervention.
Expected answer
Type 1: inadequate seal at proximal/distal attachment (native vessel) — requires immediate repair. Type 2: retrograde flow from branch vessels (lumbar/IMA) — most common, often observed if sac is stable. Type 3: flow between separate graft components — requires repair. Type 4: flow through graft fabric porosity — usually self-limited. Type 5: endotension, persistently elevated sac pressure without visualized leak. Surveillance CT is done at 1 and 12 months; a leak at 1 month prompts CTA at 6 months to decide on re-intervention.
What residents often miss
- Sending a hemodynamically unstable patient with the classic triad to CT scan instead of directly to the OR — a potentially fatal/automatic-fail error.
- Aggressively fluid-resuscitating a ruptured AAA to a normal blood pressure, disrupting the tamponading clot rather than using permissive hypotension.
- Failing to recognize that the triad of pain, pulsatile mass, and hypotension is rupture until proven otherwise, and delaying surgical/vascular involvement.
- Overlooking proximal neck and access-vessel anatomy when choosing EVAR, leading to inadequate seal or need for open conversion.
- Missing postoperative ischemic colitis — attributing bloody diarrhea or unexplained acidosis/leukocytosis to other causes instead of obtaining sigmoidoscopy.
- Neglecting cardiac risk assessment and optimization, despite cardiac ischemia being the leading cause of perioperative mortality.
- Confusing endoleak types or mismanaging them — failing to urgently repair a Type 1 or Type 3 leak, or over-treating a stable Type 2.
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This page is educational content for general-surgery board-exam practice. It is not medical advice and is not a substitute for clinical judgment, institutional protocols, or current primary literature.