Ruptured Abdominal Aortic Aneurysm

Vascular Surgery

OverviewWhoPresentationMechanismWorkupManagementPivots

Illness script · Vascular Surgery

Ruptured Abdominal Aortic Aneurysm

Life-threatening full-thickness tear of a dilated infrarenal aorta (≥3 cm), causing hemorrhage into retroperitoneum or peritoneal cavity.

This illness script for Ruptured Abdominal Aortic Aneurysm covers predisposing factors, classic presentation, mechanism, workup, management, and the clinical pivots that separate it from look-alikes—written for USMLE Step 1 and clerkship reasoning.

Updated Aug 17, 2026All scripts

01

Predisposing factors

  • Male sex (4:1 M:F); peak age 65–80
  • Smoking is the strongest modifiable risk factor
  • HTN, atherosclerosis, hyperlipidemia
  • Family history (first-degree relative with AAA)
  • COPD independently associated
  • Connective tissue disorders (Marfan, Ehlers-Danlos) in younger patients

02

Presentation

  • Classic triad: sudden severe tearing/ripping back or flank pain + pulsatile abdominal mass + hypotension
  • Retroperitoneal rupture → transient hemodynamic stability ('contained' phase) — deceptive
  • Pain may radiate to groin, mimicking renal colic
  • Syncope or near-syncope common at onset
  • Grey Turner sign (flank ecchymosis) or Cullen sign — late, rare
  • Exam: pulsatile epigastric mass; peritoneal signs if free rupture

03

Pathophysiology

  • Elastin/collagen degradation in aortic wall → progressive dilation
  • Transmural stress rises with diameter (Law of Laplace) → wall tension exceeds tensile strength
  • Rupture most commonly into retroperitoneum (tamponades temporarily) or freely into peritoneum (rapidly fatal)
  • Risk of rupture sharply increases at diameter ≥5.5 cm or expansion >0.5 cm/6 months

04

Diagnostics

  • Unstable patient → go directly to OR; NO imaging delay
  • Bedside ER ultrasound: fast, sensitive for aortic diameter; cannot reliably confirm rupture
  • CT angiography (CTA abdomen/pelvis): gold standard if patient is hemodynamically stable
  • Labs: type & crossmatch, CBC, BMP, coagulation panel, lactate — do not delay OR for results
  • Pitfall: misdiagnosed as renal colic or musculoskeletal back pain — always palpate the aorta

05

Management

  • Immediate vascular surgery consult + activate OR — time is the priority
  • 2 large-bore IVs, permissive hypotension (MAP ~50 mmHg) until operative control — avoid aggressive resuscitation
  • Massive transfusion protocol: 1:1:1 pRBC:FFP:platelets
  • Definitive treatment: emergent open surgical repair OR endovascular aortic repair (EVAR) if anatomy suitable
  • Avoid over-resuscitation (worsens coagulopathy, dislodges clot); mortality 50–80% overall with rupture

06

Clinical pivots

How to separate this script from the look-alikes that show up on exams and on the wards.

  • Renal colic (nephrolithiasis)

    AAA rupture causes hemodynamic instability and a pulsatile abdominal mass; renal colic does not.

  • Acute mesenteric ischemia

    AAA rupture features a palpable pulsatile mass and hypotension; mesenteric ischemia presents with pain out of proportion but a soft, non-pulsatile abdomen.

  • Acute MI (inferior)

    AAA rupture has abdominal/back pain with a pulsatile mass; inferior MI lacks an abdominal mass and EKG changes guide diagnosis.

  • Intact (non-ruptured) AAA

    Rupture is defined by hemodynamic instability or peritoneal signs; intact AAA is typically asymptomatic or found on screening.

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Educational use only. This illness script is a study framework, not medical advice. Confirm decisions with current guidelines and your clinical supervisors.