Aortic rupture is a full-thickness tear of the aortic wall and represents one of the most lethal cardiovascular emergencies. Rupture most commonly occurs in the setting of infrarenal abdominal aortic aneurysm (AAA); when aneurysm diameter exceeds 5.5 cm, annual rupture risk rises to 10-15%. Rupture manifests in three main forms: free intraperitoneal rupture (rapid hemodynamic collapse and death), contained retroperitoneal rupture (temporarily tamponaded by retroperitoneal hematoma — 'contained rupture'), and aortoenteric fistula (communication with bowel lumen). Retroperitoneal rupture accounts for approximately 80% of cases and may allow the patient to reach the emergency department due to temporary tamponade by retroperitoneal fat tissue. CT angiography (CTA) is the gold standard for diagnosis; active contrast extravasation, retroperitoneal hematoma, focal discontinuity of the aortic wall, and the 'draped aorta' sign are the principal findings. Without treatment, mortality exceeds 90%; emergent surgery (open repair or endovascular stent-graft/EVAR) is the only curative option.
Age Range
55-90
Peak Age
70
Gender
Male predominant
Prevalence
Rare
Aortic rupture results from the aortic wall becoming unable to withstand mechanical load due to atherosclerotic degeneration and aging. Atherosclerosis progressively thins the tunica media — elastin fibers fragment, smooth muscle cells undergo apoptosis, and collagen degradation increases → wall tensile strength decreases → when intraluminal pressure exceeds wall stress, a full-thickness tear develops (Laplace's law: wall stress = pressure × radius / 2 × wall thickness — hence stress increases exponentially with larger aneurysm diameter). Rupture typically initiates at the posterolateral wall of the aneurysm because this region has the least mechanical support, being closest to the vertebral bodies. In retroperitoneal rupture, blood extends into the retroperitoneal space where the psoas muscle, renal fascia, and periaortic fat tissue provide temporary tamponade — this 'contained rupture' state manifests on CT as retroperitoneal hematoma, draped aorta sign, and discontinuity in intraluminal thrombus. In free intraperitoneal rupture, no tamponade mechanism exists and massive hemoperitoneum develops. The active bleeding focus appears as contrast extravasation on CTA — the high-pressure arterial blood leaking outside the aorta carries contrast material with it. Disruption of wall calcification continuity ('discontinuous calcification sign') localizes the rupture point because calcified intima fragments and displaces at the rupture site.
Posterior aortic wall draping over the vertebral body like a cloth — the posterior wall loses its convexity and follows the vertebral contour. This finding indicates that posterior wall integrity has been compromised and the aorta is in direct contact with the vertebral body. One of the most reliable signs of ruptured or impending rupture aneurysm.
Active contrast leakage from the aortic lumen is seen on arterial phase CTA. Extravasated contrast appears as a focal hyperdense focus within the retroperitoneal hematoma at near-luminal density (150-300 HU). On delayed phase, expansion and increasing density of this focus ('pooling') confirms ongoing active bleeding. Contrast extravasation is the definitive diagnostic finding of rupture and constitutes an emergent surgical indication.
Report Sentence
Active contrast extravasation from the aortic lumen into the retroperitoneal space at the level of the aortic aneurysm, consistent with rupture; emergent surgical intervention is indicated.
High-density (50-70 HU) fluid collection around the aorta, in the pararenal space, and/or psoas muscle compartment on non-contrast CT. Acute hematoma is significantly denser than soft tissues due to fresh blood content. The extent of hematoma reflects bleeding volume — extension into anterior pararenal, posterior pararenal, and perirenal spaces indicates extensive rupture. In free intraperitoneal bleeding, free fluid in Morrison's pouch, pelvic recesses, and paracolic gutters accompanies the findings.
Report Sentence
High-density (__ HU) fluid collection around the aorta and in the retroperitoneal space consistent with acute hematoma, further evaluation for aneurysm rupture is recommended.
The draped aorta sign is defined as the posterior aortic wall 'draping' over the vertebral body like a cloth. In the normal aorta, the posterior wall maintains its convex contour and is separated from the vertebral body by perivertebral fat. In a ruptured or impending rupture aneurysm, the posterior wall integrity is lost, the aorta contacts the vertebral body, and follows the vertebral contour adopting a concave shape. This finding indicates posterior wall weakness and impending/actual rupture. It is frequently seen in acute and chronic contained rupture.
Report Sentence
The posterior aortic wall draping over the vertebral body (draped aorta sign) is present, consistent with aneurysm rupture or impending rupture.
Disruption or outward displacement of the calcified intima at the rupture point in the aneurysm wall. In normal atherosclerotic aneurysms, intimal calcification forms a continuous line along the wall. At the rupture point, disruption of this line, displacement of calcified fragments into the retroperitoneal hematoma, or formation of a 'gap' indicates the rupture location. Best evaluated on non-contrast CT because contrast may mask calcifications.
Report Sentence
Focal discontinuity of calcified intima in the aneurysm wall (discontinuous calcification sign), localizing the rupture point.
On MRI, retroperitoneal hematoma can be aged based on signal characteristics on T1-weighted sequences. Acute hematoma (0-48 hours) appears isointense to mildly hyperintense on T1 (deoxyhemoglobin), subacute hematoma (48 hours-1 week) appears markedly hyperintense on T1 (methemoglobin — paramagnetic effect). On T2, acute hematoma is hypointense (intracellular deoxyhemoglobin), early subacute hypointense, late subacute hyperintense. MRI is used as an alternative when CTA is unavailable or contrast is contraindicated.
Report Sentence
T1 hyperintense collection in the retroperitoneal space consistent with subacute hematoma; should be correlated with aortic aneurysm rupture.
On US, a hypoechoic to mixed echogenic fluid collection is seen around the aorta or in the retroperitoneal space. Acute hematoma shows heterogeneous echogenicity — fresh liquid blood is hypoechoic while coagulated blood may appear hyperechoic. Focal loss of aneurysm wall continuity can rarely be directly demonstrated. US has limited sensitivity because the retroperitoneal space may be obscured by bowel gas and obesity. In the hemodynamically unstable patient, bedside US detection of AAA can guide immediate CTA or direct surgical referral.
Report Sentence
Heterogeneous fluid collection around the aorta consistent with retroperitoneal hematoma; emergent further evaluation with CTA is recommended.
Focal loss of aneurysm wall continuity, wall defect, or contour irregularity on CTA. Contrast material passes through this defect into the retroperitoneal space or intraperitoneal cavity. The wall defect is usually posterolateral in location. The size of the defect and presence of active extravasation determine rupture severity. In contained rupture, the defect may be small and partially covered by thrombus, making thin-section reconstruction and multiplanar reformation important.
Report Sentence
Focal wall discontinuity at the posterolateral aspect of the aneurysm indicating the rupture point.
A hyperattenuating crescent-shaped area within the mural thrombus in the aneurysm lumen ('crescent sign') is seen. This finding indicates acute hemorrhage within the thrombus. On non-contrast CT, thrombus normally measures 50-60 HU while the acute hemorrhage focus measures 70-90 HU. Considered a warning sign of impending rupture requiring emergent intervention planning.
Report Sentence
Hyperattenuating crescent sign within the mural thrombus of the aneurysm, to be evaluated as a finding of impending rupture.
Criteria
Retroperitoneal hematoma present but patient hemodynamically relatively stable; retroperitoneal fat and fascial structures provide temporary tamponade. Accounts for 80% of cases.
Distinct Features
Draped aorta sign, periaortic/pararenal hematoma, contrast extravasation may or may not be present. Patient can reach emergency department — surgical window of opportunity exists. High risk of rapid progression to free rupture.
Criteria
Blood freely spreads into peritoneal cavity, no tamponade mechanism. Rapid hemodynamic collapse develops; mortality rate is very high (80-90% prehospital).
Distinct Features
Massive hemoperitoneum — free fluid in Morrison's pouch, pelvic recesses, paracolic gutters. Active contrast extravasation common. Most patients do not reach hospital or are lost in the emergency department.
Criteria
Rare presentation; rupture forms an organized pseudoaneurysm in retroperitoneal tissues remaining stable for weeks to months. Usually incidentally detected on CT obtained for other reasons.
Distinct Features
Organized hematoma capsule, vertebral erosion (chronic pressure), pseudoaneurysm formation. Diagnosis may be difficult in absence of acute findings. Elective surgery can be planned but risk of acute rupture persists.
Distinguishing Feature
In intact AAA, retroperitoneal hematoma, contrast extravasation, and draped aorta sign are absent; wall continuity is preserved. Crescent sign may be the only finding suggesting impending rupture.
Distinguishing Feature
In dissection, intimal flap and dual lumen (true + false) are seen; in rupture, no intimal flap is present. Dissection may have periaortic hematoma but this is intramural hemorrhage within the aortic wall, while in rupture it is extramural retroperitoneal hematoma.
Distinguishing Feature
In aortoenteric fistula, loss of fat plane between aorta and duodenum/jejunum, periaortic gas bubbles, and contrast leakage into bowel lumen are distinguishing. In rupture, bleeding is directed into retroperitoneal space without direct bowel communication.
Distinguishing Feature
In intramural hematoma, crescent-shaped hyperdense thickening within the aortic wall is seen but intimal flap, dual lumen, or retroperitoneal hematoma are absent. Hematoma is confined within the wall.
Urgency
emergentManagement
surgicalBiopsy
Not NeededFollow-up
specialist-referralAortic rupture is a cardiovascular emergency requiring emergent surgical intervention. Mortality exceeds 90% without treatment. Once diagnosis is confirmed, emergent vascular surgery or endovascular intervention (EVAR) should be planned. In the hemodynamically unstable patient, even CT may not be feasible — direct transfer to operating room. In contained rupture, a surgical window of opportunity exists but risk of conversion to free rupture is constant. Postoperative follow-up with CTA at 1, 6, and 12 months, then annually.
Aortic rupture is an emergency surgical indication. Contained rupture allows brief stabilization but carries continuous risk of progression to free rupture. Open surgical repair or emergency EVAR are treatment options. Out-of-hospital rupture mortality exceeds 90%.