An aortic dissection is a tear in the inner layer of the aorta that leads to a progressively growing hematoma in the intima-media space. Risk factors for aortic dissection include age and hypertension. Patients typically present with sudden onset severe pain radiating into the chest, back, or abdomen. A widened mediastinum on chest x-ray is characteristic of the diagnosis. The diagnosis is usually confirmed with CT angiogram in stable patients and transesophageal echocardiography (TEE) in unstable patients. Treatment options range from conservative measures (e.g., blood pressure optimization) to surgery (aortic stent graft), depending on the localization and severity of the dissection. Complete occlusion of branching vessels and aortic rupture are common complications. Even with treatment, mortality rates associated with aortic dissection are high.
- Sex: ♂ > ♀ 
- Localization 
Epidemiological data refers to the US, unless otherwise specified.
- Hypertension (most common risk factor)
- Trauma; , e.g., deceleration injury in a motor vehicle collision, or iatrogenic injury during valve replacements or graft surgery (traumatic aortic dissection)
- Vasculitis; with aortic involvement (e.g., syphilis, Takayasu arteritis)
- Use of amphetamines and cocaine
- Third-trimester pregnancy (or early postpartum period)
There are two classifications of aortic dissection to help direct management. Stanford classification groups dissections by whether the ascending or descending aorta is involved. DeBakey classification categorizes dissections according to their origin and extent.
Stanford classification 
- Stanford type A aortic dissection: any dissection involving the ascending aorta (defined as proximal to the brachiocephalic artery), regardless of origin
- Stanford type B aortic dissection: any dissection not involving the ascending aorta
DeBakey classification (rarely used) 
- Type I
- Type II
- Type III
- Common anatomic sites of origin
Transverse tear in the aortic intima (“entry”) → blood enters the media of the aorta and forms a false lumen in the intima-media space ; → hematoma forms and propagates longitudinally downwards 
- Rising pressure within the aortic wall → rupture
- Occlusion of branching vessels; (e.g., coronary arteries, arteries supplying the brain, renal arteries, arteries supplying the lower limbs) → ischemia in the affected areas (see “Complications” below)
- A second intimal tear may result in a “reentry” into the primary aortic lumen.
- Sudden and severe tearing/ripping pain
- Hypertension or hypotension
- Asymmetrical blood pressure and pulse readings between limbs
- Wide pulse pressure 
- Syncope, diaphoresis, confusion, or agitation
The optimal management approach depends on the clinical presentation, e.g.,. 
Consult cardiothoracic surgery for all patients with highly suspected or confirmed aortic dissection, regardless of . 
Hemodynamically unstable patients 
- Resuscitate with ACLS and/or stabilize using .
- Perform simultaneous bedside investigations, e.g., ECG, portable CXR, and/or bedside echocardiography (TEE, TTE, or POCUS) based on availability. 
- Immediately treat life-threatening complications, e.g., , .
- Expedite surgical management.
- Consider additional consultations: e.g., cardiology, critical care
- Consider definitive imaging (e.g., CTA) if the patient is stabilized, in consultation with a specialist.
- Admit to critical care unit or transfer to OR.
Patients with critical organ dysfunction 
- Follow the management approach of the suspected condition.
- Evaluate prior to administering thrombolytics or other invasive therapy (e.g., PCI) if time permits.
- Do not rely on ECG alone as findings of aortic dissection can resemble those of ACS and PE.
- Consider portable CXR to rapidly identify
- Consider including CTA in the diagnostic evaluation to rule out aortic dissection, e.g., add CTA Chest to CTA head and neck for stroke.
- Consider bedside TEE, TTE, or POCUS to rule in aortic dissection, if this can be done without delay. 
- Treat aortic dissection if identified (see “Treatment”).
Stable patients 
Most patients (∼ 70%) with aortic dissection are stable upon initial presentation. Some may present atypically. 
- Determine , e.g., based on clinical evaluation and/or .
- Order initial investigations, e.g., CXR, ECG, laboratory studies.
- Concurrently investigate other potential causes of symptoms: See “Chest pain”, “Syncope”, and “Dyspnea.”
- Maintain a low threshold to obtain definitive imaging for aortic dissection, e.g., CTA. 
- Begin therapy based on imaging findings and Stanford classification: See “Treatment.”
- Admit to surgical ICU with close monitoring and surveillance imaging. 
Mortality from a type A aortic dissection increases by 1–2% per hour until management is initiated. Maintain a high level of clinical suspicion and order diagnostic studies early! 
- chest pain: These increase the likelihood of aortic dissection.  accompanying
- Aortic dissection detection risk score (ADD-RS): a bedside clinical tool used to assess the risk of acute aortic dissection based on high-risk conditions, pain, and examination features. 
- ADvISED tool (not externally validated): A variant clinical prediction rule that combines the ADD-RS and the D-dimer. 
|Aortic dissection detection risk score (ADD-RS)|
|Risk categories||Features||Score if any feature present|
|Pain characteristics|| ||1|
The optimal diagnostic approach depends on each individual's pretest probability, clinical presentation, and risk profile (see “Management”).
- Order ECG for all patients.
- Order laboratory studies (consider including D-dimer). 
CXR, TTE, and POCUS are considered screening imaging and are usually only obtained as the initial study if:
- Invasive or risky testing is not desired for low-risk patients.
- Definitive imaging is not readily available.
- Patients are too unstable to undergo definitive imaging. 
Definitive imaging includes CTA (gold standard), TEE, and MRA and should be obtained as the:
- Initial study for high-risk patients
- Confirmatory study if the diagnosis remains uncertain
Definitive imaging can determine the type of lumen, location, and extent of the dissecting membrane. The identification of a false lumen on imaging is highly suggestive of aortic dissection.
|Imaging for aortic dissection |
|CXR|| || |
|Echocardiography||TTE or POCUS || || |
|Aortography (rarely performed)|| || |
Findings are variable and include: 
- Normal findings
- Signs of left ventricular hypertrophy 
- Nonspecific changes, such as ST depression and T-wave changes
- ST elevation due to coronary artery occlusion 
- D-dimer: elevated levels 
- Studies to evaluate end-organ damage: e.g., troponin, BMP, lactate
- Preoperative studies: CBC, type and screen, BMP, coagulation panel
Chest x-ray (AP view) 
Chest x-ray is often normal.
- Classic radiographic findings of aortic dissection
- Additional findings: may be present
Normal chest x-ray findings do not rule out aortic dissection. If clinical suspicion for acute aortic dissection persists, perform a second imaging study.
- Indications: stable patients, surgical planning
- Suggestive findings
Magnetic resonance angiography (MRA) chest, abdomen, and pelvis
- Indications: stable patients, contraindications to CTA
- Suggestive findings: similar to CT angiography
- Findings may include:
For other differential diagnosis considerations, see “”.
Acute aortic occlusion 
- Clinical features: The clinical features of acute aortic occlusion are due to ischemia of the tissues distal to the level of occlusion.
- Bilateral transfemoral embolectomy
- Aortobifemoral bypass
The differential diagnoses listed here are not exhaustive.
- Stanford A dissection: immediate surgery.
- Stanford B dissection: treat conservatively; (watchful waiting and ongoing medical therapy) unless complications occur. 
- Blood pressure control: essential in all patients to prevent progression of the dissection
- Supportive care
Surgical therapy 
Ascending aortic dissection is a surgical emergency!
Hypotensive patients 
- Hemodynamic support: target MAP of 70 mm Hg or euvolemia 
- Identify and treat, if possible, any comorbidities that may be contributing to the hypotension
- Expedite operative management.
Avoid inotropes as they can worsen aortic wall stress.
Hypertensive patients 
- Control hypertension and heart rate: target SBP 100–120 mm Hg and HR ≤ 60 beats per minute ; 
- Patients with dissection of the descending aorta who remain stable on IV treatment can be transitioned to oral medications and discharged with outpatient imaging surveillance.
- Consult cardiothoracic surgery urgently.
- Establish IV access: two large-bore peripheral IV lines.
- Obtain ECG.
- Order laboratory studies: D-dimer, type and screen, CBC, coagulation panel, BMP, troponin
- Begin hemodynamic monitoring, e.g., continuous telemetry, pulse oximetry, urine output, frequent BP checks.
- Control blood pressure within safe limits (i.e., MAP ≥ 70 mm Hg with SBP < 120 mm Hg)
- Initiate supportive care, e.g., pain management with IV morphine
- Admit to critical care unit and monitor for complications.
- Consult hematology if the patient is taking anticoagulants.
- Determine pretest probability (e.g., ADD-RS score) and order imaging based on risk.
- Order definitive imaging (e.g. CTA chest, abdomen, and pelvis) if suspicion is elevated.
- surgery. OR complicated : Expedite
- Uncomplicated : Continue medical therapy only.
- Initiate MAP ∼ 70 mm Hg. to target
- Obtain urgent bedside imaging: e.g., TEE (preferred), portable CXR, TTE, POCUS.
- Treat life-threatening complications immediately, e.g., .
- Expedite surgical management.
- In-hospital mortality due to aortic dissection ranges from 9 to 39%, depending on the type of dissection and treatment modality. 
- Malperfusion syndrome
- Aortic rupture and acute blood loss: acute back and flank pain; (tearing pain), symptoms of shock → indication for emergency surgery
Complications of Stanford type A dissections
- Myocardial infarction (coronary artery occlusion)
- (extension of the dissection into the aortic valve)
- progressing to cardiogenic shock
- Pericarditis, pericardial effusion, and pericardial tamponade (slow extension of the dissection into the pericardium)
- (extension of the dissection into the carotids)
- Complications of both Stanford type A dissection and Stanford type B dissections
- Bleeding into the thorax, mediastinum, and abdomen
- Arterial occlusion followed by ischemia of the:
We list the most important complications. The selection is not exhaustive.