What is the management approach for aortic dissection?

Management of Aortic Dissection

Aortic dissection requires immediate aggressive blood pressure and heart rate control with intravenous beta-blockers, followed by emergency surgical repair for Type A dissections and medical management (with selective intervention for complications) for Type B dissections. 1, 2

Immediate Stabilization and Medical Management

Hemodynamic Control

• Establish invasive arterial line monitoring and continuous three-lead ECG recording immediately upon suspicion 1, 2
• Administer intravenous beta-blockers as first-line therapy, with labetalol preferred due to combined alpha- and beta-blocking properties 2, 3
• Target systolic blood pressure <120 mmHg and heart rate ≤60 beats per minute 1, 2, 3
• Alternative beta-blockers include propranolol, esmolol, or metoprolol if labetalol is unavailable 2

Alternative Agents and Adjunctive Therapy

• If beta-blockers are contraindicated, use intravenous non-dihydropyridine calcium channel blockers (diltiazem or verapamil) for heart rate control 1, 2, 3
• Never administer dihydropyridine calcium channel blockers without prior beta-blockade, as reflex tachycardia will increase aortic wall shear stress 3
• Add sodium nitroprusside or nicardipine only after achieving adequate beta-blockade if blood pressure targets remain unmet 2, 3
• Provide adequate analgesia with morphine sulfate to reduce sympathetic surge and pain 1, 3
• Transfer to intensive care unit for continuous monitoring 1, 2

Special Hemodynamic Considerations

• In cases of malperfusion (visceral or limb ischemia), tolerate higher blood pressure (potentially >120 mmHg systolic) to optimize perfusion to threatened organs 2, 3
• Do not delay intervention in patients with visceral or limb ischemia, as 30-day mortality correlates directly with severity and duration of ischemia 2, 3

Type-Specific Definitive Management

Type A Dissection (Ascending Aorta)

• Emergency surgical intervention is mandatory to prevent aortic rupture, pericardial tamponade, and relieve aortic regurgitation 1, 2
• Obtain urgent surgical consultation immediately upon diagnosis 2
• Surgical options include composite graft implantation in the ascending aorta with or without coronary artery reimplantation 1, 2
• Supracommisural graft implantation is appropriate when the aortic root is normal and valve is intact 1
• Valve resuspension is adequate in approximately 50% of chronic Type A cases when commissures are detached 1
• Subtotal or total arch replacement may be necessary, including reconnection of supraaortic vessels during hypothermic circulatory arrest 1

Type A with Peripheral Malperfusion

• Consider percutaneous revascularization first before surgical repair to allow ischemic injury to resolve 2
• This approach may reduce 30-day mortality, which is largely dependent on severity and duration of ischemia 2

Type B Dissection (Descending Aorta)

• Initially manage medically with aggressive blood pressure control unless life-threatening complications develop 2, 4
• Emergency intervention (preferably TEVAR - Thoracic Endovascular Aortic Repair) is indicated for complicated Type B dissection with: 2
  • Malperfusion syndrome
  • Intractable pain despite medical therapy
  • Rapidly expanding aortic diameter
  • Periaortic or mediastinal hematoma
  • Dissection occurring in a previously aneurysmatic aorta

Long-Term Management and Surveillance

Transition to Oral Therapy

• Switch from intravenous to oral beta-blockers after 24 hours of hemodynamic stability if gastrointestinal transit is preserved 1, 2, 3
• Target long-term blood pressure <135/80 mmHg with beta-blockers as preferred agents, often requiring combination therapy 2, 3

Imaging Surveillance

• MRI is the preferred modality for serial follow-up as it avoids radiation exposure and nephrotoxic contrast 2, 3
• CT is an acceptable alternative, particularly in patients >60 years 2
• Perform imaging at 6 months, 12 months, then annually if stable 3
• Monitor specifically for false lumen expansion, aneurysmal degeneration, and progression of dissection 2, 3

Indications for Delayed Intervention

Chronic Type A Dissection: 1

• Development of symptoms
• Aortic regurgitation occurs
• Aortic diameter exceeds 5-6 cm

Chronic Type B Dissection: 1, 3

• Development of symptoms
• Progressive aortic enlargement reaching 6.0 cm diameter
• Consider endovascular stenting if surgical indication exists and anatomy is suitable

Reoperation Considerations

• The rate of reoperation for Type A dissection is approximately 10% at 5 years and up to 40% at 10 years after primary surgery, with even higher risk in Marfan syndrome patients 1
• Repeat sternotomy requires great care as the aorta is usually unprotected by the pericardium 1
• Replacement of affected portions with a tubular graft is standard for acute and chronic dissections of the descending aorta 1

Special Populations

Hereditary Connective Tissue Disorders

• Lifelong beta-adrenergic blockade is mandatory for patients with Marfan syndrome or Ehlers-Danlos syndrome to prevent dissection 1, 2, 3

Pregnant Patients

• Management requires a multidisciplinary team at specialized centers 1, 2
• Use drugs with the lowest teratogenic impact 1, 2