What is the treatment for an aortic dissection?

Treatment of Aortic Dissection

Emergency surgical intervention is mandatory for Type A dissections to prevent aortic rupture, pericardial tamponade, and aortic regurgitation, while Type B dissections are managed medically unless life-threatening complications develop. 1, 2

Immediate Stabilization (All Types)

• Transfer immediately to intensive care unit with invasive arterial line monitoring and continuous ECG 1, 2, 3
• Administer intravenous beta-blockers as first-line therapy (labetalol preferred due to combined alpha- and beta-blocking properties) targeting systolic blood pressure <120 mmHg and heart rate ≤60 beats per minute 1, 2, 3
• Provide pain control with morphine sulfate to reduce sympathetic stimulation 2, 3
• Never use vasodilators alone without prior beta-blockade as this increases aortic wall stress through reflex tachycardia 2
• If beta-blockers are insufficient, add sodium nitroprusside for additional blood pressure reduction 1, 2
• If beta-blockers are contraindicated, use non-dihydropyridine calcium channel blockers for heart rate control 1, 3

Type A Dissection (Ascending Aorta)

Requires emergency surgery regardless of complications 1, 2, 3

Surgical Options:

• Composite graft implantation in ascending aorta with or without coronary artery reimplantation 1, 2
• Supracommisural graft implantation when the root is normal and valve is intact 1
• Valve resuspension (adequate in approximately 50% of chronic Type A cases when commissures are detached) 1
• Subtotal or total arch replacement with reconnection of supraaortic vessels during hypothermic circulatory arrest if arch involvement 1

Surgical Approach:

• Standard median sternotomy for ascending aorta and transverse arch 2
• Extracorporeal circulation with moderate hypothermia and equalized perfusion pressures during graft implantation 1, 2

Type B Dissection (Descending Aorta)

Uncomplicated Type B:

Medical management is the primary treatment 4, 2, 5

• Continue aggressive blood pressure control with target systolic <120 mmHg and heart rate ≤60 beats per minute 2, 6
• Transition from intravenous to oral beta-blockers after 24 hours of hemodynamic stability 2, 3
• No proven superiority of surgical or interventional treatment over medical therapy for uncomplicated cases 4

Complicated Type B (Requires Intervention):

Emergency intervention is indicated for: 4, 2, 3

• Intractable pain despite medical therapy
• Rapidly expanding aortic diameter
• Periaortic or mediastinal hematoma (signs of rupture)
• Peripheral ischemic complications/malperfusion syndrome
• Dissection occurring in previously aneurysmatic aorta

Intervention Options for Complicated Type B:

• Thoracic endovascular aortic repair (TEVAR) is preferred over open surgery when anatomy is suitable 2, 3, 5
• Open surgical repair via posterolateral chest incision with tubular graft replacement using left heart bypass if TEVAR not feasible 4, 1, 2
• Catheter-guided fenestration of dissection membrane to decompress true lumen in cases of malperfusion 4
• Stenting of obstructed branch arteries for static obstruction 4
• Balloon fenestration plus stenting of aortic true lumen for dynamic obstruction 4

Long-Term Management

• Switch to oral beta-blockers with target blood pressure <135/80 mmHg 2, 3
• MRI is the preferred imaging modality for surveillance as it avoids radiation and nephrotoxic contrast 4, 3
• Regular imaging follow-up to monitor for false lumen expansion or aneurysm formation 1, 2, 3

Indications for Reoperation:

• Chronic Type A: Surgery indicated if symptoms develop, aortic regurgitation occurs, or aortic diameter exceeds 5-6 cm 4, 1
• Chronic Type B: Surgery indicated if symptoms develop or progressive enlargement reaches 6.0 cm 4, 1
• Endovascular stenting is an option if surgical indication exists and anatomy is suitable 4, 1

Critical Pitfalls to Avoid

• Never administer vasodilators before beta-blockade due to risk of reflex tachycardia increasing aortic wall stress 2
• Avoid dihydropyridine calcium channel blockers without beta-blockers for the same reason 2
• In malperfusion cases, higher blood pressure may be tolerated to optimize perfusion to threatened organs 1, 3
• Patients with visceral ischemia have poor prognosis even with TEVAR; early diagnosis and intervention are crucial 5
• Repeat sternotomy requires extreme care as the aorta is usually unprotected by pericardium 4, 2

Special Populations

• Hereditary connective tissue disorders (Marfan syndrome, Ehlers-Danlos syndrome): Lifelong beta-adrenergic blockade is mandatory for prevention 1, 2, 3
• Pregnant patients: Require multidisciplinary team management at specialized centers using drugs with lowest teratogenic impact 1, 3
• Reoperation rates: Approximately 10% at 5 years and up to 40% at 10 years after primary Type A surgery, with even higher risk in Marfan syndrome patients 4, 2