What is the current management of aortic dissection, including indications for surgical referral?

Management of Aortic Dissection

Immediate Medical Management

All patients with suspected or confirmed aortic dissection require immediate intravenous beta-blocker therapy to achieve a target heart rate ≤60 beats per minute and systolic blood pressure of 100-120 mmHg. 1, 2

Initial Hemodynamic Control

• Initiate intravenous beta-blockers immediately as first-line therapy to reduce aortic wall shear stress and prevent dissection propagation 1, 2
• Target heart rate should be ≤60 beats per minute before addressing blood pressure 1, 2
• Once heart rate is controlled, if systolic blood pressure remains >120 mmHg, add vasodilators (such as sodium nitroprusside or ACE inhibitors) to achieve target systolic blood pressure of 100-120 mmHg 1, 2

Critical Medication Pitfalls

• Never initiate vasodilator therapy before achieving rate control, as this causes reflex tachycardia that increases aortic wall stress and propagates dissection 1, 3
• If beta-blockers are contraindicated, use non-dihydropyridine calcium channel blockers (verapamil or diltiazem) as an alternative for rate control 1
• Avoid dihydropyridine calcium channel blockers without beta-blockers due to reflex tachycardia risk 2, 3
• Use beta-blockers cautiously in acute aortic regurgitation, as they block compensatory tachycardia 1

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Surgical Referral: When to Refer

Urgent surgical consultation should be obtained for ALL patients with thoracic aortic dissection regardless of anatomic location as soon as the diagnosis is made or highly suspected. 1

Type A (Ascending Aorta) Dissection

Type A dissection requires emergent surgical repair due to extremely high risk of rupture, tamponade, and death. 1, 2

• Surgery aims to prevent aortic rupture, pericardial tamponade, and relieve aortic regurgitation 1
• Do not delay surgery for extensive imaging in hemodynamically unstable patients—transesophageal echocardiography can be performed as the sole diagnostic procedure in the operating room 2
• Transfer to a high-volume aortic center with multidisciplinary team expertise should be considered if transfer can occur without significant surgical delay 1

Surgical Approach for Type A Dissection

• Aortic root replacement with mechanical or biological valved conduit is recommended when there is extensive root destruction, root aneurysm, or known genetic aortic disorder 1
• Aortic valve resuspension is recommended over valve replacement when the root is partially dissected but valve leaflets are intact 1
• Open distal anastomosis is recommended to improve survival and increase false lumen thrombosis 1
• Hemiarch repair is recommended over extensive arch replacement when there is no intimal tear in the arch or significant arch aneurysm 1

Type B (Descending Aorta) Dissection

Acute type B dissection should be managed medically unless life-threatening complications develop. 1

Indications for Surgical/Endovascular Intervention in Type B Dissection

Intervention is indicated for:

• Malperfusion syndrome (mesenteric, renal, limb ischemia) 1
• Intractable pain despite adequate medical therapy 1
• Rapidly expanding aortic diameter 1
• Periaortic or mediastinal hematoma as signs of impending rupture 1
• Inability to control blood pressure or symptoms 1
• Progression of dissection 1
• Dissection occurring in a previously aneurysmal aorta 1

Timing of Intervention for Uncomplicated Type B Dissection

• In uncomplicated acute type B dissection with high-risk features, TEVAR in the subacute phase (14-90 days) should be considered to prevent late aortic complications 1
• Uncomplicated type B dissections are typically managed conservatively with medical therapy 1

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Management of Malperfusion

In type A dissection with malperfusion (cerebral, mesenteric, lower limb, or renal), immediate aortic surgery is recommended. 1

• For cerebral malperfusion or non-hemorrhagic stroke, immediate aortic surgery should be considered to improve neurological outcomes and reduce mortality 1
• For clinically significant mesenteric malperfusion, immediate invasive angiographic diagnostics to evaluate percutaneous repair before or directly after aortic surgery should be considered in centers with expertise 1

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Chronic Dissection Management

Type B Chronic Dissection

• Treatment is recommended when descending thoracic aortic diameter reaches ≥60 mm in patients at reasonable surgical risk 1
• Intervention should be considered at ≥55 mm diameter in patients with low procedural risk 1
• Operative intervention for chronic type B dissection is directed at preventing expansion and rupture 1
• Indications for chronic dissection aneurysms are similar to other thoracoabdominal aneurysms 1

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Long-Term Management and Follow-Up

Transition to Oral Therapy

• Switch from intravenous to oral beta-blockers after 24 hours of hemodynamic stability if gastrointestinal function is preserved 1, 2
• Target long-term blood pressure <135/80 mmHg 2

Surveillance Imaging

• Perform follow-up imaging with CT and transthoracic echocardiography within 6 months, then at 12 months, and yearly if stable 2
• MRI is the preferred technique for long-term surveillance 3
• Reoperation rate is approximately 10% at 5 years and up to 40% at 10 years after primary surgery 2

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Critical Pitfalls to Avoid

• Never perform pericardiocentesis before surgery in tamponade cases, as reducing intrapericardial pressure causes recurrent bleeding 2
• If initial imaging is negative but clinical suspicion remains high, obtain a second imaging study 1
• Repeat sternotomy requires extreme caution as the aorta is usually unprotected by pericardium in reoperation cases 2
• Be aware that aortic dissection can present in younger patients, including children as young as 3 years old 1