What is the management of aortic arch dissection?

Management of Aortic Arch Dissection

Aortic arch dissection requires emergency surgical intervention with subtotal or total arch replacement under hypothermic circulatory arrest, combined with immediate medical stabilization using intravenous beta-blockers to achieve systolic blood pressure 100-120 mmHg and heart rate ≤60 beats per minute. 1, 2

Immediate Medical Stabilization

Blood Pressure and Heart Rate Control:

• Transfer immediately to intensive care unit with invasive arterial line monitoring and continuous ECG 2, 3
• Administer intravenous beta-blockers as first-line therapy: propranolol (0.05-0.15 mg/kg every 4-6 hours), esmolol (loading dose 0.5 mg/kg over 2-5 minutes, then infusion 0.10-0.20 mg/kg/min), or labetalol 1, 2, 4
• Target systolic blood pressure 100-120 mmHg and heart rate ≤60 beats per minute to reduce aortic wall shear stress 1, 2
• If beta-blockade alone is insufficient, add sodium nitroprusside (starting at 0.25 μg/kg/min) for additional blood pressure control 1, 2
• Critical pitfall: Never use vasodilators without prior beta-blockade, as this increases left ventricular ejection force and can worsen the dissection 1, 2, 3

Pain Management:

• Administer morphine sulfate for pain control to reduce sympathetic stimulation 2, 3

Surgical Management of Aortic Arch Dissection

Surgical Approach:

• Perform median sternotomy for access to ascending aorta and transverse aortic arch 2
• When dissection involves the arch or primary tear is not found in ascending aorta, explore the arch during deep hypothermic circulatory arrest 5
• Subtotal or total arch replacement is required when the arch is involved, including reconnection of some or all supraaortic vessels to the graft 1
• Use moderate to deep hypothermia with circulatory arrest for arch reconstruction 1, 5

Technical Considerations for Arch Repair:

• Fortify dissected layers using either gelatin resorcinol formaldehyde (GRF) glue or teflon felt strips 1
• GRF glue produces firm union of dissected layers and converts them to leather-like texture, facilitating secure reconstruction while obliterating dead spaces 1
• Traditional technique involves sandwiching dissected layers between teflon felt strips placed inside and outside the vessel perimeter 1
• If valve commissures are detached, perform resuspension using pledgetted transmural mattress sutures 1

Cerebral Protection During Arch Surgery:

• Pack patient's head in ice during circulatory arrest 5
• Administer steroids and induce barbiturate coma for neuroprotection 5
• If arch replacement is anticipated preoperatively, employ surface cooling in addition to cardiopulmonary bypass cooling 5

Acute vs. Chronic Arch Dissection

Acute Dissection (≤14 days):

• Emergency surgical intervention is mandatory to prevent rupture, tamponade, and death 1, 2, 5
• Mortality for acute arch dissection is approximately 21-25% with surgical intervention 5

Chronic Dissection (>14 days):

• Surgery is indicated if symptoms develop, progressive aortic enlargement occurs (diameter 5-6 cm), or aortic regurgitation develops 1, 3
• In chronic cases, valve resuspension alone is adequate in approximately 50% of patients 1
• Consider catheter-guided fenestration of dissection membrane for decompression if symptoms persist 1

Post-Operative Management

Transition to Oral Medications:

• Switch from intravenous to oral beta-blockers after 24 hours of hemodynamic stability if gastrointestinal function is preserved 2, 3, 4
• Rapid transition within 72 hours reduces ICU length of stay without increasing hypotension risk 6
• Target long-term blood pressure <135/80 mmHg 2

Surveillance:

• Perform follow-up imaging with CT and transthoracic echocardiography within 6 months, then at 12 months, and yearly if stable 4
• Monitor for false lumen expansion, aneurysm formation, and need for reoperation 2, 3
• Reoperation rate is approximately 10% at 5 years and up to 40% at 10 years after primary surgery 2, 3

Long-Term Medical Therapy:

• Lifelong beta-blocker therapy is mandatory, especially in patients with hereditary connective tissue disorders (Marfan syndrome, Ehlers-Danlos syndrome) 2, 3

Critical Pitfalls to Avoid

• Never delay surgery for extensive imaging in hemodynamically unstable patients; transesophageal echocardiography can be performed as sole diagnostic procedure in operating room 1
• Avoid pericardiocentesis before surgery in tamponade cases, as reducing intrapericardial pressure causes recurrent bleeding 1
• Do not use dihydropyridine calcium channel blockers without beta-blockers due to reflex tachycardia risk 2
• Repeat sternotomy requires extreme caution as the aorta is usually unprotected by pericardium in reoperation cases 3