Treatment of Aortic Dissection
The treatment of aortic dissection requires immediate surgical intervention for Type A dissections (involving the ascending aorta), while uncomplicated Type B dissections (limited to descending aorta) can be managed medically with aggressive blood pressure and heart rate control. 1, 2
Initial Assessment and Management
- Immediate transfer to an intensive care unit with invasive blood pressure monitoring via arterial line and continuous ECG recording 3
- Pain control with morphine sulfate to reduce sympathetic stimulation 3
- Urgent diagnostic imaging with CT angiography, transesophageal echocardiography (TEE), or MRI depending on institutional capabilities and patient stability 3, 4
- Target systolic blood pressure between 100-120 mmHg and heart rate ≤60 beats per minute to reduce shear stress on the aortic wall 3, 5
- Administer intravenous beta-blockers as first-line therapy (propranolol, esmolol, or labetalol) 3, 2
- If beta-blockers alone are insufficient, add vasodilators such as sodium nitroprusside (never use vasodilators without prior beta-blockade) 3, 5
Type A Dissection Management
- Emergency surgical intervention is required to prevent aortic rupture, pericardial tamponade, and relieve aortic regurgitation 1
- Surgical options include:
- Supracommisural graft implantation when the root is normal and valve is intact 1
- Valve resuspension when commissures are detached (adequate in about 50% of chronic Type A cases) 1
- Composite graft implantation (aortic valve plus ascending aortic tube graft) for patients with ectatic proximal aorta or Marfan syndrome 1, 2
- Subtotal or total arch replacement when necessary, including reconnection of supraaortic vessels during hypothermic circulatory arrest 1
Type B Dissection Management
- Uncomplicated Type B dissections are managed medically with aggressive blood pressure and heart rate control 1, 2
- Surgical or endovascular intervention is indicated for complicated Type B dissections with:
- Thoracic endovascular aortic repair (TEVAR) aims to stabilize the dissected aorta by covering the primary entry tear, redirecting blood flow to the true lumen 1
Surgical Techniques
- Standard approach to the ascending aorta and transverse aortic arch is through median sternotomy 1
- For descending aorta dissections, a posterolateral chest incision is commonly used 1
- Most surgeons perform the operation using extracorporeal circulation via left heart bypass 1
- Moderate hypothermia with equalized perfusion pressures during graft implantation 1
- Dissected layers are conjoined using teflon felt strips or gelatin resorcinol formaldehyde glue (GRF-glue) 1
Long-term Management
- Transition from intravenous to oral beta-blockers after 24 hours of hemodynamic stability 3, 2
- Target long-term blood pressure <135/80 mmHg 3, 5
- Regular imaging follow-up to monitor for complications such as false lumen expansion or aneurysm formation 3, 2
- Consider reoperation when the dissected aorta becomes aneurysmatic (5-6 cm in diameter) 2
- Lifelong beta-blocker therapy for patients with hereditary diseases such as Marfan syndrome 3, 2
Common Pitfalls and Caveats
- Avoid using vasodilators alone without prior beta-blockade as this can increase aortic wall stress through reflex tachycardia 5
- Avoid dihydropyridine calcium channel blockers without beta-blockers due to risk of reflex tachycardia 5
- The rate of reoperation for Type A dissection is approximately 10% at 5 years and up to 40% at 10 years after primary surgery 2
- Repeat sternotomy requires great care as the aorta is usually unprotected by the pericardium 2
- Never administer thrombolytics before ruling out aortic dissection, as this may worsen the clinical course 6