Management of Type B Aortic Dissection
All patients with acute type B aortic dissection should receive immediate medical therapy with aggressive blood pressure and heart rate control, followed by risk stratification to determine whether endovascular intervention is needed. 1
Immediate Medical Management (First-Line for ALL Patients)
Initiate anti-impulse therapy immediately upon diagnosis:
- Target systolic blood pressure <120 mmHg to reduce aortic wall stress 1
- Target heart rate <60 bpm to minimize hemodynamic forces on the dissected aorta 1
- Beta-blockers are the first-line antihypertensive agents (esmolol, metoprolol, or labetalol) 1
- Aggressive pain control is essential as pain indicates ongoing aortic wall stress 1
The rationale for beta-blockade first is that reducing heart rate decreases the rate of aortic pressure rise (dP/dt), which is more important than absolute pressure reduction alone. 2
Risk Stratification: Complicated vs. Uncomplicated
Immediately assess for features of complicated dissection:
Complicated Type B Dissection (Requires Emergency TEVAR)
- Aortic rupture or impending rupture/tamponade 1
- Malperfusion syndromes: cerebral/stroke, mesenteric ischemia, lower extremity ischemia, or renal compromise 1
- Refractory pain despite adequate medical therapy 1
- Rapidly expanding aortic diameter 1
For complicated dissection, TEVAR is the first-line intervention and should be performed emergently. 1, 3, 4 Open surgical repair is rarely required and reserved only for cases where TEVAR is anatomically impossible. 3
Uncomplicated Type B Dissection (Medical Management with Selective TEVAR)
Continue medical therapy with close surveillance for patients without complications. 1
However, certain high-risk anatomical features predict late complications and warrant consideration of TEVAR in the subacute phase (14-90 days):
- Primary entry tear >10 mm 1
- Initial aortic diameter >40 mm 1
- Initial false lumen diameter >20 mm 1
- Partial false lumen thrombosis 1
The European Society of Cardiology recommends considering TEVAR between 14-90 days for patients with these high-risk features to prevent late aortic complications. 1 This represents a shift from purely medical management, as evidence suggests these anatomical features predict aneurysmal degeneration and rupture risk.
Surveillance Protocol
For uncomplicated dissections managed medically, follow-up imaging is mandatory:
- At 1,3,6, and 12 months after onset 1
- Then yearly if stable 1
- MRI is preferred over CT (particularly in younger patients <60 years) to minimize radiation exposure 1
Monitor specifically for false lumen expansion, aneurysm formation, new intimal tears, or development of malperfusion. 1
Long-Term Management
Lifelong antihypertensive therapy is mandatory for all patients to prevent aortic expansion and reduce complication risk. 1
Intervention thresholds for chronic type B dissection (>90 days):
- Descending thoracic aortic diameter ≥60 mm warrants intervention in reasonable surgical risk patients 1
- Consider intervention at ≥55 mm in low procedural risk patients 1
Critical Pitfalls to Avoid
Never delay imaging in suspected dissection. CT angiography is the diagnostic modality of choice and should be obtained immediately. 3
Do not use vasodilators before beta-blockade. Vasodilators alone can cause reflex tachycardia, increasing dP/dt and worsening the dissection. Always achieve heart rate control first. 2
Avoid anticoagulation in acute dissection. The risk of hemorrhage into the false lumen or rupture is prohibitive. 5 If anticoagulation is absolutely necessary for another indication (e.g., atrial fibrillation), ensure aortic diameter is <6.0 cm, obtain multidisciplinary consultation, and use warfarin with tight INR control rather than DOACs. 5
Do not discharge patients without establishing close follow-up. Even uncomplicated dissections have substantial risk of late aneurysmal degeneration requiring intervention—approximately 25% will need surgery during long-term follow-up. 6