Type B Aortic Dissection Management

Type B aortic dissection (TBAD) presents distinct management challenges based on clinical presentation, anatomic extent, and timing, with contemporary practice guided by society guidelines and long-term outcomes studies. [@macgillivray2022] [@isselbacher2022] [@aha2022-isselbacher][@aha2026] [@esvs2025-b]

**Complicated versus Uncomplicated TBAD**

Complicated TBAD is defined by one or more of the following high-risk features requiring intervention:

* **Malperfusion syndrome:** Visceral, renal, or limb ischemia from true lumen compression or branch vessel involvement
* **Rupture or impending rupture:** Hemothorax, periaortic hematoma, rapidly expanding false lumen
* **Refractory hypertension:** Despite optimal medical therapy (OMT) with multiple agents
* **Refractory pain:** Persistent severe back/chest pain suggesting ongoing dissection
* **Rapid aortic expansion:** Greater than 5 mm growth in less than 6 months
* **Maximum aortic diameter exceeding 40 mm** during the acute phase (a strong predictor of late complications) [@aha2022-isselbacher][@aha2026] [@esvs2025-b]

Uncomplicated TBAD lacks these features and may be managed with medical therapy alone in the acute setting, though long-term surveillance is mandatory. Recent guidelines from the American Heart Association (AHA), American College of Cardiology (ACC), and the European Society for Vascular Surgery (ESVS) emphasize identifying "high-risk" uncomplicated patients who may benefit from early intervention. [@aha2022-isselbacher][@aha2026] [@esvs2025-b]

**Medical Management**

All patients with TBAD require aggressive blood pressure and heart rate control to reduce aortic wall stress:

* **Target systolic blood pressure:** Less than 120 mmHg
* **Target heart rate:** Less than 60 beats per minute to reduce dP/dt

First-line agents include intravenous beta-blockers (esmolol for titratability, labetalol for combined alpha/beta blockade). Non-dihydropyridine calcium channel blockers (diltiazem, verapamil) may be added for rate control. Vasodilators (nicardipine, nitroprusside) address residual hypertension only after adequate heart rate control to prevent reflex tachycardia. [@macgillivray2022] [@hiratzka2010] [@aha2023]

Pain control with opioids is essential—pain drives sympathetic activation and hypertension, creating a destructive feedback loop. Long-term medical therapy includes oral beta-blockers, statins for cardiovascular risk reduction, and aggressive management of hypertension. Smoking cessation is critical given the elevated risk of late aneurysmal degeneration. [@isselbacher2022] [@esvs2025-b]

**Endovascular Management: thoracic endovascular aortic repair (TEVAR) for TBAD**

Thoracic endovascular aortic repair (TEVAR) has become the preferred intervention for complicated TBAD when anatomy permits. TEVAR seals the primary entry tear, redirecting flow into the true lumen and promoting false lumen thrombosis with favorable aortic remodeling. [@macgillivray2022]

In stable subacute/chronic TBAD, the INSTEAD randomized trial showed no early survival advantage at 2 years with TEVAR plus optimal medical therapy compared with optimal medical therapy alone, while longer follow-up in INSTEAD-XL demonstrated improved aorta-specific outcomes emerging over time, consistent with a remodeling-mediated benefit. [@nienaber2009] [@nienaber2013]

In acute uncomplicated TBAD, randomized data suggest TEVAR can improve aortic remodeling compared with medical therapy alone. [@brunkwall2014] Current consensus suggests that for high-risk uncomplicated TBAD, TEVAR should ideally be performed in the subacute phase (2 weeks to 3 months) to maximize remodeling potential while minimizing the risk of retrograde Type A dissection. [@aha2022-isselbacher][@aha2026] [@esvs2025-b]

**Indications for TEVAR in TBAD**

According to STS/AATS 2022, AHA/ACC 2022, and ESVS 2026 guidance: [@macgillivray2022] [@aha2022-isselbacher][@aha2026] [@esvs2025-b]

* **Definite indication:** Complicated TBAD (rupture, malperfusion) with suitable anatomy
* **Strong consideration (High-risk features):** Uncomplicated TBAD with a primary entry tear >10 mm, entry tear on the outer curvature of the arch, false lumen diameter greater than 22 mm, or total aortic diameter greater than 40 mm
* **May consider:** Prophylactic TEVAR in uncomplicated TBAD to reduce late aortic events, particularly in the subacute phase for patients with suitable anatomy and low procedural risk

**Technical Considerations**

Adequate proximal landing zone (typically ≥2 cm of non-dissected aorta) is essential for secure seal. When the entry tear is in the arch, coverage of the left subclavian artery (LSA) may be required. Elective LSA revascularization is recommended (Class I) when coverage compromises antegrade flow to reduce posterior circulation stroke, arm ischemia, and spinal cord ischemia risk. [@matsumura2009] [@aha2022-isselbacher][@aha2026] [@esvs2025-b]

Spinal cord protection measures apply when:
* Coverage exceeds 20 cm of thoracic aorta
* Landing zone is within 2 cm of the celiac artery
* Prior abdominal aortic repair exists

The multimodal spinal cord protection bundle includes: cerebrospinal fluid (CSF) drainage (maintain pressure less than 10 mmHg), mean arterial pressure (MAP) greater than 80–90 mmHg, hemoglobin optimization (greater than 10 g/dL), and staged procedures when feasible. [@macgillivray2022] [@esvs2025-b]

Persistent false lumen perfusion and partial thrombosis after TBAD are associated with worse late outcomes and help identify patients who require closer follow-up and may benefit from pre-emptive intervention. [@tsai2007]