Aortic Dissection Management

Recommended Imaging Modalities

• The American College of Cardiology recommends CT angiography (CTA) as the preferred imaging modality for monitoring type B aortic dissection due to its high accuracy, wide availability, and ability to provide comprehensive anatomic detail of the entire aorta and branch vessels 1
• CTA has a sensitivity and specificity exceeding 95% for evaluating patients with aortic dissection, according to the European Heart Journal 2
• MRI is an excellent alternative for long-term monitoring with sensitivity approaching 100%, as suggested by the European Heart Journal 2
• The following table summarizes the characteristics of different imaging modalities:

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Imaging Protocols

• The American College of Radiology recommends an optimal protocol that includes non-contrast phase, arterial phase, and delayed phase (typically at 300 seconds) for detecting endoleaks in patients who have undergone TEVAR 3
• Initial follow-up should be done at 1, 3, 6, and 12 months post-dissection, and annually thereafter if stable, as suggested by the Circulation journal 4
• Annual imaging is usually sufficient for stable cases, while more frequent imaging at 1, 3, 6, and 12 months is reasonable for newly diagnosed cases, then annually if stable 4

High-Risk Features to Monitor

• The Journal of the American College of Radiology identifies high-risk features to monitor, including complete patency of false lumen, large false lumen size, and new fenestrations between true and false lumen 3
• The most proximal portion of the descending thoracic aorta is most prone to dilatation, as noted by the Circulation journal 4
• Rapid expansion of >0.5 cm per year is considered a significant growth rate 4

Measurement Techniques

• The Mayo Clinic Proceedings recommends employing standardized measurement techniques (double oblique method) for accurate and reproducible measurements 5
• Normal thoracic aortic diameter varies by location, with diameters of 3.5-4.0 cm at the aortic root and 2.4-2.7 cm at the diaphragm level, with larger diameters typically seen in older males 6

Medical Management

• The American College of Cardiology and the American Heart Association recommend strict control of blood pressure and heart rate, with intravenous beta-blockers to reduce heart rate to ≤60 beats per minute 7, 4
• Beta-blockers are the first-line treatment and have been shown to improve survival, according to the American College of Cardiology, with additional agents such as ACE inhibitors or ARBs often required 1, 8, 9, 4
• Risk reduction strategies include statin therapy, genetic counseling, and family screening if hereditary disorder is suspected, as recommended by the American Heart Association, and family history should be gathered for three generations about thoracic aortic disease 10, 11

Surgical Intervention

• Stanford Type A dissections require immediate surgical intervention, while Stanford Type B dissections require initial medical management for uncomplicated cases and endovascular intervention (TEVAR) for complicated cases, as recommended by the Society of Thoracic Surgeons and the American College of Cardiology 11
• Surgical intervention is indicated when the aortic diameter reaches ≥60 mm in patients at reasonable surgical risk, or ≥55 mm in patients with low procedural risk, or when complications develop, such as progression of dissection, aortic rupture or impending rupture, malperfusion syndrome, or uncontrollable pain despite optimal medical therapy, and elective intervention is recommended when descending thoracic aortic diameter ≥60 mm, or ≥55 mm should be considered in patients with low procedural risk, with endovascular stenting (TEVAR) considered if surgical indication exists and anatomy is suitable 10, 2

Additional Recommendations

• The American Heart Association recommends smoking cessation as critical for management of descending thoracic aortic ectasia 4
• Management of chronic obstructive pulmonary disease is also beneficial for long-term management 4
• Morphine sulfate is recommended for pain control, and invasive arterial pressure monitoring is required, with measurement of pressure in both arms to detect pseudo-hypotension 2