treatment of thoracic dissections and aneurysms

Last reviewed 01/2018

All patients with confirmed aortic dissection (or symptomatic high risk patients) should be referred to a regional cardiovascular unit for urgent diagnostic investigation and treatment (1).

Initial management of patients with suspected aortic dissection involves:

• fluid resuscitation
• monitoring heart rate, heart rhythm, blood pressure, urine output and respiratory functions
• adequate pain relief
• aggressive blood pressure control to reduce the force of left ventricular ejection
• beta blockers are the preferred agents
• target a heart rate around 60-80 beats/min and systolic blood pressure of 100-120 mm Hg
• 12-lead ECG to exclude concurrent myocardial ischaemia (1)

Type A dissection

• the International Registry of Acute Aortic Dissection have suggested that untreated proximal (Stanford type A or DeBakey type I or II) dissection is associated with a one week mortality of 50-91% (due to complications such as aortic rupture, stroke, visceral ischaemia, cardiac tamponade, and circulatory failure)
• urgent surgical management is essential since drug treatment alone was associated with a mortality of nearly 20% by 24 hours and 30% by 48 hours
• surgical approach is to replace the affected ascending aorta, with or without the aortic arch, with a prosthetic graft
• an incompetent aortic valve is replaced when it is abnormal, for example in Marfan's disease, otherwise it is re-suspended (1)

Acute type B dissection

• for uncomplicated acute type B dissection (without visceral or limb ischaemia, rupture, refractory pain, or uncontrollable hypertension) - medical management remains the gold standard
• regulation of systolic blood pressure with the use of β blockers (first line agents) or non-dihydropyridine calcium channel blockers (for patients who do not tolerate beta blockers and in patients with chronic obstructive pulmonary disease)
• for complicated acute type B dissection (defined by the presence of visceral or limb ischaemia, rupture, refractory pain, or uncontrollable hypertension) - endovascular repair using a stent graft
• long term postoperative surveillance should be carried out in these patients
• NICE state that this procedure "..is a suitable alternative to surgery in appropriately selected patients, provided that the normal arrangements are in place for consent, audit and clinical governance..." (2).

Chronic type B dissection

• is a difficult condition to treat
• can be managed conservatively but most patients ultimately develop complication which requires surgical intervention (e.g. - aneurysm which develops in 15% of chronic type B dissections)

Reference:

• (1) Thrumurthy SG et al. The diagnosis and management of aortic dissection. BMJ. 2011;344:d8290.  
• (2) NICE (June 2005).Endovascular stent–graft placement in thoracic aortic aneurysms and dissections