A chronic aortic dissection is defined as the persistence of the dissection flap and false channel more than 2 weeks following the initial event. The aorta will have a true and false lumen, see illustration. The false channel is usually larger than the true lumen. Blood flow will be present in both the true and false channel and communication between the two channels occurs through fenestrations (openings in the septum). The false lumen may be completely patent (open) or have some thrombus.
The majority of patients with chronic aortic dissections are asymptomatic. However, some patients may experience pain either from expansion of the aorta or from a new aortic dissection. The patient may experience abdominal or lower extremity pain (lack of blood flow) due to a dislodgement of a piece of blood clot (embolization) or closure of an artery as a result of the dissection or clot.
The majority of the patients with chronic dissections of the descending and abdominal aorta can be treated conservatively. These patients need close follow-up and serial imaging to follow the diameter of the dissected aorta. Pain associated with a chronic aortic dissection is concerning and needs imaging and evaluation by an aortic specialist. If the aortic diameter increases to 5.5 cm, surgical repair should be considered. Most patients with chronic aortic dissections with aneurysmal formation will be treated with open repair. On selective cases, endovascular approaches can be considered.