The Acute Aortic Syndromes Considered For Surgery

This chapter describes our present knowledge of surgical treatment options and outcomes in acute dissections and intramural hematomas. However, there is another large group of patients with acute aortic syndromes—patients with ruptured aortic aneurysms. When patients with this dramatic condition present

Figure 9.1. A 60-year-old man was admitted with a clinical presentation of aortic dissection. The CT scan on admittance showed an extensive intramural hematoma affecting both the ascending and descending aorta. At surgery, a primary tear was located in an almost completely fragmented arch demanding an arch resection.

Figure 9.1. A 60-year-old man was admitted with a clinical presentation of aortic dissection. The CT scan on admittance showed an extensive intramural hematoma affecting both the ascending and descending aorta. At surgery, a primary tear was located in an almost completely fragmented arch demanding an arch resection.

with a ruptured thoracic aorta, the patients are mainly older1, have multiple comorbidities, and have often been deemed inoperable for elective surgery2. Many of them have been evaluated for stent grafting but, due to their often very extensive disease, have also been found not to be candidates for stent-graft placements. Thus, the acute aortic syndrome in these patients is the end stage of a degenerative disease that often has been observed for years ahead of the acute episode.

Acute thoracic aortic syndromes often considered for surgery, however, are the classic dissections, their modern variant intramural hematomas, and penetrating aortic ulcers. Until recently, some uncertainties have been connected to the preferred treatment of intramural hematomas (IMH) and penetrating aortic ulcers (PAU). However, in a reasonably large series of patients with IMHs, Nienaber and coworkers3, found the prognosis for patients with this disease affecting the ascending aorta to be particularly dismal, mimicking the natural history of classic aortic dissections affecting the first part of the aorta. Four out of five patients in the Eppendorf series with an IMH affecting the ascending aorta succumbed on medical treatment alone, while all seven patients treated surgically did survive. Thus, an IMH affecting the ascending aorta should be addressed as a classic dissection, and patients should have prompt surgical treatment addressing the ascending aorta and in some cases the arch4 (Figure 9.1).

There has been some confusion when describing the morphologies and pathophysiology differentiating the IMHs and penetrating aortic ulcers (PAU), and much is still to be learned about the dynamics of these vascular wall traumas in the aorta. An IMH is thought to occur on the basis of rupture and bleeding originating in the small vessels within the aortic wall (vasa vasorum). A penetrating atherosclerotic ulcer (PAU), on the other hand, will progress from the aortic lumen with a small rupture when penetrating the elastic lamina from the atherosclerotic intimal side of the aortic wall. The first mechanism has been proposed to occur most frequently in the ascending aorta presenting as an IMH, and the primary bleed in a PAU has been found to have its predilection in the descending aorta. The PAU mechanism of an aortic dissection probably represents a particular dismal dissection in the descending aorta demanding aggressive treatment5.

When considering surgical treatment for these patients, there are a few simple rules of thumb to guide the surgeon in his or her decision making. An intramural hematoma or classic dissection of the ascending aorta should be treated surgically unless the patient is beyond salvage or has a dismal short-term prognosis from other diseases. All the other variants of this disease have to be assessed individually in the present era, considering conservative medical treatment, stent grafting, and surgery. There are few undisputable guidelines in these relatively rare and often lethal acute vascular catastrophes, and local resources and therapy traditions have to be relied upon and developed further.

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