Thoracic aortic catastrophes : towards the endovascular solution

Abstract

Descending thoracic aortic catastrophes include a variety of acute pathologies of the descending thoracic aorta, which are all associated with high morbidity and mortality rates, requiring immediate intervention. For this thesis, we explored the management and outcomes of several thoracic aortic catastrophes, including traumatic thoracic aortic injury, ruptured descending thoracic aortic aneurysm, acute type B aortic dissection, and aortobronchial and aortoesophageal fistulas. Open surgical repair has been the traditional treatment of these thoracic aortic catastrophes but thoracic endovascular aortic repair (TEVAR) recently offers a less invasive alternative for the management of thoracic aortic disease. Our studies showed that TEVAR for ruptured descending thoracic aortic aneurysms and traumatic thoracic aortic injuries significantly reduced the short-term morbidity and mortality rates compared with traditional open surgery. Endovascular repair of ruptured descending thoracic aortic aneurysms was however associated with a considerable incidence of peri-procedural stroke as well. In a different study we found that elderly patients were at increased risk for stroke, while the incidence of stroke has decreased over the years. The optimal management of acute type B aortic dissection, another aortic catastrophe, mainly depends on the presentation of the patient. We found that definitive medical management of uncomplicated acute type B aortic dissection is associated with low in-hospital mortality, however, those patients with recurrent pain or refractory hypertension have a much higher mortality rate. An aortic intervention is generally indicated if acute type B aortic dissection is associated with complications, such as acute renal failure, visceral ischemia, limb ischemia, paraplegia, or aortic rupture. Advanced age appeared to be a strong risk factor for mortality among patients with complicated acute type B aortic dissection, irrespective of the management type. For patients with aortobronchial fistulas, TEVAR appeared as a definite treatment, associated with lower mortality compared with traditional results of open surgery. After TEVAR for aortoesophageal fistulas, however, additional esophageal surgery was often needed to treat the fistula. In a meta-analysis of the literature, we found that patients with aortoesophageal fistulas that did not undergo esophageal repair after TEVAR had a significantly increased mortality rate during follow-up, primarily due to infective complications from the persistent connection with the esophagus. TEVAR of thoracic aortic catastrophes is still associated with considerable rates of endograft-related complications during follow-up, such as endoleak in 5% to 30. Thoracic aortic catastrophes are often associated with considerable blood loss and hypovolemic shock. We studied the impact of hypovolemia on the aortic dimensions, and the potential implications for the endovascular management of acute thoracic aortic disease. In an experimental porcine model and in a study of hemodynamically unstable trauma patients, we found that the aortic dimensions could decrease during hypovolemic shock. This could result in undersizing of the endograft using the pre-operative CT scan and a subsequently increased risk of endoleaks. Therefore, increased oversizing of the endograft or additional aortic imaging after fluid resuscitation for more adequate aortic measurements may be required in hypovolemic patients with acute thoracic aortic disease requiring TEVAR.