eComment. Fistulous complications of acute dissection of the ascending aorta.

We read the article by Pagni et al. [1] with great interest. The authors have documented a case of aorto-right atrial fistulization after type A aortic dissection well. We think that the discussion should be primarily focused on fistulous complications of acute ascending aortic dissection, occurring after previous cardiac or aortic surgery. Acute dissection of the ascending aorta is a life-threatening pathology and may lead to serious complications. They include rupture to neighbouring structures, aortic insufficiency, haemothorax, haemopericardium, and occlusion of the major vessels originating from the aorta [2-5]. These complications may occur as the false lumen enlarges. Free rupture of aortic dissection into the pleural and pericardial spaces often results in sudden cardiovascular collapse and death. Fistulization to the cardiac chambers (right atrium, left atrium, and right ventricle) and the pulmonary artery is a rare and often fatal occurrence [2-5]. Fistulous complications can be explained by considering the anatomy of the aortic root. Aortopulmonary, aorta-right atrial, and aorta-right ventricular fistulas produce a left-to-right shunt and congestive heart failure. Pagni et al. [1] have reported a right-to-left shunt depending on the patent foramen ovale. Fistulous complications of aortic dissection may occur in any patient, especially in those with a history of previous cardiac or aortic surgery [2-5]. The incidence of fistulous formation tends to increase with redo surgery. Postoperative adhesions may play an important role in the pathogenetic mechanism of the fistula. In such patients, the dense adhesions probably restrain the free rupture and contribute to the fistulous occurrence. Undoubtedly, prompt diagnosis and early surgical repair of the dissection and fistula would provide for an excellent outcome. In such complicated situations, we think that one should use all the information and imaging techniques available to provide a timely diagnosis and treatment. Conflict of interest: none declared.