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Thoracic Endovascular Repair and Omental Flap Revision of Aortopulmonary Fistula Involving Aortic Pseudoaneurysm

Aortopulmonary and aortobronchial fistulas are rare and serious events related to aortic aneurysm, dissection, and pseudoaneurysm. They are often a result of concomitant infection and mandate immediate intervention with endovascular, surgical, and antibiotic treatment. We present a case of an infected aortic pseudoaneurysm with resultant fistulization between the aorta and lung tissue. A 41-year-old female presented with several months of episodic massive hemoptysis requiring blood transfusions and multiple hospitalizations. Bronchoscopy localized the bleeding to the left upper lobe. Past medical history is significant for hypertension, fibrosing mediastinitis, colectomy, and descending thoracic aortic aneurysm repair with homograft. Upon transfer to our hospital, she was stable and had a small amount of hemoptysis. CT angiogram of the chest demonstrated a calcified descending aortic homograft with a small pseudoaneurysm at the proximal anastomosis. The pseudoaneurysm appeared contiguous with a consolidated portion of the apical anterior segment of the left upper lobe. We selected a hybrid management approach consisting of endovascular exclusion of the fistula and tissue transfer interposition between the aorta and the lung. Endovascular coverage of the proximal anastomotic site would exclude the orifice of the left subclavian artery. Therefore, we performed a subclavian-carotid bypass immediately followed by placement of two Gore Tag Endovascular Stents (Gore Tag Thoracic Endoprosthesis, Flagstaff, AZ), extending from the arch of the aorta to a landing site just proximal to the celiac artery. Completion angiogram revealed wellseated endografts with no endoleak and excellent flow through the innominate artery and subclavian carotid bypass. We delayed the tissue transfer to allow sufficient time for any small endoleaks to seal. Ten days later, she underwent the second stage of the operation. A redo laparotomy was performed, and the omentum was harvested as a pedicled flap based off the right gastroepiploic artery. It was passed substernally into the thorax. A redo left thoracotomy was performed. The lung was found to be adherent to the aortic homograft, and dissection demonstrated a 2 to 3 mm anastomotic dehiscence with a fistula to the surface of the lung (Fig. 1 A). There was no bleeding and further dissection of the lung off the aorta revealed an attenuated wall of the homograft with exposed aortic endograft (Fig. 1 B). There was no clear evidence of mycotic aneurysm or active infection. The fistula site and the area of exposed endograft were covered with the omentum, and the exposed lung surface was repaired with chromic sutures (Fig. 2). Complete exclusion of the aortopulmonary fistula was achieved. The patient recovered well from both operations and at three months, follow-up has had no further hemoptysis or signs of infection. Cultures grew Staphylococcus epidermidis on broth and are thought to be a contaminant. The patient was placed on lifelong suppressive antibiotics, given the potential colonization of the endograft by exposure to the pulmonary parenchyma. Aortopulmonary fistula is a rare and serious occurrence necessitating immediate intervention. Frequently, in a complication of aortic aneurysm or dissection, it almost always involves a communication between the aorta and the pulmonary artery. The most common cause is erosion of a false aneurysm of the descending thoracic aorta into the pulmonary artery, but it can also be related to pneumonia or a mycotic aortic aneurysm.1 In addition, these fistulas have been reported to occur after aortic surgery and acute and chronic dissection. Less frequently reported than aortopulmonary fistulas are aortobronchial fistulas. The major causes overlap with those of aortopulmonary fistula: thoracic aortic aneurysm with lung infection, pressure necrosis, atherosclerosis, trauma, and previous vascular surgery. Address correspondence and reprint requests to Danielle J. Brown, B.S., M.S., School of Medicine, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS 39216. E-mail: djbrown@umc.edu.