Mycotic pseudoaneurysm of the ascending aorta is a rare and potentially fatal complication of cardiac surgery, particularly in immunosuppressed heart transplantation patients. In this case, a 70-year-old man who underwent heart transplantation 4 months earlier was incidentally found to have a large pseudoaneurysm of the ascending aorta at the level of the aortic suture line. Surgical repair of the pseudoaneurysm was undertaken, and cultures from the pseudoaneurysm were found to be positive for Aspergillus fumigatus .
Case Report
A 70-year-old man who had undergone cardiac transplantation for ischemic cardiomyopathy 4 months previously presented with a 1-month history of decreased visual acuity in the left eye. A diagnosis of acute retinal necrosis of the left eye was made, for which the patient was admitted for treatment with intravenous antiviral therapy for suspected herpes infection. His medications included immunosuppressive therapy with cyclosporine, mycophenolate, and prednisone.
On initial presentation, the patient denied any complaint other than a lack of visual acuity in the left eye. He denied chest pain, shortness of breath, or palpitations. On physical examination, vital signs were within normal limits, and the results of a cardiovascular examination were unremarkable. Laboratory results at admission excluded cytomegalovirus and herpes simplex virus infection. The only abnormality was moderate anemia, with a hemoglobin level of 9.9 g/dL and hematocrit of 29.9%; other parameters (white blood cell count, creatinine, prothrombin time, and activated partial thromboplastin time) were within normal ranges.
Given the patient’s recent history of orthotopic heart transplantation, a noninvasive cardiac evaluation was performed. Resting electrocardiography revealed a diffuse reduction in voltage across all leads compared with electrocardiograms from his previous hospitalization. Marked bulging of the cardiac silhouette toward the right was seen on chest x-ray, which was also new compared with an earlier film. On transthoracic two-dimensional echocardiography, compression of the left atrium by an echogenic mass consistent with a thrombus ( Figure 1 A , Video 1 ) and a defect in the wall of the ascending aorta were found. Contained rupture of the ascending aorta just distal to the aortic sinuses of Valsalva with a large hematoma compressing the left atrium was diagnosed on transesophageal echocardiography ( Figure 1 B, Video 2 ). Chest computed tomography also demonstrated a pseudoaneurysm of the right-side ascending aorta with a very large hematoma, which measured up to 10 × 10 × 8.5 cm, with most of it filling with contrast. The diameter of the defect in the aortic wall measured about 3.5 × 2.5 cm. It began at about the level of the takeoff of the left main coronary artery and about 1.5 cm above the takeoff of the right coronary artery. There was associated marked narrowing of the right central pulmonary artery, marked narrowing of the superior vena cava, and narrowing of the right superior pulmonary vein ( Figures 2 A and 2B).
The patient subsequently underwent urgent cardiac surgery to repair the aortic pseudoaneurysm. He was intubated while awake because of possible airway compression and placed on cardiopulmonary bypass from the right groin. Intraoperative findings were consistent with a clear disruption of the aortic suture line of the heart transplantation procedure. There was evidence of an infection with purulence and a large amount of infected-looking material within the wall of the aorta and around it. Cultures revealed Aspergillus fumigatus . The patient was treated with voriconazole. Transient transaminitis required adjustment of antifungal therapy, and a transient increase in creatinine levels required a slight reduction of diuretics. Subsequently, the patient improved postoperatively on antifungal therapy, with no evidence of residual pseudoaneurysm or infection.
Discussion
Mycotic pseudoaneurysm of the ascending aorta was first described by Osler in a patient with endocarditis and is a rare complication after cardiothoracic surgery, with high mortality. In true aortic aneurysms, although the aortic diameter is increased at the site of the aneurysm, and a laminar clot may form along the aortic wall, the inner layers of the vessel wall are intact. However, as shown in Videos 1, 2, and 3 , in a pseudoaneurysm, a hematoma forms outside the aorta at the site of aortic disruption so as to contain a disrupted aortic wall, while at the same time, the false aneurysm is in communication with the true aortic lumen.
The most frequent cause of false aneurysms is prior cardiac surgery. Pseudoaneurysms as in this case usually originate at the sites of suture lines and needle holes, prior sites of aortic cannulas, and from proximal or distal aortic anastomotic disruptions. In a series of 1000 patients who received coronary artery bypass grafts, there was a mortality of 3% due to aortic pseudoaneurysm. In heart transplantation patients, because of immunosuppressive therapy, the risk for infective pseudoaneurysm is increased. In a review of 30,000 heart transplantations worldwide, only 10 cases of mycotic pseudoaneurysm were reported. Although recent data suggest that the surgical repair of aortic pseudoaneurysm can now be accomplished with low operative mortality and morbidity, it is always a surgical challenge, especially in heart transplantation patients. In a series of 442 patients who underwent orthotopic heart transplantation, 3 patients were diagnosed with infective pseudoaneurysms of the aorta, and 2 of them underwent surgical repair but died in the perioperative period; in this series, all cases of infective pseudoaneurysm were preceded by postoperative mediastinitis, as in the 2 cases reported by Anthuber et al.
The clinical presentation of ascending aortic pseudoaneurysm generally includes chest pain, heart failure, and sepsis. Chest pain can occur because of compression of the left main coronary artery, associated coronary artery disease and myocardial ischemia, stretching of the aorta, and compression of structures adjacent to the aortic pseudoaneurysm. Heart failure can also be related to cardiac compression, compression of surrounding structures, and valvular regurgitation. Sometimes the presentation can mimic an acute transplant rejection. In our case, the patient was completely asymptomatic until diagnosed on routine follow-up two-dimensional echocardiography. It is likely that the asymptomatic status of our patient was due to his immunosuppressive therapy. Infective aortic pseudoaneurysms are usually caused by Staphylococcus aureus , Candida albicans , or Pseudomonas aeruginosa ; only a few cases of A fumigatus infection have been reported.
The cardiac allograft was procured from a 29-year-old local man who had been otherwise healthy and who suffered traumatic brain injury. The donor cultures did not reveal fungi, and the lung recipient from the same donor did not have aspergillosis postoperatively. These findings make a recipient source for the fungemia likely rather than a donor source. Most reports recommend immediate surgical intervention, with excision of all the infected material and reconstruction of the vascular structure. A few case reports have demonstrated that percutaneous occlusion of aortic pseudoaneurysms is possible but limited to smaller lesions and is generally reserved for noninfected patients in whom reintervention is very high risk.
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