Prosthetic graft remnant-related pseudoaneurysm after left ventricular assist device explantation: a case report

In December 1999, a 47-year-old woman with a history of progressive dyspnea on exertion presented with a syncopal episode. She was admitted to a local hospital, where congestive heart failure was diagnosed. Echocardiography revealed an ejection fraction of 10%. The patient was transferred to St Luke’s Episcopal Hospital for further evaluation and treatment. There she underwent placement of an intra-aortic balloon pump, followed by simultaneous implantation of an LVAD (Thoratec VAD; Thoratec Corporation, Pleasanton, Calif) and performance of the Batista procedure. Three months later, in February 2000, the patient’s condition had improved to the point that the LVAD could be removed. Immediately after its removal, the patient experienced postoperative bleeding that required mediastinal exploration to control. The patient’s sternum was closed 1 day later. The patient did well for almost 1 year, until she complained of a painful swelling of the upper sternum. A computed tomography (CT) scan of the chest showed fluid anterior and posterior to the sternum extending back to the margin of the ascending thoracic aorta, a finding compatible with an abscess. The abscess was incised and drained after achievement of local anesthesia. A culture grown from a sample of the fluid grew methicillin-resistant Staphylococcus aureus. Intravenous vancomycin was instituted for 1 month. On follow-up examination, a repeat CT scan showed a 2.3-cm−diameter saccular aneurysm involving the distal ascending thoracic aorta and a parasternal collection of fluid containing air suggestive of an abscess. The abscess was surgically drained, and intravenous vancomycin was continued at a dosage of 0.5 g/d. Again, a culture grown from a sample of the drained fluid grew methicillin-resistant S aureus.

Magnetic resonance angiography (MRA) was performed to confirm the diagnosis of aneurysm of the ascending aorta. This revealed a pseudoaneurysm of the ascending aorta measuring 2.0 × 2.4 × 3.0 cm (Figure 1). Consequently, the patient was scheduled for resection of the pseudoaneurysm. The femoral vessels were exposed and readied for cannulation, and the sternum was opened with an oscillating saw. Because the pseudoaneurysm was adherent to the sternum, the opening of the sternum caused inadvertent entry into the pseudoaneurysm. The femoral vessels were immediately cannulated, and femorofemoral bypass was commenced. The patient was cooled to 18°C, and circulatory arrest combined with retrograde cerebral perfusion was initiated. Then the sternum was slowly opened. After reduction of the blood flow to 500 mL/min, the patient was placed in the Trendelenburg position to prevent air embolism. The pseudoaneurysm, together with the remnant of the prosthetic graft still attached to the ascending aorta, was resected. The pre-existing anastomosis between the prosthetic graft and the ascending aorta was found to be disrupted for about one third of its entire circumference. The disrupted portion of the anastomosis was resected, leaving a 3 × 2–cm defect at the aorta, and further dissection of the ascending aorta was done to facilitate crossclamping. After crossclamping, the patient was warmed to 32°C and then subjected to retrograde cerebral perfusion. The defect at the aorta was repaired by using an oval Dacron patch. The crossclamp was then released, and the patient was warmed to 37°C and weaned off cardiopulmonary bypass. The sternum was left open until the next day, when the patient was brought back to the surgical theater for placement of an omental graft and closure of the sternum. Even though cultures of the resected pseudoaneurysm specimen did not grow any organisms, an antibiotic therapy regimen was instituted. Postoperatively, the patient remained stable and was discharged home after 2 weeks.