Positron emission tomography (PET) is an established imaging tool in oncology that has also been used in infectious and inflammatory diseases. PET combined with computed tomography (PET/CT) can be used to visualize metabolic activity with precise localization. We report an infant with late presentation of poststernotomy mediastinitis, the diagnosis and localization of which was confirmed by PET/CT. An 8-month old infant, who had undergone the Jatene procedure and right ventricle outflow reconstruction 6 months prior, was admitted for inflammation surrounding the superior aspect of the healed scar. Cultures from the wound grew methicillin-resistant Staphylococcus aureus (MRSA). Although the only symptom was discharge from the wound, and there were no other signs or symptoms suggestive of severe general infection, substernal abscess was suspected by magnetic resonance imaging. Since PET/CT revealed high accumulation of 18-fluorodeoxyglucose at the substernal region, the diagnosis of MRSA mediastinitis was made, which was confirmed by subsequent surgical treatment.

A 79-year-old man was transferred to our hospital because of massive hematemesis. Contrast-enhanced CT scan demonstrated extravasation of contrast medium into the jejunum. Therefore, we diagnosed primary aortoenteric fistula and performed an emergency operation. At surgical exploration, the jejunum was closely adherent to the normal-sized aorta. The fistula was present between the anterior wall of the aorta and the jejunum. Operative reconstruction was performed with in-situ grafting and a pedicled omentum flap was placed around the graft. The postoperative course was uneventful, and there has been no evidence of infection during the follow-up period of 1 year.

We here report two cases of successfully treated secondary aorto or iliac arterial-enteric fistula after graft replacement for abdominal aortic aneurysm. Case 1: A 80-year-old man who complained massive anal bleeding had undergone Y-shaped graft replacement for abdominal aortic aneurysm 22 years previously. Computed tomography demonstrated an aneurysm and hematoma formation at the anastomosis of the right graft limb and the right common iliac artery. Preoperative angiography showed no leak of contrast medium at the distal anastomosis of the right graft limb. A presumptive diagnosis of secondary iliac arterial enteric fistula was made, therefore, we performed an emergency operation. Extra-anatomic bypass preceded the removal of the right graft limb, partial resection and direct reconstruction of the ileum by the retroperitoneal approach. His postoperative course was uneventful and he was discharged on the 19th postoperative day. Case 2: A 77-year-old man who had received Y-shaped graft replacement of an abdominal aortic aneurysm 9 years previously was transferred to our hospital because of sudden onset epigastralgia and massive hematemesis. Gastroduodenoscopy revealed a fresh blood clot in the third portion of the duodenum where it was compressed by for surrounding pulsatile environment. An emergency computed tomography showed aneurysm formation without extravasation of contrast medium in the duodenum at the proximal anastomosis of the prosthetic graft. A secondary aortoenteric fistula was highly suspected and emergency operation was performed. Extra-anatomic bypass preceded the removal of the graft body, infrarenal aortic stump closure, duodenal closure and the greater omentum was used to fill defects. He underwent successful staged abdominal wall closure due to bowel edema making primary closure impossible. His postoperative course was uneventful and he was discharged on the 26th postoperative day.