Primary Aortoenteric Fistula: A Rare Case of a Massive Gastrointestinal Bleed.

Aortoenteric fistulas (AEFs) are deadly, abnormal connections between the aorta and gastrointestinal (GI) tract. While secondary aortoenteric fistulas (SAEFs) are more common and arise after aortic reconstruction, primary aortoenteric fistulas (PAEFs) are generally caused by abdominal aortic aneurysms (AAAs). PAEFs may present with self-limited GI bleeds called "herald bleeds," and the fistula often goes undiagnosed until patients undergo laparotomy for a massive GI bleed. We describe a case of a PAEF in a 79-year-old man with known AAA. Due to variable clinical presentations and the rarity of the condition, many patients with PAEF die before an accurate diagnosis is made. In interpreting computed tomography (CT) scans of AEFs, the role of the radiologist is critical in the management of PAEF patients.

Unilateral Absence of the Left Pulmonary Artery With an Associated Vascular Anomaly in Adulthood.

Left-sided pulmonary artery agenesis is a rare malformation that commonly requires childhood intervention secondary to associated congenital cardiovascular anomalies. We present an uncommon case of left-sided agenesis with an associated right-sided aortic arch and significant hypoplasia of the ipsilateral lung. Additionally, there is radiographic evidence of emphysema and pulmonary artery hypertension. Pulmonary artery agenesis is not a common entity, but should be considered in adult patients presenting with recurrent pneumonias and radiographic evidence suggestive of pulmonary hypoplasia. A prompt diagnosis is beneficial for affected individuals who may be candidates for a revascularization procedure or embolization of collaterals. Earlier diagnosis also allows for proper management and follow-up care, considering pulmonary artery hypertension is a severe complication of pulmonary artery agenesis.