Pseudoaneurysm of the internal iliac artery resulting in massive per-rectal bleeding
An 83-year-old male presented to the emergency department with a history of passing a cupful of bright red blood with his morning bowel motion. His past medical history was significant for diverticular disease, which had resulted in a perforated sigmoid colon 23 years before, requiring Hartmann's procedure which was subsequently reversed.\nHe arrived with a blood pressure of 130/75 mmHg and a tachycardia of 104 beats per minute. The haemoglobin level was 13.7 g/l on arrival. Rigid sigmoidoscopy in the emergency department revealed an empty rectum with copious amounts of stool and blood up to 10 cm. The patient was presumptively diagnosed with a diverticular bleed and admitted to the general surgical unit for observation. The following day a further significant per-rectal bleed occurred on the ward, associated with chest pain and ECG changes. Blood tests revealed a haemoglobin drop to 11.3 g/l and an elevated serum troponin level of 0.19 μg/l. Myocardial infarction was diagnosed and he was placed on telemetry in a cardiac monitoring unit. A further massive per-rectal bleed was reported on the ward that evening, with a subsequent drop in haemoglobin to 7.7 g/l. Resuscitation was commenced with three units of packed red blood cells and a mesenteric CT angiogram arranged.\nAn arterial phase CT abdomen with IV contrast was performed. This revealed a contrast blush within the descending colon closely associated with an aneurysm of the internal iliac artery. The possibility of an arterial fistula to the colon was raised, and a vascular surgery consult was sought. Angiography confirmed a false aneurysm arising from the proximal aspect of the left internal iliac artery along its medial and inferior wall. Endovascular coil embolization was performed with occlusion of the vessel at the level of the aneurysm.\nNo further episodes of per-rectal bleeding have been reported in 3 months following embolization. Follow-up colonoscopy revealed multiple diverticulae in the descending colon, but the site of the previous bleed was not evident.