Spontaneous rupture of an intrasplenic arterial aneurysm presenting as an acute abdomen: CT diagnosis and surgical management

Aneurysms of the intrasplenic arterial branches are exceptionally rare. Rupture without trauma, and without the pancreatic disease behind most splenic arterial pseudoaneurysms, is rarer still, and it can be fatal. Cross-sectional imaging usually brings it to light. A 51-year-old multiparous woman with no relevant medical history presented with sudden left upper quadrant pain radiating to the left shoulder, and a positive Kehr sign. Her blood pressure was maintained and her hemoglobin normal. A heart rate of 101 beats/min, however, left open the possibility of early compensation for bleeding. Multiphasic contrast-enhanced computed tomography (CT), the arterial phase acquired as a CT angiogram, showed a ruptured saccular aneurysm of 18 × 12 mm in the mid-splenic parenchyma. There was an arterial-phase contrast blush, marking active extravasation, with a heterogeneous subcapsular hematoma and a moderate hemoperitoneum. The pancreas was normal and there had been no trauma. With no endovascular treatment on site, she underwent splenectomy. Serial counts showed no fall in hemoglobin, and she was discharged on the fifth postoperative day. Histopathology found hemorrhagic change but no malignancy, vasculitis, or fibromuscular dysplasia, and no discrete aneurysmal wall. Once rupture has occurred, CT cannot reliably tell a true aneurysm from a pseudoaneurysm, so the lesion is best called one of presumed true type. Early CT found the lesion, showed how far the bleeding had gone, and allowed treatment to start without delay. The diagnosis is worth considering in acute left upper quadrant pain, even when the blood pressure is maintained and the hemoglobin normal.