BackgroundThe mortality rate of splenic artery aneurysm rupture is very high, and patients with aneurysms larger than 30 mm are recommended for treatment, regardless of the presence or absence of symptoms. We herein report a case of splenic artery aneurysm with an abnormal bifurcation that was treated with laparoscopic ligation of the splenic artery.Case presentationA 51 year-old Japanese male was referred to our hospital because a splenic artery aneurysm was noted on abdominal echocardiography during a medical examination. The splenic artery bifurcated from the superior mesenteric artery (SMA), and a 38-mm splenic artery aneurysm was found just after the bifurcation; thus, surgery was performed. Intraoperative angiography was performed, a balloon catheter was placed before the splenic artery bifurcation, and laparoscopic splenic artery ligation was performed to prepare for sudden bleeding. After ligation of the splenic artery, angiography was performed again to confirm the absence of the splenic artery aneurysm and that the peripheral splenic artery was visible through the peripheral collateral vessels. The patient was discharged on the fourth postoperative day, with good progress. Contrast-enhanced computed tomography performed 1 month postoperatively confirmed the disappearance of the splenic artery aneurysm, and the contrast-enhanced peripheral splenic artery was visible.ConclusionThis is the first report of a safe laparoscopic artery ligation procedure for a splenic artery aneurysm with an abnormal splenic artery bifurcation from the SMA, in which a balloon catheter was placed at the splenic artery bifurcation.