Etiology and surgical treatment of splanchnic artery aneurysms HUANG Xin-tian. Department of Vascular Surgery, Shanghai Ninth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200011, China Abstract Splanchnic artery aneurysms involve the celiac, superiormesenteric, inferior mesenteric arteries and their branches. The aneurysms are important to recognize because up to 25% of them may be complicated by rupture, and the mortality rate after rupture is between 25% and 70%. Splenic artery aneurysms are the most common of the splanchnic artery aneurysms. Hepatic artery pseudoaneurysms are more common than true aneurysms because of increasing numbers of hepatobiliary interventional procedures. Majority of splanchnic artery aneurysms are asymptomatic prior to rupture, or are detected incidentally on imaging studies. The diagnosis of splanchnic artery aneurysm should be considered in any patient with abdominal pain, a pulsatile mass, or an abdominal bruit with or without associated bleeding. Treatment options are available including of surgical and endovascular treatment, if the aneurysm is more than 2 cm in diameter, if the patient is pregnant, or if there is demonstrated growth of the aneurysm.