The purpose of this study was to identify subgroups with different risks of progression and their appropriate management among the heterogeneous group of 112 patients diagnosed with splanchnic aneurysm.

Using radiology databases and medical records of our institution (Hospital Édouard-Hérriot, Lyon, France), we undertook a retrospective review of all patients diagnosed with splanchnic artery aneurysms from 1995 to 2011. Cases were analyzed by aneurysm location, etiology and a distinction was also made between true and false aneurysms.

False aneurysms were more likely than true aneurysms to be diagnosed as symptomatic and/or ruptured (TA: 50/66 patients asymptomatic vs. FA: 16/46 asymptomatic, P<0.05) with a rupture rate of 59% (27/46) which was unrelated to the size of aneurysms. Percutaneous treatment was carried in the majority of patients with a final success rate of 91%. Peripancreatic true aneurysms were associated in 75% of cases with celiac occlusive disease and diagnosed mostly in symptomatic patients (7/9: 78%) with a rupture rate of 44% unrelated to their size. Radiologic treatment has faced problems due to failure of catheterization and incomplete embolization, although there have been cases in which delayed occlusion was achieved. Common true aneurysms were incidental findings in 87% (57/66) of patients with 3 ruptured aneurysms which were larger than 2cm. Observation in that group was safe: significant growth was seen only in one patient and the embolization required was successful. Splanchnic false aneurysms and peripancreatic true aneurysms carried a high and an unpredictable risk of rupture that warranted prompt endovascular treatment as soon as possible.

Stratification by localization and by the true or false appearance of the aneurysm was an effective (means of identifying) way to identify subgroups with different risks of progression. False aneurysms and peripancreatic true aneurysms carried a high and unpredictable risk of rupture. The splanchnic aneurysms should have been treated in the case of patients of childbearing age, size≥20mm, and in the case of liver transplantation. Other splanchnic aneurysms should either have been observed, if smaller than 2cm. In the absence of rigorous published comparisons, surgical and endovascular methods should have been considered equally suitable in the elective treatment of these patients.