False aneurysm formation following arteriographic intimal dissection: serial studies in 2 patients. 
Two patients with metastatic islet-cell carcinoma underwent multiple hepatic artery catheterizations for streptozotocin infusion.  An intimal flap was raised during one of the initial arteriographic procedures and a false aneurysm developed.  The progression of the aneurysm was documented on sequential studies.  False aneurysm formation appears to be a relatively unappreciated complication of intimal dissection, and these 2 cases permitted observation of their natural history.