THE CAUSES of arterial insufficiency in the lower extremity are many and varied. Generally, the disease process falls within one of the following categories: embolic, thrombotic, degenerative, or traumatic. Despite the obvious differences in the pathogenesis of these types of obstruction, they have one common factor: in all cases the offending or precipitating factor responsible for the obstruction is located at some point within the vessel lumen or wall itself. It is most unusual for the patency of the arterial lumen to be compromised by extrinsic lesions exerting pressure upon the vessel wall. Possibly this is due to the continuous hydrostatic pressure within the larger arteries acting as an opposing force to external compression.
Although arterial obstruction by extrinsic disease processes is rare, it has been reported in the form of intermittent claudication secondary to idiopathic retroperitoneal fibrosis.1-6 This paper reports another cause of extrinsic arterial obstruction, namely that