[Left internal thoracic artery as a collateral vessel in chronic occlusion of the pelvic artery].

Four years after implantation of an aorto-bi-iliac artery graft, a 53-year-old man suffered from intermittent claudication with a walking distance of 50 meters. By transaxillary aortography the left femoral artery could not be visualized. Selective angiography of the internal thoracic artery revealed a collateral circulation from the subclavian artery via the left internal thoracic artery, the superior epigastric artery and the inferior epigastric artery into the left external iliac artery (Winslow's pathway). Prior to using the internal thoracic artery for coronary bypass surgery, a function of this vessel as a collateral to the lower extremities should be excluded.