A 55-year-old women with von Recklinghausen's disease was admitted to our hospital after sudden left-sided chest pain. She became shocked with a blood pressure of 50mmHg and pulse of 120per min. Chest radiography showed a massive left pleural effusion. Thoracentesis revealed bright blood. Emergency operation was perfomed. The source of bleeding was not clearly identified, but we suspected rupture of the intercostal artery. So we resected a part of descending aorta and implanted a Dacron graft. The bleeding was stopped. She discharged about five months later because of post-operative respiratory and hepatic failure. Histological examination of the aortic wall revealed extensive adventitial infiltration with neurofibromas. The turbulance of the aortic medial elastic fiber was also observed. We considered these histological change of the vessel caused spontaneous rupture of the intercostal artery.

A 52-year-old man presented with a pulsatile mass in the right groin. He had undergone lumbar sympathectomy and aorto-right femoral artery bypass using an 8mm Microvel double velour graft, 14 years previously, for aortoiliac occlusive disease caused by thromboangiitis obliterans. Based on a clinical diagnosis of an anastomotic aneurysm, an operation was performed. When the aneurysm was incised, it was found that the anastomosis of the graft to the femoral artery was intact and that the graft itself had a defect, 3cm in size on the anterior wall, 1.5cm proximal to the distal anastomosis. The final diagnosis was a nonanastomotic false aneurysm due to prosthetic graft failure. The failed portion of the graft was resected, and a 10mm Hemashield Gold woven double velour graft was interposed between the old graft and the right femoral artery. Generally, arterial grafts below the groin are subject to high levels of mechanical stress, and graft failure is not uncommon. Vascular surgeons should keep in mind that graft failure is not rare in patients with long-standing prosthetic grafts.