A lower abdominal tumor with thrill and bruit was pointed out in a 59-year-old female. Angiography showed a pelvic arteriovenous malformation (AVM) with remarkably dilated vessels resembling an aneurysm. Feeding arteries for this AVM originated from the right internal iliac artery, right lumbar artery and right renal artery, and drainage blood flowed into the inferior vena cava from the dilated vessel via a large vein. At operation the right internal iliac artery and right lumbar artery were ligated and the dilated vessel with AVM, which connected with the right renal artery, was resected. An angiography 16 days after the operation revealed the normal arteries without AVM and the right internaal iliac artery filled through collateral arteries. Recently catheter embolization in frequently the first choice for treatment of AVM. However, in the case of AVM with aneurysmal dilated vessels, surgical resection should be selected.

A case of non-anastomotic aneurysms of a knitted Dacron graft is reported. The patient, a 35-year-old female, had had a bypass operation with a Cooley double velour knitted Dacron graft 11 years previously for stenosis of the descending thoracic aorta caused by aortitis syndrome, was admitted complaining of a painful pulsating tumor of the left hypochondral region. We diagnosed multiple aneurysms of Dacron graft with computerized tomography and aortography. The dilated Dacron graft was resected and replaced by a woven polyester graft. The resected specimen showed longitudinal ruptures macroscopically and a decrease of the number of Dacron fibers at the dilated portion was detected microscopically. The nonuniformity of the diameter of Dacron fibers and cracks in the fibers were observed with a scanning electron microscope. Thus, for patients implanted with a knitted Dacron graft, periodical careful follow-up is required for early detection of aneurysmal changes of the graft.