OBJECTIVE: In the treatment of patients with cranial base tumors, unclippable aneurysms, or medically intractable ischemia, it may be necessary to use high-flow bypass grafts. The indications, surgical techniques and complications are discussed. METHODS: During a 10-year period, 99 saphenous vein grafts and 3 radial artery grafts were performed for 101 patients, i.e., 72 with neoplasms, 23 with aneurysms, and 6 with ischemia. Clinical follow-up monitoring of the patients was by direct examination or telephone interview, with a mean follow-up period of 41.2 months (range, 5-147 mo). Radiological follow-up monitoring was by magnetic resonance imaging, magnetic resonance angiography, or three-dimensional computed tomographic angiography, with a mean follow-up period of 32 months (range, 1-120 mo). During the follow-up period, there was one late graft occlusion and one graft stenosis. RESULTS: The use of intraoperative angiography improved the patency rate from 90 to 98% and reduced the incidence of perioperative stroke from 13 to 9.5%. Ninety-two percent of the patients were in excellent or good neurological condition at the time of discharge from the hospital, compared with 95% before surgery. The perioperative mortality rate was 2%. Other complications included three intracranial hematomas, rupture of a vein graft in a patient with Marfan's syndrome, and five tumor resection-related problems. The long-term survival rates for patients who received grafts were excellent for patients with benign tumors, fair to poor for patients with malignant tumors, good for patients with aneurysms, and excellent for patients with ischemia. CONCLUSION: The results of saphenous vein and radial artery grafting have been greatly improved by the use of intraoperative angiography, improvements in surgical techniques, and improved perioperative treatment.