LAUSR

OBJECTIVE Placing an extracranial-intracranial (EC-IC) high-flow bypass using a radial artery (RA) graft plus internal carotid artery (ICA) trapping or ligation is an option for treating patients expected to be at high risk for complications by direct surgical treatment of the ICA. We focused on the anastomosis between the external carotid artery (ECA) and the RA graft in the cervical region and present adverse events and salvage procedures. METHODS EC-IC high-flow bypass procedures using an RA graft were performed to treat 87 consecutive patients. The ECA diameter at the midpoint of the planned ECA-RA anastomosis and the non-branched length of the ECA were measured on preoperative angiograms. To study adverse events related to ECA-RA anastomoses, we reviewed the patients' surgical records and intraoperative videos. RESULTS In 11 patients (12.6%) we encountered adverse events during anastomosis between the ECA and RA. The rate of ECA dissection was significantly higher in males (4/17; 23.5%) than females (3/70; 4.3%) (p = 0.012). Logistic regression analysis revealed that males, individuals with diabetes mellitus, and patients whose non-branching length of the ECA was short (16.1 ± 6.7 mm) were at high risk of ECA problems. We set the cutoff point at 17.5 mm (the area under the ROC curve was 0.72). CONCLUSIONS Our findings indicate that patients, especially males, treated by extracranial-intracranial high-flow bypass using an RA graft are at increased risk for adverse events when the ECA length at the site of the planned anastomosis is shorter than 17.5 mm.