OBJECTIVE - The purpose of this study was to assess the rate of recanalization and collateral vessel formation after side-branch embolization during mapping angiography for planned (90)Y radioembolization.
MATERIALS AND METHODS - Patients who underwent side-branch embolization at mapping angiography before (90)Y administration were included. Embolized vessels included the gastroduodenal artery, right gastric artery, and accessory arteries. Four interventional radiologists reviewed follow-up angiograms to assess recanalization and new collateral formation of embolized vessels. The time to recanalization or new collateral formation was tracked within 60 days and after the final arteriographic study. Differences in outcome among patients who had and those who had not undergone previous arterial directed therapy were reviewed.
RESULTS - Fifty-six patients underwent side-branch embolization and follow-up arteriography; 124 treatments were performed after side-branch embolization (median, 2; range, 1-7), and the median follow-up period was 134 days (range, 7-684 days). Recanalization or new collateral vessel formation was found in 6 of 56 patients (10.7%) and in 8 of 56 patients (14.3%) 60 days after treatment or at final angiography, respectively. Embolization of 110 arteries was accomplished (42 gastroduodenal arteries, 46 right gastric arteries, and 22 accessory arteries). Two of 110 arteries (1.8%) recanalized, and four of 110 (3.6%) had new collateral vessels within 60 days. At final evaluation, 2 of 110 arteries (1.8%) had recanalized and 7 of 110 (6.4%) had new collaterals. Previous liver-directed therapy did not affect outcome (p > 0.05). No patient had symptomatic gastrointestinal ulceration.
CONCLUSION - In more than 89% of patients, side-branch embolization provides durable occlusion for (90)Y radioembolization without collateral development or recanalization for a bilobar cycle of therapy. Further recanalization and collateral development at longer-term follow-up are minimal.