[Collaterals after flow alternation in pelvic arteries: precondition for pelvic reservoir therapy].

To determine the best flow alternation in the internal iliac arteries for regional chemotherapy using a reservoir to treat pelvic malignancies, collateral arteries that arose after arterial flow alternation were evaluated on follow-up pelvic angiographies. Follow-up angiographies were obtained in 11 patients with 21 embolized arteries; six male and five female patients including three with urinary bladder cancer, two with prostate cancer, four with uterine cervical cancer and two with bone metastasis. The interval until follow-up angiography ranged from one to-28 months (mean 8.9 months). Three radiologists interpreted the angiographic results and evaluated collateral vessels. Among 21 embolized arteries, 19 were well occluded, while two were not blocked completely. The two arteries with incomplete embolization did not induce collaterals. Eight internal iliac arteries occluded at the proximal portion enhanced retrogradely via collaterals from the ipsilateral external iliac arteries. Collaterals between the bilateral internal iliac arteries were noted only in four of them. In conclusion, embolization at the proximal point of the internal iliac arteries usually induced collaterals from the ipsilateral external iliac arteries and did not always from collaterals between the bilateral internal iliac arteries, which were necessary for regional chemotherapy. This should be considered when pelvic malignancies are treated with reservoirs.