External beam radiation therapy to prevent postangioplasty dialysis access restenosis: a feasibility study.
Overview
abstract
PURPOSE: To evaluate the feasibility and short-term side-effects of postangioplasty external beam radiation for patients with compromised arteriovenous dialysis accesses. MATERIALS AND METHODS: Ten patients with compromised arteriovenous dialysis accesses were studied. Following confirmation of access compromise by an angiogram, patients were treated by a standard angioplasty +/- stent deployment. The target volume incorporated a margin of 1 cm beyond the angioplastied segment. The first 5 patients were treated to a dose of 12 Gy in two 6-Gy fractions spaced 48 h apart, whereas the next 5 patients were treated to 8 Gy in two similarly separated 4-Gy fractions. Five of the patients had at least one prior access that had failed. The current access had been in use for 6-52 months, and 5 of the 10 patients had at least one episode of compromise involving the current access. The length of stenosis ranged from 2 to 9 cm (mean 4.4 cm). All patients were followed clinically for adequacy of dialysis; a radiological follow-up with a fistulogram was performed for all in 3-monthly intervals. Follow-up ranged from 4 to 10 months, with a median follow-up of 6 months. RESULTS: There were no procedure-related complications. Three patients developed a restenosis at the site of the original stenosis, and one patient developed a restenosis at the edge of the stent. As part of the natural history of this process, five patients have also developed new lesions elsewhere in the proximal veins requiring radiological intervention. None of the patients showed any radiation-related side effects, either in the skin/ soft tissues, or in the vasculature on follow-up angiograms. CONCLUSIONS: Several different radiotherapeutic approaches are being currently investigated to prevent postangioplasty restenosis. There are several issues involved with the use of endovascular brachytherapy in these patients. On the other hand, given the superficial location of the dialysis access, we believe that external beam radiation offers a safe and simple method of radiation therapy in this setting. The clinical efficacy of this modality needs to be established through a randomized phase III trial.
