Far-infrared therapy for secondary vascular access patency of hemodialysis patients

Introduction Far-infrared radiation therapy (FIRT), which utilizes an invisible electromagnetic wave, has demonstrated its ability to improve vascular access flow for hemodialysis (HD) patients. Although previous overseas studies revealed the beneficial effects of FIRT on HD patients by improving vascular function, no study in Japan has examined the clinical efficacy of FIRT for such patients. Therefore, we aimed to evaluate the usefulness of FIRT for HD patients. We paid particular attention on secondary vascular access (VA) patency of HD patients. Methods Eighteen patients who had undergone vasodilation of VA vessels or vascularization more than once were selected from approximately 70 outpatients receiving HD in the Dialysis Unit of the Juntendo University Hospital. FIRT was administered for 40 min during HD three times per week for 1 year to the not frequent VA treatment (nf-VAT) group, for which VA intervention had been performed no more than two times during the 1 year, and to the frequent VA treatment (f-VAT) group, for which VA intervention had been performed three times or more over the 1 year. Variables including VA treatment interval were compared between those groups. Results The nf-VAT group did not require VA re-treatment during the study period. The VA treatment interval was significantly prolonged in the f-VAT group. The fistula diameter expanded, and intimal thickening improved significantly in the nf-VAT group. Oxidized low-density lipoprotein cholesterol levels decreased slightly. Conclusion This study suggested that FIRT is effective for improving secondary VA patency. Trial registration UMIN, UMIN000011965. Registered 4 October 2013, Japanese: https://upload.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000013960 , English: https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000013960