#4520 THE USE OF FAR INFRARED LIGHT DURING HEMODIALYSIS SEEMS TO MAINTAIN ARTERIOVENOUS FISTULA BLOOD FLOW BETTER THAN USING A HEAT PAD - A PILOT STUDY

Abstract

Abstract Background and Aims The use of the native arteriovenous fistula (AVF) in chronic hemodialysis (HD) patients yields great challenges to keep a patent AVF, especially among those with diabetes mellitus and cardiovascular disease. Often repeated radiological interventions or surgery of the AVF is necessary. Accumulation of advanced glycation end products (AGE) in tissue is shown to contribute to the complications of diabetes mellitus and uremia [1]. Far infrared light (FIR) irradiation of the AVF have shown protective effects in maintaining AVF blood flow [2,3]. Using a heat pad (HP) to stimulate vascular flow is another alternative. Primary aim of the study was to compare if the use of a HP is as good as FIR to maintain AVF blood flow. Secondary aim: Evaluate change in AGE accumulation in tissue after FIR and HP treatment. Method This pilot study included HD patients with a native lower arm AVF. Eighteen patients were randomly assigned to treatment during HD; Ten patients to FIR and another group of eight patients to use HP (Two of the HP-patients refused to fulfill the study). Before and after a period of 15 HD treatments each, blood tests, AVF blood-flow measured with a Transsonic® and skin autofluorescence (SAF, measuring AGE) were analyzed. The distance of the FIR emitter to the AVF puncture area was 25 cm. The HP-group was exposed to a waterfilled rubber HP that kept a temperature of 40-41°C and was positioned to the backside of the AVF arm to avoid dislodgement of or compressing needles. The patient was her/his own control and non-parametric Mann-Whitney U- and Wilcoxon sign ranked tests were used. Results The blood flow of the AVF was similar at start in the FIR group versus the HP-group median 921 ml/min IQR (714-1210) vs. 610 ml/min, IQR (538-861), p = 0.118, while after 15 treatments the blood flow was maintained in the FIR group but was lower in the HP-group; median 902 ml/min IQR (718-1241) vs. 635 ml/min IQR (531-772), p = 0.022. The FIR exposure did not alter the SAF content (in arbitrary units -AU) after treatment and was similar in the FIR group (median 3.2 AU, IQR 2.2-3.6) and in the HP group (median 3.2, IQR 2.4-3.3), p-value = 0.864.During the follow-up period after 3 and 6 months, PTA was performed due stenosis with decreased blood flow of the AVF in 3/10 patients in the FIR group and 1/6 patients in the HP group. Data are given as median and interquartile range (IQR). A two-sided p-value of <0.05 was defined as significant. Conclusion This pilot study showed that the access flow after FIR versus HP exposure during 15 HD treatments was better maintained among patients treated with FIR than with HP. SAF as a predictor for atherosclerosis was not changed. Long-term exposure to FIR may be necessary.