Effect of far infrared therapy on arteriovenous fistula maturation: an open-label randomized controlled trial.
BACKGROUND
Malfunction of the arteriovenous fistula (AVF) is an important cause of morbidity and hospitalization in hemodialysis (HD) patients. The aim of this study is to evaluate the effect of far infrared therapy on the maturation and patency of newly created AVFs in patients with chronic kidney disease stage 4 or 5.


STUDY DESIGN
Randomized controlled study.


SETTING & PARTICIPANTS
Patients with estimated glomerular filtration rate of 5-20 mL/min/1.73 m².


INTERVENTION
40 minutes of far infrared therapy 3 times weekly for a year.


OUTCOMES
The primary outcome is the rate of AVF malfunction within 12 months, with malfunction defined as either: (1) thrombosis without thrill for AVFs not undergoing HD or (2) receiving any type of interventional procedure due to a lower Kt/V (<1.2) for patients undergoing HD. Secondary outcomes include: (1) cumulative primary unassisted AVF patency, defined as time from creation of the AVF to the first episode of AVF malfunction; (2) physiologic maturation of the AVF by the definition of AVF access blood flow (Qa) ≥500 mL/min and AVF diameter ≥4 mm at 3 months; and (3) clinical maturation of the AVF suitable for HD at 1 year.


MEASUREMENTS
AVF Qa was measured by Doppler ultrasonography at 2 days and 1, 2, 3, and 12 months.


RESULTS
We enrolled 122 patients who were randomly allocated to the intervention (n = 60) and control (n = 62) groups. In comparison to controls, patients in the intervention group had higher Qa values at 1, 2, 3, and 12 months; a higher rate of physiologic maturation (90% vs 76%; P = 0.04) at 3 months; and a lower rate of AVF malfunction (12% vs 29%; P = 0.02) but higher rates of AVF cumulative unassisted patency (87% vs 70%; P = 0.01) and clinical maturation (82% vs 60%; P = 0.008) within 12 months.


LIMITATIONS
This is a single-center nonblinded study.


CONCLUSIONS
Far infrared therapy improves the access flow, maturation, and patency of newly created AVFs in patients with chronic kidney disease stages 4 and 5.