The purpose of this study is to evaluate the effectiveness of low-level laser therapy (LLLT) compared with isometric handgrip exercise and standard care in promoting vascular remodeling of arteriovenous fistulas (AVFs) among hemodialysis patients.
Hemodialysis remains a life-sustaining therapy for patients with end-stage renal disease, and the creation of a reliable arteriovenous fistula (AVF) is considered the gold standard for vascular access. However, despite its clinical advantages, AVF maturation failure occurs in up to 40% of patients, often due to inadequate vein dilation or early stenosis. Such shortcomings can delay dialysis initiation, increase the need for central venous catheters, and heighten the risk of infection and hospitalization. Interventions that can support or accelerate vascular remodeling and improve AVF usability, therefore, remain a significant focus in nephrology and vascular research. Several strategies have been investigated to enhance AVF maturation, including surgical modifications, pharmacological therapies, and rehabilitative interventions. Among conservative methods, isometric handgrip exercise has shown promise by improving venous return, stimulating shear stress, and promoting dilation of the access vein. More recently, low-level laser therapy (LLLT) has gained attention for its ability to modulate endothelial function, stimulate nitric oxide release, and improve microcirculation, with preliminary evidence suggesting beneficial effects on vascular tone and tissue healing. Nevertheless, comparative data between exercise-based and photobiomodulation-based approaches remain limited. This study is significant because it directly compares two non-invasive interventions-LLLT and isometric handgrip exercise-for their ability to enhance the vascular diameter of AVFs in hemodialysis patients. By clarifying whether photobiomodulation offers comparable or superior outcomes to exercise, the findings may help guide clinicians in selecting effective, patient-appropriate strategies to optimize AVF maturation and long-term patency. Ultimately, this research addresses a critical gap in vascular access management and may contribute to reducing access-related complications, improving dialysis efficiency, and enhancing the quality of life for patients dependent on chronic hemodialysis. To our knowledge, this is the first randomized controlled trial to evaluate extravascular low-level laser therapy head-to-head with isometric handgrip exercise for promoting radiocephalic arteriovenous fistula maturation in patients with chronic kidney disease.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
SINGLE
Enrollment
75
Patients in this group will receive low-level laser therapy using the BS-W11 semiconductor low-level laser device, which emitted a red laser at 650 nm with a power output of 5 mW per diode. The laser will be applied over the arteriovenous fistula site. Each session lasts 30 minutes and is administered three times a week for a total period of eight consecutive weeks. A trained therapist will perform all procedures, and patients were monitored for any potential adverse reactions during and after each session.
Patients will be instructed to perform daily isometric handgrip exercises using a standard squeeze ball. Patients will be positioned seated comfortably, with the forearm of the exercising limb resting on the ipsilateral thigh and the elbow maintained in slight flexion throughout the exercise, in order to minimize compensatory shoulder and elbow movement and ensure that the contraction remained isolated to the forearm muscles. The exercise protocol involves squeezing at a rate of approximately 20 squeezes per minute for a total of 30 minutes per day, at 30-40% of maximum voluntary contraction (MVC). To improve compliance, participants will be allowed to divide the daily session into two 15-minute intervals if required. The exercise program continued for 8 consecutive weeks, and patients will be instructed to maintain adherence by recording their daily sessions in a logbook
Cairo university
Cairo, Egypt
Average Vein Diameter
It will be measured by the doppler ultrasound. The internal luminal diameter of the arteriovenous fistula (cephalic vein), measured in millimeters (mm) by duplex ultrasound at a standardized point along the fistula tract, typically 5-10 cm proximal to the anastomosis, with the patient in a seated or semi-recumbent position and a tourniquet applied to standardize venous filling. A diameter ≥6 mm is generally considered indicative of adequate fistula maturation.
Time frame: 8 weeks
Rate of blood flow
It will me measured by the doppler ultrasound. The volumetric rate of blood flow through the arteriovenous fistula, measured in milliliters per minute (mL/min) using duplex ultrasound Doppler assessment at a standardized site along the fistula outflow vein. Access flow is calculated from the vessel cross-sectional area and the time-averaged mean velocity (TAMV), as follows: Access Flow (Qa) = π × (D / 2)2 × TAMV × 60 where D = vein diameter (cm), TAMV = time-averaged mean velocity (cm/s), and 60 converts cm³/s to mL/min. A flow rate \>600 mL/min is generally considered indicative of adequate fistula maturation.
Time frame: 8 weeks
Time-Averaged Mean Velocity (TAMV)
The mean blood flow velocity within the fistula vein, averaged over the complete cardiac cycle, obtained by pulsed-wave Doppler ultrasound.. TAMV is expressed in centimeters per second (cm/s) and is used, together with the vessel cross-sectional area, to derive access flow.
Time frame: 8 weeks
Maturation of arteriovenous fistulas
It will be evaluated by duplex ultrasound at 8 weeks post-creation by a vascular sonographer. A composite clinical outcome indicating that the arteriovenous fistula has developed sufficient diameter, blood flow, and depth to permit successful and sustained cannulation for hemodialysis. Maturation is assessed at a predefined postoperative time point by duplex ultrasound against standardized criteria - vein diameter ≥6 mm, access flow \>600 mL/min, and depth from the skin surface ≤6 mm - in conjunction with documented successful two-needle cannulation for dialysis.
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It includes wound and dressing management (keeping the dressing dry for the initial 48-72 hours, followed by regular dressing changes and site hygiene), activity restriction (avoiding heavy lifting or direct pressure over the access site during the early postoperative period), patient education on self-palpation of the access thrill, and routine follow-up visits at approximately 1 week and 6 weeks postoperatively to assess wound healing and access patency.
Time frame: 8 weeks
Pain intensity level
Pain intensity will be measured by applying the visual analogue scale (VAS). The VAS is a 100-mm horizontal line, with one end defined as no pain (0 mm) and the other as worst imaginable pain (100 mm). Each participant will be asked to mark a point on the line corresponding to their level of pain at the arteriovenous fistula site. This procedure will be repeated three times, and the average will be recorded
Time frame: 8 weeks
Kidney disease-related quality of life (KDQOL-36™)
The KDQOL-36™ will be used to assess health-related quality of life in patients with chronic kidney disease referred for hemodialysis vascular access. It is a validated, self-administered questionnaire that combines a generic core health survey with kidney-disease-targeted items, covering physical and mental health domains as well as burden of kidney disease, symptoms/problems, and effects of kidney disease on daily life. Higher scores reflect a better perceived quality of life.
Time frame: 8 weeks