Low-Level Laser Therapy Versus Isometric Handgrip Exercise On Arteriovenous Fistula Maturation in Hemodialysis Patients

August 24, 2026 updated by: Muhammad Atef Ibrahim, Cairo University
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.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

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

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
75

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Patients of both genders.
  • Patient age between 35 and 50 years.
  • Diagnosed with chronic kidney disease (CKD) Stage 4 or 5 with a newly created radiocephalic arteriovenous fistula (RC-AVF), including both pre-dialysis patients and those temporarily receiving hemodialysis via central venous catheter pending fistula maturation.
  • Distal forearm cephalic vein diameter ≥ 2.5 mm in the non-dominant hand

Exclusion Criteria:

  • History of prior vascular access surgery on the same limb.
  • Physical or mental disability limiting the ability to perform exercises.
  • Positive Allen's test.
  • Absent or thrombosed distal forearm cephalic vein.
  • Already undergoing regular exercise (including manual workers).
  • History of hemophilia or known coagulation disorder.
  • Personal or family history of cancer.
  • Severe cardiac disease (congestive heart failure with ejection fraction ≤ 20%).
  • Known central venous stenosis > 50% on the side of planned arteriovenous fistula creation.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Low-level laser therapy group
Patients received extravascular low-level laser therapy (LLLT) in the form of a laser watch device applied just above the wrist joint, three sessions weekly for 8 weeks.
Device: Low-level laser therapy
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.
Experimental: Isometric Handgrip Exercise group
Patients performed isometric handgrip exercise using a calibrated handgrip dynamometer/squeeze ball daily for 8 weeks.
Other: Isometric handgrip exercises
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
Active Comparator: Standard postoperative care
Patients will receive standard postoperative care only, with no additional intervention.
Other: Standard postoperative care
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.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Average Vein Diameter
Time Frame: 8 weeks
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.
8 weeks
Rate of blood flow
Time Frame: 8 weeks

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.
8 weeks
Time-Averaged Mean Velocity (TAMV)
Time Frame: 8 weeks
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.
8 weeks
Maturation of arteriovenous fistulas
Time Frame: 8 weeks
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.
8 weeks

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Pain intensity level
Time Frame: 8 weeks
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
8 weeks
Kidney disease-related quality of life (KDQOL-36™)
Time Frame: 8 weeks
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.
8 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Cairo University

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Study Director: Mohamed F Radwan, Ain Shams University
  • Study Chair: Hany E Obya, Professor, Cairo University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
September 1, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
March 15, 2027

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
March 31, 2027

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
August 24, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 24, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
August 26, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
August 26, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 24, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
August 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • P.T.REC/012/006425

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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