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NCT Number: NCT07238855

Effect of Isometric Hand Grip Exercises Using a Dynamometer on AV Fistula Maturation and Patency in Hemodialysis Patients

Patients with chronic kidney failure who require hemodialysis depend on a surgically created connection between an artery and a vein in the arm, known as an arteriovenous fistula. This connection allows blood to flow at a high enough rate for effective hemodialysis treatment. However, many arteriovenous fistulas do not enlarge or strengthen adequately after surgery, a process known as maturation. When maturation fails, the fistula may not provide enough blood flow, leading to delays in hemodialysis, repeated procedures, or the need for temporary catheters. Improving the maturation of arteriovenous fistulas is therefore essential for patient safety, comfort, and the long-term success of hemodialysis.

Isometric hand-grip exercises, such as repeatedly squeezing a hand-held dynamometer, may help increase blood flow to the arm and stimulate the blood vessels that are part of the fistula. These exercises require the muscles to contract without changing length, which can encourage enlargement of the vein and the development of new small blood vessels in the forearm. Previous research suggests that improving hand-grip strength may support better vein remodeling and improved blood flow, both of which are important for fistula maturation.

This study is designed to evaluate whether performing a structured program of isometric hand-grip exercises using a dynamometer can enhance the maturation and long-term openness (patency) of arteriovenous fistulas in adults receiving hemodialysis. Participants are randomly assigned to one of two groups: a control group that receives routine postoperative care, and an exercise group that performs hand-grip exercises for six weeks. All participants undergo ultrasound imaging of the fistula before starting the study and again after six weeks. The ultrasound measurements include fistula size, vein diameter, blood flow, and blood flow velocity.

The goal of this study is to determine whether a simple, low-cost exercise intervention can help arteriovenous fistulas mature more successfully and reduce the need for additional procedures.

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Key information

Conditions

Chronic Kidney Failure Arteriovenous Fistula Arteriovenous Malformations Cardiovascular Abnormalities Cardiovascular Diseases Chronic Disease Congenital Abnormalities Congenital, Hereditary, and Neonatal Diseases and Abnormalities Disease Attributes End-stage Renal Disease Female Urogenital Diseases Female Urogenital Diseases and Pregnancy Complications Fistula Kidney Diseases Kidney Failure, Chronic Male Urogenital Diseases Pathologic Processes Pathological Conditions, Anatomical Pathological Conditions, Signs and Symptoms Renal Insufficiency Renal Insufficiency, Chronic Urogenital Diseases Urologic Diseases Vascular Diseases Vascular Fistula Vascular Malformations

Age range

18 year–75 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Mansoura Nephrology and Dialysis Unit - Mansoura University Hospitals

Al Mansurah, Dakahlia Governorate, 35516, Egypt

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Adults aged 18 to 75 years
  • End-stage renal disease requiring hemodialysis
  • Patients undergoing hemodialysis through a surgically created arteriovenous fistula
  • Ability to provide written informed consent

Exclusion criteria

  • Failure or refusal to provide written informed consent
  • Amputation of the arm or fingers
  • Significant osteoarthritis of the hand or wrist
  • Severe physical disability preventing exercise performance
  • Active infection or ongoing hospitalization
  • Known underlying malignancy

Treatment and study plan

Isometric Hand-Grip Exercise Training Using a Hand Dynamometer

Behavioral

Participants perform a structured isometric hand-grip exercise program using a hand-held dynamometer for six weeks after creation of an arteriovenous fistula for hemodialysis. The grip handle is adjusted to the size of the hand, the elbow is flexed to a ninety-degree angle, and the participant performs repeated maximal voluntary hand-grip contractions according to a standardized schedule. Training is added to usual postoperative care and is monitored during follow-up visits.

Primary outcomes

  1. Change in arteriovenous fistula blood flow volume measured by Doppler ultrasound

    Time frame: Baseline and six weeks after starting the hand-grip exercise program or standard care

    Blood flow volume through the arteriovenous fistula (milliliters per minute) will be measured using duplex Doppler ultrasound at the outflow vein. The primary metric is the change in blood flow volume from baseline (before starting the hand-grip exercise program or standard care) to six weeks. Change will be calculated as the value at six weeks minus the baseline value for each participant.

Secondary outcomes

  1. Change in arteriovenous fistula vein diameter measured by Doppler ultrasound

    Time frame: Baseline and six weeks after starting the hand-grip exercise program or standard care

    Vein diameter of the arteriovenous fistula (millimeters) will be measured using duplex Doppler ultrasound at the inflow and outflow segments. The metric is the change in vein diameter from baseline to six weeks.

  2. Change in hand-grip muscle strength of the dominant hand

    Time frame: Baseline and six weeks after starting the hand-grip exercise program or standard care

    Maximum isometric hand-grip strength (kilograms or newtons) will be assessed using a calibrated hand-held dynamometer. Each participant performs three maximal voluntary contractions with the dominant hand, and the mean of the three values is recorded. The metric is the change in hand-grip strength from baseline to six weeks.

  3. Clinical usability of the arteriovenous fistula for hemodialysis

    Time frame: Assessed at six weeks after starting the hand-grip exercise program or standard care

    Proportion of participants whose arteriovenous fistula can be used successfully for routine hemodialysis, defined as achieving two-needle cannulation with the prescribed blood flow rate during at least three consecutive hemodialysis sessions without access failure or thrombosis.

Sponsors and collaborators

Lead sponsor

Mansoura University

Other

Registry information

Official study title

Effect of Isometric Hand Grip Exercises Using a Dynamometer on Arteriovenous Fistula Maturation and Patency in Hemodialysis Patients

Important dates

Study start
2023
Primary completion
2024
Study completion
2024
First posted
Nov 20, 2025
Registry last updated
Nov 20, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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