Introduction:
Globally, there is a rising prevalence of individuals suffering from end stage kidney disease and requiring hemodialysis treatment. In order to undergo an effective hemodialysis procedure, it is crucial for the patient to have a vascular access that is both functional and stable. An essential prerequisite for achieving effective, durable, and optimal hemodialysis in a patient suffering from chronic kidney disease (CKD) is the presence of a properly functional vascular access. As to the 2006 guidelines from the National Kidney Foundation- Kidney Diseases Outcomes Quality Initiative (NKF- KDOQI), the most optimal vascular access option is a native arterio-venous fistula (AVF). This choice is preferred because it has less difficulties compared to arterio-venous grafts (AVG) and central venous catheters (CVC). The most effective channel for generating native arteriovenous fistula (AVF) in the upper limb is the cephalic vein.
An inherent drawback of arteriovenous fistulas (AVFs) is the elevated incidence of maturation failure. Approximately 20-50% of arteriovenous fistulas (AVFs) do not successfully develop, although the rate of being open from development to failure is higher than that of grafts. The incidence of thrombosis and stenosis is minimal in mature arteriovenous fistulas (AVFs). Moreover, AVF exhibits a lower likelihood of infection, failure, and interventional treatments when compared to AVG and CVC.
Several variables contribute to the inadequate maturation of arteriovenous fistula (AVF), including advanced age, female gender, obesity, diabetes, smoking, prolonged duration of chronic kidney disease (CKD), suboptimal surgical technique, pre-existing intimal hyperplasia, AVF infection, and certain genotypic polymorphisms.
Vascular access failure (VAF) is a significant issue that arises when maintaining hemodialysis (HD). The exact cause of VAF is not fully understood, but it is believed to be a result of increased migration and growth of smooth muscle cells, turbulent blood flow causing shear stress, mechanical stretching due to a mismatch in elastic properties near the anastomosis site, and the release of oxidants by activated platelets and inflammatory cells.
Optimally functional vascular access (VA) is crucial for individuals undergoing hemodialysis (HD) in this situation.
Enhancing maturation and mitigating stenosis have emerged as crucial concerns in the management of Hemodialysis patients with AV fistulas. A wide range of pharmaceuticals and non-invasive methods have been tested to expedite the maturity of arteriovenous fistulas (AVFs) and to sustain their rate of openness, yielding inconsistent outcomes. Currently, medications such as mucopolysaccharide polysulfate cream, aspirin, clopidogrel, and isometric hand exercises, together with other routine treatments, are being utilized to extend the lifespan of AVF. However, none of these treatments have been shown to provide conclusive benefits. Far infrared ray therapy has recently been attempted as a novel treatment option for arteriovenous fistula. It has attained favorable outcomes.
Far infrared (FIR) therapy is recognized for its ability to improve blood circulation and the success rate of arteriovenous fistula (AVF) patency.
Multiple studies, systematic reviews, and meta-analyses have consistently shown positive results on the effectiveness of far infrared therapy in promoting the development and maintenance of arteriovenous fistula (AVF) maturation and patency.
The FAITH on fistula trial is a current clinical trial that is randomized. controlled, open-labeled, and multicenter. Its purpose is to investigate the impact of FIR on AVF maturation in patients who have recently undergone AVF creation (incident), as well as the rate of AVF patency after one year of treatment in patients with an existing AVF (prevalent), in comparison to a control group. The outcomes are pending
This study aims to investigate the impact of FIR on the maturation and survival of AVF among hemodialysis patients.
Methods:
Following the acquisition of informed consent from each participant, a comprehensive clinical history is documented. The duration of CKD, the existence of comorbidities, the native kidney disease, and the treatment history were recorded. As part of the enrolling process, a series of blood tests will be conducted, including a complete blood count, blood urea, serum creatinine, serum electrolytes, uric acid, calcium, phosphorus, and serum albumin.
The eGFR was determined using the CKD-EPI equation. For individuals not undergoing hemodialysis, the most recent serum creatinine value was used. For patients on hemodialysis, the creatinine level at the time of hemodialysis initiation was used. The study recorded the dialysis frequency, the duration of each hemodialysis session, and any issues that occurred throughout the sessions for patients undergoing hemodialysis.
Initial ultrasonography of the upper limb vasculature will be performed. The parameters that were assessed during an initial visit as part of the recruitment process include the following:
1) Measurement of blood flow rate (ml/mt) and peak systolic velocity (PSV) in the radial artery and brachial artery.
2) Measurement of the diameter of the radial and brachial arteries (mm).
3) Measurement of the diameter (in mm) and distensibility of the cephalic vein.
The vascular surgeons in our hospital's department of vascular surgery reviewed all patients to determine the appropriate place for AVF development. The location for the construction of the fistula was determined based on vascular mapping. The minimum diameter necessary for the artery and vein to be eligible for the procedure were 2 mm and 2.5 mm, respectively. The draining vein should be free from any stenosis or thrombosis. Subsequently, the patients were allocated at random to one of the two groups.
Intervention arm
Patients will undergo FIR therapy using a TDP far infra-red heat lamp device.. Following AVF creation, FIR therapy should be administered three times a week, with each session lasting for 40 minutes, for a total duration of 6 weeks. To ensure the safety of the skin, the distance between the source of FIR and the skin is set at 30 cm.
Control arm
Patients were not given any further treatment apart from continuing with isometric hand exercise. The intervention will be conducted with careful oversight and the patient's safety will be guaranteed. If the patient experiences any notable symptoms or signs connected to the operation, the procedure will be discontinued, and appropriate care will be given.
Outcome
During the postoperative phase
Clinical assessment and arterial Doppler ultrasound performed.
To evaluate the variation in peak systolic velocity (PSV) and the rate of blood flow.
At 4 weeks and 6 weeks
The suitability of the AVF for cannulation will be assessed 4 weeks following its formation. If not, it will be assessed on a weekly basis thereafter
The Rule of 6 criteria is employed to assess the readiness of the AVF for cannulation. An ultrasound examination, together with a clinical evaluation of AVF, is performed to assess its diameter, which should be atleast 6 mm and no more than 6 mm in depth.
The access flow will be initiated promptly following successful cannulation, ensuring a minimum blood flow rate (Qa) of 600 ml/min in the AVF access.
AVF Doppler ultrasonography
A radiologist employed at our hospital performed the ultrasound of the AVF. The radiologist was blinded from the study. The data were obtained only utilizing a high-frequency probe from a single machine. The parameters that were measured during the 4th, 6th week, and 12th month follow-up are as follows.
The diameter of the cephalic vein and the blood flow rate of the AVF are evaluated.
The blood flow through the arteriovenous fistula (AVF) was quantified at distances of 2.5 cm, 5 cm, and 10 cm from the location of the fistula. The average of these three measurements was reported as the flow through the AVF.
Cephalic vein's distance from the skin's surface (in mm).
Examine the arterial/venous limbs of the arteriovenous fistula (AVF) for the existence of atheromatous plaque, inflow/outflow stenosis, or thrombosis.
In the 12th month, evaluate the patency of the AVF, the rate of blood flow through the access, the number of AVFs that have been abandoned, any changes in vascular access to CVS or a new AVF, the level of pain experienced during cannulation, and the number of patients experiencing steal syndrome.
Results:
A total of 128 patients randomised for study.64 patients were allocated to receive FIR treatment and 64patients were allocated to control arm, not received FIR treatment.
The primary outcome was role of FIR therapy in AVF maturation and AVF survival. It is found that AVF maturation was better in the intervention arm compared to control arm and the P value was significant (p-0.05). Also, AVF survival was better in the intervention arm compared to control arm.
Failure to mature at 6 weeks was 6.25% in the intervention arm, while 18.75% in the control arm. AVF survival in one year was 87.5% in the intervention arm, while 70.31%in the control arm. Also, we assessed early fistula maturation at 4 weeks, which was more in the intervention arm (90% Vs79%) compared to control arm and the P value is significant.
The secondary outcome was the role of imaging variables with AVF maturation and patency.
In our study, there is a significant association between fistula failure and smoking, diabetes mellitus seen (p-0.03& p-0.00respectively).In our study among cigarette smokers, those received FIR treatment found to have better AVF survival compared to control.
In our study patients with POVD were also found to have increased rate of fistula failure (p-0.05),but no change in the failure rate with intervention.
Also in our study, patients with uncontrolled diabetic status with HbA1c >7,associated with more failure rate and failure rate was lower in the intervention arm compared to the control arm .
In our study patients with >60yrs age, those received intervention has less fistula non maturation compared to control and the P value is significant.
In our study fistula failure is seen more in RC AVF (40%) compared to BC AVF (10%) and is significant(p-0.00). ). Among RC AVF,no difference in the fistula maturation rate between intervention and control arm, while fistula survival was more in the intervention arm compared to control arm, but P value was not significant.
Among BCAVF, both fistula maturation and survival were more in the intervention arm compared to control arm and the P value was significant.
In our study, RC AVF with preoperative blood flow rate of ≤50ml/mt in radial artery is associated with more failure to mature at 6 weeks (p-0.02) and less survival at one year and the P value is significant(p-0.01).
No association between preblood flow ≤50ml/mt in radial artery and fistula failure in both intervention and standard arm.
In our study, RC AVF with Preoperative Peak systolic velocity of <30cm/s in the radial artery is associated with more fistula non maturation at 6 weeks, but P value is not significant.
But at one year, 85% of the RC AVF with Preoperative Peak systolic velocity of <30cm/s in the radial artery failed while only 31%of RCAVF with PSV >30cm/s failed, and the P value is significant(p-0.01).
No association between preoperative peak systolic velocity ≤30ml/mt in radial artery and fistula failure in both intervention and standard arm.
In BCAVF, the difference in PSV (post operative PSV -preoperative) in the brachial artery >50cm/s and fistula maturation at 6 weeks is significant(p-0.01). A difference in PSV of >50cm/s is associated with only 2% failure to mature, while those with <50cm/s is associated with 19% failure rate.
But no association with fistula failure at one year and no change with intervention.
In BCAVF, a difference in the brachial artery blood flow rate (post operative BFR -preoperative BFR) of >180ml/mt is associated with more fistula maturation at 6 weeks is significant. Only 2% of BCAVF with difference in blood flow rate>180ml/mt failed, while all BCAVF with <180ml/mt failed and the P value is 0.001.
But no association with fistula failure at one year and no change with intervention.
In our study ,patients with poor preoperative imaging parameters, even with FIR treatment no change in outcome is observed
The cephalic vein stenosis is the most common complication leading to fistula failure in our study.
In our study, patients in the intervention arm reported less severe cannulation pain compared to standard arm.
Conclusions:
FIR treatment is an effective noninvasive method to promote AVF maturation and AVF Survival.FIR treatment is associated with early fistula maturation at 4 weeks.
Older age, Smoking, diabetes mellitus and POAD are associated with higher fistula failure rate, but FIR treatment improved survival among elderly, smokers and diabetes.
FIR treatment improved fistula survival among RC AVF.For RCAVF, preoperative blood flow rate <50ml/mt in the radial artery associated with failure to mature as well as reduced survival.
For RCAVF, preoperative peak systolic velocity <30ml/mt associated with reduced fistula survival.For BCAVF, difference in blood flow rate in brachial artery >180ml/mt associated with improved maturation.In AVF’s with poor preoperative imaging characteristics, FIR treatment do not improve the survival.
I have no potential conflict of interest to disclose.
I did not use generative AI and AI-assisted technologies in the writing process.