Einieh, Mahmoud

Arteriovenous fistulas (AVFs) are the preferred method for establishing long-term vascular access in patients undergoing hemodialysis; however, high-flow AVFs may increase cardiovascular strain after kidney transplantation, often necessitating fistula closure. Currently, no established guideline exists for managing high-flow fistulas in post-transplant patients with stable kidney function, and available studies report heterogeneous results with small sample sizes and different methodologies. We performed a systematic search of PubMed, Cochrane, and Embase up to December 2024 for observational studies and randomized controlled trials comparing AVF ligation versus maintenance in patients with end-stage kidney disease. The meta-analysis was conducted using Cochrane’s RevMan software using mean difference (MD) and 95% confidence interval. Twelve studies including 844 patients were analyzed, of whom 409 (48%) underwent AVF ligation, with follow-up ranging from 3 to 62.5 months. AVF ligation was associated with a significant reduction in left ventricular mass index (MD −10.92 g/m 2 ; 95% confidence interval −17.84 to −3.99; p = 0.007) and cardiac index (MD −0.56 L/min/m 2 ; 95% confidence interval −1.05 to −0.07; p = 0.03), indicating attenuation of the hyperdynamic circulatory state related to a persistent AVF. No significant differences were observed in left ventricular ejection fraction or blood pressure parameters. Serum creatinine levels were modestly reduced following AVF ligation (MD −0.12 mg/dL; 95% confidence interval −0.22 to −0.03; p = 0.02), while estimated glomerular filtration rate remained unchanged. Overall, AVF ligation was associated with favorable cardiac remodeling reflected by reductions in left ventricular mass and cardiac output, with supportive changes in secondary echocardiographic parameters and no apparent deterioration in renal function.

Abstract Introduction Arteriovenous fistulas (AVF) are the preferred method for establishing long-term, reliable vascular access in patients undergoing haemodialysis for end-stage renal disease. However, previous research has shown that high-flow AVFs may increase cardiovascular strain after kidney transplantation, often necessitating fistula closure in these patients. Currently, there is no established guideline for managing high-flow fistulas in post-transplant patients with stable kidney function, and the haemodynamic effects of AVF closure are unknown. Objective This study aims to perform a systematic review and meta-analysis of haemodynamic and echocardiographic changes following AVF closure compared to AVF persistence. Methods We systematically searched PubMed, Cochrane, and Web of Science up to December 2024 for observational studies or randomised controlled trials (RCTs), including patients with chronic kidney disease (CKD) undergoing AVF ligation versus maintenance. Key parameters indicative of cardiac and renal function were assessed. The statistical analysis was performed on Cochrane’s RevMan tool, using random effects model. Heterogeneity was assessed through I² statistics. Results We included 841 patients from 12 studies, 10 observational and 2 RCTs. 406 (48.2%) patients underwent AVF ligation, and follow-up ranged from 3 to 62.5 months. Arteriovenous fistula ligation was associated with a decrease in left ventricular mass index (MD -10.88 g/m²; 95% CI -17.84, -3.93; p=0.007; I²=8%; Figure 1A), left ventricular end diastolic volume (MD -19.55 ml; 95% CI -20.52, -18.58; p=<0.00001; I²=0%; Figure 1B), and cardiac index (MD -0.56 1/min/m²; 95% CI -1.05, -0.07; p=0.03; I²=70%; Figure 1C). There was no significant difference in posterior wall thickness (MD -0.46 mm; 95% CI -1.32, 0.4; p=0.23; I2=57%), left ventricular ejection fraction (MD -0.12%; 95% CI -3.01, 2.77; p=0.92; I2=50%), and left ventricular end systolic volume (MD -6.28 ml; 95% CI -12.64, 0.07; p=0.05; I²=52%). Systolic blood pressure (MD -2.47 mmHg; 95% CI -9.57, 4.63; p=0.41 I²=62%; Figure 2A) and diastolic blood pressure (MD 1.54 mmHg; 95% CI -3.12, 6.19; p=0.44 I²=69%) were not significantly different between groups. Patients undergoing AVF ligation had a significant decrease in serum creatinine (MD -0.12 mg/dl; 95% CI -0.22, -0.03; p=0.02; I²=0%; Figure 2B), however, no difference was seen for eGFR (MD 2.78 ml/min/1.73 m²; 95% CI -3.25, 8.81; p=0.24; I²=2%; Figure 2C) between groups. Conclusion In chronic kidney disease patients, AVF ligation was associated with improved the patient’s overall echocardiographic parameters and reduced the risk of remodelling, with no significant blood pressure changes. Although creatinine seems to improve in this patient population, no differences were seen on eGFR. Further randomised studies are needed to better characterise the haemodynamic changes associated with AVF ligation.