Effect of proximal artery restriction on flow reduction and cardiac function in hemodialysis patients with high-flow arteriovenous fistulas

Right ventricular-pulmonary arterial coupling and pulmonary hypertension in hemodialysis: insights into structural cardiac changes and clinical implications

OBJECTIVES

This cross-sectional analysis from the CZecking Heart Failure in patients with advanced Chronic Kidney Disease trial (ISRCTN18275480) examined pulmonary hypertension and right ventricular-pulmonary arterial coupling in patients on chronic hemodialysis. The aims of this analysis were: 1. To analyze relations between pulmonary hypertension and right ventricular-pulmonary arterial coupling with dialysis access flow and current hydration; 2. To analyze structural heart changes associated with right ventricular-pulmonary arterial uncoupling; 3. To reveal the prevalence, etiology and severity of pulmonary hypertension in the Czech hemodialysis population.

METHODS

We performed expert echocardiography, vascular access flow measurements, bioimpedance analysis, and laboratory testing in 336 hemodialysis patients.

RESULTS

Pulmonary hypertension was present in 34% (114/336) patients and right ventricular-pulmonary arterial uncoupling was present in 25% of patients with pulmonary hypertension. Only weak associations between the flow of the dialysis arteriovenous access and estimated pulmonary arterial systolic pressure and right ventricular-pulmonary arterial coupling was proved. There was a strong association between hydration status assessed by estimated central venous pressure with pulmonary arterial systolic pressure (Rho 0.6, p < 0.0001) and right ventricular-pulmonary arterial coupling (Rho -0.52, p < 0.0001) and association between overhydration to extracellular water ratio with pulmonary arterial systolic pressure (Rho 0.31, p = 0.0001) and right ventricular-pulmonary arterial coupling (Rho -0.29, p = 0.002). The prevalence of heart failure was significantly higher in patients with right ventricular-pulmonary arterial uncoupling (88% vs. 52%, p = 0.0003).

CONCLUSION

These findings suggest that optimizing volume status and treating heart failure should be prioritized in hemodialysis patients to prevent pulmonary hypertension progression and right ventricular-pulmonary arterial uncoupling.

Effect of flow reduction surgery in a patient with high flow arteriovenous fistula with aortic dissection using 4D flow magnetic resonance imaging: A case report

This study aimed to investigate cardiovascular function in a patient with high-flow arteriovenous fistula (AVF) who underwent aortic dissection (AD) using four-dimensional (4D) flow magnetic resonance imaging (MRI) as well as analyze the effect of flow reduction surgery on AD. On March 12, 2017, a 60-year-old woman underwent emergency surgery for AD. After that, she experienced acute kidney injury, and hemodialysis was initiated. On April 24, 2017, a left brachiocephalic arteriovenous fistula (AVF) was created to facilitate her dialysis. However, after 5 years, the patient presented with a high-flow AVF, and a flow reduction surgery was performed on March 11, 2022. To evaluate the procedure's effectiveness, we measured the changes in left ventricular (LV) function and blood flow in the aorta and vascular access before and after surgery using 4D flow MRI. Notable changes were observed in LV function, blood flow in the aorta before and after the surgery, and maximum velocity and flow volume after surgery. During the 6-month follow-up after the surgery, the maximum velocity and flow volume in the aorta and vascular access were reduced; also, indicators such as LV volume, cardiac output, cardiac index, and LV mass were improved. In patients with high-flow AVF, flow reduction surgery should be considered as it may improve LV function and reduce the risk of AD recurrence by lowering the flow volume of the aorta.

Surgical Management, Prevention and Outcomes for Aneurysms of Arteriovenous Dialysis Fistulas: A Case Series Study and Review

The escalating population of individuals afflicted with end-stage renal disease necessitates the provision of secure and efficacious vascular access for hemodialysis, with arteriovenous fistulas representing a preferred option. Nonetheless, the creation of dialysis fistulas may entail complications, including the occurrence of fistula aneurysms that may require surgical intervention. This study included eight patients with large aneurysms of dialysis fistulas and aimed to evaluate the safety and effectiveness of classic, endovascular, or hybrid methods for fistula reconstruction or ligation, depending on the indications. Vascular interventions were performed on patients on chronic hemodialysis and on those in whom hemodialysis was discontinued due to the proper functioning of the transplanted kidney. Performed procedures were considered safe and effective. The reconstructed fistulas provided the patients with patent vascular access, allowing for continued hemodialysis. No re-aneurysmal dilatation of the reconstructed or ligated fistulas was observed. Regular monitoring of dialysis fistulas is crucial to detect complications in time. Guidelines should be established to specify the dimensions at which fistula aneurysm should be excised and whether to remove asymptomatic aneurysms at all. For patients who have undergone kidney transplantation, outlines should indicate when the fistula should be preserved and when it should be ligated.