A more accurate descriptive and clinically useful diagnosis based upon pathophysiology for what is commonly referred to as venous outflow stenosis is inflow-outflow imbalance. In these cases, the total outflow capacity of the AV access is inadequate to handle the inflow volume (Qa) without an increase in pressure. The relative inadequacy of the access outflow capacity in comparison to Qa results in increased outflow resistance and a proportional increase in intraluminal pressure. The clinical indicators associated with venous stenosis are the resulting manifestations of this imbalance. The point at which this occurs is dependent upon variations in these two parameters-Qa and outflow resistance. The variations in these two parameters are considerable and reciprocal. Excessive Qa results in or can lead to an entire list of serious problems that adversely affect patient morbidity and mortality. Most studies dealing with AV access Qa reduction have been for the treatment of an existing condition rather than its prevention; however, prevention of disease rather than waiting for its development is an important tenet of medical practice. The resulting clinical picture of inflow-outflow imbalance is taken as an indication for corrective treatment. In the past, in most cases this has meant angioplasty to open the outflow if it is reduced; however, this clinical picture may be associated with an excessive Qa and angioplasty in these cases creates the risk for a further increase in Qa. It is the authors' opinion that access flow measurements should be a part of the evaluation of these cases prior to planning treatment. Using this information, a bimodal approach to primary treatment should be adopted involving either angioplasty for cases with a low or normal Qa or flow reduction in cases with an elevated Qa.

• Keywords
• AV access flow reduction, Dialysis access, cardiac complications of AV access, excess AV access blood flow, interventional nephrology, techniques and procedures,
• MeSH
• Angioplasty * adverse effects   MeSH
• Arteriovenous Shunt, Surgical * adverse effects   MeSH
• Vascular Resistance MeSH
• Renal Dialysis * MeSH
• Hemodynamics * MeSH
• Humans MeSH
• Graft Occlusion, Vascular * physiopathology   therapy   etiology   diagnosis   MeSH
• Vascular Patency MeSH
• Regional Blood Flow MeSH
• Risk Factors MeSH
• Blood Flow Velocity MeSH
• Treatment Outcome MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Review MeSH

Chronic kidney disease is associated with increased cardiovascular morbidity and mortality. A well-functioning vascular access is associated with improved survival and among the available types of vascular access the arterio-venous (AV) fistula is the one associated with the best outcomes. However, AV access may affect heart function and, in some patients, could worsen the clinical status. This review article focuses on the specific cardiovascular hemodynamics of dialysis patients and how it is affected by the AV access; the effects of an excessive increase in AV access flow, leading to high-output heart failure; congestive heart failure in CKD patients and the contraindications to AV access; pulmonary hypertension. In severe heart failure, peritoneal dialysis (PD) might be the better choice for cardiac health, but if contraindicated suggestions for vascular access selection are provided based on the individual clinical presentation. Management of the AV access after kidney transplantation is also addressed, considering the cardiovascular benefit of AV access ligation compared to the advantage of having a functioning AVF as backup in case of allograft failure. In PD patients, who need to switch to hemodialysis, vascular access should be created timely. The influence of AV access in patients undergoing cardiac surgery for valvular or ischemic heart disease is also addressed. Cardiovascular implantable electronic devices are increasingly implanted in dialysis patients, but when doing so, the type and location of vascular access should be considered.

• Keywords
• Chronic kidney disease, arteriovenous fistula, heart failure, hemodialysis, peritoneal dialysis, pulmonary hypertension,
• MeSH
• Arteriovenous Fistula * MeSH
• Arteriovenous Shunt, Surgical * adverse effects   MeSH
• Renal Insufficiency, Chronic * diagnosis   therapy   MeSH
• Kidney Failure, Chronic * MeSH
• Renal Dialysis MeSH
• Humans MeSH
• Ligation MeSH
• Kidney Transplantation * MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Review MeSH

In patients with end-stage renal disease, excessive blood flow through an arteriovenous fistula (AVF) may lead to volume overload-induced cardiac remodeling and heart failure. It is unclear which patients with hyperfunctional AVF may benefit from AVF reduction or ligation. The indication for the procedure is often based on AVF flow. Because cardiac remodeling is driven by increased venous return, which is equivalent to cardiac output, we hypothesized that an elevated cardiac index (CI) might better identify subjects with reverse remodeling after AVF reduction. Thirty patients (age 52±12 years, 73% male) with AVF flow ⩾1.5 l min(-1) underwent comprehensive echocardiographic evaluations before and after AVF reduction. At baseline, 16 patients had a normal CI (2.5-3.8 l min(-1) m(-2)) and 14 had a high CI (4.0-6.0 l min(-1) m(-2)). A left ventricular end-diastolic diameter decrease after operation was predicted by elevated baseline CI (P<0.01), but not elevated AVF flow (P=0.07). There was a significant decrease in CI, left ventricular mass, left atrial and right ventricular diameter and pulmonary systolic pressure in the high CI group but not in the normal CI group. After AVF reduction, systemic vascular resistance decreased in the normal CI group, whereas it did not change in the high CI group. In conclusion, reduction of high-flow AVF leads to reverse cardiac remodeling but only in patients with elevated CI. The variability of the response of systemic vascular resistance to AVF flow may explain this observation. Increased CI but not increased AVF flow may better determine candidates for AVF reduction.

• MeSH
• Arteriovenous Fistula diagnostic imaging   physiopathology   MeSH
• Kidney Failure, Chronic diagnostic imaging   physiopathology   therapy   MeSH
• Renal Dialysis MeSH
• Adult MeSH
• Echocardiography MeSH
• Middle Aged MeSH
• Humans MeSH
• Ventricular Remodeling physiology   MeSH
• Aged MeSH
• Heart diagnostic imaging   physiopathology   MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH