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

Arteriovenous fistula (AVF) is the best method of vascular access for hemodialysis. This approach can lead to several complications, such as hyperkinetic heart failure due to a hyperfunctional AVF or dilatation of the feeding artery. These are late complications, especially in patients after a successful kidney transplantation. An observational study was performed focusing on patients more than 12 months after kidney transplantation. The AVF was evaluated by ultrasound and, if the outflow exceeded 1.5 L/min, an echocardiogram was performed. Surgical management was indicated if the cardiac index was higher than 3.9 L/min/m2 or upon finding a brachial artery aneurysm. A total of 208 post- kidney transplantation patients were examined over a 3-year period, of which 46 subjects (22.11%) had hyperfunctional AVF and 34 cases (16.34%) of feeding artery dilatation were determined. In total, 40 AVF flow reduction and 6 AVF ligation procedures were performed. The median AVF flow before and after the reduction was 2955 mL/min and 1060 mL/min, respectively. Primary patency after flow reduction was 88.3% at 12 months. Late AVF complications in patients following kidney transplantation are quite common. It is necessary to create a screening program to monitor AVFs in these patients.

• Keywords
• AVF flow reduction, AVF ligation, hyperfunctional AVF, kideny transplantation, screening,
• MeSH
• Brachial Artery surgery   MeSH
• Arteriovenous Shunt, Surgical * adverse effects   MeSH
• Renal Dialysis * MeSH
• Adult MeSH
• Echocardiography MeSH
• Middle Aged MeSH
• Humans MeSH
• Follow-Up Studies MeSH
• Postoperative Complications etiology   MeSH
• Vascular Patency MeSH
• Aged MeSH
• Kidney Transplantation * adverse effects   MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Observational Study MeSH