Patricia Briones

Fibroblast Growth Factor 23 in Patients Undergoing Peritoneal Dialysis

BACKGROUND AND OBJECTIVES Fibroblast growth factor 23 (FGF23) is an independent risk factor for mortality in patients with ESRD. Before FGF23 testing can be integrated into clinical practice of ESRD, further understanding of its determinants is needed. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS In a study of 67 adults undergoing peritoneal dialysis, we tested the hypothesis that longer dialysis vintage and lower residual renal function and renal phosphate clearance are associated with higher FGF23. We also compared the monthly variability of FGF23 versus parathyroid hormone (PTH) and serum phosphate. RESULTS In unadjusted analyses, FGF23 correlated with serum phosphate (r = 0.66, P < 0.001), residual renal function (r = -0.37, P = 0.002), dialysis vintage (r = 0.31, P = 0.01), and renal phosphate clearance (r = -0.38, P = 0.008). In adjusted analyses, absence of residual renal function and greater dialysis vintage associated with higher FGF23, independent of demographics, laboratory values, peritoneal dialysis modality and adequacy, and treatment with vitamin D analogs and phosphate binders. Urinary and dialysate FGF23 clearances were minimal. In three serial monthly measurements, within-subject variability accounted for only 10% of total FGF23 variability compared with 50% for PTH and 60% for serum phosphate. CONCLUSIONS Increased serum phosphate, loss of residual renal function, longer dialysis vintage, and lower renal phosphate clearance are associated with elevated FGF23 levels in ESRD patients undergoing peritoneal dialysis. FGF23 may be a more stable marker of phosphate metabolism in ESRD than PTH or serum phosphate.

Creation of secondary arteriovenous fistulas: maximizing fistulas in prevalent hemodialysis patients.

National Kidney Foundation Dialysis Outcomes Quality Initiative (NKF‐DOQI) guideline 29 suggests that a patient should be evaluated for a secondary arteriovenous fistula (AVF) following each episode of dialysis access failure. Regretfully, it does not appear that this approach is used, even though recent data have emphasized that veins suitable for the creation of a secondary AVF can be identified in dialysis patients who are receiving dialysis via a synthetic arteriovenous graft (AVG) or other type of potentially dysfunctional vascular access. In this study nine patients (five with an AVG and four with an AVF) with vascular access dysfunction undergoing percutaneous interventions were evaluated for secondary AVF creation. All were found to have suitable vascular anatomy and had the AVF created. The secondary fistula was successful in all nine patients with a mean follow‐up of 4.8 ± 1.4 months in post‐AVG cases and 5.6 ± 1.7 months in the post‐AVF patients. In addition, it was possible to continue uninterrupted dialysis without the use of a tunneled dialysis catheter in three of the patients with AVGs. This experience demonstrates the validity and success of this approach to the management of dialysis access dysfunction. In the ongoing effort to optimize vascular health status, we suggest that during percutaneous interventions, patients should routinely have identification of vessels suitable for creation of a secondary AVF.

Hemodialysis vascular access: percutaneous interventions by nephrologists.

Traditionally hemodialysis vascular access‐related procedures have been almost exclusively performed by surgeons and interventional radiologists. In recent years, nephrologists have taken the initiative of performing these procedures themselves. Because of their unique clinical perspective on dialysis access and better understanding of the intricacies of renal replacement therapy, nephrologists are ideally suited for this activity. This approach has minimized delays, decreased hospitalizations, and decreased the use of temporary catheters, thereby improving medical care, decreasing costs, and increasing patient convenience. Vascular access‐related procedures commonly performed by nephrologists include percutaneous balloon angioplasty, thrombectomy, and tunneled hemodialysis catheter‐related procedures. In addition, using vein obliteration and percutaneous balloon angioplasty techniques, nephrologists have recently documented successful salvage of arteriovenous fistulas that had failed to mature, whereas traditionally these fistulas have frequently been abandoned. While the performance of these procedures by nephrologists offers many advantages, appropriate training in order to develop the necessary procedural skills is critical. Recent data have emphasized that a nephrologist can be successfully trained to become a competent interventionalist. In addition to documenting excellent outcome data, multiple reports have demonstrated the safety and success of interventional nephrology. This review focuses on hemodialysis access‐related procedures performed by nephrologists and calls for a proactive approach in optimizing this aspect of patient care.

ASDIN Original Investigations: Creation of Secondary Arteriovenous Fistulas: Maximizing Fistulas in Prevalent Hemodialysis Patients

National Kidney Foundation Dialysis Outcomes Quality Initiative (NKF‐DOQI) guideline 29 suggests that a patient should be evaluated for a secondary arteriovenous fistula (AVF) following each episode of dialysis access failure. Regretfully, it does not appear that this approach is used, even though recent data have emphasized that veins suitable for the creation of a secondary AVF can be identified in dialysis patients who are receiving dialysis via a synthetic arteriovenous graft (AVG) or other type of potentially dysfunctional vascular access. In this study nine patients (five with an AVG and four with an AVF) with vascular access dysfunction undergoing percutaneous interventions were evaluated for secondary AVF creation. All were found to have suitable vascular anatomy and had the AVF created. The secondary fistula was successful in all nine patients with a mean follow‐up of 4.8 ± 1.4 months in post‐AVG cases and 5.6 ± 1.7 months in the post‐AVF patients. In addition, it was possible to continue uninterrupted dialysis without the use of a tunneled dialysis catheter in three of the patients with AVGs. This experience demonstrates the validity and success of this approach to the management of dialysis access dysfunction. In the ongoing effort to optimize vascular health status, we suggest that during percutaneous interventions, patients should routinely have identification of vessels suitable for creation of a secondary AVF.

American Society of Diagnostic and Interventional Nephrology Section Editor: Stephen Ash: Hemodialysis Vascular Access: Percutaneous Interventions by Nephrologists

Traditionally hemodialysis vascular access‐related procedures have been almost exclusively performed by surgeons and interventional radiologists. In recent years, nephrologists have taken the initiative of performing these procedures themselves. Because of their unique clinical perspective on dialysis access and better understanding of the intricacies of renal replacement therapy, nephrologists are ideally suited for this activity. This approach has minimized delays, decreased hospitalizations, and decreased the use of temporary catheters, thereby improving medical care, decreasing costs, and increasing patient convenience. Vascular access‐related procedures commonly performed by nephrologists include percutaneous balloon angioplasty, thrombectomy, and tunneled hemodialysis catheter‐related procedures. In addition, using vein obliteration and percutaneous balloon angioplasty techniques, nephrologists have recently documented successful salvage of arteriovenous fistulas that had failed to mature, whereas traditionally these fistulas have frequently been abandoned. While the performance of these procedures by nephrologists offers many advantages, appropriate training in order to develop the necessary procedural skills is critical. Recent data have emphasized that a nephrologist can be successfully trained to become a competent interventionalist. In addition to documenting excellent outcome data, multiple reports have demonstrated the safety and success of interventional nephrology. This review focuses on hemodialysis access‐related procedures performed by nephrologists and calls for a proactive approach in optimizing this aspect of patient care.

The Impact of Arteriovenous Fistulae on the Myocardium: The Impact of Creation and Ligation in the Transplant Era

Cardiac hypertrophy is a relatively common complication seen in patients with advanced chronic kidney disease (CKD) and end‐stage renal disease (ESRD). Moreover, cardiac hypertrophy is even more frequently seen in patients with ESRD who have an arteriovenous (AV) access. There has been substantial evidence pertaining to the effects of AV access creation on the heart structure and function. Similarly, there is increasing evidence on the effects of AV access closure, flow reduction, transplantation, and immunosuppressive medication on both endpoints. In this review, we present the evidence available in the literature on these topics and open the dialog for further research in this interesting field.

ASDIN Original Investigations: Creation of Secondary Arteriovenous Fistulas: Maximizing Fistulas in Prevalent Hemodialysis Patients: SECONDARY ARTERIOVENOUS FISTULAS

National Kidney Foundation Dialysis Outcomes Quality Initiative (NKF‐DOQI) guideline 29 suggests that a patient should be evaluated for a secondary arteriovenous fistula (AVF) following each episode of dialysis access failure. Regretfully, it does not appear that this approach is used, even though recent data have emphasized that veins suitable for the creation of a secondary AVF can be identified in dialysis patients who are receiving dialysis via a synthetic arteriovenous graft (AVG) or other type of potentially dysfunctional vascular access. In this study nine patients (five with an AVG and four with an AVF) with vascular access dysfunction undergoing percutaneous interventions were evaluated for secondary AVF creation. All were found to have suitable vascular anatomy and had the AVF created. The secondary fistula was successful in all nine patients with a mean follow‐up of 4.8 ± 1.4 months in post‐AVG cases and 5.6 ± 1.7 months in the post‐AVF patients. In addition, it was possible to continue uninterrupted dialysis without the use of a tunneled dialysis catheter in three of the patients with AVGs. This experience demonstrates the validity and success of this approach to the management of dialysis access dysfunction. In the ongoing effort to optimize vascular health status, we suggest that during percutaneous interventions, patients should routinely have identification of vessels suitable for creation of a secondary AVF.

American Society of Diagnostic and Interventional Nephrology Section Editor: Stephen Ash: Hemodialysis Vascular Access: Percutaneous Interventions by Nephrologists: NEPHROLOGISTS AND HEMODIALYSIS VASCULAR ACCESS

Traditionally hemodialysis vascular access‐related procedures have been almost exclusively performed by surgeons and interventional radiologists. In recent years, nephrologists have taken the initiative of performing these procedures themselves. Because of their unique clinical perspective on dialysis access and better understanding of the intricacies of renal replacement therapy, nephrologists are ideally suited for this activity. This approach has minimized delays, decreased hospitalizations, and decreased the use of temporary catheters, thereby improving medical care, decreasing costs, and increasing patient convenience. Vascular access‐related procedures commonly performed by nephrologists include percutaneous balloon angioplasty, thrombectomy, and tunneled hemodialysis catheter‐related procedures. In addition, using vein obliteration and percutaneous balloon angioplasty techniques, nephrologists have recently documented successful salvage of arteriovenous fistulas that had failed to mature, whereas traditionally these fistulas have frequently been abandoned. While the performance of these procedures by nephrologists offers many advantages, appropriate training in order to develop the necessary procedural skills is critical. Recent data have emphasized that a nephrologist can be successfully trained to become a competent interventionalist. In addition to documenting excellent outcome data, multiple reports have demonstrated the safety and success of interventional nephrology. This review focuses on hemodialysis access‐related procedures performed by nephrologists and calls for a proactive approach in optimizing this aspect of patient care.