Hemodialysis Vascular Access

Abstract

The incidence and prevalence of end stage renal disease (ESRD) continue to rise in the pediatric population. From a modality perspective, hemodialysis (HD) has been used in the majority of incident ESRD patients. The most impactful breakthrough in HD was the creation of the native arteriovenous fistula (AVF) by Brescia and Cimino in 1966. This radiocephalic AVF has become the signature surgical treatment to prepare a patient to receive optimal HD care. Years later, arteriovenous grafts (AVGs) were developed by surgically interposing a synthetic material between the arterial and venous systems. These gained favor for a few reasons: technically easier to place, ability to place in patients whose native vessels were undersized, and ability to cannulate for dialysis initiation sooner than with an AVF. Central venous catheters (CVC) are a mainstay in HD, but for the past 10–15 years, there has been a strong movement away from CVCs for long term HD in favor of AVF. While CVCs are now considered a poor choice for long term vascular access, they are often necessary in children with hemodialysis dependent ESRD who are awaiting maturation of a permanent vascular access. Uncuffed, temporary catheters, which are typically used for a week or less, are often needed in the setting of intoxications and severe acute kidney injury. The major problems with CVC (both tunneled, cuffed and temporary, uncuffed) include infection and thrombosis. The most common means by which a catheter may become infected are migration of cutaneous organisms along the portal of entry (on the external surface of the catheter) to the catheter tip (most common with short-term, uncuffed catheters, and direct contamination of the catheter or its hub by contact with hands or contaminated fluids or devices. The thrombotic and central venous stenosis risks of a HD catheter are lower when placed into the right IJ vein as opposed to the subclavian, and as such it is the site of first choice for a tunneled HD catheter. Novel insights into vascular access failure pathogenesis and treatment strategies are ongoing. Neointimal hyperplasia and its role in access failure are actively being studied; the goal being improved long term vascular access survival with reduced need for interventions to maintain patency. Similarly, improving safety of dialysis CVC’s for short term use and rarely long term use has focused on infection prevention strategies to reduce the likelihood of catheter exit site and catheter related bacteremia. In summary, pediatric vascular access is a cornerstone of hemodialysis provision in children with ESRD. While AVFs and AVGs are preferred, CVCs are still utilized in this setting. Ongoing studies continue to evolve to focus on optimizing outcomes in pediatric and adult vascular access in dialysis.