The cost and health burden of ESRD continues to increase globally. Total Medicare expenditure on dialysis has increased from 229 million USD in 1973 to 35.4 billion USD in 2016. Dialysis access can represent almost a ten...The cost and health burden of ESRD continues to increase globally. Total Medicare expenditure on dialysis has increased from 229 million USD in 1973 to 35.4 billion USD in 2016. Dialysis access can represent almost a tenth of these costs. Central venous catheters have been recognized as a significant factor driving costs and mortality in this population. Home dialysis, which includes peritoneal dialysis and home hemodialysis, is an effective way of reducing costs related to renal replacement therapy, reducing central venous catheter usage and in many cases improving the clinical and psychosocial aspects of patients' health. Addressing access-related issues for peritoneal dialysis, urgent-start peritoneal dialysis and home hemodialysis can have impact on the success of home dialysis. This article reviews issues related to dialysis access for home therapies.
Ultrasonography is increasingly being used in the practice of nephrology, whether it is for diagnosis or management of acute or chronic kidney dysfunction, until progression to end-stage kidney disease, including preoper...Ultrasonography is increasingly being used in the practice of nephrology, whether it is for diagnosis or management of acute or chronic kidney dysfunction, until progression to end-stage kidney disease, including preoperative assessment, access placement, and diagnosis and management of dysfunctional hemodialysis access. Point-of-care ultrasounds are also being used by nephrologists to help manage volume status, especially in patients admitted to the intensive care units, and more recently, for guiding fluid removal in the outpatient dialysis units. Fundamental knowledge of sonography has become invaluable to the nephrologist, and performance and interpretation of ultrasound has now become an essential tool for practicing nephrologists to provide patient-centered care, maximize efficiency, and minimize fragmentation of care. This review will address the growing role of ultrasonography in the management of a patient with CKD from the point of initial contact with the nephrologist throughout the spectrum of kidney disease and its consequences.
Thoracic central venous occlusion in hemodialysis patients can cause significant disability from arm and facial swelling and can lead to worsening function of dialysis access. Current techniques for managing thoracic cen...Thoracic central venous occlusion in hemodialysis patients can cause significant disability from arm and facial swelling and can lead to worsening function of dialysis access. Current techniques for managing thoracic central venous occlusion and some of the newer techniques for achieving dialysis access when all central veins are occluded. Techniques for dealing with acute superior vena cava thrombosis will also be covered as will the complications of central venous recanalization techniques.
Tunneled dialysis catheters remain the most common vascular access used to initiate hemodialysis. Unfortunately, their use is associated with higher morbidity and mortality when compared with arteriovenous fistulae or gr...Tunneled dialysis catheters remain the most common vascular access used to initiate hemodialysis. Unfortunately, their use is associated with higher morbidity and mortality when compared with arteriovenous fistulae or grafts. Different types of catheters with different designs and material properties function differently. Additional devices and medications can be used to decrease the rates of infection and thrombosis. The current available tunneled dialysis catheters remain far from the desired goal and innovation in the field of dialysis vascular access remains in dire need.
Endovascular salvage plays an important role in dialysis access care. Angioplasty using standard high- and ultrahigh-pressure balloon is the mainstay of therapy, while the use of cutting balloons and balloons designed to...Endovascular salvage plays an important role in dialysis access care. Angioplasty using standard high- and ultrahigh-pressure balloon is the mainstay of therapy, while the use of cutting balloons and balloons designed to deliver pharmacologically active agents to the site of recurrent stenosis is demonstrating improved performance for specific targets that have to be further defined. Stents and stent grafts are additional tools for use at access segments predisposed for inward remodeling such as the cephalic arch or basilic swing point. The juxta-anastomotic segment has particular relevance in maturation of autogenous accesses as well as maintenance of access flow volume. Depending on the location of the access in the forearm or upper arm, and which artery is feeding into the access vein, any type of balloon angioplasty and stent or stent graft placement may be used to establish and maintain patency. Successful management of dialysis access options relies on preservation of venous real estate during the chronic kidney disease phase of kidney disease as well as on knowledgeable evaluation of arm veins and the access by physical examination, bed side ultrasound, and angiographic studies.
Obtaining an arteriovenous (AV) access for initiation of hemodialysis is considered the gold standard as it reduces risks of infections, hospitalizations, and need for interventions. It is well documented that creation o...Obtaining an arteriovenous (AV) access for initiation of hemodialysis is considered the gold standard as it reduces risks of infections, hospitalizations, and need for interventions. It is well documented that creation of AV access can cause or aggravate heart failure. Once AV access is created, blood volume, cardiac contractility, and left ventricular end-diastolic volume increase in a nonphysiologic fashion resulting in an overall increase in cardiac output. Left ventricular hypertrophy, diastolic dysfunction, pulmonary hypertension, and high-output cardiac failure can occur. AV accesses that have blood flows greater than 1.5 L per minute are of high risk. When access flow exceeds 25% to 30% of cardiac output, the risk of developing high-output heart failure increases. Studies suggest that a blood flow (Qa)/cardiac output (CO) ratio of greater than 0.30 should be used as a screening tool to perform further cardiac testing. Depending on the severity of symptoms, management can range from banding procedure (flow reduction) or need for total abandonment of the AV access. The complications associated with high-flow AV accesses are often overlooked. Nephrologists and vascular access experts should work in tandem to mitigate potential harm to patients on dialysis who are afflicted by this condition.
Hand ischemia is a relatively common complication of hemodialysis arteriovenous (AV) access. Clinical manifestations frequently start with pale and cold ipsilateral hand. Symptoms can progress to pain during dialysis and...Hand ischemia is a relatively common complication of hemodialysis arteriovenous (AV) access. Clinical manifestations frequently start with pale and cold ipsilateral hand. Symptoms can progress to pain during dialysis and can eventually lead to tissue necrosis and gangrene if not addressed in a timely fashion. Comprehensive physical examination of the hand, AV access, and comparing it with the contralateral hand will assist in differentiating hand ischemia from carpal tunnel syndrome, osteoarthritis of the hand, and others. There are several treatment options for hand ischemia based on the severity of symptoms. Conservative management with careful monitoring can be applied in early stages. However, if symptoms persist or worsen, a full arteriogram of the ipsilateral extremity should be performed to evaluate for the presence of arterial stenosis. Angioplasty of the arterial stenosis, if present, will frequently lead to the resolution of symptoms. There are several percutaneous and surgical treatment options for hand ischemia, if no arterial stenosis was found or angioplasty does not relieve symptoms. We discuss in this article these treatment options in detail. Treatment goal is to improve hand ischemia symptoms while maintaining hemodialysis AV access and preserving patient's hand. Access ligation remains a treatment of last resort.
Needle cannulation of hemodialysis access is the soft underbelly of hemodialysis access care that has remained unchanged for a long time. Cannulation error results in complications such as infiltration, hematoma, subsequ...Needle cannulation of hemodialysis access is the soft underbelly of hemodialysis access care that has remained unchanged for a long time. Cannulation error results in complications such as infiltration, hematoma, subsequent revision procedures, and potential loss of hard-earned access. The "best" cannulation method is contingent upon access type and characteristics along with local expertise. The rope ladder technique of cannulation, characterized by successive rotation of puncture sites with each hemodialysis session, permits sufficient time for healing of prior cannulation sites, and reduction in complications such as bleeding, infection, and aneurysm development. A steeper needle angle, higher blood flow rates, and deep needle tip can lead to wall stress on the posterior wall and up to 10 cm from the needle cannulation site. Plastic cannulas provide a viable alternative to metallic needles; they have lower complications and a favorable cost-benefit ratio. There is lack of evidence to support an optimal arterial needle direction configuration. Needle injury may promote intimal thickening, but its effect on access outcomes is currently unknown. Percutaneous creation of arteriovenous fistula presents new challenges in dialysis access cannulation. Point-of-care ultrasound-guided cannulation will likely lead to a paradigm shift in access cannulation. Novel care delivery using cannulation stations is a promising development.
Recent advances in technology show promise in providing greater vascular access options for hemodialysis patients. This review discusses novel methods for creating an anastomosis for arteriovenous (AV) fistulas and new m...Recent advances in technology show promise in providing greater vascular access options for hemodialysis patients. This review discusses novel methods for creating an anastomosis for arteriovenous (AV) fistulas and new materials for prosthetic AV grafts. Two technologies for endovascular arteriovenous fistula creation, the Ellipsys and WavelinQ endovascular systems, are discussed. When an AV fistula is not possible, an AV graft or devices to augment the AV fistula may be appropriate. New materials that have been developed that show promise as an alternative to the expanded polytetrafluoroethylene graft are discussed. Such potential conduits include bioengineered vessels and both allogenic or xenogenic biologic grafts. Devices designed to optimize blood flow to reduce maturation failure and improve AV fistula outcomes are explored.
Adv Chronic Kidney Dis
· 2020 May · PMID 32891301
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The vascular access is the lifeline for the hemodialysis patient. Previous national vascular access guidelines have emphasized placement of arteriovenous fistulas in most hemodialysis patients. However, the new Kidney Di...The vascular access is the lifeline for the hemodialysis patient. Previous national vascular access guidelines have emphasized placement of arteriovenous fistulas in most hemodialysis patients. However, the new Kidney Disease Outcomes Quality Initiative guidelines for vascular access, soon to be published, will focus on a patient's end-stage kidney disease "life plan" and take a patient "first" approach. One of the major themes of the new Kidney Disease Outcomes Quality Initiative guidelines is selecting the "right access, for the right patient, at the right time, for the right reason". Given the availability of new advances in biomedical technologies, techniques, and devices in the vascular access field, this shift to a more patient-centered vascular access approach presents unique opportunities to individualize the solutions and care for patients requiring a dialysis vascular access. This review article will address 3 potential areas where there is an unmet need to individualize solutions for dialysis vascular access care: (1) biological approaches to improve vascular access selection and selection of therapies, (2) vascular access care for the post-transplant patient, and (3) vascular access disparities in race, gender, and the elderly patient.
Chronic kidney disease (CKD) is a major noncommunicable disorder and has become the 9th leading cause of death in the United States. Most patients with CKD in the United States choose hemodialysis as their treatment of c...Chronic kidney disease (CKD) is a major noncommunicable disorder and has become the 9th leading cause of death in the United States. Most patients with CKD in the United States choose hemodialysis as their treatment of choice. A functioning arteriovenous access is essential to reduce dependence on central venous catheters. An arteriovenous fistula (AVF), though the preferred access, has a major limitation with a high primary maturation failure rate. A functioning AVF requires well-preserved vessels, both arteries and veins, along with an acceptable cardiac pump function. Vessel preservation is crucial from a surgeon's perspective to create an AVF but is also relevant for maturation. More recently, concerns regarding the sequelae of transradial approach for percutaneous cardiac interventions have been raised. Educating and empowering the patient is the first step, but equally important is to educate all caregivers involved in providing care to a patient with advanced CKD. The current review evaluates the strategies used to preserve peripheral veins, central veins, and peripheral arteries.
The new Kidney Disease Outcomes Quality Initiative Vascular Access Guidelines now focus on a more comprehensive overall patient strategy. The patient's vascular access needs are part of a dialysis access strategy, which...The new Kidney Disease Outcomes Quality Initiative Vascular Access Guidelines now focus on a more comprehensive overall patient strategy. The patient's vascular access needs are part of a dialysis access strategy, which itself is part of an End Stage Kidney Disease Life-Plan strategy that stems from a unique patient's individualized needs. The End Stage Kidney Disease Life-Plan is an individualized and comprehensive map for dialysis modalities and dialysis access for the lifetime of the patient. New targets are introduced that align with this patient-centered approach. The Guidelines made significant changes to the use of surveillance techniques to detect stenosis and found insufficient evidence to make a recommendation for routine arteriovenous fistula surveillance by measuring access blood flow, pressure monitoring, or imaging for stenosis that was in addition to routine clinical monitoring. Routine surveillance is not recommended in arteriovenous grafts. Similarly, pre-emptive angioplasty of arteriovenous fistulas or arteriovenous grafts with stenosis, not associated with clinical indicators, is not recommended. The Guidelines represent a rigorous review of the evidence; however, the available evidence to guide vascular access practice remains limited. There is a significant need and opportunity for new and ongoing high-quality research to inform best practice.
The complement system is an evolutionarily ancient arm of the innate immune system. It remains, however, one of the last major pathways in immunology for which specific pharmaceutical antagonists have been developed. In...The complement system is an evolutionarily ancient arm of the innate immune system. It remains, however, one of the last major pathways in immunology for which specific pharmaceutical antagonists have been developed. In recent years, a fundamental role for complement has been described in many different renal diseases, including both pauci-immune as well as immune-complex diseases. Since the 2011 FDA approval of eculizumab, the only marketed complement antagonist, no new therapeutics have entered clinical practice. There are now multiple new agents in clinical trials, from oral molecules to small inhibitory RNA, that target the classical, lectin, and alternative pathways. Herein we summarize several potential renal diseases in which complement inhibitors may provide a therapeutic benefit, as well as specific complement inhibitors in development.
Adv Chronic Kidney Dis
· 2020 Mar · PMID 32553250
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The complement cascade was first recognized as a downstream effector system of antibody-mediated cytotoxicity. Consistent with this view, it was discovered in the 1960s that complement is activated in the glomeruli of pa...The complement cascade was first recognized as a downstream effector system of antibody-mediated cytotoxicity. Consistent with this view, it was discovered in the 1960s that complement is activated in the glomeruli of patients with immune complex glomerulonephritis. More recently, research has shown that complement system has many additional functions relating to regulation of the immune response, homeostasis, and metabolism. It has also become clear that the complement system is important to the pathogenesis of many non-immune complex mediated kidney diseases. In fact, in atypical hemolytic uremic syndrome and C3 glomerulopathy, uncontrolled complement activation is the primary driver of disease. Complement activation generates multiple pro-inflammatory fragments, and if not properly controlled it can cause fulminant tissue injury. Furthermore, the mechanisms of complement activation and complement-mediated injury vary from disease to disease. Many new drugs that target the complement cascade are in clinical development, so it is important to fully understand the biology of the complement system and its role in disease.
Complement-mediated disorders in pregnancy span a large spectrum and have been implicated in all three complement pathways: classical, lectin, and alternative. Our understanding of these disorders in recent years has adv...Complement-mediated disorders in pregnancy span a large spectrum and have been implicated in all three complement pathways: classical, lectin, and alternative. Our understanding of these disorders in recent years has advanced due to a better understanding of complement regulatory proteins, such as complement factor H, complement factor I, membrane cofactor protein, and thrombomodulin that particularly affect the alternative complement pathway. Enthusiasm in genotyping for mutations that encode these proteins has allowed us to study the presence of genetic variants which may predispose women to develop conditions such as pregnancy-associated hemolytic uremic syndrome (P-aHUS), thrombotic thrombocytopenic purpura, preeclampsia/hemolysis, elevated liver enzymes, low platelets (HELLP), systemic lupus erythematosus/antiphospholipid syndrome, and peripartum cardiomyopathy. The advent of the anti-C5-antibody eculizumab to quench the complement cascade has already proven in small case series to improve maternal kidney outcomes in complement-mediated obstetric catastrophes such as P-aHUS and HELLP. In this review, we will detail the pathogenesis behind these complement-mediated pregnancy disorders, the role of complement variants in disease phenotype, and the most up-to-date experience with eculizumab in this population.
Thrombotic microangiopathy is characterized by the presence of thrombocytopenia and microangiopathic hemolytic anemia and can occur in up to 50% of patients with hypertensive emergency and 10-15% with scleroderma. This r...Thrombotic microangiopathy is characterized by the presence of thrombocytopenia and microangiopathic hemolytic anemia and can occur in up to 50% of patients with hypertensive emergency and 10-15% with scleroderma. This review discusses the emerging role of complement in these 2 clinical entities. Specifically, we evaluate the evidence linking complement dysregulation with the manifestation of thrombotic microangiopathy and its clinical course in these settings. We also explore the rationale for complement blockade in these complex clinical scenarios that often have poor outcomes.
Antibody-mediated rejection (AMR) is one of the leading causes of kidney allograft failure and is usually mediated by anti-human leukocyte antigen donor-specific antibodies (DSAs). Activation of classical pathway of the...Antibody-mediated rejection (AMR) is one of the leading causes of kidney allograft failure and is usually mediated by anti-human leukocyte antigen donor-specific antibodies (DSAs). Activation of classical pathway of the complement system is responsible for downstream effects of DSA and account for significant manifestations of AMR. Currently, the treatment of AMR is based on strategies to remove preformed antibodies or to prevent their production; however, these strategies are often unsuccessful. It is theoretically possible to inhibit complement activity to prevent the effect of DSA on kidney allograft function. Complement inhibitors such as eculizumab, a complement 5 monoclonal antibody, and complement 1 esterase inhibitors (C1 INHs) have been used in prevention and treatment of AMR with variable success. Eculizumab and C1 INH seem to reduce the incidence of early AMR and allow transplantation in highly sensitized kidney transplant recipients, but data on their long-term effect on kidney allograft function are limited. Several case reports described the successful use of eculizumab in the treatment of AMR, but there are no randomized controlled studies that showed efficacy. Treatment of AMR with C1 INH, in addition to standard of care, did not change short-term outcome but long-term studies are underway.