Global variability of vascular and peritoneal access for chronic dialysis.

AIM: Vascular and peritoneal access are essential elements for sustainability of chronic dialysis programs. Data on availability, patterns of use, funding models, and workforce for vascular and peritoneal accesses for dialysis at a global scale is limited. METHODS: An electronic survey of national leaders of nephrology societies, consumer representative organizations, and policymakers was conducted from July to September 2018. Questions focused on types of accesses used to initiate dialysis, funding for services, and availability of providers for access creation. RESULTS: Data from 167 countries were available. In 31 countries (25% of surveyed countries), >75% of patients initiated haemodialysis (HD) with a temporary catheter. Seven countries (5% of surveyed countries) had >75% of patients initiating HD with arteriovenous fistulas or grafts. Seven countries (5% of surveyed countries) had >75% of their patients starting HD with tunnelled dialysis catheters. 57% of low-income countries (LICs) had >75% of their patients initiating HD with a temporary catheter compared to 5% of high-income countries (HICs). Shortages of surgeons to create vascular access were reported in 91% of LIC compared to 46% in HIC. Approximately 95% of participating countries in the LIC category reported shortages of surgeons for peritoneal dialysis (PD) access compared to 26% in HIC. Public funding was available for central venous catheters, fistula/graft creation, and PD catheter surgery in 57%, 54% and 54% of countries, respectively. CONCLUSION: There is a substantial variation in the availability, funding, workforce, and utilization of vascular and peritoneal access for dialysis across countries regions, with major gaps in low-income countries.

Variation in performing kidney biopsy amongst nephrologists in the Asia-Pacific region: A multinational survey.

AIM: Kidney biopsy (KB) is the gold standard procedure for diagnosing kidney diseases. Globally, nephrologists are trained to perform KB. However, the past few decades have witnessed a transition where interventional radiologists (IRs) are now preferentially performing the procedure. Our survey-based cross-sectional study aimed to investigate the current trends of KB operators in the Asia-Pacific region (APR) in practicing interventional nephrologists. MATERIAL AND METHODS: The Association of Vascular Access and intervenTionAl Renal Physicians (AVATAR) Foundation from India conducted a multinational online survey among interventional nephrologists from the APR to investigate who does KB, if the nephrology training curriculum includes KB, and whether nephrologists have access to ultrasound. RESULTS: Out of 21 countries from the APR that participated in our survey, 10 countries (47.4%) reported that more than 70% of their nephrologists performed KB, whereas in 11 countries (57.6%), KB was most likely done by an IR. The frequency of nephrologists performing KB ranged from 0% in Afghanistan to 100% in countries such as Pakistan, Singapore, and Thailand. Formal training for KB and access to ultrasound was available to nephrologists in 80% of the responding countries. CONCLUSION: Our study shows that despite the availability of training and access to USG, a significant number of nephrologists are not performing KB in the APR. Similar to the trends observed in Western countries, the observed pattern in the APR could be due to lack of time, less incentive, hospital policy, or interest of nephrologists in other aspects of intervention nephrology.

Global hemodialysis vascular access care: Three decades of evolution.

The development of vascular access for hemodialysis has come a long way since 1943 when the first hemodialysis treatment was performed in humans by connecting an artery and vein using an external glass canula. Since then, vascular access care has evolved robustly through contributions from numerous countries and professional nephrology societies, worldwide. To understand the global distribution and contribution of different specialties to medical literature on dialysis vascular access care, we performed a literature search from 1991 to 2021 and identified 2768 articles from 74 countries. The majority of publications originated from the United States (41.5%), followed by China (5.1%) and the United Kingdom (4.6%). Our search results comprise of observational studies (43%), case reports/series (27%), review articles (16.5%) and clinical trials (12%). A large proportion of articles were published in Nephrology journals (49%), followed by General Medicine (14%), Surgery (10%), Vascular Medicine (8%), and Interventional Radiology journals (4%). With the introduction of interventional nephrology, nephrologists will be able to assume the majority of the responsibility for dialysis vascular access care and above all maintain a close interdisciplinary collaboration with other specialties to provide optimum patient care. In this review article, we discuss the history, evolving knowledge, challenges, educational opportunities, and future directions of dialysis vascular access care, worldwide.

Evaluation of hemodialysis vascular access involving multidisciplinary integration: Perspective from Latin America and Peru.

The perspective of vascular access care in patients with end-stage renal disease has migrated from nephrology-centered or vascular surgery-centered care to multidisciplinary-focused patient-centered care. This new perspective should not only be theoretical but also have practical utility. A non-multidisciplinary focus can contribute to the low prevalence of arteriovenous fistula (AVF) in the population. Latin America has multiple health systems and the coordination of vascular access is heterogeneous. In Peru, there is a high prevalence of central venous catheter use with its associated complications, such as stenosis, thrombosis, infection, and recurrent hospitalizations in the context of fragmented care. However, in the last few years, there has been an effort to integrate the communication between vascular surgery, interventional radiology, and nephrology to improve vascular access care. In this review, we analyze the availability of care, the intervention, and the future directions from the experience of both perspectives.

Interventional nephrology and vascular access practice: A perspective from South and Southeast Asia.

South and Southeast Asia is the most populated, heterogeneous part of the world. The Association of Vascular Access and InTerventionAl Renal physicians (AVATAR Foundation), India, gathered trends on epidemiology and Interventional Nephrology (IN) for this region. The countries were divided as upper-middle- and higher-income countries as Group-1 and lower and lower-middle-income countries as Group-2. Forty-three percent and 70% patients in the Group 1 and 2 countries had unplanned hemodialysis (HD) initiation. Among the incident HD patients, the dominant Vascular Access (VA) was non-tunneled central catheter (non-TCC) in 70% of Group 2 and tunneled central catheter (TCC) in 32.5% in Group 1 countries. Arterio-Venous Fistula (AVF) in the incident HD patients was observed in 24.5% and 35% of patients in Group-2 and Group-1, respectively. Eight percent and 68.7% of the prevalent HD patients in Group-2 and Group-1 received HD through an AVF respectively. Nephrologists performing any IN procedure were 90% and 60% in Group-2 and Group 1, respectively. The common procedures performed by nephrologists include renal biopsy (93.3%), peritoneal dialysis (PD) catheter insertion (80%), TCC (66.7%) and non-TCC (100%). Constraints for IN include lack of time (73.3%), lack of back-up (40%), lack of training (73.3%), economic issues (33.3%), medico-legal problems (46.6%), no incentive (20%), other interests (46.6%) and institution not supportive (26%). Routine VA surveillance is performed in 12.5% and 83.3% of Group-2 and Group-1, respectively. To conclude, non-TCC and TCC are the most common vascular access in incident HD patients in Group-2 and Group-1, respectively. Lack of training, back-up support and economic constraints were main constraints for IN growth in Group-2 countries.

An Overlooked Link between IgA Nephropathy and Lithium Toxicity: A Case Report.

Lithium is one of the first-line agents for treating bipolar disorder. Although this agent is highly effective in treating mood disorders, renal toxicity is a frequent side effect. Lithium metabolism is affected by sodium-lithium counter-transporter (SLC-T) in erythrocytes. The high activity of SLC-T can result in decreased urinary lithium clearance and may lead to accumulation of lithium in the distal renal tubular cells, causing lithium toxicity. SLC-T is a genetic marker in primary hypertension (HTN), HTN in pregnancy, diabetic nephropathy, and IgA nephropathy (IgA-N) with HTN. Patients with IgA-N have been reported to have enhanced SLC-T activity and are likely to have considerably lower renal fractional clearance of lithium. Therefore, patients taking lithium for bipolar disorder with coexisting IgA-N can have severe lithium-induced nephropathy and nephrotoxicity even at therapeutic serum levels. Serum lithium levels reflect only extracellular lithium concentration. However, lithium exerts its effects once it has moved to the intracellular compartment. This phenomenon illustrates the reason why patients with significantly elevated serum levels might be asymptomatic. Creatinine clearance is inversely related to the duration of lithium therapy. The degree of interstitial fibrosis on renal biopsy has been known to be associated with the duration of lithium therapy and cumulative dose. We present a case with a past medical history of bipolar disorder treated with lithium for almost 20 years. His family history was significant for HTN. The patient was diagnosed with renal insufficiency of unknown causes, for which he underwent renal biopsy. The renal biopsy showed a typical lithium-induced tubulointerstitial nephritis and a coincidental finding of IgA-N. We suspect a high activity of SLC-T seen in IgA-N, and the adverse effects of lithium on SLC-T activity might cause reduction of urinary lithium clearance and accumulation of lithium in distal renal tubular cells, contributing to nephrotoxicity. There is a lack of the literature on the coexistence of IgA-N and lithium nephrotoxicity. We recommend in patients with concomitant IgA-N, taking lithium, more frequent monitoring of renal functions, and dose adjustments may reduce the risk of lithium-induced nephrotoxicity.

Post-traumatic thrombotic microangiopathy: What trauma surgeons need to know?

Thrombotic microangiopathy (TMA) is characterized by systemic microvascular thrombosis, target organ injury, anemia and thrombocytopenia. Thrombotic thrombocytopenic purpura, atypical hemolytic uremic syndrome and Shiga toxin E-coli-related hemolytic uremic syndrome are the three common forms of TMAs. Traditionally, TMA is encountered during pregnancy/postpartum period, malignant hypertension, systemic infections, malignancies, autoimmune disorders, etc. Recently, the patients presenting with trauma have been reported to suffer from TMA. TMA carries a high morbidity and mortality, and demands a prompt recognition and early intervention to limit the target organ injury. Because trauma surgeons are the first line of defense for patients presenting with trauma, the prompt recognition of TMA for these experts is critically important. Early treatment of post-traumatic TMA can help improve the patient outcomes, if the diagnosis is made early. The treatment of TMA is also different from acute blood loss anemia namely in that plasmapheresis is recommended rather than platelet transfusion. This article familiarizes trauma surgeons with TMA encountered in the context of trauma. Besides, it provides a simplified approach to establishing the diagnosis of TMA. Because trauma patients can require multiple transfusions, the development of disseminated intravascular coagulation must be considered. Therefore, the article also provides different features of disseminated intravascular coagulation and TMA. Finally, the article suggests practical points that can be readily applied to the management of these patients.

Current Status and Future of End-Stage Kidney Disease in Gulf Cooperation Council Countries: Challenges and Opportunities.

There is a paucity of data on epidemiology along with an incomplete registry of end-stage kidney disease (ESKD), nephrologist workforce, and variability among the countries of Gulf Cooperation Council (GCC). The study is an observation, descriptive study which aimed to describe current ESKD burden, nephrologist density, and kidney care infrastructure in GCC. Responses to a questionnaire-based survey obtained from representatives of the Nephrology Societies of GCC countries were analyzed. The categorical variables were compared using Chi-square test. A P = 5% was considered as significant. The mean prevalence of ESKD per million populations (pmp) was 551, highest in Oman (1000/pmp), least in Qatar (347/pmp). Predominant etiology in GCC was diabetes mellitus (DM) and hypertension (HTN) (100%, each), followed by chronic glomerulonephritis (66.7%). A transplant registry was maintained by all GCC countries. Hemodialysis (HD) (67.2%) was the most opted modality of kidney replacement therapy (KRT), followed by kidney transplantation (22%) and peritoneal dialysis (9.6%); 1.0% of patients opted for conservative management. Unplanned initiation of HD was three times more common. The access distribution among incident and prevalent HD patients respectively was (i) nontunneled central catheter (nTCC) (58.7 ± 36.6 vs. 1.5 ± 1.5), (ii) tunneled central catheter (23.5 ± 29.9 vs. 33.6 ± 10.0), and (iii) arteriovenous fistula (17.3± 14.4 vs. 57.8 ± 11.86). Death and transplantation were the reasons for dropout from HD. GCC has adequate kidney care infrastructure. There are 1686 nephrologists [range: Bahrain 9, Kingdom of Saudi Arabia (KSA) 1279]. Qatar, KSA, and Kuwait provide training in kidney biopsy; all countries except Bahrain have formal training programs for nTCC placement. ESKD prevalence is high, DM, HTN; glome-rulonephritis (GN) is the most common causes. The need for KRT is expected to rise in GCC. HD is the predominant KRT modality with a high prevalence of dialysis catheters as vascular access.

Serum magnesium, mortality and disease progression in chronic kidney disease.

INTRODUCTION: Magnesium disorders are commonly encountered in chronic kidney disease (CKD) and are typically a consequence of decreased kidney function or frequently prescribed medications such as diuretics and proton pump inhibitors. While hypomagnesemia has been linked with increased mortality, the association between elevated magnesium levels and mortality is not clearly defined. Additionally, associations between magnesium disorders, type of death, and CKD progression have not been reported. Therefore, we studied the associations between magnesium levels, CKD progression, mortality, and cause specific deaths in patients with CKD. METHODS: Using the Cleveland Clinic CKD registry, we identified 10,568 patients with estimated Glomerular Filtration Rate (eGFR) between 15 and 59 ml/min/1.73 m2 in this range for a minimum of 3 months with a measured magnesium level. We categorized subjects into 3 groups based on these magnesium levels (≤ 1.7, 1.7-2.6 and > 2.6 mg/dl) and applied cox regression modeling and competing risk models to identify associations with overall and cause-specific mortality. We also evaluated the association between magnesium level and slope of eGFR using mixed models. RESULTS: During a median follow-up of 3.7 years, 4656 (44%) patients died. After adjusting for relevant covariates, a magnesium level < 1.7 mg/dl (vs. 1.7-2.6 mg/dl) was associated with higher overall mortality (HR = 1.14, 95% CI: 1.04, 1.24), and with higher sub-distribution hazards for non-cardiovascular non-malignancy mortality (HR = 1.29, 95% CI: 1.12, 1.49). Magnesium levels > 2.6 mg/dl (vs. 1.7-2.6 mg/dl) was associated with a higher risk of all-cause death only (HR = 1.23, 95% CI: 1.03, 1.48). We found similar results when evaluating magnesium as a continuous measure. There were no significant differences in the slope of eGFR across all three magnesium groups (p = 0.10). CONCLUSIONS: In patients with CKD stage 3 and 4, hypomagnesemia was associated with higher all-cause and non-cardiovascular non-malignancy mortality. Hypermagnesemia was associated with higher all-cause mortality. Neither hypo nor hypermagnesemia were associated with an increased risk of CKD progression.

Acquired cystic kidney disease and renal tumor.

Immunosuppression is a well-known risk factor for malignancy. Renal transplant patients are at high risk for cancer in the native kidneys especially in the presence of acquired cystic disease. We report a case highlighting the importance of screening for renal malignancy in renal transplant patients.

Atypical hemolytic uremic syndrome: Laboratory characteristics, complement-amplifying conditions, renal biopsy, and genetic mutations.

Atypical hemolytic uremic syndrome (aHUS) is characterized by microangiopathic hemolytic anemia, consumptive thrombocytopenia, and widespread damage to multiple organs including the kidney. The syndrome has a high mortality necessitating the need for an early diagnosis to limit target organ damage. Because thrombotic microangiopathies present with similar clinical picture, accurate diagnosis of aHUS continues to pose a diagnostic challenge. This article focuses on the role of four distinct aspects of aHUS that assist clinicians in making an accurate diagnosis of aHUS. First, because of the lack of a single specific laboratory test for aHUS, other forms of thrombotic microangiopathies such as thrombotic thrombocytopenic purpura and Shiga toxin-associated HUS must be excluded to successfully establish the diagnosis of aHUS. Second, application of the knowledge of complement-amplifying conditions is critically important in making an accurate diagnosis. Third, when available, a renal biopsy can reveal changes consistent with thrombotic microangiopathy. Fourth, genetic mutations are increasingly clarifying the underlying complement dysfunction and gaining importance in the diagnosis and management of patients with aHUS. This review concentrates on the four aspects of aHUS and calls for heightened awareness in making an accurate diagnosis of aHUS.

Complement activation in atypical hemolytic uremic syndrome and scleroderma renal crisis: a critical analysis of pathophysiology / Ativação de complemento em síndrome urêmica hemolítica atípica e crise renal por esclerodermia: uma análise crítica da fisiopatologia

ABSTRACT Scleroderma is an autoimmune disease that affects multiple systems. While pathophysiologic mechanisms governing the development of scleroderma are relatively poorly understood, advances in our understanding of the complement system are clarifying the role of complement pathways in the development of atypical hemolytic uremic syndrome and scleroderma renal crisis. The abundant similarities in their presentation as well as the clinical course are raising the possibility of a common underlying pathogenesis. Recent reports are emphasizing that complement pathways appear to be the unifying link. This article reviews the role of complement system in the development of atypical hemolytic uremic syndrome and scleroderma renal crisis, and calls for heightened awareness to the development of thrombotic angiopathy in patients with scleroderma.

RESUMO A esclerodermia é uma doença autoimune que afeta múltiplos sistemas. Embora os mecanismos fisiopatológicos que regem o desenvolvimento da esclerodermia sejam relativamente pouco compreendidos, os avanços em nossa compreensão do sistema do complemento estão esclarecendo o papel das vias do complemento no desenvolvimento da síndrome urêmica hemolítica atípica e da crise renal da esclerodermia. As abundantes semelhanças em sua apresentação, bem como o curso clínico, estão aumentando a possibilidade de uma patogênese subjacente comum. Relatórios recentes estão enfatizando que as vias de complemento parecem ser o link unificador. Este artigo analisa o papel do sistema do complemento no desenvolvimento da síndrome urêmica hemolítica atípica e da crise renal na esclerodermia, e exige maior conscientização para com o desenvolvimento da angiopatia trombótica em pacientes com esclerodermia.

Contrast-induced nephropathy: Pathophysiology, risk factors, and prevention.

Contrast-induced acute kidney injury is a common iatrogenic complication associated with increased health resource utilization and adverse outcomes, including short- and long-term mortality and accelerated progression of preexisting renal insufficiency. The incidence of contrast-induced nephropathy (CIN) has been reported to range from 0% to 24%. This wide range reported by the studies is due to differences in definition, background risk factors, type and dose of contrast medium used, and the frequency of other coexisting potential causes of acute renal failure. CIN is usually transient, with serum creatinine levels peaking at 2-3 days after administration of contrast medium and returning to baseline within 7-10 days after administration. Multiple studies have been conducted using variety of therapeutic interventions in an attempt to prevent CIN. Of these, careful selection of patients, using newer radiocontrast agents, maintenance of hydration status, and avoiding nephrotoxic agents pre- and post-procedure are the most effective interventions to protect against CIN. This review focuses on the basic concepts of CIN and summarizes our recent understanding of its pathophysiology. In addition, this article provides practical recommendations with respect to CIN prevention and management.

Pre-Access Creation Evaluation--Is Vein Mapping Enough?

The changing demographic of the hemodialysis population in the United States is posing significant challenge for selection and creation of an optimal vascular access. An arteriovenous fistula (AVF) is by far the most reliable access provided it matures and functions successfully. System-wide changes implemented by Fistula First Breakthrough Initiative and Kidney Disease Outcomes Quality Initiative guidelines have increased the awareness and incidence of AVF in the prevalent dialysis population; however, achieving the current goal of 68% AVF rate continues to remain elusive. The present article reviews the evidence in literature in support of and against using vessel mapping alone as a strategy to improve AVF rate. The current strategy of evaluating the vessels before an access is created seems to be inadequate. A patient-centered approach for an optimal vascular access needs to be considered to improve the AVF rate.

Thrombocytopenia in ESRD patients: epidemiology, mechanisms and interventional nephrology perspective.

A well-functioning vascular access is essential for provision of life-sustaining dialysis treatment in patients with end-stage renal disease. Arteriovenous accesses are preferred form of vascular access. Although significant advances have been made in the field of dialysis access, arteriovenous access dysfunction remains the single most important cause of morbidity in ESRD patients. While thrombosis and stenosis of AV access are more frequently seen, hemorrhage from AV access can be life threatening with or without risk of permanent access loss. Aside from anticoagulation for comorbidities, qualitative and/or quantitative platelet abnormalities are often the predisposing factors. We describe an ESRD patient who developed new onset but severe thrombocytopenia due to metastatic small cell neuroendocrine carcinoma of lung. Given her persistent thrombocytopenia and presence of prolonged bleeding from the cannulation sites, a right internal jugular tunneled dialysis catheter was placed for continuation of maintenance dialysis. This review discusses the definition of thrombocytopenia, mechanisms of thrombocytopenia in patients with ESRD and with a special focus on implications of thrombocytopenia on dialysis access interventions. The review underscores the need for consensus with regard to cannulating AV access as well as guidelines specific to dialysis access-related endovascular intervention in the setting of thrombocytopenia and other coagulation abnormalities.

Cannulating the hemodialysis access through a stent graft - is it advisable?

Pseudoaneurysms frequently develop at cannulation sites in arteriovenous grafts. The current treatment options are either open surgical revision or endovascular placement of stents to cover the pseudoaneurysm. The ideal treatment option needs to be individualized based on the clinical assessment and the involved risks with the procedure. The safety of cannulating the dialysis access through a stent graft for hemodialysis has not been conclusively established and needs to be avoided when possible. This case report emphasizes the hazards associated with cannulation of stent grafts, including stent fracture and leakage of blood into the surrounding tissue with recurrence of pseudoaneurysm.

Timing of secondary arteriovenous fistula creation avoids tunneled catheter placement.

The concept of secondary arteriovenous fistula, though not novel, is seldom practiced for lack of initiative or hesitancy in deciding the appropriate timing to abandon the existing access. We report a case illustrating the benefits of implementing the strategy in an elderly diabetic dialysis patient, successfully avoiding a tunneled cuffed catheter placement.