Safety and efficacy of arteriovenous fistula angioplasties performed by nephrologists: report from a Brazilian interventional nephrology center / Segurança e eficácia de angioplastias de fístulas arteriovenosas realizadas por nefrologistas: relato de um centro de nefrologia intervencionista brasileiro

ABSTRACT Introduction: Arteriovenous fistulas (AVF) are the first choice vascular access for hemodialysis. However, they present a high incidence of venous stenosis leading to thrombosis. Although training in interventional nephrology may improve accessibility for treatment of venous stenosis, there is limited data on the safety and efficacy of this approach performed by trained nephrologists in low-income and developing countries. Methods: This study presents the retrospective results of AVF angioplasties performed by trained nephrologists in a Brazilian outpatient interventional nephrology center. The primary outcome was technical success rate (completion of the procedure with angioplasty of all stenoses) and secondary outcomes were complication rates and overall AVF patency. Findings: Two hundred fifty-six angioplasties were performed in 160 AVF. The technical success rate was 88.77% and the main cause of technical failure was venous occlusion (10%). The incidence of complications was 13.67%, with only one patient needing hospitalization and four accesses lost due to the presence of hematomas and/or thrombosis. Grade 1 hematomas were the most frequent complication (8.2%). The overall patency found was 88.2 and 80.9% at 180 and 360 days after the procedure, respectively. Conclusion: Our findings suggest that AVF angioplasty performed by trained nephrologists has acceptable success rates and patency, with a low incidence of major complications as well as a low need for hospitalization.

RESUMO Introdução: As fístulas arteriovenosas (FAV) são a primeira escolha de acesso vascular para hemodiálise. No entanto, elas apresentam uma alta incidência de estenoses venosas levando à trombose. Embora o treinamento em nefrologia intervencionista possa melhorar a acessibilidade para o tratamento das estenoses venosas, há dados limitados sobre a segurança e a eficácia desta abordagem realizada por nefrologistas treinados em países em desenvolvimento e de baixa renda. Métodos: Este estudo apresenta os resultados retrospectivos de angioplastias de FAV realizadas por nefrologistas treinados em um centro ambulatorial brasileiro de nefrologia intervencionista. O desfecho primário foi a taxa de sucesso técnico (conclusão do procedimento com angioplastia de todas as estenoses) e os desfechos secundários foram taxas de complicação e a patência geral das FAV. Achados: Duzentas e cinquenta e seis angioplastias foram realizadas em 160 FAV. A taxa de sucesso técnico foi de 88,77% e a principal causa de falha técnica foi a oclusão venosa (10%). A incidência de complicações foi de 13,67%, com apenas um paciente necessitando de internação e quatro acessos perdidos devido à presença de hematomas e/ou trombose. Hematomas de grau 1 foram a complicação mais frequente (8,2%). A patência geral encontrada foi de 88,2 e 80,9% a 180 e 360 dias após o procedimento, respectivamente. Conclusão: Nossos achados sugerem que a angioplastia de FAV realizada por nefrologistas treinados tem taxas de sucesso e patência aceitáveis, com uma baixa incidência de complicações maiores, bem como uma baixa necessidade de hospitalização.

Safety and efficacy of arteriovenous fistula angioplasties performed by nephrologists: report from a Brazilian interventional nephrology center.

INTRODUCTION: Arteriovenous fistulas (AVF) are the first choice vascular access for hemodialysis. However, they present a high incidence of venous stenosis leading to thrombosis. Although training in interventional nephrology may improve accessibility for treatment of venous stenosis, there is limited data on the safety and efficacy of this approach performed by trained nephrologists in low-income and developing countries. METHODS: This study presents the retrospective results of AVF angioplasties performed by trained nephrologists in a Brazilian outpatient interventional nephrology center. The primary outcome was technical success rate (completion of the procedure with angioplasty of all stenoses) and secondary outcomes were complication rates and overall AVF patency. FINDINGS: Two hundred fifty-six angioplasties were performed in 160 AVF. The technical success rate was 88.77% and the main cause of technical failure was venous occlusion (10%). The incidence of complications was 13.67%, with only one patient needing hospitalization and four accesses lost due to the presence of hematomas and/or thrombosis. Grade 1 hematomas were the most frequent complication (8.2%). The overall patency found was 88.2 and 80.9% at 180 and 360 days after the procedure, respectively. CONCLUSION: Our findings suggest that AVF angioplasty performed by trained nephrologists has acceptable success rates and patency, with a low incidence of major complications as well as a low need for hospitalization.

APOL1-Associated Kidney Disease in Brazil.

INTRODUCTION: Coding variants in apolipoprotein L-1 (APOL1) are associated with an increased risk of end-stage kidney disease (ESRD) in African American individuals under a recessive model of inheritance. The effect of the APOL1 risk alleles on kidney disease has been observed in studies in African American and African populations. Despite the 130 million individuals of recent African ancestry in South America, the impact of APOL1 has not been explored. METHODS: In this case-control study, we tested APOL1 genotype in 106 Brazilian HD (hemodialysis) patients with African ancestry and compared risk allele frequency with 106 healthy first-degree relatives. The association of risk alleles and ESRD was calculated with a linear mixed model and was adjusted for relatedness and additional confounders. In a broader survey, the age of dialysis initiation and APOL1 variants were analyzed in 274 HD patients. RESULTS: Two APOL1 risk alleles were 10 times more common in patients with ESRD than in controls (9.4% vs. 0.9%; odds ratio [OR]: 10.95, SE = 1.49, P = 0.0017). Carriers of 2 risk alleles initiated dialysis 12 years earlier than patients with zero risk alleles. CONCLUSION: The APOL1 risk variants were less frequent in dialysis patients of African ancestry in Brazil than in the United States. Nonetheless, carriers of 2 risk variants had 10-fold higher odds of ESRD. Age of dialysis initiation was markedly lower in 2-risk allele carriers, suggesting a more aggressive disease phenotype. The Brazilian population represents an opportunity to identify different sets of genetic modifiers or environmental triggers that might be present in more extensively studied populations.

International Society of Nephrology's 0by25 initiative (zero preventable deaths from acute kidney injury by 2025): focus on diagnosis of acute kidney injury in low-income countries.

In developing countries with limited medical infrastructure, preservation and recovery of renal function following acute kidney injury (AKI) is difficult. In conjunction with clinical presentation, rapid measurement of renal function is essential for early diagnosis and management. Especially in low- and middle-income countries, simple interventions such as hydration and avoidance of toxins have the highest probability of recovery. In such contexts, measurement of urine volume and osmolality and serum creatinine with point-of-care devices and saliva urea nitrogen dipsticks can be valuable. This review aims to identify currently available methodologies to assist in reaching the ambitious goal of the 0by25 initiative to eliminate all preventable deaths from AKI by 2025.

Persistent disorders of mineral metabolism after one year of kidney transplantation.

INTRODUCTION:: The persistence of mineral metabolism disorders after renal transplant (RT) appears to possess a negative impact over graft and patient's survival. OBJECTIVES:: To evaluate the parameters of mineral metabolism and the persistence of hyperparathyroidism (HPT) in transplanted patients for a 12-month period after the procedure. METHODS:: Retrospective analysis of 41 transplants (18 women- 44%, mean age of 39 ± 15 years) performed in a University Hospital, evaluating changes of calcium (Ca), phosphorus (P) and parathyroid hormone (PTH) and the prevalence of persistent HPT. The patients were divided into two groups accordingly to PTH levels prior to Tx: Group 1 with PTH ≤ 300 pg/mL (n = 21) and Group 2 with PTH > 300 pg/mL (n = 20). The persistency of HPT after transplant was defined as PTH ≥ 100 pg/mL. The evolution of biochemical parameters and the persistency of HPT were analyzed in each group after 1 year of transplant. RESULTS:: After a one-year of follow up, 5% of the patients presented hypophosphatemia (p < 2.7 mg/dL), 24% hypercalcemia (Ca > 10.2 mg/dL) and 48% persistency of HPT (PTH ≥ 100 pg/mL). There was a positive correlation between the PTH pre and post Tx (r = 0.42/p = 0.006) and a negative correlation between PTH and Ca pre-Tx (r = -0.45/p = 0.002). However, there was no significant difference among groups 1 and 2 regarding PTH levels pre and post Tx. CONCLUSION:: The findings in this article suggest that mineral metabolism alterations and the persistency of HPT may occur after one year of renal Tx, mainly in patients which present high PTH levels prior toTx. INTRODUÇÃO:: A persistência de distúrbios do metabolismo mineral ósseo após o transplante renal (Tx) parece possuir um impacto negativo sobre a sobrevida do enxerto e do paciente. OBJETIVOS:: avaliar os parâmetros do metabolismo mineral e a persistência de hiperparatiroidismo (pHPT) 12 meses após o Tx. MÉTODOS:: Análise retrospectiva de 41 transplantes (18 mulheres- 44%, idade de 39 ± 15 anos) realizados em um Hospital Universitário, avaliando cálcio (Ca), fósforo (P), hormônio da paratireóide (PTH) e a prevalência de pHPT. Pacientes foram divididos em dois grupos de acordo com os níveis de PTH pré Tx: Grupo 1: PTH ≤ 300 pg/ml (n = 21) e Grupo 2: PTH > 300 pg/ml (n = 20). pHPT foi definida como PTH ≥ 100pg/mL após o Tx. A evolução dos parâmetros bioquímicos e a pHPT foram analisadas após 1 ano de Tx. Resultados: após um ano, 5% dos pacientes apresentaram hipofosfatemia (p < 2,7mg/dL), 24% hipercalcemia (Ca > 10,2 mg/dL) e 48% persistência de HPT (PTH ≥ 100 pg/mL ). Houve correlação positiva entre PTH pré e pós Tx (r = 0,42/p = 0,006) e correlação negativa entre PTH e Ca pré-Tx (r = -0,45/p = 0,002). Entretanto, não houve diferença significativa entre os grupos 1 e 2 em relação aos níveis de PTH pré e pós-Tx. CONCLUSÃO:: Os resultados sugerem que alterações do metabolismo mineral e a pHPT podem ocorrer após um ano do Tx, principalmente em pacientes com níveis elevados de PTH pré-Tx.

Persistent disorders of mineral metabolism after one year of kidney transplantation / Alterações do metabolismo mineral e ósseo após um ano de transplante renal

Abstract Introduction: The persistence of mineral metabolism disorders after renal transplant (RT) appears to possess a negative impact over graft and patient's survival. Objectives: To evaluate the parameters of mineral metabolism and the persistence of hyperparathyroidism (HPT) in transplanted patients for a 12-month period after the procedure. Methods: Retrospective analysis of 41 transplants (18 women- 44%, mean age of 39 ± 15 years) performed in a University Hospital, evaluating changes of calcium (Ca), phosphorus (P) and parathyroid hormone (PTH) and the prevalence of persistent HPT. The patients were divided into two groups accordingly to PTH levels prior to Tx: Group 1 with PTH ≤ 300 pg/mL (n = 21) and Group 2 with PTH > 300 pg/mL (n = 20). The persistency of HPT after transplant was defined as PTH ≥ 100 pg/mL. The evolution of biochemical parameters and the persistency of HPT were analyzed in each group after 1 year of transplant. Results: After a one-year of follow up, 5% of the patients presented hypophosphatemia (p < 2.7 mg/dL), 24% hypercalcemia (Ca > 10.2 mg/dL) and 48% persistency of HPT (PTH ≥ 100 pg/mL). There was a positive correlation between the PTH pre and post Tx (r = 0.42/p = 0.006) and a negative correlation between PTH and Ca pre-Tx (r = -0.45/p = 0.002). However, there was no significant difference among groups 1 and 2 regarding PTH levels pre and post Tx. Conclusion: The findings in this article suggest that mineral metabolism alterations and the persistency of HPT may occur after one year of renal Tx, mainly in patients which present high PTH levels prior toTx.

Resumo Introdução: A persistência de distúrbios do metabolismo mineral ósseo após o transplante renal (Tx) parece possuir um impacto negativo sobre a sobrevida do enxerto e do paciente. Objetivos: avaliar os parâmetros do metabolismo mineral e a persistência de hiperparatiroidismo (pHPT) 12 meses após o Tx. Métodos: Análise retrospectiva de 41 transplantes (18 mulheres- 44%, idade de 39 ± 15 anos) realizados em um Hospital Universitário, avaliando cálcio (Ca), fósforo (P), hormônio da paratireóide (PTH) e a prevalência de pHPT. Pacientes foram divididos em dois grupos de acordo com os níveis de PTH pré Tx: Grupo 1: PTH ≤ 300 pg/ml (n = 21) e Grupo 2: PTH > 300 pg/ml (n = 20). pHPT foi definida como PTH ≥ 100pg/mL após o Tx. A evolução dos parâmetros bioquímicos e a pHPT foram analisadas após 1 ano de Tx. Resultados: após um ano, 5% dos pacientes apresentaram hipofosfatemia (p < 2,7mg/dL), 24% hipercalcemia (Ca > 10,2 mg/dL) e 48% persistência de HPT (PTH ≥ 100 pg/mL ). Houve correlação positiva entre PTH pré e pós Tx (r = 0,42/p = 0,006) e correlação negativa entre PTH e Ca pré-Tx (r = -0,45/p = 0,002). Entretanto, não houve diferença significativa entre os grupos 1 e 2 em relação aos níveis de PTH pré e pós-Tx. Conclusão: Os resultados sugerem que alterações do metabolismo mineral e a pHPT podem ocorrer após um ano do Tx, principalmente em pacientes com níveis elevados de PTH pré-Tx.

Chronic kidney disease (CKD) in disadvantaged populations.

Twelve March 2015 will mark the 10th anniversary of World Kidney Day (WKD), an initiative of the International Society of Nephrology and the International Federation of Kidney Foundations. Since its inception in 2006, WKD has become the most successful effort ever mounted to raise awareness among decision-makers and the general public about the importance of kidney disease. Each year WKD reminds us that kidney disease is common, harmful and treatable. The focus of WKD 2015 is on chronic kidney disease (CKD) in disadvantaged populations. This article reviews the key links between poverty and CKD and the consequent implications for the prevention of kidney disease and the care of kidney patients in these populations.

Sleep disorders in patients with end-stage renal disease undergoing dialysis: comparison between hemodialysis, continuous ambulatory peritoneal dialysis and automated peritoneal dialysis.

Sleep disorders for patients on dialysis are significant causes of a poorer quality of life and increased morbidity and mortality. No study has evaluated patients undergoing automated peritoneal dialysis (APD) to assess their sleep disorders compared to hemodialysis (HD) and continuous ambulatory peritoneal dialysis (CAPD). A total of 166 clinically stable patients who had been on dialysis for at least 3 months were randomly selected for the study and divided into HD, CAPD or APD. Socio-demographic, clinical and laboratory parameters and self-administered questionnaires were collected for the investigation of insomnia, restless legs syndrome (RLS), bruxism, rapid eye movement sleep behavior disorder, excessive daytime sleepiness (EDS), obstructive sleep apnea syndrome (OSAS), sleepwalking, sleep hygiene, depression and anxiety. Insomnia was detected in more than 80 % of patients on the three modalities. OSAS was lower for patients on HD (36 %) than on CAPD (65 %) (p < 0.01) or APD (60 %) (p < 0.04). Patients on APD were more likely to have RLS compared to those on HD or CAPD (p < 0.04) (50 vs. 23 vs. 33 %). No differences among the modalities were found in bruxism, EDS, sleepwalking, sleep hygiene, depression or anxiety. ESRD patients undergoing any one of the three dialysis modalities studied had a high prevalence of sleep disorders. Patients on HD had a lower proportion of OSAS than those on CAPD and APD, which is most likely attributed to their lower body mass indices. The possible causes of higher RLS rates in APD patients have not been established.

Chronic kidney disease: chronic kidney disease and the ageing population.

'Chronic kidney disease (CKD) in older people' is the focus of World Kidney Day 2014. In this article, we discuss the key links between kidney function, age, health and illness, as well as the implications of the ageing population for the care of people with CKD.

Vascular access in haemodialysis: strengthening the Achilles' heel.

Despite all the progress achieved since Scribner first introduced the arteriovenous (AV) shunt in 1960 and Cimino and Brescia introduced the native AV fistula in 1962, we have continued to face a conundrum in vascular access for dialysis, in that dialysis vascular access is at the same time both the 'lifeline' and the 'Achilles' heel' of haemodialysis. Indeed, findings from a multitude of published articles in this area, unfortunately mainly observational studies, reflect both our frustration and our limited knowledge in this area. Despite improved understanding of the pathophysiology of stenosis and thrombosis of the vascular access, we have unfortunately not been very successful in translating these advances into either improved therapies or a superior process of care. As a result, we continue to face an epidemic of arteriovenous fistula (AVF) maturation failure, a proliferation of relatively ineffective interventions such as angioplasty and stent placement, an extremely high incidence of catheter use, and more doubts rather than guidance with regard to the role (or lack thereof) of surveillance. An important reason for these problems is the lack of focused translational research and robust randomized prospective studies in this area. In this Review, we will address some of these critical issues, with a special emphasis on identifying the best process of care pathways that could reduce morbidity and mortality. We also discuss the potential use of novel therapies to reduce dialysis vascular access dysfunction.