Establishment of contralateral arteriovenous fistula by using the waste vein on the side of central venous lesion: a case report / 中华肝脏病杂志

Central venous lesion is a difficult problem in the vascular access complications of hemodialysis, which can cause serious clinical symptoms and affect the quality of hemodialysis and life of patients. We established arteriovenous fistula of the contralateral graft blood vessel with the used vein on the diseased side of the central vein of the patient. The arteriovenous fistula of the graft blood vessel was successfully punctured and hemodialysis was performed 2 weeks later. In this way, we not only solved the problem of venous hypertension and subsequent vascular access in the patient, but also reserved more vascular resources.

Efecto del catéter de hemodiálisis en la permeabilidad de fístulas arteriovenosas / The impact of hemodialysis catheter on arteriovenous fistula permeability

Resumen Objetivo: Evaluar el impacto que tiene el uso de catéteres de hemodiálisis en la permeabilidad de fístulas arteriovenosas. Materiales y Método: Estudio observacional, analítico, tipo cohorte retrospectiva. Se calculó un tamaño muestral de 195 pacientes, seleccionados aleatoriamente a partir del total de pacientes diagnosticados con enfermedad renal crónica (ERC) terminal, a quienes se les realizó su primera fístula arteriovenosa (FAV) entre enero de 2014 y diciembre de 2018. Como variables resultado se consideraron la trombosis de FAV y el tiempo de permeabilidad. Para el análisis inferencial se utilizaron las pruebas de Chi cuadrado; RR (IC 95%); curvas Kaplan-Meier; regresión de Cox; considerando un valor de p significativo < 0,05. Resultados: El 52,3% utilizó catéter de hemodiálisis, de los cuales el 49,5% presentó trombosis de su FAV versus el 17,7% del grupo sin este antecedente (p < 0,001); estimándose en el análisis univariado un riesgo de trombosis 2,7 veces mayor en pacientes con catéter previo a la confección de su FAV (IC 95% 1,7 a 4,4). En el análisis multivariado, se identificó como único factor significativo el antecedente de catéter de hemodiálisis, estimándose que los pacientes usuarios de catéter previo a la confección de su FAV tienen 2,8 veces más riesgo de trombosis en el tiempo que quienes no utilizaron catéter (IC 95% 1,6 a 4,9), quienes además presentaron un tiempo de permeabilidad significativamente menor (p < 0,001) en comparación con pacientes sin antecedente de catéter (28,1 vs 43,9 meses). Conclusión: Identificamos el uso del catéter de hemodiálisis como un factor de riesgo de trombosis de fístulas arteriovenosas, afectando significativamente su permeabilidad en el tiempo.

Objective: To evaluate the effects of hemodialysis catheter on arteriovenous fistula (AVF) permeability. Materials and Method: We conducted a retrospective cohort study, including 195 patients randomly selected from all patients diagnosed with chronic renal failure, who had their first arteriovenous fistula between January 2014 and December 2018. The outcomes were arteriovenous fistula thrombosis and permeability. For data analysis we used Chi-square test; Relative-Risk (CI 95%); Kaplan-Meier analysis and Cox regression; p value less than 0.05 were considered as significant. Results: The 52.3% of the patients used hemodialysis catheter, from this group, the 49.5% had AVF thrombosis versus the 17.7% of the group without history of hemodialysis catheter (p < 0.001), estimating in the univariate analysis a risk of thrombosis 2.7 times higher in patients with catheter before the creation of their AVF (CI 95% 1.7 a 4.4), as well as, in the multivariate analysis the risk of AVF thrombosis was 2.8 times higher in this group of patients, being identified the history of hemodialysis catheter as the only significative risk factor for thrombosis. Additionally, the AVF permeability time in this group was significantly less (p < 0.001) than patients without history of hemodialysis catheter (28.1 vs 43.9 months). Conclusion: We identified the hemodialysis catheter as a risk factor of arteriovenous fistula thrombosis, decreasing significantly its permeability time.

O volume de fluxo e a velocidade de pico sistólico ao ultrassom vascular com Doppler intraoperatório como preditores de perviedade precoce na fístula arteriovenosa autógena para hemodiálise / Intraoperative vascular Doppler ultrasound blood flow and peak systolic velocity predict early patency in hemodialysis arteriovenous fistula

Resumo Contexto A insuficiência renal crônica é um problema de saúde pública mundial. A hemodiálise é a principal terapia renal substitutiva. As fístulas arteriovenosas (FAV) são uma possível escolha, mas apresentam altas taxas de falência. Objetivos Este estudo tem como objetivo avaliar a relação entre as variáveis hemodinâmicas ao ultrassom vascular com Doppler no intraoperatório e a perviedade precoce da FAV para hemodiálise. Métodos Tratou-se de um estudo prospectivo observacional. Os pacientes consecutivos foram submetidos a FAV com ultrassonografia vascular com Doppler em intraoperatório nos dias 1, 7, 30 e 60. Eles foram divididos em grupos quanto à presença ou não de perviedade primária e secundária, e o volume de fluxo (VF) e a velocidade de pico sistólico (VPS) foram comparados. Foram realizadas curvas receiver operating characteristic (ROC), com definição de valores de VPS e VF com sensibilidade (S) e especificidade (E). Resultados Foram analisados 47 pacientes, os quais preencheram os critérios de inclusão. Os valores de VPS e VF intraoperatório foram maiores nos pacientes com perviedade primária e secundária comparados àqueles com falência. Os seguintes valores apresentaram maiores sensibilidade e especificidade para predizer perviedade primária aos 30 dias: 106 cm/s para VPS venoso, S: 75%, E: 71,4%; e 290,5 mL/min para VF arterial, S: 80,6%, E: 85,7%. Para perviedade secundária aos 30 dias, foram observados: 106 cm/s para VPS arterial, S: 72,7%, E: 100%; e 230 mL/min para VF venoso, com S: 86,4%, E: 100%. Para a perviedade primária no 60º dia, foram observados: 106 cm/s para VPS venoso, S: 74,4%, E: 62,5%; e 290,5 mL/min para VF arterial, S: 80%, E: 75%. Conclusões A velocidade de pico sistólico e o VF ao ultrassom vascular com Doppler intraoperatório são preditores de perviedade precoce na FAV para hemodiálise.

Abstract Background Chronic kidney disease is a major public health problem. Hemodialysis is the most common renal replacement therapy. Arteriovenous fistulas (AVF) are a possible access option, but early failure rates remain high. Objectives to investigate the value of intraoperative vascular Doppler ultrasound for predicting early AVF patency. Methods Prospective observational study. Consecutive patients undergoing AVF were assessed with vascular Doppler ultrasonography intraoperatively and on days 1, 7, 30, and 60. Patients were divided into groups according to presence or absence of primary and secondary patency. Blood flow (BF) and peak systolic velocity (PSV) were compared. ROC curves were plotted and used to define the PSV and BF values that yielded greatest sensitivity (Sens) and specificity (Spec). Results 47 patients met the inclusion criteria and were analyzed. Higher intraoperative PSV and BF values were observed in patients who had primary and secondary patency than in patients with access failure. The values with greatest sensitivity and specificity for predicting 30-day primary patency were 106 cm/s for venous PSV (Sens: 75% and Spec: 71.4%) and 290.5 ml/min for arterial blood flow (Sens: 80.6% and Spec 85.7%). Values for 30-day secondary patency were 106 cm/s for arterial PSV (Sens: 72.7%, Spec: 100%) and 230 ml/min for venous blood flow (Sens: 86.4%, Spec100%). Values for 60-day primary patency were 106 cm/s for venous PSV (Sens: 74.4%, Spec: 62.5%) and 290.5 ml/min for arterial blood flow (Sens: 80%, Spec: 75%). Conclusions Peak systolic velocity and blood flow measured using intraoperative vascular Doppler ultrasound can predict early patency of hemodialysis arteriovenous fistulas.

Primary antiphospholipid syndrome in a hemodialysis patient with recurrent thrombosis of arteriovenous fistulas / Síndrome antifosfolípide primária em paciente em hemodiálise com trombose recorrente de fístulas arteriovenosas

ABSTRACT Introduction: The antiphospholipid syndrome is a systemic autoimmune disease defined by recurrent vascular and/or obstetrical morbidity that occurs in patients with persistent antiphospholipid antibodies. Case presentation: A patient on hemodialysis with a primary antiphospholipid syndrome presented with recurrent vascular access thrombosis, obstetrical complications, and positive lupus anticoagulant. The patient had multiple arteriovenous fistulas that failed due to thrombosis. The obstetrical morbidity was defined by one miscarriage at the 7th week of gestation and a pregnancy complicated by pre-eclampsia with preterm delivery at the 28th week of gestation. A thorough thrombophilia screening confirmed the presence of antiphospholipid antibody. Lupus anticoagulant was present in plasma, measured on two occasions 12 weeks apart. Conclusion: Thrombophilias are inherited or acquired predispositions to vascular thrombosis and have been associated with thrombosis of the arteriovenous fistula. Patients on hemodialysis with recurrent vascular access thrombosis and presence of thrombophilia should be evaluated about the need for anticoagulant therapy with a vitamin K antagonist.

RESUMO Introdução: A síndrome antifosfolipídica é uma doença autoimune sistêmica definida por morbidade vascular e/ou obstétrica, recorrente, que acomete pacientes com anticorpos antifosfolípides persistentes. Apresentação do caso: Uma paciente em hemodiálise com síndrome antifosfolípide primária apresentou trombose recorrente do acesso vascular, complicações obstétricas e anticoagulante lúpico positivo. A paciente apresentava múltiplas fístulas arteriovenosas que falharam devido à trombose. A morbidade obstétrica foi definida por um aborto espontâneo na 7ª semana de gestação e uma gravidez complicada por pré-eclâmpsia com parto prematuro na 28ª semana de gestação. Um rastreamento completo de trombofilia confirmou a presença de anticorpo antifosfolípide. O anticoagulante lúpico estava presente no plasma, medido em duas ocasiões, com 12 semanas de intervalo. Conclusão: As trombofilias são predisposições hereditárias ou adquiridas para trombose vascular e têm sido associadas à trombose da fístula arteriovenosa. Pacientes em hemodiálise com trombose recorrente de acesso vascular e presença de trombofilia devem ser avaliados quanto à necessidade de terapia anticoagulante com um antagonista da vitamina K.

Effect of local papaverine on arteriovenous fistula maturation in patients with end-stage renal disease / Efeito da papaverina local na maturação de fístulas arteriovenosas em pacientes com doença renal terminal

Abstract Background: Arteriovenous fistula (AVF) maturation is one of the main concerns in patients with end-stage renal disease (ESRD) and finding a strategy for increasing success rate and accelerating fistula maturation is valuable. The aim of this study was to evaluate the effects of papaverine injection on AVF maturation and success rate. Method: This study was a randomized clinical trial that involved 110 patients with ESRD that were referred for AVF construction. Patients were allocated in papaverine group and control group with block randomization according to age and sex. In the case group, papaverine (0.1 or 0.2 cc) was injected locally within the subadventitia of artery and vein after proximal and distal control during AVF construction and in the control group, AVF construction was done routinely without papaverine injection. Results: Maturation time in case and control groups was 37.94 ± 11.49 and 44.23 ± 9.57 days, respectively (p=0.004). Hematoma was not seen in the case group but occurred in one patient in the control group. One patient of the case group developed venous hypertension. Four functional fistulas, 1 (1.8%) in the case group and 3 (5.5%) in the control group, failed to mature (p=0.618). Maturation rate did not differ between the two groups statistically (p=0.101). Conclusion: Local papaverine injection increased vessel diameter and blood flow, increasing shearing stress in both arterial and venous segment of recently created AVF. In this way, papaverine probably can decrease AVF maturation time without an increase in complications.

Resumo Introdução: A maturação da fístula arteriovenosa (FAV) é uma das principais preocupações em pacientes com doença renal terminal (DRT). Assim, é importante identificar estratégias para aumentar as taxas de sucesso e acelerar a maturação da fístula. O objetivo do presente estudo foi avaliar os efeitos da infiltração de papaverina sobre a maturação da FAV e suas taxas de sucesso. Método: O presente ensaio clínico randomizado incluiu 110 pacientes com DRT encaminhados para colocação de FAV. Os pacientes foram randomizados em bloco em função de idade e sexo e alocados nos grupos caso ou controle. Os indivíduos no grupo caso receberam infiltração local de papaverina (0,1 ou 0,2 ml) no plano da sub-adventícia da artéria e veia após o controle proximal e distal durante a construção da FAV. No grupo controle, a construção da FAV foi realizada rotineiramente sem infiltração de papaverina. Resultados: Os tempos de maturação dos grupos caso e controle foram 37,94 ± 11,49 e 44,23 ± 9,57 dias, respectivamente (p = 0,004). Foi observado hematoma em apenas um paciente do grupo controle. Um paciente do grupo caso desenvolveu hipertensão venosa. Quatro fístulas funcionais, uma (1,8%) no grupo caso e três (5,5%) no grupo controle, não amadureceram (p = 0,618). A taxa de maturação não diferiu estatisticamente entre os dois grupos (p = 0,101). Conclusão: A infiltração local de papaverina aumentou o diâmetro do vaso e o fluxo sanguíneo, elevando a tensão de cisalhamento nos segmentos arterial e venoso da FAV recentemente criada. Desta forma, a papaverina provavelmente consegue reduzir o tempo de maturação da FAV sem aumentar as complicações.

Salvage of thrombosed arteriovenous fistulae of patients on hemodialysis: report on the experience of a Brazilian center / Manejo da trombose aguda de fístulas arteriovenosas de pacientes em hemodiálise: relato de experiência em um centro brasileiro

ABSTRACT Introduction: Hemodialysis vascular access thrombosis is an acute event that can interrupt the dialytic treatment. A timely management can restore access patency, avoiding the use of central venous catheters and their complications. Objective: To present the experience from a Brazilian Interventional Nephrology Center (INC) in the salvage of arteriovenous fistula (AVF) and grafts for hemodialysis. Methods: A retrospective study was performed to evaluate the primary and secondary patencies of 41 hemodialysis accesses with thrombosis confirmed by ultrasound and submitted to endovascular salvage procedures. We considered clinical success the use of the access for at least 3 subsequent hemodialysis sessions. The procedures were done in an outpatient center by interventional nephrologists. Patients were followed for up to 18 months with Doppler every 3 months. Results: Forty-five salvage procedures were performed in 41 accesses of 40 hemodialysis patients with native AVF or grafts. Of these, 90% were AVF, mostly upper arm, and 10% were grafts. Clinical success rate was 60% (27 procedures). Primary patency at 12 months was 39% and secondary was 52%. Gender of the patient, diabetes, and location of the access did not correlate statistically with outcomes. There were 3 major complications (anastomosis rupture, grade 3 hematoma, and anaphylactic shock). Conclusion: The majority of thrombosed accesses can be successfully treated, maintaining its long-term patency. The need of repeated intervention is frequent.

RESUMO Introdução: A trombose dos acessos vasculares para hemodiálise é um evento agudo que interrompe o tratamento dialítico. O manejo em tempo hábil pode restaurar a patência do acesso, evitando o uso de cateteres centrais e suas complicações. Objetivo: Apresentar a experiência brasileira de um centro de nefrologia intervencionista no salvamento de fístulas arteriovenosas (FAV) e próteses para hemodiálise. Métodos: Estudo retrospectivo, avaliando as patências primária e secundária de 41 acessos para hemodiálise com trombose confirmada por ultrassonografia e submetidos a salvamento por via endovascular. Consideramos sucesso clínico o uso do acesso por no mínimo 3 sessões de hemodiálise. Os procedimentos foram realizados em regime ambulatorial por nefrologistas intervencionistas. Os pacientes foram acompanhados por até 18 meses com Doppler trimestral. Resultados: Foram realizados 45 procedimentos de salvamento em 41 acessos de 40 pacientes em hemodiálise por FAV ou prótese. 90% dos acessos abordados foram FAV, sendo a maioria proximais, e 10%, próteses. A taxa de sucesso clínico foi de 60% (27 procedimentos). A patência primária em 12 meses foi de 39% e a secundária, de 52%. O gênero, presença de diabetes e localização do acesso não se correlacionaram significativamente com os desfechos avaliados. Ocorreram 3 complicações maiores (rotura de anastomose, hematoma grau III e choque anafilático). Conclusões: A maioria dos acessos com trombose pode ser tratada, mantendo sua patência em longo prazo. É frequente a necessidade de intervenções repetidas.

Are high flow arteriovenous accesses associated with worse haemodialysis? / Acessos arteriovenosos de alto débito estão associados a pior hemodiálise?

ABSTRACT Introduction: An arteriovenous (AV) access flow (Qa) of 400 mL/min is usually sufficient for an effective hemodialysis (HD), but some accesses continue developing and become high flow accesses (HFA). Some authors postulated that an HFA might shift a significant portion of dialyzed blood from the cardiac output, which could decrease HD efficiency and lead to volume overload. Objective: The aim of our study was to evaluate if HFA is associated with reduced HD efficiency and/or volume overload in prevalent HD patients. Methods: We performed a 1-year retrospective study and assessed HD efficiency by the percentage of sessions in which the Kt/V > 1.4 and volume overload by bioimpedance spectroscopy. Results: The study included 304 prevalent HD patients with a mean age of 67.5 years; 62.5% were males, 36.2% were diabetics, with a median HD vintage of 48 months. Sixteen percent of the patients had a HFA (defined as Qa > 2 L/min). In multivariate analysis, patients with HFA presented higher risk of volume overload (OR = 2.67, 95%CI = 1.06-6.71) and severe volume overload (OR = 4.06, 95%CI = 1.01-16.39) and attained dry weight less frequently (OR = 0.37, 95%CI = 0.14-0.94). However, HFA was not associated with lower Kt/V. Conclusion: Our results suggest that patients with HFA have higher risk of volume overload. However, contrarily to what has been postulated, HFA was not associated with less efficient dialysis, measured by Kt/V. Randomized controlled trials are needed to clarify these questions.

RESUMO Introdução: Um débito de sangue de acesso arteriovenoso (AV) (Qa) de 400 mL/min é geralmente suficiente para uma hemodiálise (HD) eficaz, mas alguns acessos continuam se desenvolvendo e se tornam acessos de alto débito (AAD). Alguns autores postularam que um AAD poderia desviar uma porção significativa do sangue dialisado do débito cardíaco, o que poderia diminuir a eficiência da HD e levar à sobrecarga de volume. Objetivo: O objetivo do nosso estudo foi avaliar se o AAD está associado à redução da eficiência da HD e/ou à sobrecarga de volume em pacientes prevalentes em HD. Métodos: Foi realizado um estudo retrospectivo de 1 ano, e avaliada a eficiência da HD pela porcentagem de sessões em que o Kt/V > 1,4 e a sobrecarga de volume avaliada pela bioimpedância. Resultados: O estudo incluiu 304 pacientes prevalentes em HD, com média de idade de 67,5 anos; 62,5% eram do sexo masculino; 36,2% eram diabéticos, com uma mediana de tempo em HD de 48 meses. Dezesseis por cento dos pacientes apresentavam AAD (definida como Qa > 2 L/min). Na análise multivariada, os pacientes com AAD apresentaram maior risco de sobrecarga de volume (OR = 2,67; IC95% = 1,06-6,71) e sobrecarga severa de volume (OR = 4,06; IC95% = 1,01-16,39) e atingiram o peso seco com menor frequência (OR = 0,37, IC 95% = 0,14-0,94). No entanto, o AAD não foi associado uma menor razão Kt/V. Conclusão: Nossos resultados sugerem que pacientes com AAD apresentam maior risco de sobrecarga de volume. No entanto, ao contrário do que foi postulado, o AAD não foi associado à diálise menos eficiente, medida pelo Kt/V. Ensaios clínicos randomizados são necessários para esclarecer essas questões.

Occurrence of Chandleronema longigutturata (Nematoda: Acuariidae) in Procyon cancrivorus in the Neotropical region / Ocorrência de Chandleronema longigutturata (Nematoda: Acuariidae) em Procyon cancrivorus na região neotropical

Procyon cancrivorus is a wild animal that is found from Central America to Uruguay and northeastern Argentina. It is one of the least studied carnivore species in Brazil. For the purpose of identifying helminths that parasitize P. cancrivorus, individuals of this species that had been run over and killed by motor vehicles were collected from highways in the southern part of the state of Rio Grande do Sul. At necropsy, their organs, along with organ contents and mucous membranes, were examined for parasite collection. The nematodes found in the stomachs of these Procyonidae were cleared with lactophenol and Chandleronema longigutturata was identified. This report provides the first record of occurrences of C. longigutturata in the Neotropical region and its parasitism in P. cancrivorus.

Procyon cancrivorus é um animal silvestre que se distribui desde a América Central até o Uruguai e Nordeste da Argentina. Está entre as espécies de carnívoros brasileiros menos estudadas. Com o objetivo de identificar helmintos que parasitam P. cancrivorus, estes foram coletados nas estradas, quando mortos por atropelamento automobilístico, na região Sul do Rio Grande do Sul. Após a necropsia, os órgãos foram examinados, assim como suas mucosas e conteúdos para a coleta de parasitos. Os nematoides encontrados no estômago desses procionídeos foram clarificados com lactofenol e identificados à Chandleronema longigutturata. Registra-se pela primeira vez a ocorrência de C. longigutturata na região neotropical, bem como o parasitismo em P. cancrivorus.

Endovascular Recanalization of a Thrombosed Native Arteriovenous Fistula Complicated with an Aneurysm: Technical Aspects and Outcomes

OBJECTIVE: To evaluate the technical aspects and outcomes of endovascular recanalization of a thrombosed native arteriovenous fistula (AVF) complicated with an aneurysm. MATERIALS AND METHODS: Sixteen patients who had a thrombosed AVF complicated with an aneurysm (two radiocephalic and 14 brachiocephalic) were included in this study. Recanalization procedures were performed by mechanical thrombectomy using the Arrow-Trerotola percutaneous thrombectomy device and adjunctive treatments. We evaluated dose of thrombolytic agent, underlying stenosis, procedure time, technical and clinical success, and complications. The primary and secondary patency rates were calculated using the Kaplan-Meier analysis. RESULTS: The thrombolytic agents used were 100000 U urokinase mixed with 500 IU heparin (n = 10) or a double dose of the mixture (n = 6). The thrombi in aneurysms were removed in all but two patients with non-flow limiting residual thrombi. One recanalization failure occurred due to a device failure. Aspiration thrombectomy was performed in 87.5% of cases (n = 14). Underlying stenoses were found in the outflow draining vein (n = 16), arteriovenous anastomosis or juxtaanastomosis area (n = 5), and the central vein (n = 3). Balloon angioplasty was performed for all stenoses in 15 patients. Two patients with a symptomatic central vein stenosis underwent insertion of a stent after balloon angioplasty. Mean procedure time was 116.3 minutes. Minor extravasation (n = 1) was resolved by manual compression. Both technical and clinical success rates were 93.8% (n = 15). The primary patency rates at 3, 6, and 12 months were 70.5%, 54.8%, and 31.3%, respectively. The secondary patency rates at 3, 6, and 12 months were 70.5%, 70.5%, and 47.0%, respectively. CONCLUSION: Thrombosed AVF complicated with an aneurysm can be successfully recanalized, and secondary patency can be prolonged with endovascular treatment.

Aneurisma de fístula arteriovenosa para hemodiálisis / Hemodialysis arteriovenous fistula aneurysms

Los aneurismas de fístulas arteriovenosas para hemodiálisis constituyen una complicación que aparece en algunos pacientes y que no siempre se toma una conducta con relación a ellos. En este trabajo presentamos un caso de una mujer de 29 años de edad con nueve años en hemodiálisis a través de una fístula arteriovenosa braquiocefálica izquierda que desarrolló aneurisma gigante con peligro de ruptura espontánea, la cual fue sometida a tratamiento quirúrgico. Se describe la técnica y se revisa la literatura al respecto(AU)

Hemodialysis arteriovenous fistula aneurisms represent a complication that we can observe in some patients and not always is taken a procedure in relation to them. Herein, we report the case of 29 year old woman with nine years of hemodialysis treatment through left brachiocephalic arteriovenous fistula which developed a giant aneurism with the possibility of spontaneous rupture. The patient was submitted to surgical treatment. The technique was described and the literature was review(AU)

Treatment of Hemodialysis Vascular Access Rupture Irresponsive to Prolonged Balloon Tamponade: Retrospective Evaluation of the Effectiveness of N-Butyl Cyanoacrylate Seal-Off Technique

OBJECTIVE: The current study retrospectively evaluated whether the percutaneous N-butyl cyanoacrylate (NBCA) seal-off technique is an effective treatment for controlling the angioplasty-related ruptures, which are irresponsive to prolonged balloon tamponade, during interventions for failed or failing hemodialysis vascular accesses. MATERIALS AND METHODS: We reviewed 1588 interventions performed during a 2-year period for dysfunction and/or failed hemodialysis vascular access sites in 1569 patients. For the angioplasty-related ruptures, which could not be controlled with repeated prolonged balloon tamponade, the rupture sites were sealed off with an injection of a glue mixture (NBCA and lipiodol), via a needle/needle sheath to the rupture site, under a sonographic guidance. Technical success rate, complications and clinical success rate were reported. The post-seal-off primary and secondary functional patency rates were calculated by a survival analysis with the Kaplan-Meier method. RESULTS: Twenty ruptures irresponsive to prolonged balloon tamponade occurred in 1588 interventions (1.3%). Two technical failures were noted; one was salvaged with a bailout stent-graft insertion and the other was lost after access embolization. Eighteen accesses (90.0%) were salvaged with the seal-off technique; of them, 16 ruptures were completely sealed off, and two lesions were controlled as acute pseudoaneurysms. Acute pseudoaneurysms were corrected with stentgraft insertion in one patient, and access ligation in the other. The most significant complication during the follow-up was delayed pseudoaneurysm, which occurred in 43.8% (7 of 16) of the completely sealed off accesses. Delayed pseudoaneurysms were treated with surgical revision (n = 2), access ligation (n = 2) and observation (n = 3). During the follow-up, despite the presence of pseudoaneurysms (acute = 1, delayed = 7), a high clinical success rate of 94.4% (17 of 18) was achieved, and they were utilized for hemodialysis at the mean of 411.0 days. The post-seal-off primary patency vs. secondary patency at 90, 180 and 360 days were 66.7 +/- 11.1% vs. 94.4 +/- 5.4%; 33.3 +/- 11.1% vs. 83.3 +/- 8.8%; and 13.3 +/- 8.5% vs. 63.3 +/- 12.1%, respectively. CONCLUSION: Our results suggest that the NBCA seal-off technique is effective for immediate control of a venous rupture irresponsive to prolonged balloon tamponade, during interventions for hemodialysis accesses. Both high technical and clinical success rates can be achieved. However, the treatment is not durable, and about 40% of the completely sealed off accesses are associated with developed delayed pseudoaneurysms in a 2-month of follow-up. Further repair of the vascular tear site, with surgery or stent-graft insertion, is often necessary.

Ischemic monomelic neuropathy: a rare complication after vascular access formation

No abstract available.

Resultados del tratamiento con revascularización distal y ligadura intermedia, de la isquemia de mano después de acceso vascular para hemodiálisis / Distal revascularization-interval ligation for ischemic steal syndrome after hemodialysis access: experience in 23 patients

Background: The creation of vascular accesses for hemodialysis can cause distal ischemia and steal syndromes. Aim: To assess the effectiveness of the technique of distal revascularization-interval ligation to alleviate distal ischemia and preserve vascular access. Material and Methods: Retrospective review of medical records, identifying 23 patients (13 women, aged between 24 and 79 years), with distal ischemia secondary to a vascular access for hemodialysis, that were treated with distal revascularization-interval liga-tion. Patient characteristics and outcome of the surgical procedure were recorded. Results: Fourteen patients were diabetic and 15 had high blood pressure. All had the vascular access in the elbow, 20 were done with vein and three were prosthetic. Steal appeared in a lapse ranging from hours to six years after performing the procedure. In 14 patients it appeared before 12 months. Revascularization was performed between 1 day and three months after the appearance of the steal syndrome. Seventeen patients (74 percent) had a substantial relief of ischemic symptoms, with healing of ulcers and digital amputations. Three patients died soon after the procedure (13 percent). In two the pain persisted, requiring a banding of the access, that finally became thrombosed. One patient required a distal forearm amputation. Thirteen patients (56 percent) had a late death after the procedure. After revascularization, the vascular accesses were used for a mean of two years. Conclusions: Revascularization-interval ligation relieves distal ischemia and maintains the patency of the vascular access for hemodialysis. Patients with steal syndrome secondary to vascular access are of high risk.

Objetivo: Investigar la efectividad de la técnica de revascularización distal y ligadura intermedia (RDLI) en aliviar la isquemia y preservar el acceso arteriovenoso. Material y Métodos: Una revisión retrospectiva de fichas clínicas (1990-2010), identificó 26 pacientes con robo. Se excluyen 3, que se sometieron a ligadura del acceso; 23 fueron tratados con RDLI. Se obtuvo información demográfica, comorbilidades, antecedentes del acceso, morbimortalidad y respuesta al tratamiento. Resultados: De los 23 pacientes, 13 eran mujeres y 10 hombres, con edad promedio de 59 años (24-79 años). Catorce (61 por ciento) eran diabéticos y quince (65 por ciento) hipertensos. Todos con acceso en pliegue del codo, 20 con vena y 3 protésicos. La latencia en aparición del robo ocurrió antes de 12 meses, en 14 pacientes (78 por ciento); con rango desde horas a 6,5 años. La revascularización se realizó en tiempo variable entre 1 día y 13 meses; sólo 8 pacientes antes de los 30 días. El 74 por ciento de los pacientes (17), tuvo mejoría sustancial o completa de manifestaciones isquémicas, cicatrizando úlceras y amputaciones digitales. Tres fallecieron precozmente; en 2 pacientes, persistió el dolor, requiriendo banding del acceso, que finalmente se trombosó; un paciente debió ser amputado del antebrazo distal, pese a revascularización, al no ceder cuadro infeccioso. La mortalidad operatoria fue de 13 por ciento, correspondiendo a 3 pacientes muy deteriorados con isquemia severa. La mortalidad tardía fue de 56,5 por ciento (13 pacientes). El tiempo promedio de uso del acceso fue de 2 años, post revascularización. Conclusión: La RDLI es el procedimiento de elección en el tratamiento del robo, ya que elimina efectivamente la isquemia y mantiene en uso el acceso. Los pacientes con robo, especialmente diabéticos, representan un grupo de alto riesgo y mortalidad.

Interleukin-6 -634 C/G and -174 G/C Polymorphisms in Korean Patients Undergoing Hemodialysis

BACKGROUND/AIMS: Chronic inflammatory status is a possible risk factor for vascular access dysfunction in hemodialysis (HD) patients, but susceptibility differences appear among individuals. Interleukin (IL)-6 is a well-known inflammatory cytokine with various polymorphisms. We examined whether IL-6 polymorphisms are associated with vascular access dysfunction in HD patients. METHODS: A total of 80 HD patients (including 42 diabetic patients) were enrolled. Polymorphisms in the IL-6 gene promoter (-634 C/G and -174 G/C) were studied using restriction length polymorphism polymerase chain reaction analysis. Vascular access patency was compared between the patient groups with respect to IL-6 polymorphisms. An additional 89 healthy individuals were enrolled in the control group. Plasma IL-6 levels were de termined by enzyme-linked immunosorbent assay. RESULTS: The GG genotype and G allele at position -634 in the IL-6 promoter were more frequently observed in HD patients than in controls. Furthermore, the distribution of the -634 polymorphism differed according to vascular access patency in non-diabetic HD patients. However, the G allele was not a significant risk factor for early access failure. No significant association appeared between the IL-6 -634 C/G polymorphism and plasma IL-6 levels. The C allele of the IL-6 -174 G/C polymorphism was not detected in our study population. CONCLUSIONS: The IL-6 -634 G allele appears with greater frequently in patients with end-stage renal disease and may be associated with vascular access dysfunction in non-diabetic HD patients.

Avaliação do acesso vascular para hemodiálise em crianças e adolescentes: um estudo de coorte retrospectivo de 10 anos / Hemodialysis vascular access in children and adolescents: a ten-year retrospective cohort study

INTRODUÇÃO: As intercorrências do acesso vascular têm sido a maior causa de internação entre os pacientes com estágio V da doença renal crônica (DRC) em hemodiálise (HD). Apesar de campanhas para a diminuição do uso de cateter venoso central (CVC) como via de acesso para HD, este ainda representa a principal via de acesso para crianças e adolescentes que iniciam HD. OBJETIVOS E MÉTODOS: Este estudo tem o objetivo de avaliar, por meio de um coorte retrospectivo, o tipo de acesso vascular inicial, a incidência de complicações dos acessos vasculares e as razões de falência dos acessos em crianças e adolescentes com idade entre 0 e 18 anos que iniciaram HD no período de 1997 a 2007. RESULTADOS: Foram estudados 251 acessos em 61 pacientes, sendo 97 fístulas arteriovenosas (FAV) e 154 CVC de curta permanência. Dos pacientes do estudo 51 por cento iniciaram HD pelo CVC. A média de idade dos pacientes no início da HD foi de 12,5 anos. A doença de base predominante foi glomerulopatia (46 por cento). A principal causa de retirada de CVC foi infecção, em 35 por cento. A sobrevida média do CVC foi de 40 dias. A falência primária da FAV foi detectada em 37,8 por cento das FAV confeccionadas. Para as FAV funcionantes, a principal causa de falência foi a trombose (84 por cento). A infecção não foi a causa de nenhuma falência de FAV. Comparando-se os tipos de acesso, constatou-se risco de infecção 34 vezes maior para os pacientes em uso de CVC em relação aos em uso de FAV. CONCLUSÃO: A infecção foi a maior causa de retirada de CVC temporário. Esse estudo sugere que o CVC temporário deve ser evitado, e, sempre que possível, substituído por FAV ou CVC de longa permanência. A trombose foi a principal causa de perda da FAV, reforçando a importância de um programa para a detecção precoce da disfunção do acesso.

INTRODUCTION: The complications of vascular access have been the major cause of hospitalization among patients with end stage renal disease (ESRD) on Haemodialysis (HD). Despite recommendations to decrease the use of central venous catheter (CVC) it still represents the main access for children and adolescents who start HD. OBJECTIVES AND METHODS: This study aimed to evaluate, through a retrospective cohort study, the initial type, the incidence of complications and reasons for failure of vascular access in children and adolescents aged 0 to younger than 18 years who started HD from 1997 to 2007. RESULTS: 251 accesses were studied in 61 patients, 97 arteriovenous fistula (AVF) and 154 temporary uncuffed CVC. 51 percent of study patients began HD with CVC. The mean age of patients at the start of HD was 12.5 years. The predominant underlying disease was glomerulonephritis (46 percent). The main cause of CVC removal was infection in 35 percent. The mean survival of the uncuffed CVC was 40 days. AVF primary failure was detected in 37.8 percent of the fistulas. Considering the patent fistulas, the main cause of failure was thrombosis (84 percent). Infection did not caused any loss of AVF. When comparing the two types of access we find a risk of infection 34 times higher in patients using CVC against AVF. CONCLUSION: Infection was the major cause of CVC removal, and our results suggest that uncuffed CVC must be avoided for ESRD children and adolescents on HD and replaced by AVF or cuffed CVC, whenever it is feasible. Thrombosis was the main cause of AVF loss, urging the need of implementation of a program for early detection of access failure.

Latero-lateral femoro-femoral arteriovenous fistula: a new surgical approach for hemodialysis patients with no vascular access / Fístula artériovenosa fêmoro-femoral látero-lateral: uma nova abordagem para hemodiálise de pacientes sem opção de acesso vascular

Purpose: A new surgical approach for vascular access for hemodialysis using a latero-lateral arteriovenous fistula (AVF) in the thigh between the femoral artery (FA) and superficial femoral vein (SFV) transposed to the subcutaneous layer in patients with no other access options is described. Methods: Ten patients (mean age: 37,9 years) for whom all possible sites for execution of any other procedure had been exhausted, underwent latero-lateral AVF close to the adductor channel between the FA and the SFV. The FSV was released and sectioned 2 cm from its confluence with the deep femoral vein and transposed in the subcutaneous tissue with extensions using saphenous vein or prosthetic material (PTFE) when needed. Follow -up included patency, flow evaluation and complications. Results: Postoperative follow-up ranged from 3 to 96 months, with a mean of 38 months. The AVFs presented a flow of more than 350 ml/min and the AVFs remained patent for a mean period of 38 months. There were three failures of the procedures at 3, 5 and 7 months during postoperative follow-up due to graft infection and thrombosis (a case), anaphylactic shock and thrombosis (a case) and calf pain during dialysis (a case). Two patients developed slight inferior limb edema. Conclusion: The new surgical approach for access for hemodialysis represents a feasible procedure, with acceptable patency rates in exceptional cases where no other access option is available.

Objetivo: Nova abordagem para acesso vascular para hemodiálise usando fistula artério-venosa (FAV) látero-lateral na coxa entre a artéria femoral (AF) e a veia femoral superficial (VFS) transposta no subcutâneo em pacientes sem opção de acesso. Métodos: Dez pacientes (idade média 37,9 anos), cuja possibilidade de acesso havia sido exaurido, foram submetidos a FAV látero-lateral na coxa entre a AF e a VFS.Esta veia foi liberada e seccionada 2 cm de sua confluência com a veia femoral profunda e transposta no plano superficial com extensão usando a veia safena ou material protético (PTFE) quando necessário.O seguimento incluíu a perviedade , fluxo e complicações. Resultados: O seguimento pós-operatório foi de 3 a 96 meses (média 38). A FAV apresentou fluxo mínimo de 350 ml/min e permaneceu pérvia no período médio de 38 meses. Houve 3 falências aos 3, 5, e 7 meses pós-operatórios por infecção de prótese e trombose da FAV (um caso), choque anafilático e trombose (um caso) e dor na panturrilha na hemodiálise (um caso). Dois pacientes desenvolveram discreto edema de membro inferior. Conclusão: A nova abordagem para acesso vascular para hemodiálise representa um procedimento factível, com aceitável perviedade em casos excepcionais onde nenhum outro acesso é disponível.

Arteriovenous fistula [AVF] formation: comparison of end-to-side and side-to-side techniques in end stage renal disease

To compare the success and complications of the side-to-side and end-to-side techniques of AV fistula formation. A prospective randomized comparative analysis of 344 cases. The study was carried out from February 2006 to July 2010 in the Department of Urology, Punjab Medical College and Al-Noor Hospital Faisalabad. A total number of 344 patients with end stage renal disease [ESRD] were included in the study for AV. fistula formation for hemodialysis access. 304 patients completed their follow up. AV fistula was made by end-to-side and side-to-side techniques. Patients were followed after 24 Hours, 1 week, 1 month and 6 months after the operation. These 304 patients were divided into 2 groups. Group 1 comprises of 154 patients and group 2 comprises of 150 patients. AV fistula worked successfully in 88.3%, 70.78%, 68.18% and 61.04% of 154 group 1 patients after 24 hours, one week, one month and six months followup respectively. AV fistula worked successfully in 76%, 65.33%, 63.33% and 58% of 150 group 2 patients after 24 hours, one followup respectively. Hemorrhage from fistula site was among 9.09%patients in group 1 and in 7.33% in group 2 patients after 24 hours of surgery while it was 2.6% and 1.33% patients in group 1 and group 2 patients respectively after one moth follow up. Aneurysm was seen in 1.3% patients at one month and six months follow up respectively in group 1. It was seen in 0.67 and 1.33% patients at one month and six months follow up in group 2 patients. Ischemia was seen among 1.3% patients in group 1 and 8% in group 2 patients. No limb edema was present up to 1 week in any group. Odema was in 9.74% and 13% patients of group 1 patients at one month and six months follow up and 14.67% and 17.33% of group 2 patients at one month and six months follow up respectively. Both operative techniques for AV fistula formation are equally good for hemodialysis access but complication rate with end-to-side technique is lower as compared to side-to-side technique

Interleukin-10 and Tumor Necrosis Factor-alpha Polymorphisms in Vascular Access Failure in Patients on Hemodialysis: Preliminary Data in Korea

Neointimal hyperplasia causes vascular stenosis and subsequent thrombosis, which result in vascular access failure in patients undergoing hemodialysis. Interleukin-10 (IL-10) and tumour necrosis factor-alpha (TNF-alpha) are involved in this inflammatory process. The aim of this study was to investigate the relationship between vascular access failure and various inflammatory markers including the genetic polymorphisms of IL-10 and TNF-alpha. Seventy-five patients on hemodialysis with an arteriovenous fistula in place or an artificial graft (18 with vascular access failure and 82 without failure) and 98 healthy individuals were genotyped for IL-10 and TNF-alpha single nucleotide polymorphisms. Clinical and laboratory data including serum IL-10 and TNF-alpha levels were compared. Stimulated IL-10 levels, from in vitro incubation of blood with lipopolysaccharide, were also obtained and compared. Female gender, hypoproteinemia, and hypertriglyceridemia were associated with vascular access failure. The basal TNF-alpha level was significantly higher in patients with access failure. The distribution of IL-10 and TNF-alpha genotype did not differ among patients with or without access failure. This study could not demonstrate a relationship between genetic polymorphisms and vascular access failure. However, an altered immune response and inflammation might contribute to vascular access failure.

Isquemia sintomática en accesos vasculares parahemodiálisis / Symptomatic ischemia of hemodialysis vascular access

El objetivo de este estudio es dar a conocer nuestra experiencia en el manejo de pacientes con isquemia sintomática severa asociada a los accesos vasculares para hemodiálisis (AVHD). Entre Enero de 2000 y Junio del 2005 se construyeron 1926 accesos vasculares para hemodiálisis en 1537 pacientes en el Servicio de Cirugía del Hospital Barros Luco Trudeau, seleccionando aquellos pacientes que fueron manejados por presentar elementos de isquemia sintomática severa. El grupo está constituido por 18 pacientes, 9 (50 por ciento) hombres y 9 (50 por ciento) mujeres, 14 (78 por ciento) diabéticos. La edad promedio fue de 61 años. El diagnóstico se hizo en base a la anamnesis, examen físico y laboratorio no invasivo. En algunos casos se realizó eco doppler y angiografía. La incidencia encontrada es 1,17 por ciento, correspondiendo 61,1 por ciento a diabéticos mayores de 60 años y 16,7 por ciento a no diabéticos menores de 60 años (p< 0,05). Se presentó en 1,1 por ciento de los pacientes con AVHD nativo y 1,93 por ciento con AVHD protésico (ns). Las manifestaciones aparecieron en el post operatorio inmediato en 7 (39 por ciento) pacientes y en forma tardía en 11 (61 por ciento). La etiología fue enfermedad arterial oclusiva en 13 casos (72,2 por ciento), mecanismo de robo arterial en 3 (16,7 por ciento) y estenosis funcional en 2 (11,5 por ciento). El manejo consistió en revascularización en 8 casos (44,5 por ciento) y cierre de la fístula mas instalación de catéter tunelizado en 10 (55,5 por ciento). Al término del seguimiento, 15 (83,3 por ciento) presentaban regresión completa de los síntomas y 3 (16,7 por ciento) presentaban secuelas. La isquemia sintomática es una complicación poco frecuente, que puede presentarse tanto en forma precoz como tardía especialmente en pacientes diabéticos mayores de 60 años o con enfermedad vascular periférica, pudiendo significar la pérdida del acceso o dejar secuelas invalidantes. Son importantes las medidas de prevención.

Background: Symptomatic ischemia occurs in 1 to 8 percent of hemodialysis vascular accesses and may result in its loss. Aim: To report our experience in the management of patients with severe symptomatic ischemia associated to a vascular access for hemodialysis. Material and methods: All patients operated for a severe ischemia associated to a hemodialysis vascular access, between 2000 and 2005, were included in this study. Results: Of a total of 1926 vascular accesses, symptomatic ischemia was diagnosed in 18 patients (9 males) aged between 27 and 84 years. Fourteen (78 percent) were diabetic. Thus, the incidence of severe ischemia was 1.2 percent. It appeared in 1.1 percent of native and 1.9 percent of prosthetic vascular accesses. Clinical manifestations appeared in the early postoperative period in seven patients (39 percent). In the rest, they appeared more than 30 days after the procedure. Surgical treatment consisted in revascularization in eight patients (45 percent) and closure of fistula and installation of a tunneled catheter in 10 (55 percent). At the end of follow up, 15 patients (83 percent) had a complete regression of symptoms and three (17 percent) had sequelae. Conclusions: Symptomatic vascular access ischemia occurs in 1.2 percent of procedures, is much more common among diabetics and can be successfully managed in 80 percent of cases.