Hemodialysis Vascular access maintenance in the Covid-19 pandemic: Positioning paper from the Interventional Nephrology Committee of the Brazilian Society of Nephrology / Manutenção de acessos vasculares para hemodiálise na pandemia da Covid-19: posicionamento do Comitê de Nefrologia Intervencionista da Sociedade Brasileira de Nefrologia

ABSTRACT Vascular accesses for hemodialysis are considered the patient's lifeline and their maintenance is essential for treatment continuity. Following the example of institutions in other countries affected by the Covid-19 pandemic, the Brazilian Society of Nephrology developed these guidelines for healthcare services, elaborating on the importance of carrying out procedures for the preparation and preservation of vascular accesses. Creating definitive accesses for hemodialysis, grafts and arteriovenous fistulas are non-elective procedures, as well as the transition from the use of non-tunneled catheters to tunneled catheters, which cause less morbidity. In the case of patients with suspected or confirmed coronavirus infection, one may postpone the procedures for the quarantine period, to avoid spreading the disease.

RESUMO Os acessos vasculares para hemodiálise são considerados a linha da vida do paciente, e sua manutenção é essencial para o seguimento do tratamento. A exemplo de instituições de outros países atingidos pela pandemia da Covid-19, a Sociedade Brasileira de Nefrologia elaborou estas orientações para os serviços de saúde, esclarecendo a importância da realização dos procedimentos de confecção e preservação de acessos vasculares. Consideramos como não eletivos os procedimentos de confecção de acessos definitivos para hemodiálise, próteses e fístulas arteriovenosas, bem como a transição do uso de cateteres não tunelizados para cateteres tunelizados, os quais acarretam menor morbidade. Nos casos de pacientes com infecção suspeita ou confirmada por coronavírus, é aceitável o adiamento dos procedimentos pelo período de quarentena, para evitar disseminação da doença.

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.

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.

Transcatheter closure of perimembranous ventricular septal defects in children using a Wire-Drifting Technique

OBJECTIVE: Explore the feasibility and safety of transcatheter closure of perimembranous ventricular septal defects using a wire-drifting technique (WT) in children. METHODS: We retrospectively analyzed 121 pediatric patients diagnosed with perimembranous ventricular septal defects who underwent interventional treatment at the First Affiliated Hospital of Xi'an Jiaotong University from Dec 2011 to Dec 2014. Based on the method used for arteriovenous loop establishment during the procedure, the patients were divided into a conventional technique (CT) group and a WT group. RESULTS: In total, 51 of the 53 patients (96.2%) in the CT group and 66 of the 68 patients (97.1%) in the WT group achieved procedural success, with no significant difference between the two groups (p>0.05). The CT group showed a nonsignificantly higher one-time success rate of arteriovenous loop establishment (94.3% vs. 91.2%, p>0.05). The procedure time was 46.0 (14.0) min and 46.5 (10.0) min in the CT and WT groups, respectively. The CT procedure was discontinued in the 2 cases (3.8%) of intraprocedural atrioventricular block in the CT group. In the one case (1.9%) of postprocedural atrioventricular block in the CT group, a permanent pacemaker was implanted to resolve third-degree atrioventricular block three months after the procedure. In the WT group, no cases of intraprocedural atrioventricular block occurred, and one case (1.5%) of postprocedural atrioventricular block occurred. In this case, intravenous dexamethasone injection for three days returned the sinus rhythm to normal. Aggravated mild to moderate tricuspid regurgitation was observed in 2 patients (3.8%) in the CT group during the 2-year follow-up period; aggravated tricuspid regurgitation was not observed in the WT group. During the 2-year follow-up period, there was no evidence of residual shunting in either group. CONCLUSION: Transcatheter closure of perimembranous ventricular septal defects with the WT is safe and effective in children.

Cierre percutáneo de conducto arterioso mediante un asa arteriovenosa en un paciente con síndrome de la cimitarra / Percutaneous closure of ductus arteriosus through an arteriovenous loop in a patient with scimitar syndrome

Resumen: Introducción: El síndrome de la cimitarra consiste en una rara malformación, caracterizada por una conexión anómala parcial de una o ambas venas pulmonares derechas a la vena cava inferior, hipoplasia de pulmón derecho y circulación sistémica desde la aorta descendente. El síndrome de la cimitarra en ocasiones se asocia con otras malformaciones congénitas, entre las que se incluye la persistencia del conducto arterioso (PCA). Caso clínico: Paciente de sexo femenino de cuatro años de edad con síndrome de la cimitarra, variedad ''adulto'', asociado con PCA sintomático. Se realizó exitosamente oclusión del conducto mediante un asa arteriovenosa femoral con un dispositivo Amplatzer® PDA, sin complicaciones. Conclusiones: El manejo del síndrome de la cimitarra es complejo y amerita de un estudio hemodinámico completo para determinar el tratamiento adecuado. La hipertensión arterial pulmonar es un factor de mal pronóstico.

Abstract: Background: Scimitar syndrome consists in a rare malformation characterized by a partial abnormal connection in one or both right pulmonary veins to the inferior vena cava, right lung hypoplasia and systemic circulation from the descending aorta. Scimitar syndrome is occasionally associated to other congenital malformations, such as patent ductus arteriosus (PDA). Case report: We report a 4-year-old patient with ''adult'' variety of scimitar syndrome associated to symptomatic PDA, which was successfully occluded using retrograde guidewire-established femoral arteriovenous loop with an Amplatzer® PDA occluder, without complications. Conclusions: Scimitar syndrome is complex and requires a complete hemodynamic study for the determination of the appropriate treatment. Pulmonary arterial hypertension is a factor associated with poor prognosis.

Stent Placement in a Neonate with Sano Modification of the Norwood using Semi-Elective Extracorporeal Membrane Oxygenation / Colocação de Stent em um Recém-Nascido Submetido à Modificação de Sano da Operação de Norwood Usando Oxigenação por Membrana Extracorpórea Semi-Eletiva

Abstract Extracorporeal membrane oxygenation (ECMO) is a well-established tool of cardiopulmonary circulatory support for cardiopulmonary failure in children and adults. It has been used as a supportive strategy during interventional procedures in neonates with congenital heart disease. Herein, we describe a neonate with hypoplastic left heart syndrome who underwent stenting of the Sano shunt and left pulmonary artery after Norwood Sano operation using intra-procedural ECMO support. The use of ECMO as a bridge to recovery might be a feasible and reasonably safe adjunctive approach in the treatment of complications in selective case of neonates having undergone the Norwood Sano procedure.

Resumo A oxigenação por membrana extracorpórea (ECMO) é uma ferramenta bem estabelecida de suporte circulatório em casos de insuficiência em crianças e adultos. A ECMO tem sido utilizada como uma estratégia de suporte durante procedimentos interventistas em recém-nascidos com doença cardíaca congênita. Descrevemos o caso de um recém-nascido com síndrome do coração esquerdo hipoplásico que foi submetido à colocação de um stent em shunt de Sano e artéria pulmonar esquerda após procedimento de Norwood-Sano utilizando-se a ECMO como suporte. O uso da ECMO pode ser uma estratégia adjunta viável e segura no tratamento de complicações em casos eletivos de recém-nascidos submetidos à operação de Norwood-Sano.

Transposition of Great Arteries with Intramural Coronary Artery: Experience with a Modified Surgical Technique

Abstract Objective: Transposition of the great arteries is a common congenital heart disease. Arterial switch is the gold standard operation for this complex heart disease. Arterial switch operation in the presence of intramural coronary artery is surgically the most demanding even for the most experienced hands. We are presenting our experience with a modified technique for intramural coronary arteries in arterial switch operation. Methods: This prospective study involves 450 patients undergoing arterial switch operation at our institute from April 2006 to December 2013 (7.6 years). Eighteen patients underwent arterial switch operation with intramural coronary artery. The coronary patterns and technique used are detailed in the text. Results: The overall mortality found in the subgroup of 18 patients having intramural coronary artery was 16% (n=3). Our first patient had an accidental injury to the left coronary artery and died in the operating room. A seven-day old newborn died from intractable ventricular arrhythmia fifteen hours after surgery. Another patient who had multiple ventricular septal defects with type B arch interruption died from residual apical ventricular septal defect and sepsis on the eleventh postoperative day. The remainder of the patients are doing well, showing a median follow-up duration of 1235.34±815.26 days (range 369 - 2730). Conclusion: Transposition of the great arteries with intramural coronary artery is demanding in a subset of patients undergoing arterial switch operation. We believe our technique of coronary button dissection in the presence of intramural coronary arteries using coronary shunt is simple and can be a good addition to the surgeons' armamentarium.

Comportamiento de las fístulas arteriovenosas para hemodiálisis en el anciano / Behavior of arteriovenous fistulas for hemodialysis in elderly patients

Introducción: en los últimos años se ha observado un incremento de pacientes ancianos en los servicios de hemodiálisis. Este hecho, unido al número creciente de pacientes diabéticos con lecho vascular deteriorado, ha aumentado la dificultad para la creación de un acceso vascular en esta población en riesgo. Objetivo: observar el comportamiento de las fístulas arteriovenosas en pacientes de 65 años o más en régimen de hemodiálisis. Métodos: se realizó un estudio observacional descriptivo prospectivo en pacientes de 65 años o más a los que se le construyó una fístula arteriovenosa entre marzo de 2011 y marzo de 2013 en el servicio de Hemodiálisis del Instituto de Nefrología de La Habana. El grupo de estudio fue de 58 pacientes. Resultados: Hubo predominio del sexo masculino (55,2 por ciento). Las enfermedades de base que más se observaron fueron la Diabetes mellitus (43,1 por ciento) y la Hipertensión arterial (37,9 por ciento). Las complicaciones que más se registraron fueron: flujo insuficiente (15,2 por ciento) y trombosis (12,1 por ciento). Mostraron mayor supervivencia las fístulas arteriovenosas en hombres (78 %), en pacientes no diabéticos (73 por ciento) y las de localización radiocefálica (73 por ciento). La supervivencia primaria global al año de las fístulas arteriovenosas en nuestros pacientes fue de 69,0 por ciento. Conclusiones: Las fístulas arteriovenosas autólogas pueden ser realizadas como primera opción en pacientes de 65 años o más y se obtienen tasas de supervivencia adecuadas, comparables a las de otros grupos de pacientes(AU)

Introduction: In the last few years, the number of old patients in the hemodialysis service has increased. This fact along with this growing number of diabetic patients that show damaged vascular bed has brought about more difficulties in creating a vascular access in their risk population. Objective: To observe the behavior of arteriovenous fistulae in patients aged 65 years or more subjected to hemodialysis. Methods: Prospective, descriptive and observational study conducted in 65 years old and over whom an arteriovenous fistula was created from March 2011 to March 2013 at the hemodialysis service of the Institute of Nephrology in Havana. The study group was made up of 58 patients. Results: The male sex predominated (55.2 percent). The most observed underlying diseases were diabetes mellitus (43.1 percent) and hypertension (37.9 percent). The most found complications were insufficient flow (15.2 percent) and thrombosis (12.1 percent). The highest survival rate was seen in arteriovenous fistulae in men (78 percent); non-diabetic patients (73 percent) and radiocephalic location (73 percent). The global primary survival rate after one year of the arteriovenous fistulae in our patients was 69 percent. Conclusions: The autologous arteriovenous fistulae may be performed as a first option in patients aged 65 years or more, and adequate survival rates, comparable to those of other groups of patients, were reached(AU)

Fístula arterio-venosa como tratamiento de EPOC grave / Arteriovenous fistula in the treatment of severe COPD

COPD patients have dyspnea limiting their exercise capacity due to different mechanisms. The origin of the arterial blood gases anomaly is an alteration of the ventilation/perfusion (V'/Q') ratio causing venous admixture which has not been addressed therapeutically so far. Theoretically an arteriovenous fistula (AVF) could increase venous content of O2 so that blood leaving the left ventricle has a higher than expected PaO2 .This, along with the associated increase in cardiac output leads to an increased delivery of O2 to tissues particularly skeletal muscle thus improving its performance. We present a patient with advanced COPD. Full conventional therapy failed to improve his dyspnea and hypoxemia which limits his exercise capacity. We made a peripheral arteriovenous fistula on him as a therapeutic intent. Spirometry showed an initial FEV1 of 0.74 L, a FVC of 1.97 L, he had hypoxemia (PaO2 :56.8 mmHg, oxyhemoglobin saturation (SaO2 ): 82.9 percent). A 6 min walking test with a distance of300 m corresponding to 61 percent of predetermined value that improved by 108 m providing O2 2 L/min. Echocardiography showed a pulmonary artery systolic pressure of 26 mm Hg and a 60 percent of left ventricle ejection fraction. The patient obtained 73.8 percent in Saint George's Respiratory Questionnaire (SGRQ), 38 points in COPD Assesment Test (CAT) and 6 points in BODE Index. After 4 weeks of AVF neither spirometric nor echocardiographic changes were observed, but there was an improvement in PaO2 to 68 mmHg and in SaO2 to 93 percent. The 6 min walking test showed an increase to 425 m. SGRQ improved to 3.88 points, BODE index improved to 3 points and CAT to 21 points. We conclude that in this patient an AVF determined an improvement in exercise capacity with a better control of disease that resulted in a better quality of life constituting an important non pharmacological aid in an advanced COPD patient who failed to improve with full medical therapy. In patients selection...

El paciente portador de EPOC tiene disnea que limita su capacidad de ejercicio por diferentes mecanismos entre los cuales está la incapacidad de la musculatura respiratoria para responder al aumento de las demandas, que puede ser secundaria a la disminución de la entrega de O2. La anomalía gasométrica propia de la enfermedad tiene como origen una alteración de la relación ventilación/ perfusión (V'/Q') que causa un aumento de la admisión venosa el cual no ha sido enfrentado terapéuticamente hasta el momento. Teóricamente una fístula arteriovenosa (FAV) podría aumentar el contenido venoso de O2 ,de modo que la sangre que sale del ventrículo izquierdo lo haga con una PaO2 mayor que la esperada. Esto, junto con el aumento del gasto cardíaco asociado llevaría a una mayor entrega de O2 a los tejidos mejorando de esa forma el desempeño de la musculatura esquelética. En un paciente con EPOC avanzada que con terapia máxima no logra mejorar la disnea ni la hipoxemia que limitan seriamente su capacidad de ejercicio, confeccionamos una fistula entre la vena safena interna y la arteria femoral superficial con intención terapéutica. La espirometría inicial mostró un VEF1de 0,74 L (26 por ciento del valor predeterminado) con CVF de 1,97 L (57 por ciento). Presentaba hipoxemia (PaO2 :56,8 mmHg y SaO2 :82,9 por ciento), un test de caminata de 6 min (TC6M) con un recorrido de 300 m que corresponde a un 61 por ciento del teórico que mejoraba al aportar O2 2 L/min a 408 m correspondiente a un 80 por ciento del teórico. El ecocardiograma detectó una presión sistólica de arteria pulmonar de 26 mmHg y una fracción de eyección del ventrículo izquierdo de 60 por ciento. En el cuestionario respiratorio de Saint George el paciente obtuvo 73,8 por ciento su CAT (COPD Assessment Test) fue de 38 puntos y su índice BODE (Body mass, Obstruction, Dyspnea, Exercise capacity) de 6 puntos. Al mes de realizada la FAVno hubo cambios espirométricos ni ecocardiográficos, pero la PaO2 mejoró a...

Microembolia gasosa em operação cardíaca com uso de circulação extracorpórea: emprego de shunt venoarterial como método preventivo / Gaseous microemboli in cardiac surgery with cardiopulmonary bypass: the use of veno-arterial shunt as a preventive method

As complicações neurológicas representam importante causa de morbidade no período pós-operatório de cirurgia cardíaca e sua incidência alcança até 75% dos pacientes. Uma importante causa desses eventos é a formação de microbolhas na corrente sanguínea durante a circulação extracorpórea. Realizou-se revisão integrativa sobre microembolia gasosa na circulação extracorpórea. Esse trabalho analisou estudos com abordagens metodológicas diferentes, mas que contemplam o tema. O resultado sugere que a desnitrogenação do sangue causada pela hiperoxia dissolve microbolhas formadas no sangue e o shunt venoarterial pode equilibrar os parâmetros respiratórios alterados pela hiperoxia.

Neurological complications are an important cause of morbidity in the postoperative period of cardiac surgery and its incidence reaches up to 75% of patients. An important cause of these events is the formation of microbubbles in the bloodstream during cardiopulmonary bypass. Integrative review was carried out on gaseous microemboli in cardiopulmonary bypass. This study analyzed studies with different methodological approaches, but that address the issue. The result suggests the denitrogenation of blood by hyperoxia dissolved microbubbles in the blood and venoarterial shunt can balance the respiratory parameters changed with hyperoxia.

Buttonhole, em casa de botão ou botoeira: uma técnica antiga redescoberta: [carta ao editor] / Buttonhole: an old technique rediscovered: [letter to the editor]

A presente carta ao Editor aborda os artigos de Silva et al. Õ e de Castro et al. ² que nos levam a dois tipos de comentários: o primeiro de ordem linguística, e o segundo referente a aspectos médicos.

The present letter to the Editor regards the articles by de Silva et al. Õ and de Castro et al. ² that lead us to two kinds of comments, the first refers to the language, and the second comment refers to the medical aspects.

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.

Percutaneous Intervention in Axillary Loop-Configured Arteriovenous Grafts for Chronic Hemodialysis Patients

OBJECTIVE: The purpose of this study was to evaluate the fistulographic features of malfunctioning axillary loop-configured arteriovenous grafts and the efficacy of percutaneous interventions in failed axillary loop-configured arteriovenous grafts. MATERIALS AND METHODS: Ten patients with axillary loop-configured arteriovenous grafts were referred for evaluation of graft patency or upper arm swelling. Fistulography and percutaneous intervention, including thrombolysis, percutaneous transluminal angioplasty and stent placement, were performed. Statistical analysis of the procedure success rate and the primary and secondary patency rates was done. RESULTS: Four patients had graft related and subclavian venous stenosis, two patients had graft related stenosis and another four patients had subclavian venous stenosis only. Sixteen sessions of interventional procedures were performed in eight patients (average: 2 sessions / patient) until the end of follow-up. An interventional procedure was not done in two patients with central venous stenosis. The overall procedure success rate was 69% (11 of 16 sessions). The post-intervention primary and secondary patency rates were 50% and 63% at three months, 38% and 63% at six months and 25% and 63% at one year, respectively. CONCLUSION: Dysfunctional axillary loop-configured arteriovenous grafts almost always had subclavian venous and graft-related stenosis. Interventional treatments are helpful to overcome this and these treatments are expected to play a major role in restoring and maintaining the axillary loop-configured arteriovenous loop grafts.

Adición de un cortocircuito arterio-venoso durante el soporte vital extracorpóreo veno-arterial de un paciente con síndrome cardiopulmonar por Hantavirus: Caso clínico / Addition of an arterio-venous shunt during veno-arterial extracorporeal life support in a patient with Hantavirus pulmonary syndrome

A subgroup of patients infected with the Hantavirus develops a pulmonary syndrome (HPS) characterized by severe acute respiratory failure and myocardial depression, that has a high mortality rate. Extracorporeal life support (ECLS) could be a valuable therapeutic tool in such patients. We report a 24 years old male with HPS that was successfully managed when an arterio-venous shunt was added to a conventional veno-arterial ECLS technique. Precise criteria have been developed to predict which patients should be considered for this treatment.

Shunt atricova A propósito de dos casos: Report of two cases / Atriocaval shunt

The mortality of grade V and VI liver trauma fluctuates between 30percent and 70percent. The atriocaval shunt, described by Shrock et al, in 1968, is a therapeutic option that, after being installed, allows to repair the suprahepatic veins and retrohepatic cava in a bloodless surgical field. Its use requires an experienced and skilled surgeon to obtain survival rates similar to those obtained with other methods. We report two male patients of 17 and 18 years old treated successfully with this technique after suffering a blunt and a penetrating liver trauma by a shotgun, respectively.

Experience with arteriovenous fistulas for chronic hemodialysis in children: technical details and refinements

OBJETIVO: Relatar a experiência dos autores na execução de fístulas artério-venosas em crianças, com a utilização dos recursos da microcirurgia vascular, com especial ênfase aos detalhes de técnica cirúrgica. MÉTODOS: Os pacientes foram operados entre julho de 1997 e março de 2004. Foram utilizadas lupas cirúrgicas (aumento de 3,5 vezes). Após a dissecção da veia e da artéria, a anastomose veno-arterial foi realizada de forma término-lateral, com quatro suturas contínuas de fio 7/0 ou 8/0. RESULTADOS: Vinte e nove crianças foram operadas para a realização de 33 fístulas - 21 rádio-cefálicas, 6 bráquio-cefálicas, 4 bráquio-basílicas e 2 safeno-femorais. Obteve-se permeabilidade em 17/21 (80,9%) fístulas rádio-cefálicas, 5/6 (83,3%) bráquio-cefálicas, 3/4 (75,0%) bráquio-basílicas e 2/2 (100%) safeno-femorais. 2 pacientes apresentaram obstrução da fístula e da artéria radial e 2 outras fístulas rádio-cefálicas obstruíram-se entre a primeira e segunda semana de pós-operatório. Tardiamente, verificou-se que as fístulas safeno-femorais causaram edema do membro inferior correspondente e houve formação de aneurisma em uma fístula bráquio-cefálica. Quanto à permeabilidade, verificou-se que as fístulas bráquio-cefálicas e bráquio-basílicas apresentaram a mesma incidência de permeabilidade em comparação com as fístulas rádio-cefálicas (p>0,05). CONCLUSÃO: A presente casuística demonstra que as fístulas artério-venosas persistem como um bom acesso vascular para hemodiálise em crianças. A utilização de microcirurgia e alguns detalhes técnicos aqui descritos permitem a obtenção de bons índices de permeabilidade das fístulas.

Arteriovenous fistula construction in chronic haemodialysis patients: comparison of end-to-side and side-to-side techniques

To compare the techniques of end-to-side and side-to-side anastomosis in arteriovenous fistulae construction in terms of success rate and immediate postoperative complications. Design: Comparative study. Place and Duration of Study: Ayub Hospital Complex, Abbottabad, from October 1999 to December 2002 and Khyber Teaching Hospital, Peshawar, from January 2003 to December 2003. Patients and One hundred and ninety patients with end stage renal disease [ESRD] were included in the study. Arteriovenous fistula was constructed in these patients by two techniques i.e. end-to-side and side-to-side anastomosis. The two methods were compared in terms of duration of surgery, immediate success rate and short-term complications. Among 190 patients, 118 [62%] were males and 72 [38%] females. The age ranged between 24 to 66 years with average age of 54 years. Side-to-side anastomosis was done in 120 [63%] patients while end-to-side in 70 [37%] patients. The average duration of surgery in side-to-side group was 50 minutes and in end-to-side group it was 75 minutes. Bleeding occurred in 4[5.7%] cases in end-to-side group and 2[1.7%] patients in side-to-side group requiring reexploration. The immediate failure rate of the procedure was 2.5% in side-to-side group and 7.5% in end-to-side group. Wound infection occurred in 1[1.4%] case in end-to-side group and 2[1.7%] cases in side-to-side group. In patients with end stage renal disease [ESRD] arteriovenous fistula construction by side-to-side anastomosis is less time-consuming and has less complications as compared to end-to-side technique

Off-pump bidirectional Glenn shunt by active decompression of the superior vena cava.

We report 2 cases of infants in whom off-pump bidirectional Glenn shunts were performed. A technique of decompressing the superior vena cava by active manual aspiration has been described. The challenges of maintaning the hemodynamic status, and cerebral protection maneuvers in association with mild hypothermia and a high transcranial pressure have been highlighted.