Outcomes of endovascular treatment of renal arterial stenosis in transplanted kidneys

ABSTRACT Objective To evaluate the effectiveness and outcomes of endovascular treatment of TRAS with PTA. Materials and Methods We searched our prospectively collected database looking at cases of TRAS between January 2005-December 2011. CCT was the gold-standart for diagnosis of TRAS. Parameters analysed comprised technical aspects, arterial blood pressure variation, and renal function. A minimum follow-up of 24 months was considered. Results Of the 2221 renal transplants performed in the selected period, 22 (0.9%) patients were identified with TRAS. Fourteen (63.6%) were male and mean age was 377±14.8years (12-69). Kidney graft was from deceased donnors in 20 (80%) cases. On doppler evaluation, mean blood flow speed after transplantation, at TRAS diagnosis and after TAP was 210.6±99.5, 417±122.7 and 182.5±81.6mL/sec, respectively (p<0.001). For SBP and DBP, there was a significant difference between between pre-intervention and all post-treatment time points (p<0.001). After 1 month of the procedure, there was stabilization of the Cr level with a significant difference between mean Cr levels along time (p<0.001). After a mean follow-up of 16±4.2 (3-24) months, overall success rate was 100%. Conclusions Endovascular treatment with PTA/stenting is a safe and effective option for managing TRAS, ensuring the functionality of the graft and normalization of blood pressure and renal function.

Abordagem percutânea das doenças da artéria renal / Percutaneous approach to renal artery disease

A estenose da artéria renal (EAR) é uma importante causa de hipertensão arterial sistêmica (HAS) secundária e disfunção renal. O principal mecanismo é por doença aterosclerótica unilateral ou bilateral. O diagnóstico precoce é importante para se evitar falência renal terminal e graves complicações cardiovasculares. O início de HAS precoce ou tardia, sopros abdominais, déficit renal sem causa aparente e HAS resistente são achados clínicos para se suspeitar de EAR, sendo necessários exames complementares como o Doppler colorido, angiotomografia ou ressonância nuclear magnética das artérias renais. A arteriografia renal é o padrão ouro para confirmação diagnóstica. O tratamento medicamentoso está indicado para os pacientes assintomáticos ou que mantêm controle clínico satisfatórios. A intervenção percutânea da artéria renal com uso de stents tem sido motivo de controvérsia, ficando restrita aos pacientes com perda progressiva da função renal e estenose bilateral, hipertensão arterial resistente ao tratamento medicamentoso, edema agudo de pulmão hipertensivo de repetição e disfunção de enxerto renal no caso de pacientes submetidos ao transplante renal

Renal artery stenosis (RAS) is an important cause of secondary systemic hypertension and renal dysfunction. The main mechanism is unilateral or bilateral atherosclerotic disease. Early diagnosis is important to avoid terminal renal failure and severe cardiovascular complications. The onset of early or late secondary systemic hypertension, abdominal murmurs, renal failure without apparent cause, and resistant secondary systemic hypertension are clinical findings to suspect RAS, and complementary exams such as color Doppler, angiotomography or magnetic nuclear magnetic resonance imaging of the renal arteries are necessary. Renal arteriography is the gold standard for diagnostic confirmation. Drug treatment is indicated for patients who are asymptomatic or who maintain satisfactory clinical control. Percutaneous renal artery intervention with stents has been controversial, being restricted to patients with progressive renal function loss and bilateral stenosis, drug-resistant hypertension, acute repetitive hypertensive pulmonary edema and renal graft dysfunction in patients submitted to kidney transplant

Collared Pecary (tayassu tajacu) as a new model of renal ischemic injury induced by clamping the renal artery

PURPOSE: The use of the collared peccary as an experimental model for ischemic nephropathy. METHODS: A total of 12 collared peccary (Tayassu tajacu) was used and ischemic nephropathy was induced in six of these animals that constituted the experimental group (G1) while the other six formed the control group (G2). Ischemic nephropathy was induced surgically by partial occlusion of the left renal artery. The disease course was assessed by hematological tests, serum chemistry, urinalysis, ultrasound (US) and doppler ultrasound function of the renal artery before induction, and at five, 10, 15 and 20 days after surgery. Twenty days after the occlusion, unilateral nephrectomy and histopathological examination were performed to assess renal morphology. RESULTS: Statistical analysis by Fischer's test showed a significant difference (p<0.05) between the control group and the experimental group. The histopathological examination showed glomerular, tubular and interstitial lesions. In the experimental group, 83.3% (5 /6) showed moderate renal lesions and only 16.7% (1/6) were classified with no lesions. The ultrasound examination of the right kidney presented statistical difference between day 5 and day 10 post occlusion. CONCLUSION: The collared peccary as a good experimental model for ischemic renal disease, because it could be manipulated during the research time without death, with health conditions that permit any subsequent procedure for disease therapy. .

Avaliação da sensibilidade e especificidade dos exames não invasivos no diagnóstico da estenose de artéria renal / Analysis of the sensitivity and specificity of noninvasive imaging tests for the diagnosis of renal artery stenosis

FUNDAMENTO: O envelhecimento e a aterosclerose estão relacionados à hipertensão renovascular em indivíduos idosos. Independentemente das comorbidades, a estenose de artéria renal é, por si só, importante causa de morbidade e mortalidade cardiovascular. OBJETIVO: Definir a sensibilidade, a especificidade, o valor preditivo positivo e o valor preditivo negativo dos exames não invasivos utilizados no diagnóstico de estenose da artéria renal. MÉTODOS: Um grupo de 61 pacientes recrutados permitiram a análise de 122 artérias e a definição de sensibilidade, especificidade e da contribuição relativa de cada exame realizado (Doppler, cintilografia e angiotomografia, comparados a arteriografia renal). RESULTADOS: A média das idades foi de 65,43 (desvio padrão: 8,7) anos. Das variáveis relacionadas à população do estudo e comparadas à arteriografia, duas estiveram correlacionadas à estenose da artéria renal, à disfunção renal e aos triglicerídeos. A mediana do ritmo de filtração glomerular foi de 52,8 mL/min/m². O Doppler identificou sensibilidade de 82,90%, especificidade de 70%, valor preditivo positivo de 85% e valor preditivo negativo de 66,70%. Para a tomografia, encontraram-se sensibilidade de 66,70%, especificidade de 80%, valor preditivo positivo de 87,50% e valor preditivo negativo de 55,20%. Esses achados permitiram identificar os exames que melhor detectavam a estenose. CONCLUSÃO: A tomografia e o Doppler mostraram qualidade e grande possibilidade no diagnóstico de estenose da artéria renal, com vantagem para o segundo, pois não há necessidade do uso de meio de contraste na avaliação de uma doença que, frequentemente, ocorre em diabéticos e associa-se à disfunção renal e à disfunção ventricular esquerda grave.

BACKGROUND: Aging and atherosclerosis are related to renovascular hypertension in elderly individuals. Regardless of comorbidities, renal artery stenosis is itself an important cause of cardiovascular morbidity and mortality. OBJECTIVE: To define the sensitivity, specificity, positive predictive value, and negative predictive value of noninvasive imaging tests used in the diagnosis of renal artery stenosis. METHODS: In a group of 61 patients recruited, 122 arteries were analized, thus permitting the definition of sensitivity, specificity, and the relative contribution of each imaging study performed (Doppler, scintigraphy and computed tomographic angiography in comparison to renal arteriography). RESULTS: The mean age was 65.43 years (standard deviation: 8.7). Of the variables related to the study population that were compared to arteriography, two correlated with renal artery stenosis, renal dysfunction and triglycerides. The median glomerular filtration rate was 52.8 mL/min/m². Doppler showed sensitivity of 82.90%, specificity of 70%, a positive predictive value of 85% and negative predictive value of 66.70%. For tomography, sensitivity was 66.70%, specificity 80%, positive predictive value 87.50% and negative predictive value 55.20%. With these findings, we could identify the imaging tests that best detected stenosis. CONCLUSION: Tomography and Doppler showed good quality and efficacy in the diagnosis of renal artery stenosis, with Doppler having the advantage of not requiring the use of contrast medium for the assessment of a disease that is common in diabetics and is associated with renal dysfunction and severe left ventricular dysfunction.

Neurofibromatosis with bilateral renal artery stenosis and end stage renal disease: case report

Neurofibromatosis type 1 [NF-1] is an autosomal dominant, hereditary, neurocutaneous syndrome that may, primarily or secondarily, affect different organs or systems of the body including the cardiovascular system. The most common vascular abnormality in patients with NF-1 is renal artery stenosis. Here we report the case of a middle-aged gentleman who presented at Sultan Qaboos University Hospital, Oman, with end stage renal disease and severe hypertension and was diagnosed to have NF-1 with bilateral renal artery stenosis. He was started on renal replacement therapy

Percutaneous Transluminal Angioplasty of Renal Artery Fibromuscular Dysplasia: Mid-term Results

OBJECTIVE: To evaluate mid-term imaging, clinical follow-up, and restenosis rates from patients that had undergone percutaneous transluminal renal artery angioplasty (PTRA) for symptomatic renal artery fibromuscular dysplasia (FMD). MATERIALS AND METHODS: Between March 1999 and July 2006, 16 consecutive renal artery FMD patients underwent PTRA for poorly controlled hypertension. The patients were enrolled into this retrospective study after receiving 19 primary and four secondary PTRAs in 19 renal artery segments. Follow-up monitoring of blood pressure, use of antihypertensive medication, and the serum creatinine level after PTRA were assessed at 1, 3, 6, 9, 12 months, and each following year. The degree of restenosis was evaluated with computed tomographic angiography (CTA) after PTRA at 6, 12 months, and every year if possible. Technical and clinical success rates for the treatment of FMD, and restenosis rates for the renal artery were evaluated. RESULTS: The technical success rate for primary PTRA was 79% (15/19) and the complication rate was 16% (3/19). Hypertension improved in 80% (12/15) of the patients after four weeks follow-up, and was finally cured or improved in 93% (14/15) during the mean follow-up period of 23.6 months. There was a cumulative 22% (4/18) restenosis rate during the follow-up period. All of the patients were treated with a second PTRA without complications and all of the patients were cured of hypertension after the second PTRA. CONCLUSION: Percutaneous transluminal renal artery angioplasty for clinically symptomatic renal FMD is technically and clinically successful and safe to perform. For all patients with restenosis, there was a good response after undergoing a second PTRA.

Eficácia clínica da revascularização renal percutânea com implante de stent em pacientes com doença renovascular aterosclerótica / Clinical efficacy of percutaneous renal revascularization with stent placement in atherosclerotic renovascular disease

OBJETIVO: Avaliar a eficácia da revascularização renal percutânea com implante de stent no controle da hipertensão e na preservação/restauração da função renal, em pacientes com doença renovascular aterosclerótica. MÉTODOS: De maio/1999 a outubro/2003, foram revascularizados 46 pacientes com estenose da artéria renal aterosclerótica (EAR-A), os quais foram submetidos ao implante de stent. A indicação para o procedimento foi controle da hipertensão e/ou preservação/restauração da função renal. Características gerais - Idade: 33-84 anos (mediana: 58,5±10,7), homens: 26 (56,5 por cento), diabéticos: 4 (10 por cento), DAC: 21 (46 por cento), creatinina < 2,0 mg/dl: 39 (64 por cento), ICC: 6 (14 por cento), estenoses ostiais 20 (43 por cento), estenose bilateral 15 (33 por cento). O controle da hipertensão foi averiguado pelo número de agentes utilizado antes do procedimento e durante o seguimento, e pela aferição da pressão arterial (PA). RESULTADOS: O seguimento mínimo foi de sete meses e variou de 7-52 (mediana: 23, média: 24,2±15,2). Houve apenas um óbito não-cardíaco (2 por cento) e uma falha técnica de tratamento (2 por cento). Não houve complicação grave do procedimento. Nenhum paciente apresentou evento cardiovascular. A função renal melhorou ou permaneceu inalterada em 32 (82 por cento) pacientes, e piorou em 4 (10 por cento). O controle da pressão arterial melhorou em 19/44 (43,8 por cento) dos pacientes e continuou descontrolada ou piorou em 6 (14 por cento). CONCLUSÃO: A angioplastia renal com implante de stent em pacientes com EAR demonstrou ser uma estratégia eficaz na recuperação e preservação da função renal e no controle da pressão arterial.

OBJECTIVE: To evaluate the clinical efficacy of percutaneous renal revascularization with stenting to control hypertension and preserve/restore renal function in patients with atherosclerotic renovascular disease. METHODS: From May/1999 to October/2003, 46 patients with atherosclerotic renal artery stenosis (ARAS) underwent revascularization with stenting. The indication for the procedure was hypertension control and/or renal function preservation/restoration. Clinical characteristics: age range: 33-84 years (median = 58.5 ±10.7), males: 26 (56.5 percent), 4 (10 percent) patients with dia betes mellitus, 21 (46 percent) patients with coronary artery disease, creatinine <2.0mg/dl: 39 (64 percent), 6 patients (14 percent) with congestive heart failure, 20 (43 percent) patients with ostial stenosis and 15 (33 percent) patients with bilateral stenosis. Hypertension control was evaluated by the number of drugs used before the procedure and at follow-up (FU) and by blood pressure (BP) measurement. RESULTS: The minimum follow-up was 7 months (range of 7-52, median: 23, mean: 24.2 ± 15.2). There were no major complications. No patient experience any cardiovascular event. There was only one non-cadiac death (2 percent) and one technical failure in the treatment(2 percent). There was no serious complication in the procedure. None of the patients presented cardiovascular events. The renal function improved or stabilized in 32 patients (82 percent) and worsened in 4 (10 percent). The BP control improved in 19/44 (43,8 percent) patients and worsened / stabilized in 6 patients (14 percent). CONCLUSION: Angioplasty with renal artery stenting for ARAS showed to be an effective treatment strategy to restore and preserve renal function and to control blood pressure.

Trombosis de la arteria renal después de suspender la terapia anticoagulante en una trasplantada renal con trombofilia: Caso Clínico / Renal artery thrombosis after withdrawal from anticoagulation therapy in a kidney transplant recipient with thrombophilia: Report of one case

Kidney graft loss because arterial thrombosis is not common and is related to risk factors such as recurrent vascular hemodialysis access thrombosis, collagen-vascular disease, repeated miscarriage, diabetes mellitus and thrombophilia. Patients having this last disorder have an increased risk of repeated thrombosis in successive transplants unless they receive anticoagulation therapy. We report a 51 year-old diabetic woman who had a history of recurrent vascular hemodialysis access thrombosis (both native and prosthetic) while on dialysis and received a cadaveric donor kidney. One month after transplantation she had axillary vein thrombosis complicated with pulmonary embolism and received anticoagulants for six months. Just days after stopping the anticoagulation, she became suddenly anuric due to renal artery thrombosis and complete graft infarction. The coagulation study showed moderate hyperhomocysteinemia and a significant protein C deficiency (39 percent). Days after nephrectomy she suffered a femoral vein thrombosis and anticoagulation was prescribed for life.

Hipertensão arterial renovascular: sugestöes práticas de conduta diagnóstico-terapêutica / Renovascular hypertension: practical suggestions for clinical diagnosis and treatment

Nos últimos anos, muitos avanços têm ocorrido na área clínica da hipertensão renovascular. O uso de métodos diagnósticos e de modalidades terapêuticas menos invasivas tem recebido ênfase especial. Este artigo de revisão procura apresentar orientações clínicas práticas e confiáveis atualmente em uso nos centros médicos de vanguarda

The prevalence and associated risk factors of renal artery stenosis in patients undergoing cardiac catheterization

Renal artery stenosis may be a cause of hypertension and a potential contributor to progressive renal insufficiency. However, the prevalence of renal artery disease in a general population is poorly defined. The purposes of this study were to evaluate the prevalence of angiographically-determined renal artery narrowing in a patient population undergoing routine cardiac catheterization, and to identify the risk factors for renal artery stenosis. After left ventriculography, abdominal aortography was performed to screen for the presence of renal artery stenosis. A total of 427 patients (274 males, 153 females) were studied and the mean age was 59 years. Renal artery narrowing was identified in 10.5% of patients. Significant (> or = 50% diameter narrowing) renal artery stenosis was found in 24 patients (5.6%) and insignificant stenosis was found in 21 patients (4.9%). Significant unilateral stenosis was present in 4.2% of patients and bilateral stenosis was present in 1.4%. The stem of the renal artery was a more common site of stenosis in 62.2% of patients than in the ostium (37.8%), but the severity of stenosis was not significantly different according to the site of stenosis. By univariate and multivariate logistic regression analysis, the association of clinical variables with renal artery stenosis was assessed. Multivariable predictors included age, hypertension and peripheral vascular disease (p < 0.05). The variables such as sex, smoking history, hyperlipidemia, renal insufficiency, as well as the presence of obesity, severity of coronary heart disease and D.M., were not associated. In conclusion, the prevalence of angiographically-determined renal artery narrowing in a patient population undergoing cardiac catheterization is 10.5%. Old age, hypertension and evidence of peripheral vascular disease represent the predictors of renal artery stenosis.

Ischemic nephropathy.

Atherosclerotic narrowing of the renal arteries may result in severe consequences including chronic renal ischemia, renal artery atheroembolism and renal vascular hypertension. Ischemic renal disease is increasingly recognised as a potentially treatable cause of chronic renal failure. Its precise prevalence is still poorly determined as there is no population based studies. The patients with ARD, particularly those with high grade stenosis and systolic hypertension are at very high risk for renal atrophy and renal failure. Angiogram is usually required to confirm the diagnosis. However, the diagnosis is likely in the elderly patient with systemic atherosclerosis and hypertension in whom a rapid rise in serum creatinine concentration is associated with decreased renal length. Disease is associated with high mortality when treated medically. In contrast, clinical improvement is reported after renal revascularisation. Therefore, consider the diagnosis in the patients at risk, because revascularisation (surgical or endovascular) can successfully preserve renal function in selected patients.

Transplant renal artery stenosis treated by angioplasty and stenting

Renal artery stenosis in an increasingly recognized and curable cause of hypertension. Though seen in only 1 percent of cases of hypertension, the condition is especially common after renal transplantation, occurring in 23 percent of transplants. Suspected by deteriorating renal function and hypertension, the stenosis can be diagnosed non-invasively by duplex ultrasound. Definitive diagnosis and anatomical details are achieved only by renal arteriography. The disease is amenable to surgical correction though angioplasty and stenting offers excellent results with negligible morbidity and mortality. We report a case of transplant renal artery stenosis successfully treated with angioplasty and stenting

Frequência de estenose de artéria renal em 676 transplantes renais / Frequency of stenosis of renal the artery in 676 renal transplants

O transplante renal é um tratamento seguro e efetivo para os pacientes portadores de falência renal e em regime de diálise. Apesar de bem padronizada, a cirurgia pode apresentar complicaçoes urológicas, clínicas e vasculares sendo a estenose de artéria renal a complicaçao vascular mais comum. Objetivo. Verificar a freqüência de estenose de artéria renal nos pacientes submetidos a transplante renal, no período de fevereiro de 1985 a dezembro de 1994, na Unidade de Transplante Renal do Hospital Sao Paulo, da Universidade Federal de Sao Paulo - UNIFESP - Escola Paulista de Medicina, comparando-se as anastomoses arteriais término-terminal e término-lateral. Casuística e Método. Foram analisados, retrospectivamente, 676 prontuários de pacientes submetidos a trnasplante renal, com idade mediana de 34 anos. O teste exato de Fischer foi aplicado para comparar os grupos etários, étnicos e sexo em relaçao a presença de estenose, sendo calculado os limites inferior e superior para a porcentagem de casos com estenose. Resultados. A estenose de artéria renal foi encontrada em 11 pacientes (1,63 por cento). Destes, 0,74 por cento foram submetidos a anastomose arterial término-terminal e 0,89 por cento término-lateral. Todos os casos ocorreram em transplantes realizados com rim de doador cadáver. Conclusao. A freqüência de estenose de artéria renal foi baixa, verificada apenas em receptores de rins de doador cadáver, nao diferindo de modo significante em relaçao ao tipo de anastomose realizada,e e nao sofrendo interferência quanto à idade, ao sexo e ao grupo étnico dos pacientes transplantados.

Angioplastia renal transluminal percutánea: experiencia en tres enfermos / Study of three patients with renal angioplasty

El presente trabajo tiene como objetivo, demostrar nuestra experiencia inicial con el empleo de la angioplastia renal transluminal percutánea (ATP), como alternativa terapéutica no quirúrgica para el tratamiento de la hipertensión arterial de origen renovascular; se describe la técnica de dilatación con catéteres con balón, presentándose los resultados en tres pacientes con estenosis de la arteria renal de diferente etiología, los cuales presentaron una mejoría clínica evidente. Se comenta la utilidad de esta técnica en este trabajo preliminar realizado en una unidad del Instituto Mexicano del Seguro Social del sureste del país

Complicaçöes cirúrgicas de 78 transplantes renais em crianças / Surgical complications of 78 kidney transplantation in children

Entre outubro de 1979 e novembro de 1993, foram realizados 78 transplantes renais em 73 crianças com idade entre um e 14 anos. Sessenta e dois transplantes foram realizados com doador vivo e 16 com doador-cadáver. Ocorreram oito complicaçöes cirúrgicas precoces (10,2 por cento) e quatro tardias (5,1 por cento) com quatro perdas de enxertos (5,1 por cento) no período de seguimento. Cinco complicaçöes foram de ordem vascular (6,4 por cento), seis urológicas (7,6 por cento) e uma linfocele. Houve maior incidência de complicaçöes vasculares em pacientes receptores de rim de doador-cadáver. A sobrevida atuarial de um ano do enxerto e do paciente foi de 85 por cento e 95 por cento respectivamente para receptores de rim de doador vivo e 56 por cento e 66 por cento para receptores de rim de doador-cadáver. Säo discutidos os fatores implicados na origem das complicaçöes e seu tratamento

Trasplante renal: complicaciones vasculares / Renal transplantation: vascular complications

Estudio retrospectivo donde se revisan las complicaciones vasculares y su manejo en pacientes de trasplante renal. A partir de 1975 se han efectuado 293 trasplantes en nuestro servicio, lográndose revisar 238 fichas clínicas correspondientes a 256 trasplantes. El injerto fue de donante vivo en 57 por ciento de los casos y donante cadáver en 43 por ciento. La anastomosis venosa se realizó a vena cava inferior (53.3 por ciento) y a vena ilíaca (46,7 por ciento). La anastomosis arterial termino terminal (TT) a hipogástrica (78,3 por ciento) y término lateral (TL) a ilíaca (21.7 por ciento). Se presentaron 48 complicaciones de las cuales 12 (4.89 por ciento) fueron de tipo vascular 9 estomosis, 2 trombosis y 1 hematoma perirrenal. Para su manejo se realizaron 9 revascularizaciones con diversas técnicas y un reforzamiento de sutura. Un paciente requirió trasplantectomía. Tenemos 5 (40 por ciento) injertos funcionantes y no hubo mortalidad derivadas de las complicaciones o su manejo

Estenosis de arteria renal: características angiográficas en 210 casos / Stenosis or the renal artery: angiographic characteristics in 210 cases

Se presentan 210 casos de enfermos portadores de lesiones estenosantes de arteria renal, estudiados en el Departamento de Angiología del Hospital de Especialidades del Centro Médico Nacional, durante un periodo de 29 años (1963-1992), documentados angiográficamente. La indicación del estudio fue la hipertensión arterial severa y las manifestaciones de insuficiencia arterial crónica de miembros inferiores, así como enfermedad aortoiliaca. De estos casos, 92 correspondieron al sexo femenino y 118 al masculino. La edad varió de 9 a 76 años. En cuanto a la localización de la lesión de la arteria renal, en 58 casos, fue en el ostium y/o en el tercio proximal y, en 50 de ellos, la lesión fue bilateral y estaba asociada a otras lesiones del territorio aórtico y correspondieron a mujeres jóvenes los cuales se consideraron de etiología inflamatoria (artritis). En otros 75 casos, la lesión se localizó en el tercio medio con estenosis única o múltiple, y extensión al tercio distal, en la mayoría fue unilateral y solamente en 15 casos, la lesión estaba presente en forma bilateral. Estos casos predominaron en el sexo masculino, entre la tercera y cuarta década de la vida y correspondieron a discplasia fibromuscular. En cambio en los 65 casos restantes, la lesión estenosante se presentó en personas de la sexta década de la vida predominando también en el sexo masculino, donde la angiografía mostró lesiones muy importantes del eje aortoiliaco y se consideraron de origen ateroscleroso. En 12 casos, la estenosis estuvo en relación a otras patologías. Algunos de estos casos fueron sometidos a procedimientos quirúrgicos, del tipo de las derivaciones arteriales, angioplastia transluminal y en los últimos años al autotrasplante renal (descenso renal), con excelentes resultados