RESUMEN
ABSTRACT Introduction: Cystinuria is an autosomal recessive disorder due to intestinal and renal transport defects in cystine and dibasic amino acids, which result in recurrent urolithiasis and surgical interventions. This study aimed to assess the impact of surgical interventions on renal function by analyzing estimated glomerular filtration rates. Methods: Thirteen pediatric patients with cystinuria, who were followed-up in a single tertiary institution between 2004 and 2016, were included in the study. Medical records were reviewed to collect data on clinical presentation of patients, urine parameters, stone formation, medical treatment, surgical intervention, stone recurrence after surgical procedure, stone analysis, ultrasonography, 99m-technetium dimercaptosuccinic acid (99mTc-DMSA) radionuclide imaging results, and follow-up time. Creatinine clearances estimated by modified Schwartz (eGFR) formula before and after surgery were used to assess renal function and compared statistically. Results: Nine patients (69.2%) had renal scarring which were detected with 99mTc-DMSA radionuclide imaging. In ten patients (76.9%), open surgical intervention for stones were needed during follow-up. Significant difference was not detected between eGFR before and after surgical intervention (mean 92 versus 106, p = 0.36). Nine of the patients (69.2%) were stone free in the last ultrasonographic examination. Relapses of stone after surgery were seen in 66.6% of patients who underwent surgical intervention. Conclusions: Surgical interventions for urinary stones are commonly required in patients with cystinuria. Renal scarring is a prevalent finding in cystinuric patients. Surgical interventions have no negative impact on eGFR in patients with cystinuria according to the present study.
RESUMO Introdução: A cistinúria é um distúrbio autossômico recessivo causado por defeitos de transporte intestinal e renal da cistina e aminoácidos dibásicos que resultam em urolitíase recorrente e necessidade de intervenção cirúrgica. O presente estudo teve por objetivo avaliar o impacto das intervenções cirúrgicas sobre a função renal por meio da análise da taxa de filtração glomerular estimada. Métodos: Treze pacientes pediátricos com cistinúria acompanhados em uma instituição terciária entre 2004 e 2016 foram incluídos no estudo. Os prontuários médicos foram analisados e utilizados como fonte de dados sobre a apresentação clínica dos pacientes, parâmetros urinários, formação de cálculos, tratamento clínico, intervenção cirúrgica, recidiva de cálculos após procedimento cirúrgico, análise de cálculos, ultrassonografia, resultados de imagens com ácido dimercaptossuccínico marcado com tecnécio metaestável (99mTc-DMSA) e tempo de seguimento. A depuração de creatinina estimada pela fórmula modificada de Schwartz (TFGe) antes e após a cirurgia foi utilizada para avaliar e comparar estatisticamente os níveis de função renal. Resultados: Nove pacientes (69,2%) apresentaram cicatrizes renais detectadas por exame de imagem com 99mTc-DMSA. Dez pacientes (76,9%) necessitaram intervenção cirúrgica aberta por cálculo renal durante o seguimento. Não foram detectadas diferenças significativas entre os valores de TFGe anteriores e posteriores à intervenção cirúrgica (média de 92 vs. 106, p = 0,36). Nove pacientes (69,2%) não apresentaram cálculos no último exame ultrassonográfico. Recidivas de cálculos renais após cirurgia foram observadas em 66,6% dos pacientes submetidos a cirurgia. Conclusões: Intervenções cirúrgicas relativas a cálculos renais são frequentemente necessárias em pacientes com cistinúria. Cicatrizes renais são um achado prevalente em pacientes com cistinúria. De acordo com o presente estudo, cirurgia não afeta negativamente a TFGe de pacientes com cistinúria.
Asunto(s)
Humanos , Masculino , Femenino , Lactante , Preescolar , Cálculos Urinarios/cirugía , Cistinuria/fisiopatología , Tasa de Filtración Glomerular , Riñón/fisiopatología , Cálculos Urinarios/complicaciones , Estudios Retrospectivos , Resultado del Tratamiento , Cistinuria/complicaciones , Pruebas de Función RenalRESUMEN
INTRODUCTION: Cystinuria is an autosomal recessive disorder due to intestinal and renal transport defects in cystine and dibasic amino acids, which result in recurrent urolithiasis and surgical interventions. This study aimed to assess the impact of surgical interventions on renal function by analyzing estimated glomerular filtration rates. METHODS: Thirteen pediatric patients with cystinuria, who were followed-up in a single tertiary institution between 2004 and 2016, were included in the study. Medical records were reviewed to collect data on clinical presentation of patients, urine parameters, stone formation, medical treatment, surgical intervention, stone recurrence after surgical procedure, stone analysis, ultrasonography, 99m-technetium dimercaptosuccinic acid (99mTc-DMSA) radionuclide imaging results, and follow-up time. Creatinine clearances estimated by modified Schwartz (eGFR) formula before and after surgery were used to assess renal function and compared statistically. RESULTS: Nine patients (69.2%) had renal scarring which were detected with 99mTc-DMSA radionuclide imaging. In ten patients (76.9%), open surgical intervention for stones were needed during follow-up. Significant difference was not detected between eGFR before and after surgical intervention (mean 92 versus 106, p = 0.36). Nine of the patients (69.2%) were stone free in the last ultrasonographic examination. Relapses of stone after surgery were seen in 66.6% of patients who underwent surgical intervention. CONCLUSIONS: Surgical interventions for urinary stones are commonly required in patients with cystinuria. Renal scarring is a prevalent finding in cystinuric patients. Surgical interventions have no negative impact on eGFR in patients with cystinuria according to the present study.