The impact of surgical intervention on renal function in cystinuria

Abstract

O impacto da intervenção cirúrgica sobre a função renal na cistinúria Introdução: A cistinúria é um distúrbio autossô-mico recessivo causado por defeitos de transporte intestinal e renal da cistina e aminoácidos dibási-cos 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. ResumoIntroduction: 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. Re...

Clinical profile of a Polish cohort of children and young adults with cystinuria

“…Data from Brazil showed significant scarring in 13 (69%) pediatric patients with cystinuria, who had a follow-up in a single tertiary institution between 2004 and 2016. However, mean eGFR was not decreased at 92–106 mL/min/1.73 m 2 [ 15 ]. In a large study of adolescents and adults with cystinuria, a significant increase in serum creatinine was detected in cystinuric patients when compared to calcium oxalate stone formers [ 16 ].…”

“…However, even after introducing pharmacological therapy, the majority of children were operated on. On the other hand, in 17 out of 18 cases, surgery was required due to the formation of stones before pharmacological treatment, so we can postulate the need for surgery was in fact reduced [ 11 , 15 , 16 ].…”

Cystinuria: An Overview of Challenges and Surgical Management

“…Typically, cystine stone formers produce stones at a faster rate and from an earlier age than noncystine stone formers ( 8 ). Streeper et al looked at cystinuria patients’ overall quality of life and found that stones formed in this cohort, on average, every 12–24 months, with the typical patient having undergone up to seven endourological procedures by middle age ( 9 ). In comparison, noncystinuria patients have an overall lifetime risk of urolithiasis of between 10 and 15% and a 10-year risk of recurrence of around 50% ( 10 ).…”

“…In total, 8% of our patient cohort had already undergone a nephrectomy, secondary to stone disease, by the time they were seen in our clinic ( 5 ). This highlights the importance of prompt recognition and diagnosis of the condition so treatment can be initiated to slow stone formation, with an overall aim to preserve renal function ( 3 , 5 , 9 , 11 ).…”

Reporte de un caso de Cistinuria: Uso de herramientas de diagnóstico a nivel nacional

“…La repercusión renal que presentan los pacientes con cistinuria se centra en el riesgo de presentar hipofunción e insuficiencia renal. Esto sumado a la elevada tasa de recurrencia hacen que sea imprescindible un estricto seguimiento de los pacientes con litiasis de cistina (6) .…”