Antegrade pressure measurement of the upper urinary tract in children with postoperative persistent hydronephrosis

Orientadores: Márcio Lopes Miranda, Joaquim Murray Bustorff SilvaDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências MédicasResumo: Introdução: A dilatação do trato urinário pode existir sem a presença de obstrução. Os métodos diagnósticos dependentes da função renal podem suscitar diagnósticos equivocados. Whitaker (1973) propôs a avaliação da pressão do trato urinário submetida a um fluxo constante. Outros investigadores propuseram a perfusão da pelve renal sob pressão controlada, tornando o método mais fisiológico e reprodutível. Este estudo tem o objetivo de avaliar os resultados da aferição da pressão anterógrada do trato urinário alto (APA) em crianças com hidronefrose persistente pós-operatória e com suspeita de obstrução. Pacientes e Métodos: No período de doze anos, 26 unidades renais com hidronefrose persistente pós-operatória (12 anomalias da junção pieloureteral-JUP e 14 anomalias da junção ureterovesical-JUV), foram submetidas à avaliação da pressão do trato urinário alto para a orientação da conduta. As cintilografias renais dinâmicas (CRD), urografias excretoras (UE) e ultrassonografias (US) prévias, foram consideradas como indeterminadas para obstrução em 10 ocasiões e obstrutivas em 16. A APA foi realizada por punção da pelve renal sob radioscopia ou via estoma confeccionado previamente. Procedeu-se a infusão de solução salina com azul de metileno mais contraste iodado, sob pressão constante de 40cm de água para preenchimento do sistema urinário, aferindo-se a pressão de abertura ureteral a partir da drenagem do sistema e estabilização da coluna d'água. Resultados: Dentre os dez testes com diagnósticos prévios indeterminados, dois foram considerados não obstrutivos após a APA e tratados conservadoramente. Oito foram considerados obstrutivos e reoperados. Dos dezesseis testes classificados como obstrutivos previamente, nove confirmaram obstrução e foram submetidos à cirurgia. Sete foram considerados não obstrutivos, tratados conservadoramente e mantiveram hidronefrose e DMSA estáveis. Conclusão: A APA evitou cirurgia desnecessária em um terço dos casos e orientou o procedimento em 100%. Acreditamos que este teste simplificado é uma opção diagnóstica, quando utilizada seletivamente e principalmente, na presença de déficit funcionalAbstract: Introduction: The dilation of the urinary tract can exist even without obstruction. The diagnostic methods that depend on renal function may give rise to misdiagnosis. Whitaker (1973) proposed the evaluation of the urinary tract pressure subjected to a steady flow. Other researchers have proposed the perfusion of the renal pelvis under controlled pressure, making the method most physiological and reproducible. The aim of this study is evaluate the results of antegrade pressure measurements of the upper urinary tract (APA) in children with persistent hydronephrosis with suspected postoperative obstruction. Patients and Methods: During twelve years, 26 renal units with persistent postoperative hydronephrosis (12 JUP and 14 JUV), underwent pressure evaluation of the urinary tract to guide the patient management. The previous scintigraphy (DTPA), intravenous pyelography and ultrasonography were considered indeterminate for obstruction on 10 times and obstructive in 16. The APA was performed by puncture of the renal pelvis under fluoroscopy or by stoma previously performed. After accessing the renal pelvis, infusion of a mix of saline, methylene blue and contrast medium was performed, under constant pressure of 40cm of water, filling the urinary tract. Measurements of the uretheral opening pressure were taken after the water column was stabilized. Results: Often cases that had a previous undetermined diagnostics, after APA test, two cases were considered non-obstructive and had a conservative treatment. Eight tests were considered obstructive and the patients had a re-do operation. Of sixteen cases previously classified as obstructive, nine units showed obstruction on APA test and these patients underwent to a new operation. The remaining 7 units were considered non-obstructive and treated conservatively, with stable hydronephrosis and DMSA in the follow up. Conclusion: The APA test guided all patient management and avoided unnecessary surgical intervention in one third of these cases. We believe that this simplified test is a diagnostic option when used selectively and mainly in the presence of poor renal functionMestradoFisiopatologia CirúrgicaMestra em Ciência

Antegrade pressure measurement of urinary tract in children with persistent hydronephrosis

INTRODUCTION: Dilation of urinary tract occurs without the presence of obstruction. Diagnostic methods that depend on renal function may elicit mistaken diagnosis. Whitaker (1973) proposed the evaluation of urinary tract pressure submitted to constant flow. Other investigators proposed perfusion of renal pelvis under controlled pressure, making the method more physiological and reproducible. The objective of the present study was to evaluate the results of the anterograde pressure measurement (APM) of the urinary tract of children with persistent hydronephrosis after surgery suspected to present persistent obstruction. MATERIALS AND METHODS: Along 12 years, 26 renal units with persistent hydronephrosis after surgery (12 PUJ and 14 VUJ) were submitted to evaluation of the renal tract pressure in order to decide the form of treatment. Previous radionuclide scans with DTPA, intravenous pyelographies and ultrasounds were considered undetermined in relation to obstruction in 10 occasions and obstructive in 16. APM was performed under radioscopy through renal pelvis puncture or previous stoma. Saline with methylene blue + iodine contrast was infused under constant pressure of 40 cm H2O to fill the urinary system. The ureteral opening pressure was measured following the opening of the system and stabilization of the water column. RESULTS: Among the 10 cases with undetermined previous diagnosis, APM was considered non-obstructive in two and those were treated clinically and eight were considered obstructive and were submitted to surgery. Among the 16 cases previously classified as obstructive, nine confirmed obstruction and were submitted to surgery. Seven cases were considered non-obstructive, and were treated clinically, with stable DMSA and hydronephrosis. CONCLUSIONS: APM avoided unnecessary surgery in one third of the cases and was important to treatment decision in 100%. We believe that this simple test is an excellent diagnostic tool when selectively applied mainly in the presence of functional deficit