The course of alterations in ureteral jet dynamics following kidney transplantation: a prospective observational cohort study

ABSTRACT

SUMMARY OBJECTIVES To prospectively investigate the alterations and normal ranges of ureteral jet dynamics after double-J-stent (DJS) removal in patients who underwent renal transplantation (RTx). METHODS Patients who underwent RTx were prospectively evaluated between November 2017 and June 2018. After RTx, Doppler ultrasonography (D-US) was performed on all patients after DJS removal. Renal artery resistive index (RA-Ri), renal pelvis anterior-posterior diameter (RP-APD), pelvicalyceal system dilation (PCSD), and ureteral jet flow dynamics (maximum and average velocity; JETmax and JETave) were measured by D-US. Also, patients' demographics, estimated glomerular filtration rate (eGFR) levels, and acute rejection were investigated in the study. Patients were assessed two different times by D-US, about 6 and 12 weeks after DJS removal, and the two different measurements were compared with the Wilcoxon test and Chi-square test. RESULTS A total of 25 patients were evaluated in the study. Nonobstructive PCSD rate (12% vs 8%), JETave (18.8 vs 12.9 cm/sec), and JETmax (29.2 vs 20 cm/sec) levels were significantly decreased (p values are 0.01, 0.010 and 0.014, respectively). In addition, monophasic and square pattern rates were significantly observed to increase over time (p=0.035); however, ureteral jet patterns were correlated between the two different D-US measurements (R=0.225, p=0.032). CONCLUSION After RTx, dilation rate and ureteral jet flow velocities were significantly decreased, and monophasic and square JETpattern rates were significantly increased over time. Ureteral jet dynamics can provide useful information about the follow-up of peristaltic activity in the pelvic-ureteric system.

RESUMO

RESUMO OBJETIVOS Investigar prospectivamente as alterações e as variações normais da dinâmica do jato ureteral após a remoção do J-stent duplo (DJS) em pacientes submetidos a transplante renal (RTx). MÉTODOS Pacientes submetidos a RTx foram avaliados prospectivamente entre novembro de 2017 e junho de 2018. Após o RTx, o D-US foi realizado em todos os pacientes após a remoção do DJS. Índice de resistência da artéria renal (RA-Ri), diâmetro ântero-posterior da pelve renal (AP-DPR), dilatação do sistema pelvicaliceal (PCSD) e dinâmica do jato ureteral (velocidade máxima e média; JETmax e JETave) foram medidos por D-US. Além disso, a demografia dos pacientes, os níveis estimados de taxa de filtração glomerular (eGFR) e a rejeição aguda foram investigados no estudo. Os pacientes foram avaliados em dois momentos diferentes pelo D-US, cerca de 6 e 12 semanas após a remoção do DJS, e as duas medidas diferentes foram comparadas com o teste de Wilcoxon e o teste do qui-quadrado. RESULTADOS Um total de 25 pacientes foi avaliado no estudo. Taxa de PCSD não obstrutiva (12% vs. 8%), JETave (18,8 vs. 12,9 cm/seg) e JETmax (29,2 vs. 20 cm/seg), os níveis foram significativamente diminuídos (valores de p são 0,01, 0,010 e 0,014, respectivamente). Além disso, as taxas de padrão monofásico e quadrado foram significativamente observadas para aumentar ao longo do tempo (p=0,035); no entanto, padrões de jato ureteral foram correlacionados entre as duas diferentes medidas D-US (R=0,225, p=0,032). CONCLUSÃO Após o RTx, a velocidade de dilatação e as velocidades de fluxo do jato ureteral foram significativamente diminuídas e as taxas de JET padrão monofásico e quadrado foram significativamente aumentadas ao longo do tempo. A dinâmica do jato ureteral pode fornecer informações úteis sobre o acompanhamento da atividade peristáltica no sistema pélvico-ureteral.