Predictive Value Of Ureteral Jet Dynamics To Differentiate Postrenal Obstruction After Renal Transplantation: A Prospective Cohort Study

Objective: This study aimed to prospectively investigate the predictive value of ureteral jet dynamics measured by Doppler ultrasonography (D-US) to differentiate postrenal obstruction from other reasons after double-J stent (DJS) removal in patients who underwent renal transplantation (RTx) due to chronic renal failure.Materials and Methods: Patients who underwent RTx between 2017 and 2018 were prospectively evaluated. After RTx, D-US was performed on all patients following 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 (JETmax) and average velocity (JETave)] were measured by D-US. Patients' demographics, estimated glomerular filtration rate (eGFR), acute rejection, and hemodialysis (HD) time were investigated. Patients were divided into two groups as patients without PCSD (group 1) and patients with PCSD during follow-up (group 2). In addition, group 2 was also divided into two subgroups as patients with postrenal obstruction (group 2a) and without postrenal obstruction (group 2b). All values were compared between the groups.Results: A total of 28 patients were evaluated in the study. HD time and RP-APD were significantly higher in group 2 than in group 1 (p<0.05). Ureteral jet dynamics between the groups were comparable. In group 2, RA-Ri and RP-APD were comparable, but JETave and JETmax were significantly lower in group 2a.Conclusion: In patients who underwent RTx with PCSD (especially dilation with suspected acute rejection and low eGFR) after DJS removal, investigation of ureteral jet flow dynamics can provide important information that can help determine and differentiate postrenal obstruction.