Role of color-coded Doppler sonography in the assessment of internal ureteral stent patency

Objective: To evaluate the role of color-coded Doppler sonography (CCDS) in the assessment of internal ureteral stent patency. Patients and Methods: We compared micturating cystography (MC) and CCDS in 48 patients with internal ureteral stents. Forty-five of these patients had pyelocaliectasis on renal sonography. Results: In all of the 48 patients, the distal end of the internal ureteral stent could be seen sonographically in the bladder. The color images of 30 patients showed typical flow from the distal holes of the stent. Micturating cystography demonstrated patency of the stents in 36 patients. The two procedures showed the same results in 42 of 48 patients, Six patients had no detectable flow by CCDS, but the MCs showed patency of the stents, Conclusion: The CCDS is a valid noninvasive method for the assessment of internal ureteral stent patency with a sensitivity of 100%, a specificity of 83%, a positive predictive value of 67%, and a negative predictive value of 100%.