Evaluation of encrustation of double J stents with artificial urine.

Purpose: To evaluate the formation of encrustation on double J stents (DJSs) using artificial urine.

Materials and methods: In this study, a static urinary system containing artificial urine was created, and a total of 45 DJSs were used to evaluate the formation of encrustation. Three groups of 15 DJSs were tested for 4, 8, or 14 weeks. The formation of encrustation on the DJSs over the weeks was analyzed using methods including X-ray powder diffraction (XRD), inductively coupled plasma spectrophotometer (ICP), and scanning electron microscope (SEM). Statistical analysis and the uncertainty test were used for data analysis using R language.

Results: The ICP analyzed the weight of the calcium and magnesium, which are the major components of urinary stones and encrustation, and showed that it was the heaviest at 14 weeks. Measurement of the area of encrustation on the outer surface of the DJSs revealed that the encrustation area at the bottom of the stent was greater than that at the top of the stent, regardless of the experimental period (proximal part: ≤ 41,099 µm², distal part: ≤ 183,259 µm²). Encrustation occurred around the side holes of DJSs and became bigger over time to fill up the side holes.

Conclusion: Encrustation spots included the bottom zone of the DJS and around the side holes. These results indicate that the performance of DJSs would be improved by modifying the shape of DJSs located near the bladder and side holes.