A single center study that evaluates the preclinical use of a newly developed software and moving bed system to facilitate the spontaneous excretion of residual fragments after primary stone treatment (RIRS or PCNL).

PURPOSE: We developed a Postural Drainage Lithotripsy System (PDLS) that uses the patient's computed tomography urography (CTU) data to reconstruct the three-dimensional figure of the renal pelvis, provides an individualized inversion and overturning angle and uses gravity to remove residual fragments (RFs). The purpose of this study was to investigate PDLS in the treatment of renal RFs. METHODS: A stone with a diameter of 4.0 mm was placed in the upper, middle, and lower calyx of the renal model. A total of 60 trials were applied to 20 renal models. The movement trajectory, passage rate, and postural drainage angle of calculi during the treatment of PDLS were observed. RESULTS: All of the stones in 60 trials were observed to move during treatment, and 53/60 (88%) were relocated successfully to the renal pelvis. The passage rate of the upper calyx was 14/20 (70%), that of the middle calyx was 20/20 (100%), and that of the lower calyx was 19/20 (95%). CONCLUSIONS: PDLS can provide individualized inversion and reversal angles and remove stones from the renal model. More clinical trials are needed to verify the above view and evaluate its efficacy.