Development of a novel predictive model for a successful stone removal after flexible ureteroscopic lithotripsy based on ipsilateral renal function: a single-centre, retrospective cohort study in China

Abstract

ObjectivesThe aims of this study were to investigate the effect of preoperative ipsilateral renal function on the success of kidney stone removal with flexible ureteroscopic lithotripsy and to develop a predictive model based on the results.DesignRetrospective cohort study.SettingData from the 2001–2012 period were collected from the electronic records of West China Hospital, Sichuan University.Participants576 patients who underwent flexible ureteroscopic lithotripsy were included in the study.Primary outcomeStone-free rate (SFR) after the procedures.ResultsIn patients with suspected impaired kidney function, the overall SFR was 70.1%. Stone volume (OR 1.46; 95% CI 1.18 to 1.80), lower calyx stones (OR 1.80; 95% CI 1.22 to 2.65), age (OR 1.02; 95% CI 1.00 to 1.04), body mass index (OR 1.10; 95% CI 1.04 to 1.17) and estimated glomerular filtration rate of the affected kidney (OR 0.95; 95% CI 0.94 to 0.97) were identified as independent predictors of SFR. Lasso regression selected the same five predictors as those identified by univariate and multivariate logistic regression analyses, thus verifying our model. The mean area under the curve, based on 1000 iterations and 10-fold validation, was 0.715 (95% CI 0.714 to 0.716). The Hodges-Lehmann test and calibration curve analysis revealed no significant mismatch between the prediction model and the retrospective cohort.ConclusionIpsilateral renal function may be a novel independent risk factor for kidney stone removal with flexible ureteroscopic lithotripsy. A novel nomogram for predicting SFR that uses stone volume, lower calyx stones, age, body mass index and estimated glomerular filtration rate was developed, but remains to be externally validated.

Effect of retrograde intrarenal surgery on the inflammatory reaction, renal function indicators and clinical efficacy in male patients with kidney stones

“…Currently, both percutaneous nephrolithotripsy and retrograde intrarenal surgery are optimal treatments in clinical practice for kidney stones less than 3 cm in diameter, but there are distinct views on which method to use in clinical practice [24][25][26]. In this article, two therapies were compared in the treatment of male kidney stones less than 3 cm.…”

Predicting stone free rate after retrograde intrarenal surgery using RIRS scoring system versus Resorlu Unsal stone score (RUSS)

“…Regarding the clinical characteristics, the current research reported that the stone-free patients had significantly lower stone size, stone density, multiple stones, lower pole stones, and RIRS than those with residual stones. Stone size and location are known to be significant predictors of SFR after FURS [ 14 ]. In line with these findings, Kim et al retrospectively reviewed the records of 237 patients who underwent URSL for ureteral stones and declared that stone diameter, length, and density significantly affected the stone-free rate [ 15 ].…”

Percutaneous nephrolithotomy guided by 5G-powered robot-assisted teleultrasound diagnosis system: first clinical experience with a novel tele-assistance approach (IDEAL stage 1)

“…The length, width and height of stones were measured on NCCT images with digital calipers. Total stone volume (TSV) of a staghorn stone or multiple stones as well as residual stone volume (RSV) was calculated as the sum of each partial volume using the following formula: length× width× height × π × 1/6 [ 19 ]. The network-connecting parameters during each tele-assistance were monitored and recorded by an appointed engineer.…”