Development and validation of a prediction model for failed shockwave lithotripsy of upper urinary tract calculi using computed tomography information: the S3HoCKwave score.

PURPOSE: To develop and validate a new clinical prediction model that accurately predicts the failure of shockwave lithotripsy (SWL) using information obtained from non-contrast-enhanced computed tomography (NCCT). METHODS: This multicentre retrospective cohort study consecutively enrolled patients diagnosed with upper urinary tract calculi by NCCT at five hospitals in Japan from January 1, 2006 to December 31, 2016. Among the candidate predictors, we selected the six most significant predictors a priori. The main outcome was SWL failure after three sessions. Model calibration was evaluated by the calibration slope and the Hosmer-Lemeshow test. Discrimination was evaluated by the receiver-operating characteristic curves and the area under the curve (AUC). A multivariable logistic regression analysis was performed; based on the estimated ß coefficients, predictive scores were generated. RESULTS: Of 2695 patients, 2271 were included. Patients were divided into the development cohort (1666 patients) and validation cohort (605 patients) according to geographical factors. We developed a clinical prediction model with scores ranging from 0 to 49 points. We named the prediction model the S3HoCKwave score based on the initials of the predictors (sex, skin-to-stone distance, size, Hounsfield units, colic, and kidney or ureter). As a result of internal validation, the optimism-corrected AUC was 0.72. In the validation cohort, the Hosmer-Lemeshow test did not show statistical significance (P = 0.33), and the AUC was 0.71 (95% confidence interval 0.65-0.76). CONCLUSIONS: The S3HoCKwave score is easy to understand, has a relatively high predictive value, and allows clinicians to make appropriate treatment selections.

Chronological changes in epidemiological characteristics of lower urinary tract urolithiasis in Japan.

OBJECTIVES: To determine changes and trends in the annual incidence and epidemiological aspects of lower urinary tract stones in Japan. METHODS: Data about patients who had been diagnosed by urologists in 2015 with first and recurrent lower urinary tract stones were collected from 301 hospitals approved by the Japanese Board of Urology. The estimated annual incidence according to sex, age and stone composition was compared with previous nationwide surveys between 1965 and 2005. RESULTS: The incidence of lower urinary tract stones in Japan has steadily increased from 4.7 per 100 000 in 1965 to 12.0 per 100 000 in 2015. However, the age standardized annual incidence of lower urinary tract stones has remained relatively stable over the same period at 5.5 per 100 000 and 6.0 per 100 000 in 1965 and 2015, respectively. The increase in incidence was most evident among individuals aged ≥80 years. The incidence of calcium oxalate stones has steadily increased among males and females, whereas that of infection-related stones has significantly decreased from 26.2% to 14.3% among men over the past 50 years. CONCLUSIONS: Nationwide surveys suggest a steady increase in the incidence of lower urinary tract stones over a 50-year period in Japan. This trend might reflect changes in the aging population and improved Japanese medical standards.

Chronological changes in the epidemiological characteristics of upper urinary tract urolithiasis in Japan.

OBJECTIVES: To assess epidemiological and chronological trends of upper urinary tract stones in Japan in 2015. METHODS: Patients with a first episode of upper urinary tract stones in 2015 were enrolled in this nationwide survey. The study included all hospitals approved by the Japanese Board of Urology, therefore covering most of the hospitals where urologists practice in Japan. The annual incidence and composition of urolithiasis were evaluated by age and sex. These results were compared with the previous results of the nationwide surveys from 1965 to 2005 to analyze temporal trends. RESULTS: The estimated annual incidence of a first-episode upper urinary tract stone in 2015 was 137.9 (191.9 in men and 86.9 in women) per 100 000. The estimated age-standardized first-episode upper urinary tract stone incidence in 2015 was 107.8 (150.6 in men and 63.3 in women) per 100 000, which did not represent a significant increase since 2005. An equivalent incidence was observed in patients aged >50 years, whereas a reduced incidence was observed in patients aged <50 years in both sexes. The proportion of patients who received percutaneous nephrolithotomy and/or ureteroscopy increased by approximately fivefold in the past 10 years. CONCLUSIONS: The steady increase in the annual incidence of upper urinary tract stones since 1955 leveled off in 2015. The current results show novel trends in the incidence and treatment modalities in the nationwide surveys of urolithiasis in Japan.

[Clinical study of influential factors on renal scarring after ESWL monotherapy for renal stone disease].

OBJECTIVE: ESWL is now widely used for the treatment of renal stone disease. Although ESWL has many advantages for patients' quality of life, few reports have demonstrated the long-term outcomes of the alterations of renal morphology after ESWL. We reported renal scarring after ESWL monotherapy in patients with renal calyceal stones. In this study, we evaluated a large series of patients' cohort treated at our institution, and assessed the causal effect of ESWL on the late occurrence of renal scar formation. PATIENTS AND METHODS: ESWL was performed with EDAP (LT-01,02) that generates shock wave energy by piezoelectric discharge. We analyzed the records of 285 kidneys treated between Dec. 1986 and Nov. 1998. Renal scarring was noted in 44 kidneys and not in 241 kidneys with periodical ultrasonography. We compared the backgrounds of the two groups using chi-square or non-parametric analysis. The Kaplan-Meier method and Cox regression model determined the analysis of renal scar formation. RESULTS: Univariate and multiple regression analysis revealed that the total amount of ESWL emission and hyperuricemia independently affected the probability of renal scar formation. CONCLUSIONS: Over-emission of ESWL (over 10,000 shots) must be care for the prevention of renal scarring in patients with renal calyceal calculi, especially when associated with hyperuricemia. After ESWL, periodical checkups with ultrasonography will provide useful information for the clinical diagnosis of renal scarring.

[A clinical study on renal pelvic and ureteral cancer].

We investigated the clinicopathological features of 62 patients with transitional cell carcinoma of the renal pelvis and/or ureter who underwent total nephroureterectomy at our department from April, 1987 to October, 2000. The patients consisted of 48 males and 14 females, with a mean age of 67 years, ranging from 46 to 86 years. The mean follow-up period was 40 months. The 1-, 3- and 5-year cause-specific survival rates (Kaplan-Meier's method) for all of the patients were 90.8, 82.9%, and 68.6%, respectively. The prognostic significance of the 5 pathological factors (grade, pT, pV, pL and pN) were evaluated. All these factors affected the survival rates significantly in univariate analysis using the generalized Wilcoxon test. According to multivariate analysis by the Cox proportional hazard model, the most influential prognostic factor was grade.