Doo Yong Chung

Stone heterogeneity index as the standard deviation of Hounsfield units: A novel predictor for shock-wave lithotripsy outcomes in ureter calculi

We investigated whether stone heterogeneity index (SHI), which a proxy of such variations, was defined as the standard deviation of a Hounsfield unit (HU) on non-contrast computed tomography (NCCT), can be a novel predictor for shock-wave lithotripsy (SWL) outcomes in patients with ureteral stones. Medical records were obtained from the consecutive database of 1,519 patients who underwent the first session of SWL for urinary stones between 2005 and 2013. Ultimately, 604 patients with radiopaque ureteral stones were eligible for this study. Stone related variables including stone size, mean stone density (MSD), skin-to-stone distance, and SHI were obtained on NCCT. Patients were classified into the low and high SHI groups using mean SHI and compared. One-session success rate in the high SHI group was better than in the low SHI group (74.3% vs. 63.9%, P = 0.008). Multivariate logistic regression analyses revealed that smaller stone size (OR 0.889, 95% CI: 0.841–0.937, P < 0.001), lower MSD (OR 0.995, 95% CI: 0.994–0.996, P < 0.001), and higher SHI (OR 1.011, 95% CI: 1.008–1.014, P < 0.001) were independent predictors of one-session success. The radiologic heterogeneity of urinary stones or SHI was an independent predictor for SWL success in patients with ureteral calculi and a useful clinical parameter for stone fragility.

Impact of colic pain as a significant factor for predicting the stone free rate of one-session shock wave lithotripsy for treating ureter stones: a Bayesian logistic regression model analysis

Purpose This study was conducted to evaluate colic pain as a prognostic pretreatment factor that can influence ureter stone clearance and to estimate the probability of stone-free status in shock wave lithotripsy (SWL) patients with a ureter stone. Materials and Methods We retrospectively reviewed the medical records of 1,418 patients who underwent their first SWL between 2005 and 2013. Among these patients, 551 had a ureter stone measuring 4–20 mm and were thus eligible for our analyses. The colic pain as the chief complaint was defined as either subjective flank pain during history taking and physical examination. Propensity-scores for established for colic pain was calculated for each patient using multivariate logistic regression based upon the following covariates: age, maximal stone length (MSL), and mean stone density (MSD). Each factor was evaluated as predictor for stone-free status by Bayesian and non-Bayesian logistic regression model. Results After propensity-score matching, 217 patients were extracted in each group from the total patient cohort. There were no statistical differences in variables used in propensity- score matching. One-session success and stone-free rate were also higher in the painful group (73.7% and 71.0%, respectively) than in the painless group (63.6% and 60.4%, respectively). In multivariate non-Bayesian and Bayesian logistic regression models, a painful stone, shorter MSL, and lower MSD were significant factors for one-session stone-free status in patients who underwent SWL. Conclusions Colic pain in patients with ureter calculi was one of the significant predicting factors including MSL and MSD for one-session stone-free status of SWL.

Ureteral stenting can be a negative predictor for successful outcome following shock wave lithotripsy in patients with ureteral stones

Purpose To evaluate ureteral stenting as a negative predictive factor influencing ureteral stone clearance and to estimate the probability of one-session success in shock wave lithotripsy (SWL) patients with a ureteral stone. Materials and Methods We retrospectively reviewed the medical records of 1,651 patients who underwent their first SWL. Among these patients, 680 had a ureteral stone measuring 4–20 mm and were thus eligible for our study. The 57 patients who underwent ureteral stenting during SWL were identified. Maximal stone length (MSL), mean stone density (MSD), skin-to-stone distance (SSD), and stone heterogeneity index (SHI) were determined by pre-SWL noncontrast computed tomography. Results After propensity score matching, 399 patients were extracted from the total patient cohort. There were no significant differences between stenting and stentless groups after matching, except for a higher one-session success rate in the stentless group (78.6% vs. 49.1%, p=0.026). In multivariate analysis, shorter MSL, lower MSD, higher SHI, and absence of a stent were positive predictors for one-session success in patients who underwent SWL. Using cutoff values of MSL and MSD obtained from receiver operator curve analysis, in patients with a lower MSD (≤784 HU), the success rate was lower in those with a stent (61.1%) than in those without (83.5%) (p=0.001). However, in patients with a higher MSL (>10 mm), the success rate was lower in those with a stent (23.6%) than in those without (52.2%) (p=0.002). Conclusions Ureteral stenting during SWL was a negative predictor of one-session success in patients with a ureteral stone.

Optimal Skin-to-Stone Distance Is a Positive Predictor for Successful Outcomes in Upper Ureter Calculi following Extracorporeal Shock Wave Lithotripsy: A Bayesian Model Averaging Approach

Objectives To investigate whether skin-to-stone distance (SSD), which remains controversial in patients with ureter stones, can be a predicting factor for one session success following extracorporeal shock wave lithotripsy (ESWL) in patients with upper ureter stones. Patients and Methods We retrospectively reviewed the medical records of 1,519 patients who underwent their first ESWL between January 2005 and December 2013. Among these patients, 492 had upper ureter stones that measured 4–20 mm and were eligible for our analyses. Maximal stone length, mean stone density (HU), and SSD were determined on pretreatment non-contrast computed tomography (NCCT). For subgroup analyses, patients were divided into four groups. Group 1 consisted of patients with SSD<25th percentile, group 2 consisted of patients with SSD in the 25th to 50th percentile, group 3 patients had SSD in the 50th to 75th percentile, and group 4 patients had SSD≥75th percentile. Results In analyses of group 2 patients versus others, there were no statistical differences in mean age, stone length and density. However, the one session success rate in group 2 was higher than other groups (77.9% vs. 67.0%; P = 0.032). The multivariate logistic regression model revealed that shorter stone length, lower stone density, and the group 2 SSD were positive predictors for successful outcomes in ESWL. Using the Bayesian model-averaging approach, longer stone length, lower stone density, and group 2 SSD can be also positive predictors for successful outcomes following ESWL. Conclusions Our data indicate that a group 2 SSD of approximately 10 cm is a positive predictor for success following ESWL.

Meta-Analysis of the Relationship between CXCR4 Expression and Metastasis in Prostate Cancer.

Purpose Experimental studies have suggested that the stromal-derived factor-1 (SDF-1)/CXCR4 axis is associated with tumor aggressiveness and metastasis in several malignancies. We performed a meta-analysis to elucidate the relationship between CXCR4 expression and the clinicopathological features of prostate cancer. Materials and Methods Data were collected from studies comparing Gleason score, T stage, and the presence of metastasis with CXCR4 levels in human prostate cancer samples. The studies were pooled, and the odds ratio (OR) of CXCR4 expression for clinical and pathological variables was calculated. Results Five articles were eligible for the current meta-analysis. We found no relationship between CXCR4 expression and Gleason score (<7 vs. ≥7). The forest plot using the fixed-effects model indicated an OR of 1.585 (95% confidence interval [CI]: 0.793~3.171; p=0.193). Further, CXCR4 expression was not associated with the T stage (<T3 vs. ≥T3), and the relevant meta-analysis showed OR=1.803 (95% CI: 0.756~4.297, p=0.183). However, increased CXCR4 expression was strongly associated with metastatic disease with a fixed-effects pooled OR of 7.459 (95% CI: 2.665~20.878, p<0.001). Conclusions Our meta-analysis showed that the higher CXCR4 protein expression in prostate cancer specimens is significantly associated with the presence of metastatic disease. This supports previous experimental data supporting the role played by the SDF-1/CXCR4 axis in metastasis.

Correlation of Prostatic Urethral Angle with the Severity of Urinary Symptom and Peak Flow Rate in Men with Small Prostate Volume

Purpose To evaluate the effects of prostatic anatomical factors on male lower urinary tract symptoms (LUTS) and the peak flow rate (Qmax) in patients with small prostate volume (PV). Materials and Methods Records were obtained from a prospectively maintained database of first-visit men with LUTS. Patients whose total PV (TPV) was greater than 30 mL were excluded; 444 patients were enrolled in the study. The TPV, transitional zone volume (TZV), transitional zone index (TZI), intravesical prostatic protrusion (IPP), and prostatic urethral angle (PUA) were measured by transrectal ultrasonography. LUTS were evaluated using the International Prostate Symptom Score (IPSS) and the Overactive Bladder Symptom Score (OABSS) questionnaires. Uroflowmetric measurements were also made. Results PUA (r = 0.269, P<0.001), TZV (r = 0.160, P<0.001), and TZI (r = 0.109, P = 0.022) significantly correlated with the IPSS. Qmax (r = −0.334, P<0.001) and OABSS (r = 0.211, P<0.001) correlated only with PUA. In a multivariate regression analysis, PUA and age were independently associated with IPSS, OABSS, and Qmax. For IPSS of 20 or greater, the area under the ROC curve (AUC) of PUA was 0.667 and the cut-off value was 43.7°. When Qmax was 10 mL/s or less, the AUC of PUA was 0.664 and the cut-off value was 43.5°. Conclusions PUA has a significant association with symptom severity and Qmax among prostatic anatomical factors analyzed in men with LUTS and small PV. PUA should be considered as an important clinical factor in male LUTS management. Furthermore, the impact of PUA on response to medical treatment and disease progression needs to be investigated.

Clinical experiences of incidental prostate cancer after transurethral resection of prostate (TURP) according to initial treatment: a study of a Korean high volume center.

Purpose These are the clinical experiences of Korean incidental prostate cancer patients detected by transurethral resection of the prostate according to initial treatment: active surveillance (AS), radical prostatectomy (RP) and hormone therapy (HT). Materials and Methods We retrospectively reviewed the records of 156 incidental prostate cancer patients between 2001 and 2012. The clinicopathologic outcomes were reviewed and follow-up results were obtained. Results Among 156 patients, 97 (62.2%) had T1a and 59 (37.8%) had T1b. Forty-six (29.5%) received AS, 67 (42.9%) underwent RP, 34 (21.8%) received HT, 4 (2.6%) received radiotherapy, and 5 (3.2%) chose watchful waiting. Of 46 patients on AS, prostate-specific antigen (PSA) progression occurred in 12 (26.1%) patients. Among them, 3 patients refused treatment despite PSA progression. Five patients, who underwent RP as an intervention, all had organ-confined Gleason score ≤6 disease. In 67 patients who underwent RP, 50 (74.6%) patients had insignificant prostate cancer and 8 (11.9%) patients showed unfavorable features. During follow-up, biochemical recurrence occurred in 2 patients. Among 34 patients who received HT, 3 (8.8%) patients had PSA progression. Among 156 patients, 6 patients died due to other causes during follow-up. There were no patients who died due to prostate cancer. Conclusion The clinical outcomes of incidental prostate cancer were satisfactory regardless of the initial treatment. However, according to recent researches and guidelines, immediate definite therapy should be avoided without a careful assessment. We also believe that improved clinical staging is needed for these patients.

Feasibility and Efficacy of Intermediate-Supine Percutaneous Nephrolithotomy: Initial Experience

We evaluated the feasibility and efficacy of intermediate-supine percutaneous nephrolithotomy (PCNL) in patients with renal calculi. Fifteen patients were included in this study. The intermediate-supine operative position was modified by using a 1-L saline bag below the ipsilateral upper flank. A nephrostomy and stone extraction were performed as usual. After completion of the stone removal, a nephrostomy tube was used when necessary according to the surgeons decision. If there was no significant bleeding or renal pelvic injury, tubeless PCNL was performed. The mean stone size was 5.48±5.69 cm2, the mean operative time was 78.93±38.72 minutes, and the mean hospital stay was 2.60±1.29 days. Tubeless PCNL was performed in 13 cases (86.7%), and retrograde procedures were simultaneously performed without a change of position in 2 patients (ureteroscopic ureterolithotomy in one patient and transurethral placement of an occlusion catheter in one patient). There were two complications according to the Clavien-Dindo classification (Grade I in one patient and Grade II in one patient). The success rate was 80.0% and the complete stone-free rate was 73.3%. Three patients with a significant remnant stone were also successfully managed with additional procedures (one patient underwent a second-look operation, and the remaining two patients were treated with shock wave lithotripsy). In the treatment of renal calculi, intermediate-supine PCNL may be a safe and effective choice that offers several advantages with excellent outcomes. Thus, a prospective study with a larger population is needed to verify our outcomes.

Delayed redo pyeloplasty fails to recover lost renal function after failed pyeloplasty: Early sonographic changes that correlate with a loss of differential renal function

Purpose To evaluate changes in differential renal function (DRF), as a functional outcome, in children who underwent redo pyeloplasty for management of failed pyeloplasty and to examine the factors that affect functional outcomes. Materials and Methods Between January 2002 and November 2010, a total of 18 patients who underwent redo pyeloplasty for persistent ureteropelvic junction obstruction after failed pyeloplasty were enrolled in this study. We assessed perioperative factors and evaluated changes in renal cortical thickness (RCT), renal function, and hydronephrosis by use of serial ultrasound and diuretic renography. Results The mean follow-up period was 44.83±28.86 months. After redo pyeloplasty, prevention of further functional deterioration was observed in only 12 of the 18 patients. After dividing the patients according to this observation, we discovered significant differences in both change in DRF (dDRF) and change in RCT (dRCT) (difference between before and after initial pyeloplasty) between the two groups (p<0.001). Additionally, we noted a significant positive correlation between dRCT and dDRF. All patients showed improvements in hydronephrosis grade and relief of symptoms compared with before redo pyeloplasty. Conclusions Redo pyeloplasty should be considered in cases of failed pyeloplasty to preserve renal function and obtain relief from symptoms. If patients show severe deterioration of DRF or a decrease in RCT after initial pyeloplasty, preservation of DRF in these patients after redo pyeloplasty could be difficult. Therefore, redo pyeloplasty should be performed before severe deterioration of DRF or decrease in RCT.

Intraoperative Patient Selection for Tubeless Percutaneous Nephrolithotomy

This study was conducted to report our experience of intraoperative patient selection for tubeless percutaneous nephrolithotomy (PCNL) based on a tentative decision-making algorithm. Thirty-four consecutive patients who were scheduled to undergo tubeless PCNL were included and medical records were obtained from a prospectively maintained database for these patients. After completion of PCNL, the nephrostomy site was observed with a safety guidewire in place. If there was no significant bleeding through the tract, tubeless PCNL was performed, and in cases with significant bleeding or other complications, nephrostomy catheter insertion was performed as usual. In 29 cases (85.3%), tubeless PCNL was performed according to our decision-making protocol. Mean stone size was 7.33 ± 9.35 cm(2). Mean hospital stay was 2.61 ± 1.01 days. The difference between preoperative and postoperative hemoglobin was 0.68 ± 1.22 g/dL (p > 0.05). Visual analog pain scale scores immediately post-operation, on postoperative day one and on the day of discharge were 4.62 ± 1.80, 3.25 ± 1.68 (postoperative day one vs. operative day; p = 0.001), and 1.87 ± 0.83 (the day of discharge vs. operative day; p = 0.001), respectively. The success rate with insignificant remnant stones was 85.2% and complete stone-free rate was 76.5%. In conclusion, tubeless PCNL was performed successfully with low complication rate and reduced pain score through our decision-making algorithm.