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Purpose Recently, the needs for supine percutaneous nephrolithotomy (PCNL) have become more increased because of an easy approach for endoscopic combined intrarenal surgery. However, making a nephrostomy tract during supine PCNL is more difficult than prone position due to movable kidney. To overcome this limitation, we used a modified nephrostomy tract dilation (MTD) technique using guidewire traction. Materials and Methods From January 2014 to June 2019, a total of 259 patients underwent PCNL in the modified supine position. Among them, the MTD technique was performed in 171 patients. For the MTD technique, two hydrophilic guidewires were passed from the nephrostomy tract and brought out through the urethra, then both proximal and distal ends were contralaterally pulled with tension for the easy placement of a fascia-cutting needle and a balloon catheter. We analyzed the efficacy of this technique in comparison with the conventional method. Results Intraoperative radiation exposure time (RET) (68.87 vs. 212.11 s) and hospital stay (5.90 vs. 6.74 days) were significantly shorter, while the success rate (77.2% vs. 63.6%) was significantly higher in the MTD group. Multivariate analysis showed that only the maximal stone diameter (odds ratio [OR], 1.928; 95% confidence interval [CI], 1.314–2.828; p=0.001) and MTD technique (OR, 0.017; 95% CI, 0.007–0.040; p, Graphical Abstract

Purpose Basal metabolic rate (BMR) is an indicator of overall body metabolism and may portend unique aberrations in urine physico-chemistry and stone recurrence. The present study examined the effect of predicted BMR on 24 hours urinary metabolic profiles and stone recurrence in obese stone patients. Materials and Methods Data from 308 obese patients (body mass index [BMI] ≥30 kg/m2) diagnosed with urinary stone disease between 2003 and 2015 were analyzed retrospectively. BMR was calculated using the Harris–Benedict equation, and patients were classified into two predicted BMR categories (, Graphical Abstract

Purpose To compare the treatment success rate and safety of reduced (30 shocks/min, 1,200 shocks/session) versus standard (60 shocks/min, 2,400 shocks/session) extracorporeal shockwave lithotripsy for the management of renal stones. Materials and Methods We retrospectively analyzed 404 patients who underwent extracorporeal shockwave lithotripsy for 5–20-mm renal stones between April 2011 and March 2019. Patients selected the reduced or standard protocol (group R and S) after explaining the potential benefits and disadvantages. The primary outcome was treatment success within 12 weeks, which was defined as no residual fragment or fragments, Graphical Abstract

Purpose Urinary stones can be successfully treated using a Holmium: Yttrium-Aluminum-Garnet (Ho: YAG) laser. Regarding success rates, laser pulse energy, frequency, and pulse width are well-known contributing factors. Whether the pulse shape might be a further factor influencing the laser efficiency is unclear. This study aimed to evaluate different modes of laser pulse shapes in a real-world setting. Materials and methods The Dornier Medilas® H Solvo (Wesling, Germany) was used in the treatment of ureter and kidney stones. Patients were randomized into standard pulse shape (SPS) and new pulse shape groups (NPS1; ureter) and (NPS2; kidney pelvis), depending on the stone localization. The primary endpoint was laser efficiency defined as mm³ stone destruction per overall operating time. Secondary endpoints encompassed number of stone recoveries and stone-free rate. Results Altogether 145 patients (24 SPS vs. 32 NPS1; 51 SPS vs. 38 NPS2) were included. No differences in sex, age, body mass index, stone localization and stone composition were found, except for preoperative stone size (133±95 [SPS] vs. 197±139 [NPS1] mm³; p=0.023) and (348±298 [SPS] vs. 525±429 [NPS2] mm³; p=0.042). Regarding the primary endpoint, a significant increase in laser efficiency could be detected for the NPS1 and NPS2 groups compared to the SPS groups (39.9±44.9 vs. 28.8±30.2 and 51.7±61.3 vs. 22.4±24.2 mm³/min [mean±standard deviation]). No statistically significant differences were found for secondary endpoints and perioperative complication rates. Conclusions Efficiency of the Ho: YAG laser can be positively influenced by different pulse shapes. This adds the variable of individualized intraoperative decision making.

Purpose We present surgical techniques and operative results of laparoscopic reconstruction for patients with retrocaval ureter (RCU) and review similar papers. Materials and methods Ten patients with RCU were enrolled in this study from April 2005 to January 2017. The mean age of 7 males and 3 females was 40.5 years old. The chief complaint was flank pain in 6 patients; the remaining patients were detected incidentally. All patients showed hydronephrosis and typical S-shaped deformity of the ureter on imaging studies. Five patients showed obstructed patterns on the renal scans. Two surgeons performed laparoscopic ureteroureterostomies with transperitoneal approaches including excision of the compressed ureter. Double-J ureteral stents were inserted intraoperatively. The operative and follow-up results were checked and compared with published papers. Results All laparoscopic reconstructions were successfully completed without conversion to open surgery. The mean operative time was 199.6 minutes. The estimated blood loss was 154.4 mL. No operative complications were encountered. There were no obstruction and symptom after the mean follow-up of 40.7 months. We found 7 papers from PubMed, which had more than five cases of laparoscopic reconstruction of RCU. We reviewed and summarized the clinical and operative parameters. Conclusions Our results show that transperitoneal laparoscopic ureteroureterostomy with excision of the compressed ureter is a safe and effective treatment for RCU. Data from published papers and ours summarize clinical parameters of RCU, and suggest that the laparoscopic reconstruction can be considered as the standard treatment for it.

Purpose To evaluate the characteristics of urinary stone composition in a Korean population using a large database of stone composition. Materials and Methods From January 1, 2014, to June 30, 2019, a total of 33,078 urinary stone composition data were analyzed. Stone composition was classified into four main groups: calcium oxalate (CaOx), struvite, uric acid (UA), and calcium phosphate (CaP). We examined the relationship between stone composition and sex, age, geographic region, calendar month, and season. Results The CaOx group (46.41%) was the largest, followed by the struvite group (29.66%), UA group (19.61%), and CaP group (4.32%). The CaOx group tended to decrease with age, but the UA group increased with age. Also, the CaOx group had the highest percentage in summer and the lowest in spring (p, Graphical Abstract

Purpose: This study aims to identify clinical factors that may predispose struvite stone patients to urosepsis following percutaneous nephrolithotomy (PCNL). Materials and Methods: A retrospective review was conducted on patients who received PCNL for struvite stones. The Systemic Inflammatory Response Syndrome (SIRS) criteria and quick-Sepsis Related Organ Failure Assessment (q-SOFA) criteria were used to identify patients who were at an increased risk for urosepsis. Statistical analysis was performed using Fisher's exactness test, Wilcoxon rank test, and logistic regression. Results: Chart review identified 99 struvite stone patients treated with PCNL. Post-operatively, 40 patients were SIRS positive (≥2 criteria) and/or q-SOFA positive (score ≥2). Using SIRS as an approximation for urosepsis, longer operative times (p

Purpose: To evaluate the quality of videos for retrograde intrarenal surgery (RIRS) on YouTube (Google, LLC) from the perspective of both patients and physicians. Materials and Methods: All videos longer than 2 minutes returned by the YouTube search engine in response to the keyword search “retrograde intrarenal surgery” were included in this study. The quality of content was analyzed by using the validated Journal of the American Medical Association Benchmark Score (JAMAS) and the Global Quality Score (GQS). Two surgeons developed the RIRS Scoring System (RIRSSS) to evaluate the technical quality of the videos. A video power index (VPI) was used to score the popularity of the videos. Results: A total of 63 videos with a median of 389 views were included in the present study. Forty-three videos (68.3%) were provided by health care professionals and 53 videos (84.1%) included technical aspects about RIRS. The median (interquartile range) GQS, JAMAS, RIRSSS, and VPI scores were 2 (1–3), 1 (1–2), 2 (1–5), and 0.41 (0.08–1.29), respectively. Videos with audio had significantly higher GQS and RIRSSS scores than did with videos with no audio (p

Purpose A prospective study evaluating impact of percutaneous nephrolithotomy (PCNL) on renal function following PCNL using ethylenedicysteine (EC) renal scan. Does multiplicity of access tracts play a role? Materials and methods A prospective observational study was done and patients undergoing PCNL for renal calculi at our urology department were selected. Renal Tc99m EC scan was done pre-surgery and at 3 months follow-up. An assessment was done on decline in glomerular filtration rate (GFR) in postoperative period based on number of access tracts required. Results A total of 110 patients were enrolled in the study. The total number of punctures was 170 with 141 being supra-costal puncture and 29 infra-costal. The total number of single punctures were 60 and classified as Group I whereas patients with double puncture and triple puncture (40 and 10 patients, respectively) were classified as Group II. Mean postoperative split renal function (in Tc99m EC scans) of patients of Group I (40.93±19.62%) was found to be higher than that of Group II (32.82±16.98%). Mean change (decline) in GFR for single, double and triple tracts were 2.68 mL/min, 3.80 mL/min, and 4.2 mL/min, respectively. Conclusions PCNL used for stone removal can improve renal function by eradicating obstruction; however, this procedure may itself negatively impact the functions of the targeted kidney. Our study showed post PCNL decrease in GFR which worsens with an increasing number of accesses.

Purpose: To compare patients with sepsis due to obstructive urolithiasis (Sep-OU) and underwent drainage by percutaneous nephrostomy (PCN) or a double-J (DJ)-ureteral stent and to identify predictive risk factors of DJ stent failure in these patients. Materials and Methods: We reviewed our records from January 2013 to July 2018 and identified 286 adult patients with Sep-OU out of which 36 had bilateral involvement, thus total 322 renal units were studied. Urologic residents in training carried out both ureteral stenting and PCN tube placement. Demographic data and stone characteristics were recorded along with Charlson comorbidity index. For predicting risk factors of DJ stent failure, those variables that had a p-value

Purpose: Ureteroscopic lithotripsy (URS) is gaining popularity for the management of ureteral stones and even renal stones, with high efficacy and minimal invasiveness. Although this procedure is known to be safe and to have a low complication rate, febrile urinary tract infection (UTI) after URS is not rare. Therefore, we aimed to analyze the risk factors and causative pathogens of febrile UTI after URS. Materials and Methods: Between January 2013 and June 2015, 304 patients underwent URS for ureteral or renal stones. The rate of postoperative febrile UTI and the causative pathogens were verified, and the risk factors for postoperative febrile UTI were analyzed using logistic regression analysis. Results: Of 304 patients, postoperative febrile UTI occurred in 43 patients (14.1%). Of them, pathogens were cultured in blood or urine in 19 patients (44.2%), and definite pathogens were not identified in 24 patients (55.8%). In patients with an identified pathogen, Pseudomonas aeruginosa had the highest incidence. Multivariate analysis showed that the operation time (p

Purpose Despite advances in flexible ureteroscopy, the high cost and long repair time of ureteroscopes limit their use in the urology. We compared the performance of a novel flexible ureteroscope (fURS) 'HF-EH' with that of the two contemporary fURSs 'URF-P6' and 'COBRA'. Materials and methods We compared in vitro measurements of deflection angle, irrigation flow rate, and image quality between HF-EH and URF-P6 while also inspecting renal collecting systems in five female pigs. For clinical testing, we performed retrograde intrarenal surgeries using HF-EH in four patients. Experienced urologists compared performance parameters (irrigation, convenience, and maneuverability) between the HF-EH and COBRA. Results The flow rate of HF-EH (21.0 mL/min) was worse, and its resolution (1.59 line pairs/mm) was inferior to that of URF-P6 (28.7 mL/min and 3.17 line pairs/mm, respectively). However, HF-EH was superior to URF-P6 in terms of loss of deflection angle with the insertion of accessories (1.8% vs. 12.7%). In vivo and clinical testing revealed that the performance parameters of HF-EH were slightly inferior to those of conventional domestic fURSs. We successfully performed retrograde intrarenal surgeries using HF-EH in four patients and achieved stone-free statuses in two. None of the patients exhibited any procedure-related complications. Conclusions Although we observed that two of the three performance parameters of the novel ureteroscope 'HF-EH' were inferior to those of the conventional ureteroscope, we successfully used HF-EH to perform retrograde intrarenal surgeries in patients. Further studies on performance and durability are warranted for making HF-EH commercially available.

Purpose Placement of pre-operative ureteral catheters for colorectal surgery can aid in the identification of ureteral injuries. This study investigates whether simultaneous ureteral catheterization with surgery skin preparation can minimize operating room times without increasing post-operative complications. Materials and methods Patients undergoing simultaneous colorectal surgery skin preparation and placement of pre-operative ureteral catheters (n=21) were compared to those who underwent these events sequentially (n=28). Operative time-points of anesthesia ready (AR), surgery procedure start (PS), dorsal lithotomy and catheter insertion (CI) times were compared to assess for differences between groups. Complications were compared between groups. Results There were no differences in age, gender, body mass index (BMI), American Society of Anesthesiologists (ASA), comorbidities, current procedure terminology (CPT) or International Classification of Diseases, 9th revision (ICD-9) codes between groups. Simultaneous catheterization saved 11.82 minutes of operative time between CI to PS (p=0.005, t-test). There was a significant difference in mean time between CI to PS (11.82 minutes, p=0.008) between simultaneous and sequential ureteral catheterization groups in a linear regression multivariate analysis controlling for age, BMI, CPT and ICD-9 codes. There were 4 complications in the simultaneous (19%) and 3 in the sequential group (11%) (p=0.68). Conclusions Ureteral catheterization and colorectal surgery skin preparation in a simultaneous fashion decreases the time between CI and PS without significant increase in complications. Mean time saved with simultaneous ureteral catheterization was 11.82 minutes per case. Simultaneous ureteral catheterization may be an option in colorectal surgery and may result in cost savings without additional complications.

Purpose This study aims to assess the predictive factors and treatment outcomes of Steinstrasse formation following shock wave lithotripsy (SWL) for ureter stone. Materials and methods The medical records of 1,418 ureter stone patients who underwent one-session SWL from November 2005 to May 2013 at our medical institute were retrospectively reviewed. Finally, 551 patients met inclusion criteria. Maximal length and location of stone, stone attenuation (Hounsfield units), and skin-to-stone distance (SSD) were determined on pretreatment non-contrast computed tomography. Results Of 551 patients, 12 patients (2.2% of total cohort) developed Steinstrasse after one-session SWL. The Steinstrasse incidence was significantly associated with stone size, stone attenuation value, and SSD. Prophylactic ureter stenting was not a statistically significant predictor of Steinstrasse formation. After propensity-score matching, Steinstrasse group showed a significant shorter SSD compare to non-Steinstrasse group. Multivariate logistic regression and Bayesian analysis revealed that stone size, stone attenuation and SSD were significant predictor of Steinstrasse formation following SWL for ureter stone. The Steinstrasse resolved spontaneously in six patients and remaining six patients were treated by additional SWL. None of patients with Steinstrasse required ureteral stenting, percutaneous drainage, or consequent surgical intervention. Conclusions Steinstrasse formation following SWL for ureter stone was rare event but nonnegligible. Large stone size, high stone attenuation and short SSD were significant predictors of Steinstrasse formation following SWL for ureter stone. Majority of patients with Steinstrasse formation could be treated conservatively in this clinical scenario.

Purpose To investigate the risk of symptomatic urolithiasis requiring surgical treatment according to obesity and metabolic health status using a nationwide dataset of the Korean population. Materials and Methods Of the 5,300,646 persons who underwent health examinations between the year 2009 and 2016, within one year after the health examination, 35,137 patients who underwent surgical treatment for urolithiasis were enrolled. Participants were classified as “obese” or “non-obese” using a body mass index (BMI) cutoff of 25 kg/m2. People who developed ≥1 metabolic disease component in the index year were considered “metabolically unhealthy”, while those with none were considered “metabolically healthy”. Results Out of 34,330 participants excluding 843 missing, 16,509 (48.1%), 4,320 (12.6%), 6,456 (18.8%), and 7,045 (20.5%) subjects were classified into the metabolically healthy non-obese (MHNO), metabolically unhealthy non-obese (MUNO), metabolically healthy obese (MHO), and metabolically unhealthy obese (MUO) group, respectively. Mean BMI was 22.1±1.9 kg/m2, 22.9±1.6 kg/m2, 26.9±1.8 kg/m2, and 27.9±2.4 kg/m2 respectively. After adjusting the age and sex, the subjects in the MUNO group had an HR (95% CI) of 1.192 (1.120–1.268), those in the MHO group, 1.242 (1.183–1.305), and those in the MUO group, 1.341 (1.278–1.407) for either extracorporeal shockwave lithotripsy or surgery, compared to those in the MHNO group. Conclusions Metabolically healthy, obese individuals have a higher risk of developing symptomatic urolithiasis than non-obese, unhealthy, but have a lower risk than obese, unhealthy. It suggests that metabolic health and obesity have collaborative effects, independently affecting the development of symptomatic urinary stone diseases., Graphical Abstract

Purpose: To compare the results of a chemical method of kidney stone analysis with the results of Fourier transform infrared (FT-IR) spectroscopy. Materials and Methods: Kidney stones collected between June and October 2015 were simultaneously analyzed by chemical and FT-IR methods. Results: Kidney stones (n=449) were collected from patients from 1 to 81 years old. Most stones were from adults, with only 11.5% from children (aged 3–16 years) and 1.5% from children aged

Purpose To determine the predictive value of certain radiological parameters for an objective asssessment of the presence of ureteral stone impaction. Materials and methods Seventy-nine patients with a single proximal ureteral stones were retrieved from the departmental database. Both clinical and particularly radiological data of all cases were well evaluated on this aspect. In addition to the time period between the first colic attack and definitive management; diameter of proximal ureter and renal pelvis, longitudinal and transverse stone size, Hounsfied unit (HU) of the stone and lastly ureteral wall thickness at the impacted stone site were all carefully evaluated and noted. Results Patients had a single proximal ureteral stone. While mean age of the cases was ranged 20 to 78 years; mean stone size was 15.62±4.26 mm. Evaluation of our data demonstrated that although there was a statistically significant correlation between ureteral wall thickness and patients age, transverse diameter of the stone, ureteral diameter just proximal to the stone, renal pelvic diameter and the duration of renal colic attacks; no correlation could be demonstrated between patients sex and the HU of the stone. Conclusions Prediction of the presence and degree of proximal ureteral stone impaction is a challenging issue and our data indicated a highly significant correlation between ureteral wall thickness and the some certain radiological as well as clinical parameters evaluated which will give an objective information about the presence of impaction which may in turn be helpful in the follow-up and also management plans of such calculi.

Purpose: To analyze postoperative outcomes of prostate surgery, resected specimen weight is commonly used. The difference between the preoperative calculated transitional zone volume and actual enucleated specimen weight following holmium laser enucleation of the prostate (HoLEP) is reported at over 20%. The reason for this difference is unclear. We assessed the association of volume of the prostatic adenoma with enucleated weight, the volume and calculated volume of the adenoma by pre- and postoperative ultrasonographic measurement. Materials and Methods: All patients were prospectively enrolled who underwent HoLEP by two surgeons (SJO and JKO) between 2010 and 2015. Preoperative and postoperative prostate ultrasonography examinations were performed by a single examiner (JKO) during surgery, and weight and volume of the enucleated adenoma were measured. We compared preoperative adenoma size with postoperative weight and volume of the enucleated adenoma, calculated enucleated volume using ultrasonography, and calculated the correlation coefficients between preoperative adenoma volume and postoperative parameters. Results: One hundred forty-two patients with a mean age (±standard deviation) of 69.8 (±8.8) years were analyzed. The mean preoperative ultrasound-measured adenoma volume was 31.7 (±21.4) mL, while postoperatively the mean retrieved weight of the adenoma was 22.3 (±17.0) g and the mean volume was 22.3 (±16.8) mL. Postoperatively calculated enucleated volume using ultrasonography was most strongly correlated with preoperative adenoma size (Pearson correlation coefficient 0.965, p

Purpose This study aimed to determine the urethral stricture (US) rate and identify clinical and surgical risk factors associated with US occurrence after transurethral resection of the prostate using the bipolar Gyrus PlasmaKinetic Tissue Management System (PK-TURP). Materials and methods This was an age-matched case-control study of US occurrence after PK-TURP. Retrospective data were collected from the hospital records of patients who had a minimum of 36 months of follow-up information. Among the data collected for analysis were prostate-specific antigen level, estimated prostate weight, the amount of prostate resected, operative time, history of urinary tract infection, previous transurethral resection of the prostate, and whether the PK-TURP was combined with other endourological procedures. The resection rate was calculated from the collected data. Univariate and multivariate analyses were performed to identify clinical and surgical risk factors related to US formation. Results A total of 373 patients underwent PK-TURP between 2003 and 2009. There were 13 cases of US (3.5%), and most of them (10 of 13, 76.9%) presented within 24 months of surgery. Most of the US cases (11 of 13, 84.6%) occurred at the bulbar urethra. Multivariable logistic regression analyses identified slow resection rate as the only risk factor significantly associated with US occurrence. Conclusions The US rate of 3.5% after PK-TURP in this study is comparable to contemporary series. A slow resection rate seems to be related to US occurrence. This should be confirmed by further studies; meanwhile, we must be mindful of this possibility when operating with the PK-TURP system.

Purpose To evaluate the effect of 'Bernoulli maneuver' (bringing the access sheath to horizontal plane) on operative time and stone free rates in patients undergoing mini-percutaneous nephrolithotomy (PCNL). Materials and methods All consecutive patients with a solitary kidney stone undergoing a mini-PCNL between 2015 and 2016 were included into this study. Patients were randomized either to standard prone or control (C) group patients or to tilted prone with 'Bernoulli maneuver' group (B) patients. Pre-, intra-, and postoperative characteristics of these 2 groups were recorded and analyzed. Results A total of 67 patients were included in the study. Of these, 40 patients were randomized to group C and 27 to group B. The mean (95% confidence limits) stone size (mm) in group C and B was 14 (13, 15) and 13 (11, 14), respectively (p=0.26). Nephroscopy time was shorter in Bernoulli group (35 minutes vs. 23 minutes, p=1.5·10-5, and Bayes factor BF10=2,340, and Cohen standardized effect size dst=1.2). The difference made it up 12 minutes (with 95% confidence interval from 8 to 18 minutes). There were no statistically significant differences between groups regarding white blood cell, creatinine level and stone-free status defined by computed tomography on the first postoperative day. Conclusions In our study the 'Bernoulli maneuver' led to a shorter nephroscopy time in mini-PCNL. This maneuver can significantly reduce nephroscopy time and save significant amount of operative time, especially in tertiary referral centers with high-volume mini-PCNL procedures.

Purpose: Extracorporeal shock wave lithotripsy (ESWL) is an established modality for renal calculi. Its role for large stones is being questioned. A novel model of temporary double J (DJ) stenting followed by ESWL was devised and outcomes were assessed. Materials and Methods: The study included 95 patients with renal calculi sized 1 to 2 cm. Patients were randomized into 3 groups. Group 1 received ESWL only, whereas group 2 underwent stenting followed by ESWL. In group 3, a distinct model was applied in which the stent was kept for 1 week and then removed, followed by ESWL. Procedural details, analgesic requirements, and outcome were analyzed. Results: Eighty-eight patients (male, 47; female, 41) were available for analysis. The patients’ mean age was 37.9±10.9 years. Stone profile was similar among groups. Group 3 received fewer shocks (mean, 3,155) than did group 1 (mean, 3,859; p=0.05) or group 2 (mean, 3,872; p=0.04). The fragmentation rate was similar in group 3 (96.7%) and groups 1 (81.5%, p=0.12) and 2 (87.1%, p=0.16). Overall clearance in group 3 was significantly improved (83.3%) compared with that in groups 1 (63.0%, p=0.02) and 2 (64.5%, p=0.02) and was maintained even in lower pole stones. The percentage successful outcome in groups 1, 2, and 3 was 66.7%, 64.5%, and 83.3%, respectively (p=0.21). The analgesic requirement in group 2 was higher than in the other groups (p=0.00). Group 2 patients also had more grade IIIa (2/3) and IIIB (1/2) complications. Conclusions: Stenting adversely affects stone clearance and also makes the later course uncomfortable. Our model of brief stenting followed by ESWL provided better clearance, comfort, and a modest improvement in outcome with fewer sittings and steinstrasse in selected patients with large renal calculi.

Purpose To determine the efficacy of phosphodiesterase type 5 inhibitors (PDE5i) as medical expulsive therapy (MET) for the treatment of distal ureteral calculi. Materials and methods A search strategy was conducted in the MEDLINE, CENTRAL, and Embase databases. Searches were also conducted in other databases and unpublished literature. Clinical trials were included without language restrictions. The risk of bias was evaluated with the Cochrane Collaboration's tool. An analysis of random effects due to statistical heterogeneity was conducted. The primary outcome was the expulsion rate of the distal ureteral calculus in 28 days. The secondary outcomes were the time to expulsion, side effects of treatment, and amount (mg) of nonopioid analgesia. The measure of the effect was the risk difference (RD) with a 95% confidence interval (CI). The planned interventions were PDE5i vs. placebo, tadalafil vs. placebo, and tadalafil vs. tamsulosin. Results Four articles were included in the qualitative and quantitative analysis. Records of 580 patients were found among the four studies. A low risk of bias was shown for the majority of the study items. The calculi expulsion rate had an RD of 0.26 (95% CI, 0.15-0.37) and a less prolonged expulsion as a secondary outcome with a mean difference of -4.39 days (95% CI, -6.69 to -2.09) in favor of PDE5i compared with the placebo. No significant difference was found for these outcomes when comparing tadalafil with tamsulosin. Conclusions Compared with a placebo, PDE5i could be effective as MET for the treatment of distal ureter calculi.

Purpose We evaluated the comparative effect of miniaturized percutaneous nephrolithotomy (mini-PCNL) and retrograde intrarenal surgery (RIRS) on perioperative kidney function by use of diethylenetriamine penta-acetic acid (99mTc-DTPA) scintigraphy and identified significant predictors associated with deterioration or amelioration of renal function after surgery. Materials and Methods All 70 patients who underwent mini-PCNL or RIRS between 2012 and 2016 were monitored by 99mTc-DTPA scintigraphy preoperatively. Patients with abnormal renal function were monitored from 3 to 12 months postoperatively. Logistic regression analyses were conducted to estimate the predictors of aggravated renal dysfunction and improvement. Results The difference in preoperative renal function between the contralateral and the operative side was >10% in 57 patients (81.4%). Among those in the group with abnormal renal function, 40 (70.2%), 10 (17.5%), and 7 (12.3%) patients showed stability, deterioration, and improvement in renal function at postoperative year 1, respectively. Functional changes did not differ according to the type of surgery. A high level of serum creatinine preoperatively (p=0.060) and a history of previous stone procedures (p=0.051) showed borderline significance for prediction of deterioration in renal function. Conclusions RIRS and mini-PCNL had similar effects and favorable outcomes on renal function during a 1-year follow-up period. High baseline serum creatinine levels and a history of procedures warrant careful attention.

Purpose: A few experimental and observational studies have reported that atorvastatin prevents calcium oxalate stone formation. Our study is the first to investigate the effect of atorvastatin on 24-hour urinary metabolites, urinary malondialdehyde (U-MDA) (an oxidative stress marker) and urinary neutrophil gelatinase-associated lipocalin (U-NGAL) (a renal tubular injury marker) in patients with calcium stones and hyperoxaluria. Materials and Methods: This randomized, double-blind, placebo-controlled, parallel-group clinical trial included 32 adults with recurrent calcium stone formation and hyperoxaluria. All participants received a 3-month course of either atorvastatin (20 mg/d) or placebo of an identical shape. Both groups received the usual nutritional care based on the European Association of Urology guidelines. Results: Twenty-eight participants completed the study. Serum levels of total and low-density lipoprotein cholesterol decreased in the atorvastatin group, and these changes were significantly different between groups (p

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.

Purpose: This study aimed to compare the safety and efficacy of tamsulosin and tadalafil as medical expulsive therapy for distal ureteral stones. Materials and Methods: This prospective randomized study was conducted at the Department of Urology of Bir Hospital over a period of 12 months in patients with distal ureteral stones sized 5 to 10 mm. Patients were randomly divided into 2 groups: group A received tamsulosin 0.4 mg and group B received tadalafil 10 mg at bedtime for 2 weeks. Stone expulsion rate, number of ureteric colic episodes and pain score, analgesic requirements, and adverse drug effects were noted in both groups. Statistical analyses were performed by using Student t-test and chi-square test. Results: Altogether 85 patients, 41 in group A and 44 in group B, were enrolled in the study. The patients’ average age was 31.72±12.63 years, and the male-to-female ratio was 1.5:1. Demographic profiles, stone size, and baseline investigations were comparable between the 2 groups. The stone expulsion rate was significantly higher in the tadalafil group than in the tamsulosin group (84.1% vs. 61.0%, p=0.017). Although the occurrence of side effects was higher with tadalafil, this difference was not significant (p=0.099). There were no serious adverse effects. Conclusions: Tadalafil has a significantly higher stone expulsion rate than tamsulosin when used as a medical expulsive therapy for distal ureteral stones sized 5–10 mm. Both drugs are safe, effective, and well tolerated with minor side effects.

Purpose: This study aimed to determine the predictors of ipsilateral hydronephrosis after ureteroscopic lithotripsy for ureteral calculi. Materials and Methods: From January 2010 to December 2014, a total of 204 patients with ureteral calculi who underwent ureteroscopic lithotripsy were reviewed. Patients with lack of clinical data, presence of ureteral rupture, and who underwent simultaneous percutaneous nephrolithotomy (PNL) were excluded. Postoperative hydronephrosis was determined via computed tomographic scan or renal ultrasonography, at 6 months after ureteroscopic lithotripsy. Multivariable analysis was performed to determine clinical factors associated with ipsilateral hydronephrosis. Results: A total of 137 patients were enrolled in this study. The mean age of the patients was 58.8±14.2 years and the mean stone size was 10.0±4.6 mm. The stone-free rate was 85.4%. Overall, 44 of the 137 patients (32.1%) had postoperative hydronephrosis. Significant differences between the hydronephrosis and nonhydronephrosis groups were noted in terms of stone location, preoperative hydronephrosis, impacted stone, operation time, and ureteral stent duration (all, p

Purpose: Based on the experiences of our center, we sought to verify the necessity of actively removing stones during retrograde intrarenal surgery (RIRS) for the management of renal stones. Materials and Methods: From March 2010 to March 2015, 248 patients underwent RIRS at our center. We classified these patients into 2 groups according to the performance of active stone removal; group A (n=172) included the patients whose stones were actively removed using a stone basket, and group B (n=76) included the patients whose stones were fragmented with laser lithotripsy without active removal of the fragments. We retrospectively compared the operation time, success rate, and complication rate between the 2 groups. Results: There were no significant differences between groups A and B in terms of mean age (56.1 years vs. 58.6 years), male to female ratio (115:57 vs. 46:30), mean body mass index (24.5 kg/m2 vs. 25.0 kg/m2 ), mean preoperative size of stone (11.1 mm vs. 11.1 mm), the ratio of unilateral and bilateral stones (136:36 vs. 64:12), success rate (89.0% vs. 86.8%), operation time (82.5 minutes vs. 82.1 minutes), overall complication rate (9.9% vs. 11.8%), incidence of febrile urinary tract infection (6.4% vs. 2.6%), gross hematuria (1.7% vs. 2.6%), or postoperative de novo hydronephrosis (2.9% vs. 5.3%). Conclusions: This study demonstrated that during RIRS, fragmentation only, without the active removal of stones, is a safe and effective technique in which the surgical outcomes are comparable to those of procedures involving the active removal of stones.

Purpose: The traditional prone positioning of percutaneous nephrolithotomy (PCNL) is associated with various anesthetic and logistic difficulties. We aimed to compare the surgical outcomes of PCNLs performed using our modified supine position with those performed in the standard prone position. Materials and Methods: A prospective group of 236 renal units (224 patients) undergoing PCNL were included in this 2 site study: 160 were performed in the modified supine position were compared with 76 undergoing PCNL in the prone position. The outcomes of radiation dose, radiation time, stone free rate, body mass index (BMI), stone size, operative time, length of stay (LOS), in hospital and complications were compared. Chi-square and t-tests were used. Results: There were no significant differences in mean radiation time, radiation dose or stone size between the modified supine and prone groups. The supine group had a higher mean BMI (31 kg/m2 vs. 28 kg/m2 , p=0.03), shorter mean surgical time (93 minutes vs. 123 minutes, p

Purpose: To evaluate a physician's impression of a urinary stone patient's dietary intake and whether it was dependent on the medium through which the nutritional data were obtained. Furthermore, we sought to determine if using an electronic food fre- quency questionnaire (FFQ) impacted dietary recommendations for these patients. Materials and Methods: Seventy-six patients attended the Stone Clinic over a period of 6 weeks. Seventy-five gave consent for enrollment in our study. Patients completed an office-based interview with a fellowship-trained endourologist, and a FFQ admin- istered on an iPad. The FFQ assessed intake of various dietary components related to stone development, such as oxalate and cal- cium. The urologists were blinded to the identity of patients' FFQ results. Based on the office-based interview and the FFQ results, the urologists provided separate assessments of the impact of nutrition and hydration on the patient's stone disease (nutrition im- pact score and hydration impact score, respectively) and treatment recommendations. Multivariate logistic regressions were used to compare pre-FFQ data to post-FFQ data. Results: Higher FFQ scores for sodium (odds ratio (OR), 1.02; p=0.02) and fluids (OR, 1.03, p=0.04) were associated with a higher nutritional impact score. None of the FFQ parameters impacted hydration impact score. A higher FFQ score for oxalate (OR, 1.07; p=0.02) was associated with the addition of at least one treatment recommendation. Conclusions: Information derived from a FFQ can yield a significant impact on a physician's assessment of stone risks and decision for management of stone disease.

Purpose: We aimed to determine the influence of nutritional status on urinary metabolic abnormalities and stone recurrence in patients with urolithiasis. Materials and Methods: We analyzed data for 464 stone-formers and 464 propensity-score-matched control patients that had been collected between 2003 and 2015. Nutritional status was evaluated by use of the Controlling Nutritional Status (CONUT) score, and patients were placed into two CONUT score categories (0–1 and ≥2). Serum and 24-hour urinary metabolites were evaluated in 464 stone-formers. Kaplan–Meier and multivariate Cox regression analyses were performed to assess the influence of nutritional status on stone recurrence. Stone recurrence was defined as radiographic appearance of new stones during the follow-up period. Results: Stone-formers showed a higher prevalence of poor nutrition (CONUT score ≥2) than did the propensity-score-matched control patients (p

Purpose This study aimed to assess the accuracy of low-dose dual-energy computed tomography (DECT) in predicting the composition of urinary calculi. Materials and Methods A total of 52 patients with urinary calculi were scanned with a 128-slice dual-source DECT scanner by use of a low-dose protocol. Dual-energy (DE) ratio, weighted average Hounsfield unit (HU) of calculi, radiation dose, and image noise levels were recorded. Two radiologists independently rated study quality. Stone composition was assessed after extraction by Fourier transform infrared spectroscopy (FTIRS). Analysis of variance was used to determine if the differences in HU values and DE ratios between the various calculus groups were significant. Threshold cutoff values to classify the calculi into separate groups were identified by receiver operating characteristic curve analysis. Results A total of 137 calculi were detected. FTIRS analysis differentiated the calculi into five groups: uric acid (n=17), struvite (n=3), calcium oxalate monohydrate and dihydrate (COM-COD, n=84), calcium oxalate monohydrate (COM, n=28), and carbonate apatite (n=5). The HU value could differentiate only uric acid calculi from calcified calculi (p80% sensitivity and specificity to differentiate them. The DE ratio could not differentiate COM from COM-COD calculi. No study was rated poor in quality by either of the observers. The mean radiation dose was 1.8 mSv. Conclusions Low-dose DECT accurately predicts urinary calculus composition in vivo while simultaneously reducing radiation exposure without compromising study quality.

Purpose To investigate surgical outcomes between retrograde intrarenal surgery (RIRS) and percutaneous nephrolithotomy (PNL) groups for a main stone sized 15 to 30 mm and located in the lower-pole calyx. Materials and Methods Patients who underwent PNL or RIRS for a main stone sized 15 to 30 mm and located in the lower-pole calyx were retrospectively reviewed. Each patient in the RIRS group was matched to one in the PNL group on the basis of calculated propensity scores by use of age, sex, body mass index, previous treatment history, stone site, maximum stone size, and stone volume. We compared perioperative outcomes between the unmatched and matched groups. Results Patients underwent PNL (n=87, 66.4%) or RIRS (n=44, 33.6%). After matching, 44 patients in each group were included. Mean patient age was 54.4±13.7 years. Perioperative hemoglobin drop was significantly higher and the hospital stay was longer in the PNL group than in the RIRS group. The operative time was significantly longer in the RIRS group than in the PNL group. Stone-free rates were higher and complications rates were lower in the RIRS group than in the PNL group without statistical significance. The presence of a stone located in the lower-anterior minor calyx was a predictor of stone-free status. Conclusions RIRS and single-session PNL for patients with a main stone of 15 to 30 mm located in the lower-pole calyx showed comparable surgical results. However, RIRS can be performed more safely than PNL with less bleeding. Stones in the lower-anterior minor calyx should be carefully removed during these procedures.

Purpose: The aim of our study was to evaluate the association of several factors with spontaneous stone expulsion, including ureteral stone characteristics (size, location, hydronephrosis, perinephric stranding), types of medications prescribed (α-blocker, lowdose steroid), and other possible demographic and health-history factors (gender, age, serum creatinine, underlying diabetes mellitus [DM], and hypertension). Materials and Methods: A total of 366 patients with ureteral stones were enrolled. All patients underwent watchful waiting without any invasive procedures. Initial diagnoses of ureteral stones were confirmed by computed tomography scans, which were taken at approximately 1-month intervals to check for stone expulsion. Univariate and multivariate analyses were conducted to identify significant factors that contributed to stone expulsion. Results: Among 366 patients, 335 patients (91.5%) experienced spontaneous stone passage during a mean follow-up period of 2.95±2.62 weeks. The patients were divided into two groups depending on the success of spontaneous stone passage. Univariate analyses revealed that stone location (p=0.003), stone size (p=0.021), and underlying DM (p

PURPOSE To evaluate the outcomes of rigid ureterorenoscopy (URS) for renal pelvic stones (RPS) sized 1 to 2 cm and to determine the predictive factors for the requirement for flexible URS (F-URS) when rigid URS fails. MATERIALS AND METHODS A total of 88 patients were included into the study. In 48 patients, the RPS were totally fragmented with rigid URS and F-URS was not required (group 1). In 40 patients, rigid URS was not able to access the renal pelvis or fragmentation of the stones was not completed owing to stone position or displacement and F-URS was utilized for retrograde intrarenal surgery (RIRS) (group 2). The predictive factors for F-URS requirement during RIRS for RPS were evaluated. Both groups were compared regarding age, height, sex, body mass index, stone size, stone opacity, hydronephrosis, and previous treatments. RESULTS The mean patient age was 48.6±16.5 years and the mean follow-period was 39±11.5 weeks. The overall stone-free rate in the study population was 85% (75 patients). In groups 1 and 2, the overall stone-free rates were 83% (40 patients) and 87% (35 patients), respectively (p>0.05). The independent predictors of requirement for F-URS during RIRS were male gender, patient height, and higher degree of hydronephrosis. CONCLUSIONS Rigid URS can be utilized in selected patients for the fragmentation of RPS sized 1 to 2 cm with outcomes similar to that of F-URS. In case of failure of rigid URS, F-URS can be performed successfully in this group of patients.

PURPOSE The objective was to determine whether stone density on plain radiography (kidney-ureter-bladder, KUB) could predict the outcome of extracorporeal shockwave lithotripsy (ESWL) for ureteral stones. MATERIALS AND METHODS A total of 223 patients treated by ESWL for radio-opaque ureteral stones of 5 to 20 mm were included in this retrospective study. All patients underwent routine blood and urine analyses, plain radiography (KUB), and noncontrast computed tomography (NCCT) before ESWL. Demographic, stone, and radiological characteristics on KUB and NCCT were analyzed. The patients were categorized into two groups: lower-density (LD) group (radiodensity less than or equal to that of the 12th rib, n=163) and higher-density (HD) group (radiodensity greater than that of the 12th rib, n=60). Stone-free status was assessed by KUB every week after ESWL. A successful outcome was defined as stone free within 1 month after ESWL. RESULTS Mean stone size in the LD group was significantly smaller than that in the HD group (7.5±1.4 mm compared with 9.9±2.9 mm, p=0.002). The overall success rates in the LD and HD groups were 82.1% and 60.0%, respectively (p=0.007). The mean duration of stone-free status and average number of SWL sessions required for success in the two groups were 21.7 compared with 39.2 days and 1.8 compared with 2.3, respectively (p

Purpose We measured ureter length in healthy Koreans using reformatted computed tomography (ULCT) and found ways to indirectly estimate ureter length by measuring LLCT, the length between the ureteropelvic junction and the ureterovesical junction, and standing and sitting height. Materials and methods A total of 508 ureters of 254 healthy patients (median age, 55.0 years; 148 males and 106 females) were included in this retrospective study. ULCT, LLCT, and sitting and standing body height were measured. Results The mean left and right ULCT were 25.2±2.2 and 25.0±2.2 cm, respectively. The mean left and right LLCT were 21.1±1.8 and 20.3±1.9 cm, respectively. Standing and sitting body height were 164.1±8.9 and 88.3±4.3 cm, respectively. Height was significantly correlated with ULCT, but this relation was not linear (r2=0.064 standing height, 0.062 sitting height). However, LLCT showed a significant linear correlation with ULCT (r2=0.485). ULCT can be estimated indirectly by the following equation: ULCT=0.823×LLCT+8.093. Conclusions We could measure the ureteral length of healthy Koreans by ULCT. ULCT could be estimated indirectly by LLCT and standing and sitting height. Of these variables, LLCT provided the most accurate estimate of ureteral length.

Purpose Well-validated risk prediction models help to stratify individuals on the basis of their disease risks and to guide health care professionals in decision-making. The incidence of nephrolithiasis has been increasing in Korea. Racial differences in the distribution of and risk for nephrolithiasis have been reported in Asia but no population-specific nephrolithiasis models have been developed. We aimed to develop a simplified nephrolithiasis prediction model for the Korean population by using data from general medical practice. Materials and methods This was a prospective, population-based cohort study in Korea. A total of 497,701 participants from the National Health Insurance Service-National Sample Cohort (NHIS-NSC) were enrolled from 2002 to 2010. A Cox proportional hazards model was used. Results During a median follow-up time of 8.5 years (range, 2.0-8.9 years) and among 497,701 participants, there were 15,783 cases (3.2%) of nephrolithiasis. The parsimonious model included age, sex, income grade, alcohol consumption, body mass index, total cholesterol, fasting blood glucose, and medical history of diseases. The Harrell's C-statistic was 0.806 (95% confidence interval [CI], 0.790-0.821) and 0.805 (95% CI, 0.782-0.827) in the derivation and validation cohorts, respectively. Conclusions The results of the present study imply that nephrolithiasis risk can be predicted by use of data from general medical practice and based on predictors that clinicians and individuals from the general population are likely to know. This model comprises modifiable risk factors and can be used to identify those at higher risk who can modify their lifestyle to lower their risk for nephrolithiasis. This study also offers an opportunity for external validation or updating of the model through the incorporation of other risk predictors in other settings.

Purpose: Ultrasound (US) is highly sensitive in the detection of renal masses. However, it may not be able to differentiate benign and malignant lesions in smaller masses. The purpose of this study was to determine the diagnostic efficacy of contrast-enhanced ultrasound (CEUS) for small renal masses. Materials and Methods: From January 2011 to December 2013, a total of 85 patients underwent CEUS for evaluation of renal masses. Of these patients, CEUS findings were retrospectively analyzed for small renal cell carcinoma (RCC) cases (n=38) and angiomyolipoma (AML) cases (n=11). The tumor echogenicity and enhancement patterns and degrees were evaluated. The diagnostic efficacy of CEUS in differentiating the two diseases was compared. Results: On CEUS, the findings of diffuse heterogeneous enhancement (observed in 78.9% of RCCs and 27.3% of AMLs, p=0.003), washout from hyperenhancement or isoenhancement to hypoenhancement in late phase (73.7% of RCCs and 18.2% of AMLs, p=0.001), and perilesional rim-like enhancement (57.9% of RCCs and 9.1% of AMLs, p=0.006) were significantly different between AML and RCC cases. The corresponding sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 86.8% (33/38), 63.6% (7/11), 89.2% (33/37), 58.3% (7/12), and 81.6% (40/49), respectively. Conclusions: Our results suggest that the characteristic CEUS features could have diagnostic value in the evaluation of small renal mass. CEUS showed a higher diagnostic efficacy than conventional US for differentiating RCC and AML.

Purpose We evaluated the association between shock wave lithotripsy (SWL)-related pain and patient positioning during SWL. Materials and Methods We retrospectively reviewed the medical records of 162 patients who underwent their first SWL session for single renal stones from May 2010 to August 2011. One hundred thirteen patients underwent SWL in the supine position and 49 did so in the lateral position. To evaluate an unbiased estimation of the positional effect on pain severity during SWL, both groups (supine vs. lateral) were matched according to sex, age, body mass index, stone location, and stone size. Thirty-four patients from each group were selected for analysis. Pain was evaluated with an average visual analogue scale (VAS-avg) and maximum visual analogue scale (VAS-max). Analgesic usage was also compared between the groups. Results All patients (n=34) in the supine group had radio-opaque stones compared with only 47.1% of the patients in the lateral group (n=16). The VAS-avg and VAS-max of the lateral group were significantly lower than those of the supine group (1.2±1.0 and 3.1±1.7 for VAS-avg and 2.5±1.8 and 4.7±1.9 for VAS-max, respectively, p

Purpose: Although percutaneous nephrolithotomy (PCNL) has been accepted as a standard method for the management of large renal stones, the incidence of renal hemorrhage is relatively high. This study investigated the variables that affect bleeding during PCNL. Materials and Methods: The medical records of 370 patients who underwent PCNL by a single surgeon from January 2005 to December 2010 were reviewed retrospectively. All patients were divided into two groups according to median blood loss (lesser bleeding group and higher bleeding group). Various clinical and perioperative factors including age, sex, stone size and position, degree of hydronephrosis, operative time, underlying disease, history of anticoagulant medication, presence of previous nephrostomy catheter, stone composition, and thickness of the renal cortex were assessed. For statistical assessment, univariate and multivariate logistic regression analyses were used. Results: The mean patient age was 48.8 years (range, 22 to 75 years). Forty-three patients (11.6%) received a transfusion and 9 patients (2.4%) underwent angioembolization after surgery. The mean blood loss was 511.8±341.3 mL. Body mass index (BMI), stone size, stone position, operation time, and degree of preoperative hydronephrosis were predictive factors for severe bleeding during PCNL. Conclusions: On the basis of the results achieved by a single surgeon, staghorn stones, high BMI, large stones, prolonged operation time, and absence of hydronephrosis were significantly associated with the risk of severe bleeding during PCNL.

Purpose Percutaneous nephrolithotomy (PCNL) has been the preferred procedure for the removal of large renal stones in Iran since 1990. Recently, we encountered a series of devastating neurologic complications during PCNL, including paraplegia and hemiplegia. There are several reports of neurologic complications following PCNL owing to paradoxical air emboli, but there are no reports of paraplegia following PCNL. Materials and Methods We retrospectively reviewed the medical records of patients who had undergone PCNL in 13 different endourologic centers and retrieved data related to neurologic complications after PCNL, including coma, paraplegia, hemiplegia, and quadriplegia. Results The total number of PCNL procedures in these 13 centers was 30,666. Among these procedures, 11 cases were complicated by neurologic events, and four of these cases experienced paraplegia. All events happened with the patient in the prone position with the use of general anesthesia and in the presence of air injection. There were no reports of neurologic complications in PCNL procedures performed with the patient under general anesthesia and in the prone position and with contrast injection. Conclusions It can be assumed that using room air to opacify the collecting system played a major role in the occurrence of these complications. Likewise, the prone position and general anesthesia may predispose to these events in the presence of air injection.

Purpose The use of ultrasound in percutaneous nephrolithotomy (PCNL) has not been shown to translate to better clinical and stone outcomes. To compare the operative outcomes, postoperative outcomes and complication rates of ultrasound-guided access PCNL (USGA-PCNL) versus fluoroscopy-guided access PCNL (FGA-PCNL). Materials and methods A total of 184 consecutive patients who underwent PCNL from July 2008 to September 2014 were identified from our PCNL database. Seventy-two patients underwent USGA-PCNL and 112 FGA-PCNL. Results The patients were similar in age, sex, race, American Society of Anesthesiologists physical status classification, mean largest stone diameters, side of PCNL, number of stones and the degree of hydronephrosis between both groups. There were higher rates of upper pole (5.6% vs. 3.6%), mid pole (8.3% vs. 2.7%) and multiple pole punctures (4.2% vs. 0%) in USGA-PCNL compared to FGA-PCNL (p=0.027). There was no difference in the stone free rates of both groups in univariate analysis. Those who had FGA-PCNL were 2.26 (95% confidence interval, 1.09-4.75; p=0.029) times more likely to require a second-look procedure compared to USGA-PCNL on univariate analysis but not on multivariate analysis. There were no differences in Clavien-Dindo complications. No patient in the USGA-PCNL group experienced organ injuries during puncture compared to 1 patient in the FGA-PCNL group who had pneumothorax requiring urgent chest tube insertion. Conclusions The use of ultrasonography to guide access puncture during PCNL eliminates the risk of inadvertent organ injuries. Similar operative and stone outcomes show that the learning curve for USGA is minimal compared to conventional FGA.

Purpose Thulium vaporesection of the prostate (ThuVARP) is a new and safe approach for patients receiving anticoagulant therapy in whom transurethral resection of the prostate (TURP) may possess a high bleeding risk. We aimed to demonstrate the efficacy and safety of ThuVARP in patients receiving oral antiplatelet/anticoagulant (OAP/OAC) therapy. Materials and methods A total of 103 patients who underwent ThuVARP between 2011 and 2013 were enrolled in the study. Patients were divided into 2 groups. Group A consisted of 47 patients who underwent low molecular weight heparin (LMWH) bridging and group B consisted of 56 patients who were operated on while receiving OAP/OAC therapy. Results The drop in hemoglobin levels in the pre- and postoperative periods was significantly higher in group A than in group B. When subgroups were analyzed, the mean drop in hemoglobin was significantly lower in the warfarin and ticlopidine subgroups of group B than in group A. International Prostate Symptom Scores were significantly lower 3, 12, 18, and 24 months after surgery in group A than in group B. Quality of life scores, maximal flow rate values, and postmicturition residual urine volumes (mL) were similar between the 2 groups. A total of 38 and 41 patients in groups A and B, respectively, had no complications. Conclusions Our study showed the safety profile of continuing different OAP/OAC therapies in terms of bleeding problems in patients undergoing ThuVARP. We strongly recommend abandoning LMWH bridging and maintaining the OAP/OAC regimen patients are already receiving.

Purpose: Percutaneous nephrolithotomy (PCNL) is conventionally conducted in the prone position. However, the prone position increases anesthesia-related morbidity and position changes lengthen the operation time. We report perioperative outcomes and the learning curve for flank PCNL on the basis of a single surgeon’s experience. Materials and Methods: This study investigated 53 cases of flank PCNL performed for renal stones at our institution from April 2008 to September 2010. We compared mean operative time, stone-free rate, drop in hemoglobin level, length of hospital stay, complications, and need for additional procedures after the surgery. The 53 cases were divided into three groups by case number to compare therapeutic effect, stability, and the learning curve for flank position PCNL. Results: The mean operation time for the 53 patients was 97.3±43.1 minutes. The mean operation time gradually decreased as the surgeon accumulated experience. From the 36th case, the mean operation time showed a statistically significant decrease to 72.2± 24.1 minutes (p=0.003). The overall stone-free rate was 64.2% for all procedures (range, 61.1-76.5%). There were no significant differences in the drop in hemoglobin level, stone-free rate, re-treatment, hospital stay, or complication rate. There was no injury to the bowel or renal vessels, and no other major complications occurred. Conclusions: Flank PCNL can be used to remove renal stones effectively while overcoming the disadvantages of the existing prone position PCNL. After 36 cases, the learning curve showed acquisition of surgical competence. The clinical experience reported here suggests that flank PCNL is a safe and feasible technique.

Purpose To compare the safety and efficacy of xylocaine gel and ketorolac as opioid-sparing analgesia compared with pethidine for shock wave lithotripsy (SWL) pain. Materials and methods A single-blinded randomized controlled trial (RCT) was performed in 132 patients with renal and upper ureteral stones amenable to treatment with SWL. The first patient group received intravenous (IV) pethidine and placebo gel; the second group received IV ketorolac plus placebo gel; the third group received lidocaine gel locally plus normal saline IV. Stone disintegration was classified as none (no change from basal by kidney, ureter, bladder X-ray or ultrasound [US] imaging), partial (fragmented and >4-mm residual fragments), and complete (≤4-mm residual fragments). Stone disintegration was assessed by kidney-ureter-bladder X-ray and US imaging. Pain was evaluated by use of the Numeric Pain Rating Scale (NPRS). Results The NPRS scores were highest in the xylocaine group at 10, 20, and 30 minutes (p=0.0001) with no significant difference between the ketorolac and pethidine groups, except at 10 minutes (p=0.03) and a near significant difference at 30 minutes (p=0.054) in favor of ketorolac. Results for stone disintegration (none, partial, and complete, respectively) were as follows: 25 (50.0%), 23 (46.0%), and 2 (4.0%) for pethidine; 19 (35.8%), 23 (43.4%), and 11 (20.8%) for ketorolac; and 26 (89.7%), 3 (10.3%), and 0 (0.0%) for lidocaine (p=0.008). Conclusions Ketorolac is a safe and more effective alternative to morphine derivatives for SWL analgesia. Lidocaine gel should not be used as mono-analgesia for SWL.

PURPOSE We performed laparoendoscopic single-site (LESS) partial nephrectomy in a porcine model with the objectives of overcoming the technical challenges of this surgery and exploring its feasibility. MATERIALS AND METHODS Six partial nephrectomies were performed on a pig aged 5 months, three cases on each kidney, by four surgeons: two urologists with much experience in laparoscopic surgery (E1, E2) and two less-experienced urologists (B1, B2). While under general anesthesia, the swine was placed in a lateral flank position. Umbilical placement of an Octoport was done with a 2.5 cm incision. After dissection of the renal hilum and Gerota's fascia, a bulldog clamp was applied on the renal artery and parenchymal resection was done. Renorrhaphy was then performed with interrupted sutures with the use of a sliding knot technique. RESULTS All six partial nephrectomies were performed successfully after repair of the vascular and collecting system at the resection margin and renorrhaphy without the need to introduce any additional ports. There were no noticeable intra- or postoperative complications. The mean warm ischemic time was 42 minutes (range, 30-60 minutes). The shortest warm ischemic time, 30 minutes, was achieved by using the early unclamping technique during renorrhaphy. The longest warm ischemic time was 60 minutes. The average number of renorrhaphy stitches was 3.2 (range, 2-5). CONCLUSIONS LESS partial nephrectomy was successfully performed in a porcine model but resulted in a longer ischemic time than that of conventional laparoscopic surgeries. Therefore, further laboratory disciplinary efforts are needed to decrease the warm ischemic time and to improve this surgical technique.

This article compared the amount and frequency of radiation exposure of patients between the year 1990 and 2013 during diagnostic procedures due to the change in imaging equipment. Considering the rise in interest of the safety issues concerning over-exposure of radiation, this paper merits further consideration. Though it is difficult to draw a definitive conclusion due to the small case numbers, the authors were unable to show that there was a clear disparity in radiation exposure between the 2 groups. Simple comparison may show that patients undergoing computed tomography (CT) scans are exposed to higher amounts of radiation than intravenous urography (IVU). However CT scans allow faster diagnosis and requires less concurrent studies and thus the overall exposure is not very different. I believe this the message that the authors wish to present to the readers. If possible, remarks on the composition of stones that were examined are advised. The authors mention in their manuscript that the radiation exposure during CT scans were approximately 3.5 mSV, which is probably a protocol for low dose CT scans. The amount of radiation exposure for traditional renal stone protocol is approximately 9–16 mSV which is considerably higher [1]. Many patients will likely have recurrences and will need additional scans, adding to radiation exposure. A study on the frequency of CT scans reports that patients with acute stone episodes will require an average of 1.7 CT scans within the following year [2]. The diagnostic imaging method the authors used for comparison in 1990 was in fact an IVU. The IVU is a relatively invasive procedure with risks concerning complication due to contrast. The IVU is also slow in diagnosis and is currently no longer used in practice. No studies have yet reported the effects of continuous low dose radiation exposure, but due to advancement of diagnostic imaging tools, the amount of radiation exposure is increasing. It has been reported in the United States there has been a 600% (from 0.54 to 3.0) increase in radiation exposure from medical sources per capita from the year 1982 to 2006 [3]. This concern is augmented in ureter stone patients where radiation is frequently used during diagnosis, treatment and follow-up. Considering the high rate of recurrence in ureter stones, urologists should always be concerned of the risk of overexposure in their patients and try to minimize the amount of radiation during procedures. Recent studies on low dose (3 mSv), and ultra-low dose (1–2 mSv) CT scans show that even with low amounts of radiation, stones larger than 3 mm in patients with body mass index less than 30 can be detected with comparable sensitivity and specificity to standard CT scans [4,5,6]. Fluoroscopy used during percutaneous nephrolithotomy, ureteroscopy or extracorporeal shock-wave lithotripsy is also a major source of medical radiation and should follow the "as low as reasonably achievable" principle whenever possible during procedures to lessen the chance of radiation exposure.

Purpose To assess the potential of dual-energy computed tomography (DECT) to identify urinary stone components, particularly uric acid and calcium oxalate monohydrate, which are unsuitable for extracorporeal shock wave lithotripsy (ESWL). Materials and Methods This clinical study included 246 patients who underwent removal of urinary stones and an analysis of stone components between November 2009 and August 2013. All patients received preoperative DECT using two energy values (80 kVp and 140 kVp). Hounsfield units (HU) were measured and matched to the stone component. Results Significant differences in HU values were observed between uric acid and nonuric acid stones at the 80 and 140 kVp energy values (p

Purpose: The combined interaction of epidemiology, environmental exposure, dietary habits, and genetic factors causes kidney stone disease (KSD), a common public health problem worldwide. Because a high water intake (>3 L daily) is widely recommended by physicians to prevent KSD, the present study evaluated whether the quantity of water that people consume daily is associated with KSD and whether the quality of drinking water has any effect on disease prevalence. Materials and Methods: Information regarding residential address, daily volume of water consumption, and source of drinking water was collected from 1,266 patients with kidney stones in West Bengal, India. Drinking water was collected by use of proper methods from case (high stone prevalence) and control (zero stone prevalence) areas thrice yearly. Water samples were analyzed for pH, alkalinity, hardness, total dissolved solutes, electrical conductivity, and salinity. Average values of the studied parameters were compared to determine if there were any statistically significant differences between the case and control areas. Results: We observed that as many as 53.6% of the patients consumed