The Role of Tissue Persistent Organic Pollutants and Genetic Polymorphisms in Patients with Benign and Malignant Kidney Tumors.

This study aimed to explore whether there is an association between environmental exposure to POPs and kidney tumor induction, and whether blood POP concentrations reflect kidney tissue concentrations. POP derivatives were determined in blood, tumor tissue, tumor surrounding tissue, and perirenal fat tissue samples taken from patients who underwent surgery for renal tumors. A voluntary control group was recruited for blood and urine samples as well. Urinary excretions of o,o'-dityrosine, chlorotyrosine, nitrotyrosine, and 8-OHdG were measured in the same patients. The possible role of genetic polymorphisms in CYP1A1, GST isozymes P, M, and T, and hOGG1 genes on the predisposition to renal cancer was investigated. Some POPs have been found to be associated with kidney cancer, as evidenced by their significantly high ORs. 8-OHdG levels were significantly higher compared to the control group. The GSTT1 null polymorphism can be a risk factor for malignant but not for benign kidney tumors.

COVID-19 Lung Findings Detected by 68Ga-PSMA PET/CT for Staging Purposes in Patients With Prostate Cancer.

ABSTRACT: We report 3 patients with COVID-19 findings in 68Ga-PSMA PET/CT taken for staging. The first patient, A 64-year-old man with prostate cancer, who had COVID-19 in November 2020 and whose treatment was completed, was observed to continue with COVID-19 findings in 68Ga-PSMA PET/CT in December 2020 before surgery. Other patients were asymptomatic for the disease. It was determined that a PSMA uptake in the lungs corresponding to the CT findings of COVID-19 had increased in 68Ga-PSMA PET/CT.

Comparison of Tumor Enucleation and Standard Partial Nephrectomy According to Trifecta Outcomes: A Multicenter Study by the Turkish Academy of Urology, Uro-Oncology Working Group.

INTRODUCTION: We aimed to evaluate the impact of the resection technique (tumor enucleation (TE) or standard partial nephrectomy (SPN)) on trifecta outcomes in patients having undergone partial nephrectomy (PN). MATERIALS AND METHODS: We retrospectively analyzed the clinical and pathologic parameters in patients with localized renal cell carcinoma (pT1-2N0M0) who had undergone PN between January 2001-December 2018 at one of 15 different tertiary referral centers. Multivariable logistic regression analysis was applied to investigate independent predictors of trifecta failure, decreased postoperative renal functions (decreased estimated glomerular filtration rate (eGFR) > 10%), perioperative complications (Clavien-Dindo > 1), and positive surgical margins. RESULTS: A total of 1070 patients with a mean age 56.11 ± 11.88 years were included in our study. PN was performed with TE in 848 (79.25%) and SPN in 222 (20.75%) patients. Trifecta failure rate was 56.2% for TE and 64.4% for SPN (p = 0.028). On multivariable analysis, TE was associated with less trifecta failure (p = 0.025) and eGFR decrease >10% rates (p = 0.024). On the other hand, there was no statistically significant difference between TE and SPN according to positive surgical margins (p = 0.450) and complication > Clavien-Dindo grade 1 (p = 0.888) rates. The only independent predictive factor for complications > Clavien-Dindo 1 was the Charlson comorbidity index (CCI) (p = 0.001). CONCLUSION: TE is associated with less trifecta failure than SPN. This result is mainly due to better preservation of renal function with TE.

Factors affecting the success of pediatric extracorporeal shock wave lithotripsy therapy: 26-year experience at a single institution.

Despite its widespread use, few studies have evaluated the success of extracorporeal shock wave lithotripsy (ESWL) in pediatric patients with several parameters and a large group of patients. In the present study, we aimed to analyze the factors that affect the outcomes of pediatric ESWL treatment, which we have practiced for 26 years. This study included 1012 pediatric patients who underwent ESWL between March 1991 and November 2017. Pre-procedure radiological evaluations were performed using kidney-ureter-bladder and/ or urinary system ultrasonography. Demographic data, stone characteristics, and ESWL treatment data and complications were recorded and univariate and multivariate analyses were performed for the stone-free rate (SFR). Receiver operating characteristic (ROC) analysis was performed to determine the cut-off values for stone size to predict ESWL success for both kidney and ureteral stones. Age, body mass index (BMI), congenital renal anomaly, stone location, stone size, number of stones, and stone composition significantly affected the SFRs in univariate analysis; however, only age, BMI, stone location, and stone size were significant in the multivariate analysis. If no residual fragments were detected after three sessions of ESWL application, the procedure was considered successful. The cut-off stone size values for the kidney and ureter that predicted treatment success were 96.28 mm2 and 44.16 mm < sup > 2 < /sup > , respectively. ESWL is an effective and safe treatment in the pediatric age group that provides high SFRs. Age, BMI, and stone location, size, and composition are particularly critical factors that can predict the success of ESWL.

Visual clarity of irrigants used during flexible ureterorenoscopy: an in vitro comparison.

INTRODUCTION: Saline solution is the standard irrigant used during ureteroscopy. However, there is an opinion that water has better visual clarity. We aimed to compare the visual clarities of saline, water, and 5% mannitol as an irrigant during ureteroscopy. MATERIAL AND METHODS: An in vitro model consisting of an irrigant-filled container and a fiberoptic flexible ureteroscope was designed. A 1951 USAF Resolution Test Target and color checker within irrigants were used to evaluate the clarity of vision. The visual clarity was compared for 0.9% saline, distilled water and 5% mannitol solution with screen resolution and color contrast. The tests were repeated after adding human blood (2/400 ml) and contrast (20/400 ml) to the irrigants. RESULTS: There was no significant difference in resolution values of three plain irrigants at a distance of 10 mm. However, when blood was added to the irrigants, a better resolution of 29.3% for water and 20.6% for mannitol was achieved compared to saline. At 20 mm of distance, it was observed that the difference was more pronounced in irrigants with blood. Water and mannitol had 55.6% and 37.1% better resolution than saline, respectively. In the color reproduction test, there was no significant difference in the three plain irrigants, however, water had better color contrast compared to the others. CONCLUSIONS: Water and 5% mannitol did not provide a significant image clarity advantage compared to saline. However, when blood was added to the irrigants, water provided significantly better visual clarity compared to saline. The use of water during various clinical scenarios in flexible ureteroscopy should be further investigated.

Ho:YAG laser versus pneumatic lithotripsy for management of pediatric ureteral stones: a prospective-comparative analysis with adults.

BACKGROUND: There are limited number of studies comparing the results of Holmium:YAG laser lithotripsy (LL) and pneumatic lithotripsy (PL) for pediatric ureteral stones. OBJECTIVES: To perform a comparative analysis of LL and PL in the management of ureteral stones in children and adults. STUDY DESIGN: Ninety-eight children (56 boys and 42 girls) and 623 adults (360 men and 263 women), who were treated for ureteral stones at our clinic between 2017 and 2019, were the subjects of this study. Patients were grouped according to their age as group 1 (n:98, pediatric [<18 age]) and group 2 (n:623, adult [≥18 age]). The patients were then grouped according to lithotripter type as laser (n:580) and pneumatic (n:141). The effects of lithotripter type, stone size and location, and operative times on success and complication rates were investigated. RESULTS: In both groups, mean operation time was in favor of PL (14.6 vs 22.8 min, p = 0.042 and 26.4 vs 36.3 min, p = 0.013, respectively). In both groups, overall stone-free rates (SFR) were in favor of LL (86.8% vs 66.7%, p < 0.001, and 83% vs 73.9%, p = 0.005, respectively), but there was no significant difference in overall SFRs between adults and children (78.4% vs 76.7, p = 0.390). Retreatment rates were higher in the pneumatic group in both children and adults (p = 0.026 and p = 0.041, respectively). While there was no significant difference in the overall complication rates between adults and children (53.5% vs 40.6%, p = 0.816), the rate of complications with LL was lower in adults (37.7% vs 69.4%, p < 0.001) (TABLE). DISCUSSION: This paper is the first to report a comparative analysis of factors affecting URS success in adults and children. SFRs were higher in all ureteral locations for LL. LL, lower ureteral location, and <6 mm ureteral stone were determined as the predictors of success for both pediatric and adult patients. The presence of multiple surgeons with different levels of experience is the main limitation of this study. CONCLUSION: Both LL and PL are safe in children and adults with similar clinically insignificant complication rates. However, in the short term, LL provides better SFRs in both children and adults, especially in the upper ureteral stones. Surgeons should decide the energy technique to be used in URS according to the characteristics of the stone rather than the patient's age group.

Comparison of long-term outcomes of laparoscopic and robot-assisted laparoscopic partial nephrectomy.

In this study, we compared the long-term oncological and functional outcomes of laparoscopic partial nephrectomy (LPN) and robot-assisted laparoscopic partial nephrectomy (RAPN) performed in the treatment of renal tumors. The data of 142 patients (RAPN = 71, LPN = 71) were evaluated. Demographic data, perioperative and postoperative outcomes, long-term (5-year) overall survival (OS) and cancer-specific survival (CSS) rates of the patients were compared between the two groups. A P value of less than 0.05 was considered statistically significant. The mean follow-up time was 61.38 months. There were more complex tumors in the RAPN group (P = 0.014). The duration of warm ischemia time (WIT) was shorter in the RAPN group (P = 0.019). Perioperative and postoperative outcomes were similar. There were no differences between the groups in terms of 5-year metastasis-free survival, OS, and CSS rates. Hypertension, diabetes, and preoperative estimated glomerular filtration rate (eGFR) were the predictive factors for renal insufficiency; and preoperative eGFR, WIT, and positive surgical margin were the predictive factors for 5-year CSS. We concluded that RAPN is an important minimally invasive treatment method for partial nephrectomy with long-term favorable results, especially in complex tumors. Comparisons of two methods should be made with comparative, prospective, randomized, high case number studies, and the place of RAPN in the treatment of these tumors should be clarified.

Robotic partial nephrectomy in a child with kidney tumor.

Robotic surgery is gaining wider utility in adults; however, few reports have addressed the applicability of robotic surgery for renal tumors in children. The aim of this report is to share our experience in an 8-year-old child with metanephric stromal tumor. To our knowledge, besides being a rare tumor, this is the youngest case reported in the literature whose kidney tumor has been successfully removed with robotic partial nephrectomy. There is a worldwide tendency to perform minimal invasive surgery for kidney tumors. In the presence of an experienced team and proper conditions, we believe that robotic partial nephrectomy will be the preferred option in future.

Investigation of the synergistic effects of paclitaxel and herbal substances and endemic plant extracts on cell cycle and apoptosis signal pathways in prostate cancer cell lines.

Paclitaxel, which isolated from Taxus brevifolia, is recently started to be used against prostate cancer treatment and it is a very effective compound against cancer. In this study, we aimed to test the synergistic effect of two plant active compounds (sulphoraphane (SFN) and silymarin (SILY)) and several endemic plant species from Turkey (such as Phlomis leucophracta, Rubia davisiana, Alkanna tinctoria), which are known to have anticarcinogenic effect on androgen-independent PC3 and DU145, and androgen-dependent VCaP prostate cancer cell lines, with paclitaxel on the expression of cell cycle signaling and apoptosis regulator genes. Herbal substances and endemic herbal extracts were combined with Paclitaxel drug. IC50 doses were identified as real-time online. The most effective synergistic doses were determined according to isobologram analysis. The apoptotic effects of effective combined doses were evaluated by TUNEL, Annexin V, and JC-1 methods. Apoptotic and/or cell cycle arrest effects of confirmed combined doses on the expression of genes in these pathways were assessed by real-time online. Endemic plant extracts (Alkanna tinctoria, Phlomis leucophracta and Rubia davisiana, IC50 < 220 µg/ml) and herbal substances (SILY, and SFN IC50 < 130 µM) indicated antiproliferative and apoptotic effects in prostate cancer cell lines. They testified to the synergistic effect of paclitaxel with endemic plant extracts (Combination Index CI, ED50 < 0.41). The combinations, which indicate the synergistic effect was increased to the Bax/Bcl­2 ratio by suppressing Bcl­2 gene expression into the prostate cancer cell lines. Besides, they increased the expression of TNFRSF10A, TNFRSF1A, CHEK1, CDKN1A, CDKN2B, CDK8, CDKN3 and CASP14 and decreased BAD, CDK5RAP1, CDC20, cyclin H, CDK5RAP1, CDC20. The effective doses of paclitaxel were reduced and G2/M arrest was induced by the endemic plant extracts and herbal substances that indicate a synergistic effect with paclitaxel. By using different combination of herbal extracts or active substances with paclitaxel, more economical and efficient treatment strategies can be developed.

Inter-individual and inter-organ variability in the bioactivation of paracetamol by human liver and kidney tissues.

Paracetamol (PAR) overdose is associated with massive hepatic injury; it may induce kidney toxicity as well. It is essential to measure organ-specific activities of related CYPs for evaluating the overdose cases. Available HPLC-based methods require high amounts of tissue samples. In order to develop liquid chromatography mass spectrometry (LC-MS)-based methods to process small amounts of human tissues, liver and kidney samples were obtained. Individual microsomes were prepared and incubated with PAR (for quantifying bioactivation), with nifedipine (for measuring CYP3A4 activity) and with p-nitrophenol (for measuring CYP2E1 activity). The small amount of tissue microsomes was sufficient to measure both the formation of NAPQI and the activities of CYP enzymes. Although the sample size in group was relatively low, both NAPQI formation and activity of CYP2E1 were significantly higher in males compared to females in kidney. Considerable variations in the metabolic capacity of individuals were observed for both organs.

Benign prostatic hyperplasia: Case report of a 17-year-old.

INTRODUCTION: Benign prostatic hyperplasia (BPH) is generally common in men older than 50 years of age but is extremely rare in childhood. In the literature to date, fewer than five cases have been reported under 18 years of age. Owing to the limited number of cases, the etiology and management of BPH in the first two decades is not clear. OBJECTIVE: We herein report a 17-year-old boy who presented with acute urinary retention due to BPH and was treated with endoscopic transurethral resection of the prostate (TUR-P). CASE REPORT: A 17-year-old male patient with a history of intermittent hematuria was admitted elsewhere with acute urinary retention. An increase in prostate size was detected on digital rectal examination. Pelvic ultrasound revealed a large mass arising from the prostate and filling the bladder lumen. Transrectal ultrasound-guided prostate biopsy (TRUS-Bx) was performed to exclude malignancy. After the documentation of benign prostate tissue in the histopathological analysis, the patient was referred to our clinic for further evaluation and management. Magnetic resonance (MR) imaging revealed a 48 × 55 × 68 mm mass arising from the middle lobe of prostate and filling the bladder lumen (Figure) with an initial diagnosis of a non-ductal malignant tumor because of his age. Enlarged lymph nodes or any sign of metastasis were not detected. Re-examination of the previous biopsy specimens confirmed the absence of malignancy; therefore he underwent endoscopic treatment with TUR-P. Histopathological examination reported BPH. The postoperative 1-year follow-up was uneventful. DISCUSSION: The patient was extensively evaluated with a suspicion of malignancy, especially rhabdomyosarcoma, which is more expected for this age group. Reviewing juvenile cases with BPH in the literature, two authors explained the possible etiologic factors of their cases as gonadotropin supplement therapy for undescended testes and the mother's utilization of a human chorionic gonadotropin-containing agent during pregnancy to prevent spontaneous abortion. Our case had no history of drug intake, endocrinologic abnormality, or any other possible relevant factor. Owing to the limited number of cases, there is not enough data to understand the etiology and also no consensus on the treatment of BPH in the adolescents. Therefore, experiences gained from adult cases guide the pediatric treatment modalities. CONCLUSION: Despite the fact that BPH is very rare in childhood, one should keep it in mind in the differential diagnosis of acute urinary retention and malignant prostate diseases. The endoscopic method is the treatment of choice in BPH.

Safety and Feasibility of Laparoscopic Nephrectomy for Big Tumors (≥ 10 cm): A Retrospective Multicentric Study.

OBJECTIVE: Evaluate the feasibility of laparoscopic nephrectomy for big tumors. MATERIAL AND METHODS: Data from 116 patients were retrospectively collected from 16 tertiary centres. Clinical and operative parameters, tumor characteristics, pre- and postoperative parameters, and renal function before and after surgery were analyzed. RESULTS: Mean age and body mass index were 61 years and 27.8 kg/m(2), respectively. Males represented 63.8% of patients, and 54.4% presented symptoms at diagnosis. Median tumor size was 11 cm, and 75% of the cases were performed by expert surgeons. Median operative time and blood loss were 180 minutes and 200 mL respectively. Conversion to open surgery was necessary in 20.7% of cases. Intraoperative complications related to massive hemorrhage occurred in 16.4% of patients, resulting in open conversion in 62.5%. Major postoperative complications occurred in only 10 patients (8.6%). In univariate analysis, intraoperative complications, age, and blood loss were predictive factors of conversion to open surgery. Positive surgical margins occurred in 6 patients (5.2%). None of them presented a local recurrence. Predictive factors of recurrence or progression were lymph node invasion, metastases, and Furhman grade. CONCLUSION: Laparoscopic nephrectomy for tumors > 10 cm can be performed safely. Complication rate and positive surgical margins are similar to open surgery. In experienced hands, the benefit of a mini invasive surgery remains evident.

Extracorporeal shock wave lithotripsy in infants less than 12-month old.

There is a lack of literature on children compared to adults regarding the long-term effects of extracorporeal shock wave lithotripsy (SWL), specifically in infants. The aim of the present study was to analyze the efficacy and safety of SWL in infants and also evaluate its potential adverse effects in the mid-term. Between May 1999 and December 2013, 36 infants with 39 renal units underwent SWL treatment for kidney stones with an electrohydraulic lithotripter (Dornier MPL 9000/ELMED Multimed Classic). All children were less than 12-month old. The mid-term effects of SWL were examined at the last follow-up by measuring arterial blood pressure, random blood glucose level and ipsilateral kidney size. Evaluation of treatment and its consequences was based on clinical examination, blood tests and conventional imaging (plain abdominal radiography and ultrasound). Overall stone-free rate was 84.6 % after 3-month follow-up without any major complications. Mid-term follow-up was available in 20 of 36 children with a mean follow-up of 3.2 ± 2.8 years (range 0.5-15.3). None of the infants were found to develop new onset of hypertension or diabetes. All treated infant kidneys' sizes were in the normal percentile range. SWL for management of infant kidney stones is effective and safe in the mid-term.

Three-dimensional Technology Facilitates Surgical Performance of Novice Laparoscopy Surgeons: A Quantitative Assessment on a Porcine Kidney Model.

OBJECTIVE: To determine whether the use of 3-dimensional (3D) imaging translates into a better surgical performance of naïve urologic laparoscopic surgeons during pyeloplasty (PY) and partial nephrectomy (PN) procedures. MATERIALS AND METHODS: Eighteen surgeons without any previous laparoscopic experience were randomly assigned to perform PY and PN in a porcine model using initially 2-dimensional (2D) and 3D laparoscopy. A surgical performance score was rated by an "expert" tutor through a modified 5-item global rating scale contemplating operative field view, bimanual dexterity, efficiency, tissue handling, and autonomy. Overall surgical time, complications, subjective perception of participating surgeons, and inconveniences related to the 3D vision were recorded. RESULTS: No difference in terms if operative time was found between 2D or 3D laparoscopy for both the PY (P = .51) and the PN (P = .28) procedures. A better rate in terms of surgical performance score was noted by the tutors when the study participants were using 3D vs 2D, for both PY (3.6 [0.8] vs 3.0 [0.4]; P = .034) and PN (3.6 [0.51] vs 3.15 [0.63]; P = .001). No complications occurred in any of the procedures. Most (77.2%) of the participating naïve laparoscopic surgeons had the perception that 3D laparoscopy was overall easier than 2D. Headache (18.1%), nausea (18.1%), and visual disturbance (18.1%) were the most common issues reported by the surgeons during 3D procedures. CONCLUSION: Despite the absence of translation in a shorter operative time, the use of 3D technology seems to facilitate the surgical performance of naïve surgeons during laparoscopic kidney procedures on a porcine model.

The place of androgen receptor gene mutation analysis in the molecular diagnosis of prostate cancer and genotype-phenotype relationship.

AIM: To determine the relationship between androgen receptor (AR) gene polymorphism and prostate cancer in our society. MATERIALS AND METHODS: Thirty-nine patients diagnosed with prostate cancer and 34 benign prostatic hyperplasia (BPH) patients who were diagnosed in 2010 met the study criteria. The inclusion criteria included patients whose diagnosis was confirmed with a biopsy, with the presence of adequate pathologic material for review, between the ages of 40 and 80, and who were healthy men without a family history of prostate cancer. The exclusion criteria excluded men diagnosed with another cancer and those who had kin with a history of prostate cancer. A direct DNA sequencing method was utilized for detection of polymorphisms. RESULTS: CAG repeat length varied from 13 to 28 (mean: 21.67) for the BPH group and 12 to 28 (mean: 21.74) for the prostate cancer group. Prostate-specific antigen (PSA) density and the androgen receptor (AR) CAG repeat had a statistically significant negative correlation in the BPH group. A statistically significant difference was associated between AR CAG repeat and PSA density. CONCLUSION: Randomized prospective studies should be planned with larger patient and control groups and with more variables, which may open new horizons in prostate cancer screening and early detection.

The relationship between lower urinary tract symptoms associated with benign prostatic hyperplasia and erectile dysfunction: the role of autonomic hyperactivity.

BACKGROUND/AIM: To investigate whether autonomic nervous system (ANS) hyperactivity may be a potential cause for the relationship between lower urinary tract symptoms (LUTS) and erectile dysfunction (ED). MATERIALS AND METHODS: Twenty-four patients were recruited for this study. Complete physical examinations, urine analysis, uroflowmetry, and postvoid residual urine volume (PVRU) analysis were performed. The potential impact of some factors such as hyperglycemia, obesity, and hyperlipidemia were analyzed. These values were correlated with the various symptom scores. We performed an electromyographic and an electrocardiographic evaluation. The alterations after treatment with 2 different alpha-blockers were also analyzed. RESULTS: The electromyographic and electrocardiographic assessments revealed a minimal increase in ANS activity and it did not change significantly after treatment (P > 0.05). After treatment, maximum flow rate increased and PVRU decreased significantly (P < 0.001 and P < 0.001, respectively); total and free testosterone levels increased significantly (P = 0.0068 and P = 0.0071, respectively). There was a statistically significant difference between the 2 treatment groups regarding the outcomes of the Danish Prostate Symptom Score questionnaire (P = 0.047). CONCLUSION: This current study suggested that the effect of ANS hyperactivity is not the fundamental factor underlying the relationship between LUTS and ED.

Relationship between erectile dysfunction and silent coronary artery disease: detection with multidetector computed tomography coronary angiography.

AIM: Our aim was to determine the relationship between erectile dysfunction (ED) and silent coronary artery disease (CAD) by multidetector computed tomography (MDCT) coronary angiography. METHODS: Thirty consecutive men with nonhormonal and nonpsychogenic ED and with no cardiac symptoms were evaluated. Medical history, physical examination and laboratory investigation were performed. The five-item brief form of the International Index of Erectile Function (IIEF-5) was performed for evaluation of ED. The Agatston score (AS) was determined from MDCT images under beta blockade to induce bradycardia. The MDCT coronary angiography findings were evaluated by two radiologists blinded to the clinical findings. Patients were classified into three categories (mild, moderate and severe ED) according to IIEF-5 scores and into five categories (very low, low, moderate, moderately high and high CAD risk) according to the AS. RESULTS: Mean age was 58.3 ± 8.7 years (46-79). 6 patients had hypertriglyceridemia, 4 had hypercholesterolemia and 4 had hyperglycemia. All patients had normal early morning testosterone levels. Regarding IIEF-5 scores, none of them had mild ED, 14 had moderate ED and 16 had severe ED. Of the 14 patients with moderate ED, 21.4% had low and 28.5% had moderate CAD risk regarding AS. Of the 16 patients with severe ED, 25% had moderate, 31.2% had moderately high and 25% had high CAD risk regarding AS. Increasing age was a risk factor for high AS (p = 0.045). There was a significant correlation between AS and ED severity (p = 0.01). CONCLUSIONS: ED and CAD often coexist. MDCT coronary angiography can detect coronary lesions and allow appropriate medical intervention.

Impact of stone density on outcomes in percutaneous nephrolithotomy (PCNL): an analysis of the clinical research office of the endourological society (CROES) pcnl global study database.

OBJECTIVE: This study aimed to explore the relationship between stone density and outcomes of percutaneous nephrolithotomy (PCNL) using the Clinical Research Office of the Endourological Society (CROES) PCNL Global Study database. MATERIAL AND METHODS: Patients undergoing PCNL treatment were assigned to a low stone density [LSD, ≤ 1000 Hounsfield units (HU)] or high stone density (HSD, > 1000 HU) group based on the radiological density of the primary renal stone. Preoperative characteristics and outcomes were compared in the two groups. RESULTS: Retreatment for residual stones was more frequent in the LSD group. The overall stone-free rate achieved was higher in the HSD group (79.3% vs 74.8%, p = 0.113). By univariate regression analysis, the probability of achieving a stone-free outcome peaked at approximately 1250 HU. Below or above this density resulted in lower treatment success, particularly at very low HU values. With increasing radiological stone density, operating time decreased to a minimum at approximately 1000 HU, then increased with further increase in stone density. Multivariate non-linear regression analysis showed a similar relationship between the probability of a stone-free outcome and stone density. Higher treatment success rates were found with low stone burden, pelvic stone location and use of pneumatic lithotripsy. CONCLUSIONS: Very low and high stone densities are associated with lower rates of treatment success and longer operating time in PCNL. Preoperative assessment of stone density may help in the selection of treatment modality for patients with renal stones.

A nephrolithometric nomogram to predict treatment success of percutaneous nephrolithotomy.

PURPOSE: Imaging is routinely done preoperatively and postoperatively to assess patients treated with percutaneous nephrolithotomy. We developed a nomogram for percutaneous nephrolithotomy success. MATERIALS AND METHODS: From November 2007 to December 2009 the CROES (Clinical Research Office of the Endourological Society) collected data on consecutive patients at 96 centers globally. Patients were evaluated for stone-free status using plain x-ray of the kidneys, ureters and bladder. Treatment success was defined as no visible stones or residual fragments less than 4 mm. Multivariate regression was used to model the relationship between preoperative descriptors and the stone-free rate. Variables included case load, prior treatment, body mass index, staghorn stones, renal anomalies, and stone burden, location and count. Bootstrapping techniques were used to validate the model. Adjusted chi-square statistic values were used to rank the prognostic value of variables. A nomogram was developed using significant predictors from the model. We assessed the predictive accuracy of the nomogram using the ROC curve AUC. The nomogram was calibrated. RESULTS: Stone burden was the best predictor of the stone-free rate (chi-square = 30.27, p <0.001). Other factors associated with the stone-free rate were case volume (chi-square = 35.75, p <0.001), prior stone treatment (chi-square = 14.55, p <0.012), staghorn stone (adjusted chi-square = 4.73, p <0.029), stone location (chi-square = 14.74, p <0.001) and stone count (chi-square = 4.78, p <0.004). A nephrolithometric nomogram was developed with predictive accuracy (AUC 0.76). CONCLUSIONS: The percutaneous nephrolithotomy stone-free rate can be predicted using preclinical data and radiological information. We present a nephrolithometric nomogram for percutaneous nephrolithotomy.