Monitoring Intrarenal temperature changes during Ho: YAG laser lithotripsy in patients undergoing retrograde intrarenal surgery: a novel pilot study.

Ho: YAG laser lithotripsy is widely used for urinary stone treatment, but concerns persist regarding its thermal effects on renal tissues. This study aimed to monitor intrarenal temperature changes during kidney stone treatment using retrograde intrarenal surgery with Ho: YAG laser. Fifteen patients were enrolled. Various laser power settings (0.8 J/10 Hz, 1.2 J/12 Hz) and irrigation modes (10 cc/min, 15 cc/min, 20 cc/min, gravity irrigation, and manual pump irrigation) were used. A sterile thermal probe was attached to a flexible ureterorenoscope and delivered into the calyceal system via the ureteral access sheath. Temperature changes were recorded with a T-type thermal probe with ± 0.1 °C accuracy. Laser power significantly influenced mean temperature, with a 4.981 °C difference between 14 W and 8 W laser power (p < 0.001). The mean temperature was 2.075 °C higher with gravity irrigation and 2.828 °C lower with manual pump irrigation (p = 0.038 and p = 0.005, respectively). Body mass index, laser power, irrigation model, and operator duty cycle explained 49.5% of mean temperature variability (Adj. R2 = 0.495). Laser power and operator duty cycle positively impacted mean temperature, while body mass index and specific irrigation models affected it negatively. Laser power and irrigation rate are critical for intrarenal temperature during Ho: YAG laser lithotripsy. Optimal settings and irrigation strategies are vital for minimizing thermal injury risk. This study underscores the need for ongoing research to understand and mitigate thermal effects during laser lithotripsy.

PCNL vs RIRS in management of stones in calyceal diverticulum: outcomes from a global multicentre match paired study that reflects real world practice.

INTRODUCTION: Calyceal diverticulum (CD) is the outpouching of a calyx into the renal parenchyma, connected by an infundibulum. Often associated with recurrent stones, common surgical options include percutaneous nephrolithotomy (PCNL) or retrograde intrarenal surgery (RIRS). We aim to present the real-world practises and outcomes comparing both approaches and the technical choices made. MATERIALS AND METHODS: Retrospective data including 313 patients from 11 countries were evaluated. One hundred and twenty-seven underwent mini-PCNL and one hundred and eighty-six underwent RIRS. Patient demographics, perioperative parameters, and outcomes were analysed using either T test or Mann-Whitney U test. Categorical data between groups were analysed using the Chi-squared test. Propensity score matching (PSM) was performed matching for baseline characteristics. Subgroup analyses for anomalous/malrotated kidneys and difficult diverticulum access were performed. RESULTS: After PSM, 123 patients in each arm were included, with similar outcomes for stone-free rate (SFR) and complications (p < 0.001). Hospitalisation was significantly longer in PCNL. Re-intervention rate for residual fragments (any fragment > 4 mm) was similar. RIRS was the preferred re-intervention for both groups. Intraoperative bleeding was significantly higher in PCNL (p < 0.032) but none required transfusion. Two patients with malrotated anatomy in RIRS group required transfusion. Lower pole presented most difficult access for both groups, and SFR was significantly higher in difficult CD accessed by RIRS (p < 0.031). Laser infundibulotomy was preferred for improving diverticular access in both. Fulguration post-intervention was not practised. CONCLUSION: The crux lies in identification of the opening and safe access. Urologists may consider a step-up personalised approach with a view of endoscopic combined approach where required.

The learning curve for pure retroperitoneoscopic donor nephrectomy by using cumulative sum analysis.

INTRODUCTION: This study aimed to identify a precise learning curve for pure retroperitoneoscopic donor nephrectomy (RDN). METHODS: Data from 172 consecutive kidney donors who underwent pure RDN between January 2010 and July 2019 were prospectively collected and evaluated. Cumulative sum (CUSUM) analysis was used for testing the operation time. Changepoints were determined by using the r program and BINSEG method. The cohort was divided into three groups - group 1: competence, including the first 10 cases; group 2: 11-48 cases as proficiency; and group 3: the subsequent 124 cases as expert level. Continuous variables were evaluated using one-way ANOVA, and categorical data were evaluated using the Chi-squared test. RESULTS: Right RDN was performed in 39 (22.7%) donors. The eighth patient was converted to open surgery due to vena cava injury and excluded from the CUSUM analysis. Depending on experience in pure RDN, a significant decrease was detected in operative time (p<0.001), warm ischemia time (p=0.006), and blood loss (p<0.001). Recipient complications and graft function were found to be statistically comparable. CONCLUSIONS: In our study, the attainment of expertise in pure RDN was observed after performing 50 cases. The transperitoneal technique, which is a feasible alternative, is far more widely used than pure RDN. We believe that understanding the learning curve associated with pure RDN could facilitate the adoption of this approach as a viable alternative to the transperitoneal approach.

Intraoperative Ultrasound Can Facilitate Laparoscopic Partial Nephrectomy in Adherent Perinephric Fat.

Background: Adherent perinephric fat (APF) is one of the challenging factors of laparoscopic partial nephrectomy (LPN). The aim of this study was to investigate the effect of intraoperative laparoscopic ultrasound (ILUS) on determining renal tumor localization and dissection in patients with APF who underwent LPN. Methods: Prospectively collected data from 517 patients who underwent LPN from October 2010 to September 2020 in tertiary university hospital were evaluated retrospectively. The cohort was divided into two main groups according to the Mayo Adhesive Probability (MAP) score: Group 1 (MAP score ≤3) and Group 2 (MAP score ≥4). After implementing propensity score-matched analysis including the complexity of tumor, age, and body mass index, Group 1 consisted of 202 patients with ≤3 MAP score and Group 2 included 46 patients. Then, both groups were allocated into two subgroups according to whether ILUS was used. Demographics, perioperative features such as perirenal fatty tissue dissection, tumor excision, operation time, and perioperative outcomes accepted as trifecta, considering warm ischemia time, negative surgical margin, and complications were compared. Results: In Group 1, ILUS use did not seem to affect perioperative outcomes in both subgroups. However, ILUS has a positive effect on perirenal fatty tissue dissection (10 versus 19 minutes, P = .011), tumor excision (4 versus 7 minutes, P = .005), and operation time (78 versus 90 minutes, P = .046) in Group 2. Trifecta outcomes were also better in higher MAP scores and ultrasound-used subgroups (P = .019). Conclusions: ILUS should be considered a helpful and effective instrument in overcoming APF in LPN. It might also have a positive effect on trifecta outcomes.

The effect of the Incontinence Health Belief Development Program on women's urinary incontinence awareness and health beliefs: a randomized controlled trial.

INTRODUCTION AND HYPOTHESIS: This study is aimed at determining the effects of the Incontinence Health Belief Development Program (IHBDP) on the urinary incontinence awareness and health beliefs of women in the pre-menopausal period. METHODS: This randomized controlled study was conducted in 160 eligible women. The pre-test and post-test data of the study were collected from experimental and control groups using the Socio-Demographic Characteristics Information Form, the Incontinence Awareness Scale, the Health Belief Scale on Urinary Incontinence and Kegel Exercise, and the Broome Pelvic Muscle Self-Efficacy Scale. The IHBDP was implemented with members of the experimental group for 5 weeks. RESULTS: The women in the experimental group showed a significant difference in mean scores at the end of the program on the UI Awareness Scales, the Health Belief Scale on UI, and the Kegel Exercise compared with pre-training scores (p<0.05). In the experimental group, the factor scores and the total score of the Broome Pelvic Muscle Self-Efficacy Scale also increased. Furthermore, a statistically significant total score increase (p<0.05) was observed at the end of the program (79.8±8.8) compared with before the program (35.2±19.6). CONCLUSIONS: The training given to the women in the pre-menopausal period based on the Health Belief Model appears highly effective in raising awareness about UI, fostering beliefs about Kegel exercises and increasing pelvic floor muscle self-efficacy.

Clinical practice in vesicoureteral reflux with respect to EAU guidelines: A multicenter study.

PURPOSE: We designed a multicenter, retrospective study to investigate the current trends in initial management of reflux with respect to European Association of Urology (EAU) Guidelines in Urology clinics of our country. MATERIALS AND METHODS: The study group consisted of 1988 renal units (RU) of 1345 patients treated surgically due to vesicoureteral reflux (VUR) (between years 2003 and 2017) in nine different institutions. Patients were divided into two groups according to time of initial treatment and also grouped according to risk factors by "EAU guidelines on VUR." RESULTS: In this series, 1426 RUs were treated initially conservatively and 562 RUs were initially treated with surgery. In initially surgically treated group, success rates of surgery decreased significantly in low and moderate risk groups after 2013 (P = .046, P = .0001, respectively), while success rates were not significantly different in high risk group (P = .46). While 26.6% of patients in low risk group were initially surgically treated before 2013, this rate has increased to 34.6% after 2013, but the difference was not statistically significant (P = .096). However, performing surgery as the initial treatment approach increased significantly in both moderate and high risk groups (P = .000 and P = .0001, respectively) after 2013. Overall success rates of endoscopic treatments and ureteroneocystostomy (UNC) operations were 65% and 92.9% before 2013 and 60% and 78.5% after 2013, respectively. Thus, the overall success rate for surgery was 72.6%. There was significant difference between success rates of UNC operations before and after 2013 (P = .000), while the difference was not significant in the injection group (P = .076). CONCLUSION: Current trends in management of reflux in our country do not yet follow the EAU guidelines on VUR in low and moderate risk groups despite these reliable and accepted guidelines were expected to influence our daily approach.

Ultrasound-guided erector spinae plane block for postoperative analgesia in patients undergoing open radical prostatectomy: A randomized, placebo-controlled trial.

STUDY OBJECTIVE: The aim of this study was to evaluate the effect of ultrasound-guided erector spinae plane (ESP) block on postoperative pain in radical prostatectomy, which leads to both visceral and somatic pain. DESIGN: Prospective, randomized, placebo controlled, double-blinded. SETTING: University hospital. PATIENTS: A total of ASA I-III, 50 patients aged 18-65 who were scheduled for elective open radical prostatectomy surgery. INTERVENTIONS: Patients were randomly allocated to receive an ultrasound-guided ESP block, with either local anesthetic (10 mL of 1% lidocaine +10 mL of 0.5% bupivacaine) or placebo bilaterally. MEASUREMENTS: The primary outcome was morphine consumption in the first 24 h after surgery. The secondary outcomes were NRS pain scores at rest and coughing, intraoperative remifentanil consumption and need for rescue analgesic during the first 24 h after surgery. MAIN RESULTS: Both NRS scores for post-anesthesia care unit and NRSrest scores for 1st hours were lower in Group ESPB (p < 0.001 and p = 0.033, respectively). Cumulative morphine consumption at 24 h post-surgery was similar between the groups (p = 0.447). Rescue analgesic requirement was higher in the placebo injection group than in the ESPB group at the 1st postoperative hour (p = 0.002). CONCLUSIONS: In open radical prostatectomies, except for the first hour, ESP block is ineffective for pain scores and on morphine consumption compared to the placebo injection group in the postoperative period.

Percutaneous Nephrolithotomy in Young-Old, Old-Old, and Oldest-Old Patients: A Multicenter Study.

Introduction: To compare percutaneous nephrolithotomy (PCNL) outcomes between the elderly and young age groups and examined differences between young-old, old-old, and oldest-old patients. Methods: A retrospective analysis was conducted on 8191 renal units that underwent PCNL between September 1997 and March 2020 at three Turkish academic institutions. Patients were classified into young (18-64 years) and elderly (65+ years) age groups. The elderly age group was classified into young-old (65-69 years), old-old (70-79 years), and oldest-old (80+ years). Demographics, stone features, and perioperative and postoperative outcomes were compared between groups. The factors affecting stone-free rates and complications were determined in the elderly age group. Results: The patients' median age was 47 years (18-100) and the female to male ratio was 1:1.72. The stone-free and complication rates were 78.9% and 16.4%, respectively. General complications, blood transfusion, postoperative urinary tract infections, and major complications rate were similar between the young and elderly age groups (P = .902, P = .740, P = .659, P = .219, respectively). The stone-free rate was higher in the elderly age group (P = .002). Presence of partial or complete staghorn stones and number of stones were independently associated with stone-free rates for elderly age group patients (P = .006, P < .001, respectively). Stone burden (≥400 mm2) and presence of partial or complete staghorn stones were significantly associated with complications for the elderly age group patients (P = .038, P = .014, respectively). Conclusions: In the young-old, old-old, and oldest-old age group, PCNL appears like the preferred treatment with high stone-free rates but similar complication rates compared to their younger counterpart.

Which Is the Best Predictor to Achieve Trifecta in Patients Undergoing Elective Laparoscopic Partial Nephrectomy with Global Hilar Clamping? Comparative Analysis in Patients with Clinical T1a and T1b Renal Tumors.

Background: Partial nephrectomy (PN) is the standard of treatment in patients with cT1 renal tumors. Current guidelines recommend PN as a standard of treatment in patients with cT1 renal tumors. However, the commonly accepted criteria for which surgical outcomes are evaluated both functionally and oncologically are not yet clear. The aim of this study was to evaluate compounding factors that affect the operative and functional outcomes for laparoscopic partial nephrectomy (LPN) in patients with cT1 renal tumors. Methods: This study was registered at NCT04213157 for patients who underwent LPN with the diagnosis of clinical T1 renal tumors. Between November 2009 and August 2018, 292 patients were included in the study. The patients were allocated into two groups according to the tumor size: T1a (n = 215) and T1b (n = 77). Demographic features, clinical tumor characteristics, and intraoperative and postoperative outcomes were analyzed. A negative surgical margin, warm ischemia time of <20 minutes, and no postoperative major complications were accepted to achieve the trifecta outcomes. Pentafecta was defined as trifecta criteria plus >90% preservation of baseline renal function (RF) and no stage upgrade of chronic kidney disease at 12 months after surgery. Univariate and multivariate analyses were used to identify factors predicting trifecta and pentafecta. Results: Preoperative variables including age, gender, and baseline RF were similar between the two groups. The warm ischemia time was 13.4 vs 15.9 minutes (P = 0.001). The positive margin rate was 0.9% vs 2.6% (P = 0.284), and the major complication rate was 3.3% vs 2.6% (P = 0.548). The achievement of the trifecta rate was 88.4% vs 75.3% (P = 0.006) and pentafecta rate was 72.6% vs 42.9% (P = 0.001). Multivariate analysis showed that tumor complexity, baseline RF, and diabetes mellitus are independent predictors of achieving pentafecta outcomes. Conclusion: LPN is an effective and reliable method for renal tumors even in T1b with satisfying surgical and functional outcomes.

Laparoscopic Partial Nephrectomy in Allograft Kidney.

The incidence of renal tumor on the allograft kidney is relatively rare. There is no standard treatment available for the management of such cases. However, if technically feasible nephron-sparing surgical approaches, whether open or minimally invasive, should be preferred for the management of these challenging cases. To our knowledge, there is no pure laparoscopic technique reported in the literature but only 3 cases of robot-assisted partial nephrectomy. In this article, we aimed to present the application of pure transperitoneal laparoscopic partial nephrectomy for the management of a renal mass on the allograft kidney.

Clinical Effectiveness of Single Pigtail Suture Stent on Patient Comfort: A Double-Blind Prospective Randomized Trial.

Background: A double-pigtail ureteral stent (DPUS) can cause untoward symptoms, such as urgency, frequency, urinary incontinence, hematuria, and body pain that are bothersome to patient's quality of life (QoL). By reducing the quantity of material in the bladder, it could be reasonable to decrease stent-related symptoms (SRSs). We aimed to evaluate the tolerability of single pigtail suture stent (SPSS) with a validated questionnaire after uncomplicated retrograde semirigid ureteroscopic lithotripsy (URSL). Materials and Methods: A total of 130 patients who underwent ureteral stent placement after URSL for unilateral symptomatic ureteral stones with <15 mm diameter were randomized prospectively into two groups. Polyurethane ureteral stent (6 Fr, 24 or 26 cm) was placed in all patients, which was removed postoperatively with a mean of 14 days. There were 65 patients in both groups. All subjects completed the ureteral stent symptoms questionnaire (USSQ), which explores the SRSs. The questionnaires were conducted on the day of stent removal (at week 2) with the stent in situ and 4 weeks after removal (at week 6, poststent). The severity of SRSs and QoL were compared between the two groups. Results: SPSS was associated with perfect effect on all domains of USSQ, except from sexual and general health index scores. Pain index scores, visual analog scores (VAS), and analgesic requirements in SPSS group were found significantly low compared with those in the DPUS group. The QoL scores were significantly better in patients indwelling SPSS. Conclusion: SPSS is a potentially beneficial option to minimize ureteral SRSs after uncomplicated URSL.

Nutcracker Syndrome in Children: Role of Doppler Ultrasonographic Indices in Detecting the Pattern of Symptoms.

The purpose of this study was to evaluate the clinical characteristics of 44 pediatric patients who were diagnosed as having nutcracker syndrome (NCS). We also investigated the left renal vein Doppler ultrasonography (DUS) results, to determine whether or not there was an association between clinical symptoms and DUS findings among these patients. The clinical data from 44 pediatric patients who were diagnosed as having NCS from January 2008 to December 2015 were retrospectively reviewed. We grouped the patients according to the presenting symptoms as symptomatic (loin pain; macroscopic hematuria or both) and non-symptomatic (microscopic hematuria and proteinuria were detected incidentally) and evaluated the left renal vein DUS indices in these two groups separately. Asymptomatic NCS was found in 27 (61.4%) patients; 21 (47.7%) of whom were admitted for the evaluation of proteinuria. The most frequent presenting symptoms were left flank pain (20.5%) and macroscopic hematuria (13.6%); and 2 (4.5%) patients presented with a combination of left flank pain and macroscopic hematuria. The mean ratio of the diameter of the hilar portion of the left renal vein (LRV) to that of the aortomesenteric portion was 4.36 ± 1.55. The mean ratio of the peak velocity (PV) between the two sites of the LRV was 7.32 ± 2.68 (3.1⁻15.6). The differences in the ratio of the diameters were statistically significant between the two groups and significantly higher in children with asymptomatic NCS (p = 0.025). The PV ratios of the LRV (p = 0.035) were significantly higher in asymptomatic children with NCS than in the symptomatic group. Our study identifies that increased compression ratio of the LRV entrapment is most observed in orthostatic proteinuria and microscopic hematuria.

Renal Autotransplantation at Three Academic Institutions in Turkey.

OBJECTIVE: The objective of this study is to present the experience of 3 institutions performing renal autotransplantation (RAT) and to discuss surgical techniques employed and the results in the light of the medical literature. MATERIALS AND METHODS: A total of 14 patients (11 male and 3 female) with a mean age of 47 ± 8 years (35-61 years), who underwent RAT procedure at 3 different institutions between October 2006 and November 2014, in Turkey, were evaluated retrospectively. Indications for RAT procedure are ureteral avulsion, renal artery aneurysm and intimal dissection caused by percutaneous transluminal renal artery angioplasty (PTRA). Twelve patients with ureteral avulsion, 1 patient with renal artery aneurysm and 1 patient with intimal dissection caused by PTRA were followed-up for 103 months. Seven (50%) open and 7 (50%) laparoscopic nephrectomies were performed. Nine patients (64.3%) were right-sided and 5 patients (35.7%) were left-sided. Complications of grade III and above as per Clavien-Dindo classification were assessed. RESULTS: Mean time from injury to RAT was 21.2 ± 40.1 days. However, 5 (35.7%) patients were treated on the same day of the injury. As per Clavien-Dindo classification, 2 (14.2%) grade IVa and 1 (7.1%) grade IIIa complications were reported. However, no significant correlation was observed between the complications and graft loss regarding type and side of the nephrectomy performed (p = 0.462 and p = 0.505, respectively) and timing of the intervention (p = 0.692). CONCLUSION: RAT is a safe procedure in combination with minimally invasive laparoscopic technique in carefully selected patients; however, it requires expertise and proficiency in laparoscopy, reconstructive urology and transplantation. Nevertheless RAT should be considered as the last resort, when other modalities fail.

Laparoscopic Nephron-sparing Surgery for Metanephric Adenoma in Children: A Report of 2 Cases.

Metanephric adenoma (MA) is an epithelial benign tumor of the kidney and very rare in children. Here we present 2 cases of MA treated by laparoscopic nephron-sparing surgery in children. To the best of our knowledge, we report the first cases of laparoscopic nephron-sparing surgery for MA in children.

Laser prostatectomy: holmium laser enucleation and photoselective laser vaporization of the prostate.

Historically, transurethral resection of the prostate has been the gold standard for the treatment of benign prostatic hyperplasia (BPH). Laser technology has been used to treat BPH for > 15 years. Over the past decade, it has gained wide acceptance by experienced urologists. This review provides an evidence-based update on laser surgery for BPH with a focus on photoselective laser vaporization and holmium laser enucleation of the prostate surgeries and assesses the safety, efficacy, and durability of these techniques.

Risk factors for systemic inflammatory response syndrome following percutaneous nephrolithotomy.

The aim of this study was to analyze the pre- and intraoperative risk factors that affect the development of postoperative systemic inflammatory response syndrome (SIRS) after percutaneous nephrolithotomy (PCNL). Medical records on 317 adult patients with the complete data who underwent single-stage PCNL and followed at our center were retrospectively studied. Patients' data were collected through a database which was collected prospectively. All patients' vital signs were recorded hourly in the postoperative period and were divided into two groups as patients developing SIRS and not developing SIRS. There were 202 men and 115 women with a mean age of 48 ± 13.7 (range 19-82) years. There were 53 (16.7 %) in the SIRS and 264 (83.3 %) patients in the non-SIRS group. Preoperative positive urine cultures (UCs), intraoperative positive renal pelvic urine cultures (RPUCs), and stone cultures (SCs) were strongly correlated with the development of SIRS (p = 0.001). In the SIRS developers' group, preoperative UCs, intraoperative RPUCs, and SCs were positive in 33.9, 22.5, and 28.6 % of patients, respectively, but only 9.8, 3.3, and 4.2 % for the corresponding specimens in non-SIRS group. Positive preoperative UCs, intraoperative RPUCs, and SCs are important factors indicating the development of postoperative SIRS. Appropriately treated preoperative urinary infections may not prevent infected urine at PCNL. RPUCs and SCs may be the only way to identify the causative organism and direct antimicrobial therapy, so we recommend collecting RPUCs and SCs routinely to identify the offending organism and guide treatment.

Primary testicular leiomyosarcoma.

Primary testicular leiomyosarcoma is an extremely rare tumor, and, to the best of our knowledge, only 20 cases in adults have been reported in the literature to date. Herein, we present a case of a 68-year-old man who complained of left scrotal swelling for 2 months. Radiological examination revealed a left testicular tumor with no metastases to other organs. A left inguinal orchiectomy was carried out and histopathologic examination revealed an intratesticular leiomyosarcoma. The patient was treated successfully by orchiectomy and received no adjuvant therapy. During follow up until 12 months after surgery, there has been no recurrence or metastases of the disease.

Correlation between benign prostatic hyperplasia and inflammation.

PURPOSE OF REVIEW: This review aims to evaluate the available evidence on the role of prostatic inflammation in the pathogenesis and progression of benign prostatic hyperplasia (BPH). RECENT FINDINGS: Although there is still no evidence of a causal relation, accumulating evidence suggests that inflammation may contribute to the development of BPH and lower urinary tract symptoms (LUTS). Inflammatory infiltrates are frequently observed in prostate tissue specimens from men with BPH and the presence or degree of inflammation has been found to be correlated with prostate volume and weight. The inflammatory injury may contribute to cytokine production by inflammatory cells driving local growth factor production and angiogenesis in the prostatic tissue. This proinflammatory microenvironment is closely related to BPH stromal hyperproliferation and tissue remodeling with a local hypoxia induced by increased oxygen demands by proliferating cells which supports chronic inflammation as a source of oxidative stress leading to tissue injury in infiltrating area. SUMMARY: Although the pathogenesis of BPH is not yet fully understood and several mechanisms seem to be involved in the development and progression, recent studies strongly suggest that BPH is an immune inflammatory disease. The T-cell activity and associated autoimmune reaction seem to induce epithelial and stromal cell proliferation. Further understanding of the role of inflammation in BPH and clinical detection of this inflammation will expand the understanding of BPH pathogenesis and its histologic and clinical progression, allow risk stratification for patients presenting with BPH-related LUTS, and suggest novel treatment strategies.

The double wire technique: an alternative method for difficult ureteroscopic access.

We read with great interest the study report by Ji et al. (Urol Res, doi: 10.1007/s00240-012-0476-0 , 2012) about the impact of the intentional ureteral stenting on the success rate of calculus extraction by second ureteroscopy, when the initial ureteroscopy failed. Actually, sometimes ureteral stone treatment pose challenging problems for the urologists. This study has filled an important gap on this field. If flexible ureteroscopy and laser lithotripter are not available pre-existing stent may improve the success rate of a subsequent ureteroscopy for impacted ureteral stones. Because, post-stent ureteroscopy has the advantage of working through a dilated ureter. We would like to add some additional comments and suggestions in addition to the authors' discussion, which is noteworthy in several respects.

Long-term outcomes of percutaneous nephrolithotomy in patients with chronic kidney disease: a single-center experience.

OBJECTIVE: To present our long-term follow-up data from patients with kidney stones and chronic kidney disease to identify the factors that could help predict the likelihood of long-term deterioration in renal function. METHODS: From January 2002 to July 2010, we performed 1117 percutaneous nephrolithotomy (PNL) procedures in 1051 patients. We retrospectively analyzed 69 PNL procedures for 67 patients (47 men and 20 women) in whom the estimated glomerular filtration rate (eGFR) was <60 mL/min/1.73 m(2). Two outcomes were measured. The percentage of change in the eGFR was measured comparing the preoperative and postoperative values. A 5% change in renal function was arbitrarily chosen to divide the population into 3 groups: group 1, an eGFR change of ≤ 5%; group 2, an eGFR increase of >5%; and group 3, an eGFR decrease of <5%. The second outcome measure was the presence of chronic kidney disease progressing in the first and consecutive years. RESULTS: The mean patient age was 57 ± 14.1 years. The complication rate was 23.1% using the Clavien classification. The mean follow-up time was 45.7 ± 17.08 months. The mean eGFR before and after PNL was 37.9 ± 14.05 and 45.1 ± 16.8, respectively. Diabetes mellitus (odds ratio 15.82, P = .036) and urinary infection (odds ratio 10.6, P = .04) were predictive of renal function deterioration at 1 year on multivariate analysis. CONCLUSION: PNL in patients with chronic kidney disease is safe and results in renal function preservation for a 5-year period. Diabetes mellitus and urinary infection were independent predictive of renal function impairment. Therefore, patients with diabetes mellitus and urinary tract infection should be followed up carefully and informed about hazardous potential of those diseases.