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Patients presenting with nephrolithiasis often undergo repeated imaging studies before, during, and after management. Considering the significant risk of stone recurrence in primary stone-formers, repeated imaging studies are not uncommon. Cumulative effects of ionizing radiation exposure from various imaging studies could potentially increase the risk for developing cataracts and solid malignancies in urolithiasis patients. Therefore, practitioners planning or performing imaging studies with ionizing radiation are compelled to keep radiation exposure to humans and the environment as low as possible, thus strictly adhering to the ALARA (As Low as Reasonably Achievable) principles. This chapter will review the latest literature on lifetime radiation exposure of nephrolithiasis patients and present the latest recommendations in minimizing radiation exposure to them pre-, intra-, and postoperatively. For patients presenting with acute renal colic, especially those with body mass index of < 30, low-dose noncontrast computed tomography is the current gold standard of imaging. Patients with opaque stones are followed with ultrasonography (US) and plain radiography (kidney, ureter, and bladder or KUB). Intraoperatively, pulsed fluoroscopy could be used to significantly reduce radiation during ureteroscopy and percutaneous nephrolithotomy. Immediately postoperatively and in the long term, US and KUB could be used to follow up patients with nephrolithiasis. Only symptomatic patients suspected of ureteral stricture should obtain tri-phasic CT urography. Following these latest imaging guidelines from the American Urological Association will dramatically reduce lifetime radiation exposure to patients with nephrolithiasis.

Aim: To determine the place of laparoscopic pyelolithotomy in surgical management of nephrolithiasis., Materials and Methods: We analyzed 16 laparoscopic pyelolithotomies performed in our clinic over the last few years for large and stag-horn stones of anomalous kidneys (n=8), the "giant" (>30-40 cc) monolithic stones of the large extrarenal pelvis (n=3), multiple stones of PCS with the stone burden of more or equal 40 cm (n=2) and large recurrent (after PCNL) kidney stones in patients at risk of bacteriotoxic complications of percutaneous nephroscopy (n=3). The age of the patients ranged from 39 to 72 years (mean age 51+/-8 years). The average density of stones was 1012 (160-1483) HU., Results: There were no conversions to open surgery. The mean operating time of laparoscopic pyelolithotomy was 137 (96-255) minutes, flexible transabdominal pyelocalycoscopy 31.2 (12-110) min. The stone-free rate was 87%. Residual clinically insignificant stones were found in two (13%) patients with staghorn horseshoe kidney calculi and complex PCS. The preoperative hospital stay was 1 day, postoperative-from 2 to 18 (mean 6) days., Discussion: We believe that laparoscopic pyelolithotomy supplemented by transabdominal flexible pyelocalycoscopy may be recommended for surgical management of patients with "giant", multiple and infected kidney stones, because the length of their percutaneous removal is beyond the recommended time intervals and it is accompanied by an increased risk of septic complications.

The purpose of this article is to outline the role and possible applications of 3D printing in urology. At present, this technique provides the opportunity to choose the individual strategy of patient management, to conduct preoperative planning and surgical rehearsal; for medical specialists to reduce the learning curve in mastering modern complex surgical techniques, and for doctors and students to improve understanding of pathological processes in the kidney and the prostate gland.

Objectives: The present study was aim to evaluate the safety and efficacy of Mini-PNL to treat kidney stones in patients aged <3 years. This is the one of the largest series in the literature in this age group of patients., Material and Methods: From May 2012 to April 2016, the medical records of 74 infant patients who underwent mini-PNL for renal stones were reviewed retrospectively. All infants were evaluated with the plain abdominal radiograph, urinary ultrasound, noncontrast computerized tomography and/or intravenous urogram. Pre-operative, intraoperative and post-operative data were analyzed., Results: A total of 74 infant (42 male, 32 female) with a mean age 21.5±8.2 (10-36) months were included in this study. The mean size of the stones was 22.0±5.9 (14-45) mm. A 17 Fr rigid pediatric nephroscope with a pneumatic intracorporeal lithotripsy were used through 20-22 Fr access sheath. The stone-free rate was 84.7% at 1 month after the operation. Mean operative time was 74.0 (40-140) min. Mean fluoroscopy screening time was as 4.3(3.1-8.6) min. Average hospitalization time was 3.8 (2-9) day. Auxiliary procedures were performed to 11(15.3%) patients (7 extracorporeal shock wave lithotripsy, 3 re- percutaneous nephrolitotomy, 1 retrograde intrarenal surgery). No major complication classified as Clavien IV-V observed in study group., Conclusions: Mini-PNL with pneumatic intracorporeal lithotripsy can be performed safely and effectively to manage kidney stones in infants with high stone free rate and low complications., Competing Interests: Conflict of interest: None declared., (Copyright® by the International Brazilian Journal of Urology.)

Percutaneous nephrolithotomy has become the preferred treatment modality for patients with large renal calculi. The technique provides excellent stone clearance, but complication rates are higher than those of minimally invasive techniques, such as ureteroscopy and shockwave lithotripsy. Guy's stone score, S.T.O.N.E. nephrolithometry, the CROES nomogram, and S-ReSC are contemporary scoring systems introduced to provide standardized grading of stone complexity and outcomes of percutaneous stone surgery. Guy's stone score is easy to apply and has been validated in multiple studies. The S.T.O.N.E. score is based on factors determined through CT imaging, which is the currently preferred imaging modality for patients with nephrolithiasis. The CROES nomogram was developed from data in a large multicentre database and has high statistical power. Determination of the S-ReSC score relies on stone location only, providing a simple approach to grading disease complexity. Each system has advantages and disadvantages, but several studies suggest that their ability to predict stone-free rate is comparable. The optimal system should have a high predictive ability, should be simple to use and should be widely applicable. Additional studies are required to evaluate patient clinical factors that influence stone complexity and are predictive of outcomes. A future unified scoring system might incorporate the strengths of each currently available system and optimize care of patients with nephrolithiasis.

Introduction: Renal stone disease diagnosed in the first year of life is relatively uncommon. While risk factors such as low birth weight, furosemide exposure, and metabolic disorders are well established, there exists little information regarding resolution rates and need for surgical intervention. Our study objective was to evaluate urolithiasis and renal calcification resolution rates, time to resolution, and need for surgical intervention in children diagnosed in their first year of life., Material and Methods: REB approved retrospective chart review of children younger than 12 months of age (corrected for prematurity) diagnosed with nephrolithiasis and/or nephrocalcinosis in a tertiary pediatric hospital between April 2000 and August 2015 with a minimum 1-year follow-up period. Exact logistic regression was performed to assess the relationship between size of the largest stone (on either side) and the need for surgical intervention. Kaplan-Meier curves were constructed to examine time to stone resolution among those not requiring surgical intervention., Results: 62 patients (61% male) were diagnosed with stones or nephrocalcinosis by ultrasound at a median age of 2.9 months. Of these, 37% had been admitted to the NICU because of prematurity, low birth weight or comorbidities. A total of 45 patients were found to have stones (Table); 35 of these had a stone at initial ultrasound and 10 initially diagnosed as nephrocalcinosis were later confirmed to have a stone. 67% of all stones were asymptomatic on presentation. Metabolic anomalies were present in 56% (35/62), and 16% (10/62) required medical treatment. Seven patients ultimately required surgical intervention. Stone size was found to predict the eventual need for surgical intervention (OR 3.52, 95% CI 1.47-12.78) for each 0.1 mm increase in diameter). Among patients not requiring surgical intervention (n = 38), the estimated median time to spontaneous resolution of urolithiasis was 1.1 years (95% CI 0.89-1.53, range 2 months-6 years) and 1.2 years for nephrocalcinosis (95% CI 0.59-2.13)., Conclusions: Spontaneous resolution was a common outcome for newborns and infants diagnosed with urolithiasis in the first year of life, but high variability in time-to-resolution was observed. Only a small proportion who had confirmed stones on ultrasound required surgical intervention (15%), and large stone size was a predictive factor for surgery., (Copyright © 2017 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.)

Background: Simple nephrectomy is the procedure of choice in the treatment of excluded kidneys. The purpose of this study was to describe and compare surgical results in open simple retroperitoneal nephrectomies in patients with and without nephrostomy., Methodology: 58 patients were analyzed. The demographic parameters of patients with nephrostomy were compared to patients without nephrostomy (age, gender, weight, lithium localization, transoperative variables (surgical time, transoperative bleeding) and postoperative variables (need for intensive care, need for transfusion, surgical wound infection and hospital stay days) RESULTS: Statistically significant differences were found for the variables of operative bleeding (p=0.0442), surgical time (p=0.0093), hospital stay days (p=0.0040), and transfusion requirements (p=0.0170). There were no differences in the need for intensive care (p=0.6314), transoperative complications (p=0.7414) and surgical wound infection (p=0.2762)., Conclusions: The presence of a nephrostomy catheter in patients undergoing open simple nephrectomy leads to an increased risk of morbidity, with increased bleeding, surgical time, need for transfusion, and hospital stay days., (Copyright © 2017 Academia Mexicana de Cirugía A.C. Publicado por Masson Doyma México S.A. All rights reserved.)

Introduction: We sought to determine the rate of and factors associated with patient nonadherence to prescribed follow-up after uncomplicated ureteroscopy., Materials and Methods: The records of 247 consecutive patients who underwent ureteroscopy at a tertiary referral center from November 2010 to February 2016 were reviewed. Bivariate and multivariate analyses were performed to determine the impact of demographic, procedural, socioeconomic, and environmental factors on the rate of compliance with secondary prevention counseling., Results: Forty-five patients (18.5%) were lost to scheduled follow-up for secondary prevention counseling after ureteroscopy. Lost to counseling rates were broad based and not associated with traditional predictors of poor follow-up such as age, gender, marital status, and distance traveled. On multivariate analysis, compared with those using commercial insurance, patients with Medicare (odds ratio [OR] for follow-up 0.48, 95% confidence interval [CI] 0.21, 1.1 p = 0.095) and Medicaid (OR for follow-up 0.25, 95% CI 0.1, 0.6, p < 0.001) were less likely to be adherent to prescribed follow-up., Conclusions: Nearly one in five patients will be lost to follow-up for secondary prevention counseling after ureteroscopy. Lack of follow-up may prevent the diagnosis of postoperative complications and limit the ability to counsel patients on stone prevention. Efforts to improve follow-up following ureteroscopy should focus on including more postoperative counseling in the preoperative period and a more individualized approach to specific patient populations, particularly those with a lower socioeconomic status.

Objectives: The objective of this article is to show the current situation regarding two surgical techniques for the treatment of renal lithiasis, RIRS (Retrograde intrarenal surgery) and PCNL (Percutaneous nephrolithotomy), specially concerning the larger size stones. We perform a literature review on the topic and add the experience with both techniques at our center. Besides, we also analyze the role of RIRS in comparison with the percutaneous techniques in smaller size lithiasis., Methods: We review the results obtained in the literature and our experience. We offer our opinion in reference to the indications of RIRS in these cases based on such review and our experience., Results/conclusions: RIRS is a safe and effective technique, with a similar success rate to PCNL if one assumes the possibility of retreatment in stones >2cm. Its low complication rate, fast postoperative recovery and short hospital stay make this technique a therapeutic alternative to PCNL in this type of patients. Compared with percutaneous techniques less invasive than classical 24 to 30 Ch. accesses (miniperc or microperc), RIRS offers a higher stone free rate. If we also consider that RIRS is associated with shorter hospital stay and lower bleeding risk, even without significant differences in the global complication rate we could consider RIRS as the first line endourological treatment in stones <2cm.

Comparative analysis of two variants of transcutaneous nephrolithotripsy (TCNLT) in 45 patients, suffering nephrolithiasis, was performed. In 17 patients (the first group) the ultra-mini (UM) TCNLT, using tubus 11Сh, was done, and in 28 patients (the second group) – TCNLT, using a standard tubus 24Сh. The operation duration in the first group have had constituted (86.2 ± 16.3) min at average, and in the second group – (51 ± 13.6) min. The method of UМ TCNLT is a secure, miniinvasive, owing low rate of morbidity, comparing with a standard procedure, but with equal efficacy, concerning the «stone free» status (accordingly, 95.3 and 96.5%) in patients when calculi’s diameter up to 2 sm. Тubus 11Ch guarantees lesser risk of hemorrhagic complications occurrence, permits to conduct UM TCNLT without nephrostomic draining of the renal calyx and pelvis system more confidently.

The creation of the access is one of the main steps in percutaneous nephrolithotomy, the most complicated for many urologists and the one that limited most the universalization of the technique. From a purely technical point of view, it includes puncture of the excretory tract and dilatation of the percutaneous tract to end with the introduction of an Amplatz type working sheath. The objective of the puncture is to try to access the excretory system through the renal papilla, minimizing the risk of bleeding. The puncture may be guided by ultrasound, fluoroscopy, both, under endoscopic or laparoscopic control, by CT scan or MRI, or even by application of new technologies (Robotic, augmented reality, electromagnetic navigation,...). Due to the versatility and independence involved in having the ability to perform the renal puncture in the operative room, as well as its influence in the results of PCNL, it must be the urologist himself who performs this basic step of percutaneous surgery. The tract may be dilated by Alken type metallic dilators, semirrigid Amplatz type dilators or high pressure balloons. To date, there is no single ideal dilatation method, being the selection based on the endourologist's experience and the knowledge of the advantages and limitations of each option. The objective of this review is to present the main methods for puncture guiding and tract dilatation for PCNL, as well as to provide technical details to improve its result.

Objective: Urolithiasis of the transplanted kidney has an incidence of 0.2 to 1.7%, it increases the risk of infection in immunosuppressed patients and it can lead to ureteral obstruction that is often associated with deterioration of renal function. Urolithiasis of the transplanted kidney has different characteristics compared to the native kidney, due to the absence of innervation, which does not lead to colic pain. Percutaneous approach is an optimal choice in transplant patients., Material and Methods: Here we report our experience in two cadaveric transplant patients with urolithiasis. The first case was a patient of 68 years with a 20 mm stone located in the transplanted kidney pelvis and another smaller in a lower calyx. The second case was a patient of 65 years with a 15 mm stone in the distal part of the transplanted ureter. In both cases the patients were asymptomatic, but they had a reduction in urine output associated with worsening of the transplanted kidney function. The diagnosis was performed in both cases with ultrasound study, showing a severe hydronephrosis and it was confirmed by computed tomography scan. In both cases, we performed a Percutaneous Nephrolithotomy (PCNL). Access was made after targeting the stone, through a lower pole puncture under ultrasound guidance. The first case was treated with pneumatic and laser energy, breaking stones through a nephroscope. In the second case we performed a laser lithotripsy of the ureteral stone, using a flexible videoureteroscope. At the end of both procedures a Double-J stent and a 14 Fr Malecot nephrostomy were positioned, that were removed at 6 weeks and 10 days, respectively., Results: Both patients achieved a resolution of the worsening of renal function, recovering the spontaneous diuresis. The surgical procedure using ultrasound guidance was safe and allowed quick access to the renal pelvis. Both patients experienced no bleeding or infection during hospitalization., Conclusions: Percutaneous Nephrolithotomy (PCNL) is an established safe and effective surgical treatment option for larger renal calculi in renal allografts. The ultrasound guided access to the transplanted kidney in percutaneous treatment of urolithiasis is useful and fast, minimizing patient exposure to ionizing radiation.

Keratinizing desquamative squamous metaplasia (KDSM) in the renal pelvis is a rare condition with unclear malignant potential. Recent reports suggest it is likely benign and favor endoscopic treatment approaches. Medical record review was completed on two cases at our center to obtain history, physical examination, radiographic findings, and management. A literature review was completed to identify all published cases of KDSM. Both patients at our center suffered recurrent urolithiasis, hypothesized to be secondary to KDSM. Both were managed with a percutaneous approach to ensure complete stone and KDSM plaque removal. Our cases highlight that percutaneous surgery is an excellent management option for stone and KDSM eradication from the collecting system. This approach also allows adequate oncologic surveillance of the underlying urothelium.

Purpose: Post-ureteroscopy ureteral stent omission remains controversial. Although omission is associated with reduced postoperative discomfort, concern remains for early obstruction. We performed a systematic review and meta-analysis of trials to compare the risk of unplanned visits with vs without a stent following ureteroscopy for nephrolithiasis., Materials and Methods: Randomized, controlled trials and observational studies comparing post-ureteroscopic stent omission vs placement and reporting unplanned visits within 30 days were identified via a search of MEDLINE® (1946 to 2015), CENTRAL (Cochrane Central Register of Controlled Trials, 1898 to 2015), Embase® (1947 to 2015), ClinicalTrials.gov (1997 to 2015), AUA (American Urological Association) Annual Meeting abstracts (2011 to 2015) and reference lists of included articles as last updated in October 2015. Two reviewers independently extracted data and assessed methodological quality. ORs, RRs and weighted mean differences were calculated as appropriate for each outcome., Results: Of the initial 1,992 studies 17 in a total of 1,943 participants met inclusion criteria. Unstented patients were significantly more likely to have an unplanned medical visit compared to those who received a post-ureteroscopy stent (OR 1.63, 95% CI 1.15-2.30). Unstented patients had shorter operative time (weighted mean difference -3.19 minutes, 95% CI -5.64--0.74) and were less likely to experience dysuria (RR 0.39, 95% CI 0.25-0.62). They were also less likely to experience postoperative infection (OR 0.89, 95% CI 0.59-1.33) and pain (OR 0.64, 95% CI 0.39-1.05), although these results were not significant., Conclusions: Stent omission is associated with an increased risk of unplanned medical visits despite reduced symptoms compared to those in stented patients. Patients and physicians should weigh these trade-offs when considering post-ureteroscopy stent placement., (Copyright © 2016 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.)

Aim: To assess the learning curve of flexible ureteroscopic stone extraction using the UroMentor™ simulator and transfer of flexible ureteroscopic stone extraction skills to the operating theatre., Materials and Methods: After obtaining ethics approval, urology Post-Graduate Trainees (PGTs) from Post-Graduate Years (PGYs) 1 to 4 were recruited. During phase I, participants completed 3 weekly 1-hour training sessions on the UroMentor simulator practicing task 10, where two stones from the left proximal ureter and renal pelvis were extracted using a basket. Objective assessments by the simulator and subjective assessments using the validated Ureteroscopy-Global Rating Scale (URS-GRS) were used to establish the learning curve. During phase II, the URS-GRS tool was used to assess performance of participants in the operating theatre. URS-GRS scores obtained on the simulator and in the operating theatre were correlated., Results: In phase I, eight urology PGTs (PGY1-4) with mean age of 27.8 ± 2 (25-31) years participated in the study. PGTs practiced a total of 52 times, with a mean operative time of 14.6 ± 4.3 minutes and a mean fluoroscopy time of 10.4 ± 12 seconds. Competency in task 10 was achieved after seven trials on the UroMentor simulator. In phase II, 5 PGTs were assessed during 55 consecutive flexible ureteroscopic stone extraction in the operating theatre. The mean operative time was 51.4 ± 15.2 minutes and the mean fluoroscopy time was 29 ± 6 seconds. There was a significant positive correlation between URS-GRS scores obtained on the simulator and in the operating theatre (r = 0.9, p = 0.03), thus establishing predictive validity of performance on the UroMentor simulator., Conclusions: Competency in task 10 on the UroMentor simulator (flexible ureteroscopic stone extraction) was achieved after seven trials. Since there was a strong positive correlation between URS-GRS scores on the simulator and in the operating theatre, the skills obtained on the simulator could be transferred to the operating theatre.

Nephrolithiasis, or stones, is one of the oldest urological diseases, with descriptions and treatment strategies dating back to ancient times. Despite the enormous number of patients affected by stones, a surprising lack of conceptual understanding of many aspects of this disease still exists. This lack of understanding includes mechanisms of stone formation and retention, the clinical relevance of different stone compositions and that of formation patterns and associated pathological features to the overall course of the condition. Fortunately, a number of new tools are available to assist in answering such questions. New renal endoscopes enable kidney visualization in much higher definition than was previously possible, while micro-CT imaging is the optimal technique for assessment of stone microstructure and mineral composition in a nondestructive fashion. Together, these tools have the potential to provide novel insights into the aetiology of stone formation that might unlock new prevention and treatment strategies, and enable more effective management of patients with nephrolithiasis.

A rhesus macaque (Macaca mulatta) was presented for anuria. Examination revealed calcium oxalate concrements in the bladder. A cystotomy was performed, and a therapy with alfuzosin was conducted. Over 1 year after the treatment, the rhesus macaque had not shown any more signs of stranguria. This is the first case reporting the successful treatment of urolithiasis in a rhesus macaque., (© 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

In 2014 - 2016 yrs transcutaneous nephrolithotripsy was performed in 245 patients for nephrolithiasis, of them in 228 (93.1%) - in position of patient lying on the abdomen (1st group), in 17 (6.9%) - lying on the back (2nd group) because of various concur- rent cardio-vascular and respiratory diseases present. Mini- transcutaneous nephro- lithotripsy was performed under regional epidural anesthesia in 224 (91.4%) patients, and under endotracheal narcosis - in 21 (8.6%). While conduction of mini- transcu- taneous nephrolithotripsy in position of patient lying on the back the operation duration is reducing, and it is possible to perform simultant endoscopic interventions (trans- ureteric, transcutaneous). Position of patient lying on the back while performing tran- scutaneous nephrolithotripsy in a complex with regional (epidural) anesthesia consti- tutes a relatively secure procedure. Hemodynamical and respiratory parameters are simply intraoperatively controlled, what is important for the patients, urologists and anesthesiologists. The complications rate and results of treatment are comparable with such while performing transcutaneous nephrolithotripsy in accordance to standard in position of patient lying on the abdomen.

Introduction: The European Association of Urology (EAU) and the American Urological Association (AUA) guidelines recommend percutaneous nephrolithotomy (PCNL) as the first-line treatment of renal stones greater than 20 mm, however multistage retrograde intrarenal stone surgery (RIRS) is reported to have high stone-free rates (SFR), fewer complications and a rapid learning curve. This study presents our experience of RIRS in the management of 2 cm-4 cm renal stones., Materials and Methods: A retrospective study was performed of all patients who underwent RIRS for 2 cm-4 cm renal stones over a period of 22 months. The demographics of 71 patients as well as the stone and procedural demographics were recorded. Pre and postoperative radiological assessment was performed by NCCT scanning in 83% of the patients and ureteral access sheaths were used in only 12% of the patients. The severity of surgical complications was determined according to the Clavien-Dindo system., Results: RIRS was performed on 71 patients for renal stones with a mean size of 26 mm. The mean number of procedures per patient was 2.1 and the overall SFR was 81%. Few complications were encountered and only 1 patient had III-b Clavien complication., Conclusion: The study further supports RIRS as a safe and efficacious treatment option for renal stones of 2 cm-4 cm in size. Although both the EAU and AUA do not currently recommend RIRS as the first-line treatment of such stones, it appears to be emerging as a commonly utilized primary modality.

Background and Objectives: Multiple sclerosis is a demyelinating disease of the brain and spinal cord, characterized by muscle weakness, cognitive dysfunction, memory loss, and personality disorders. Factors that promote disease exacerbation are stress, physical trauma, infection, surgery, and hyperthermia. The objective is to describe the anesthetic management of a case referred to urological surgery., Case Report: A female patient, 44 years of age, with multiple sclerosis, diagnosed with nephrolithiasis, referred for endoscopic ureterolythotripsy. Balanced general anesthesia was chosen, with midazolam, propofol and remifentanil target-controlled infusion; sevoflurane via laryngeal mask airway; and spontaneous ventilation. Because the patient had respiratory difficulty presenting with chest wall rigidity, it was decided to discontinue the infusion of remifentanil. There was no other complication or exacerbation of disease postoperatively., Conclusion: The use of neuromuscular blockers (depolarizing and non-depolarizing) is a problem in these patients. As there was no need for muscle relaxation in this case, muscle relaxants were omitted. We conclude that the combination of propofol and sevoflurane was satisfactory, not resulting in hemodynamic instability or disease exacerbation., (Copyright © 2014 Sociedade Brasileira de Anestesiologia. Published by Elsevier Editora Ltda. All rights reserved.)

Purpose: Obstructing nephrolithiasis is a common condition that can require urgent intervention. In this study we analyze patient factors that contribute to delayed intervention during acute stone admission., Materials and Methods: We retrospectively reviewed the HCUP SID (Healthcare Cost and Utilization Project State Inpatient Database) for Florida and California from 2007 to 2011. Patients who were admitted urgently with nephrolithiasis and an indication for decompression (urinary tract infection, acute renal insufficiency and/or sepsis) were included in the study. Intervention was timely or delayed, defined as a procedure that occurred within or after 48 hours, respectively. Adjusted multivariate models were fit to assess factors that predicted a delayed procedure as well as mortality., Results: Overall 10,301 patients were admitted urgently for nephrolithiasis with indications for decompression. Early intervention occurred in 6,689 patients (65%) and was associated with a decrease in mortality (11, 0.16%), compared to delayed intervention (17 of 3,612, 0.47%, p=0.002). On multivariate analysis timely intervention significantly decreased the odds of inpatient mortality (OR 0.43, p=0.044). Weekend day admission significantly influenced time to intervention, decreasing patient odds of timely intervention by 26% (p <0.001). Other factors decreasing patient odds of timely intervention included nonCaucasian race and nonprivate insurance. Presenting medical diagnoses of urinary tract infection, sepsis and acute renal failure did not appear to influence time to intervention., Conclusions: Delayed operative intervention for acute nephrolithiasis admissions with indications for decompression results in increased patient mortality. Nonmedical factors such as the "weekend effect," race and insurance provider exerted the greatest influence on the timing of intervention., (Copyright © 2016 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.)

Purpose: Renal function following percutaneous nephrolithotomy has long been a concern to urologists, especially in the setting of multi-tract access. We determined whether the risk of renal injury after multi-tract percutaneous nephrolithotomy was greater than after a single access approach., Materials and Methods: We retrospectively reviewed the records of 307 consecutive patients treated with percutaneous nephrolithotomy from 2011 to 2012 at Wake Forest Health. Perioperative (99m)Tc-mercaptoacetyltriglycine nuclear renogram parameters along with serum creatinine values were assessed within 1 year of the procedure. Patients were stratified by single access vs multi-access (2 or more)., Results: We identified 110 cases in which renography was done before and after percutaneous nephrolithotomy. A total of 74 patients (67.3%) underwent single access percutaneous nephrolithotomy while 36 (32.7%) underwent multi-access percutaneous nephrolithotomy. Serum creatinine did not significantly differ between the 2 cohorts postoperatively (p = 0.09). There was a significant 2.28% decrease in renal function based on mercaptoacetyltriglycine nuclear renogram results after percutaneous nephrolithotomy of the affected kidney in patients with multiple accesses (p <0.01). This relationship was not observed when patients were stratified by multiple comorbidities associated with nephrolithiasis., Conclusions: Multi-access percutaneous nephrolithotomy is associated with a small reduction in the function of the targeted kidney compared to a single access approach., (Copyright © 2016 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.)

Nephrolithiasis is a common affliction, affecting approximately 10% of adults. Potentially presenting with acute abdominal or flank pain, nausea, or emesis, it may pose as a general surgical condition. Therefore, recognition, diagnosis, and management concerns are pertinent to the general surgeon. Furthermore, the risk of nephrolithiasis is increased in common general surgical conditions, including inflammatory bowel disease, hyperparathyroidism, and short gut. Nephrolithiasis may be induced as a result of general surgical interventions, including gastric bypass and bowel resection with ileostomy. An understanding of this common disease will improve coordination of patient care between urologists and general surgeons., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Background: The aim of the study is to assess the contemporary patterns of utilization of various therapeutic options for the management of nephrolithiasis in our tertiary referral institution in Auckland, New Zealand., Methods: A retrospective audit was conducted for all urinary stone procedures between January 2007 and December 2013. Procedure-related information was collected for each year. All elective and emergency procedures were included. Data were collected on the elective waiting lists for each procedure., Results: A total of 5512 stone-related cases were performed during the study period. Six hundred and fifty-three cases were performed in 2007 compared with 945 in 2013. Total number of percutaneous nephrolithotomy (PCNLs) performed, as well as the proportion of PCNL cases, demonstrated a significant decline from 84 (12.9%) in 2007 to 67 (7.1%) in 2013. While the annual numbers of extracorporeal shock wave lithotripsy (ESWLs) have increased, the percentage of ESWLs performed relative to total stone procedures has declined from 33% to 23% over the last 4 years of this audit. There has been a significant rise in the numbers of rigid and flexible ureteroscopies, with these now being the most utilized procedure. The number of patients awaiting elective procedures declined over the duration of this audit, with an associated improvement in meeting annual demand for treatment of nephrolithiasis from 78% in 2007 to 91% in 2013., Conclusions: A proportional decline in PCNL and ESWL utilization with a significant increase in flexible and rigid ureteroscopic procedures has been observed over this time and this pattern has been associated with improved adherence to surgical targets despite an increasing number of cases., (© 2015 Royal Australasian College of Surgeons.)

Background: Gaining access into non-dilated renal collecting systems for percutaneous nephrolithotripsy, particularly in patients with prohibitive body habitus and/or scoliosis, is often challenging using conventional techniques., Objective: To evaluate the feasibility of cone-beam CT for percutaneous nephrostomy placement for subsequent percutaneous nephrolithotripsy in children and adolescents., Materials and Methods: A retrospective review of percutaneous nephrostomy revealed use of cone-beam CT and 3-D guidance in 12 percutaneous nephrostomy procedures for 9 patients between 2006 and 2015. All cone-beam CT-guided percutaneous nephrostomies were for pre-lithotripsy access and all 12 were placed in non-dilated collecting systems., Results: Technical success was 100%. There were no complications., Conclusion: Cone-beam CT with 3-D guidance is a technically feasible technique for percutaneous nephrostomy in children and adolescents, specifically for nephrolithotripsy access in non-dilated collecting systems.

Background: Flexible and semirigid ureteroscopy (URS) are widely performed for the treatment of upper tract calculi and tumors. Ureteral avulsion is a rare, but devastating complication of endoscopic stone removal having multiple possible etiologies. Awareness and avoidance of this rare complication depend on identifying responsible mechanisms. This study examines the situations in which ureteral avulsion occurs as described anonymously in the Manufacturer and User facility Device Experience (MAUDE) database., Materials and Methods: The MAUDE database was systematically reviewed to account for all reported complications of flexible and semirigid URS. Keywords "ureteroscopy, injury, death, malfunction and other" were entered in the database and medical device reports were reviewed to capture any cases resulting in ureteral avulsion. Attention was paid to the type of ureteroscope involved and the mechanism for avulsion., Results: A total of 104 entries were found detailing the reported complications of flexible and semirigid URS. Ureteral avulsion was clearly noted in six reports with flexible (2) and semirigid ureteroscopes (4). Potential mechanisms included locked deflection of a flexible ureteroscope (1), bunching of the distal bending rubber in a flexible ureteroscope (1), scabbard avulsion (3), and stone basketing (1)., Conclusions: Although the incidence of ureteral avulsion cannot truly be determined from this study, some potentially novel mechanisms for this rare complication are observed. This may target future educational efforts to maximize awareness and avoidance of this complication.

Although primary hyperparathyroidism (PHPT) is asymptomatic in most patients, its main clinical manifestation is nephrolithiasis. In general, hypercalcemia would lead to unilateral renal stones, which may become bilateral over time. We present a rare case of a large unilateral asymptomatic ureteral stone in a patient with hypercalcemia secondary to PHPT, which eventually led to renal atrophy.The diagnosis of PHPT should be considered in patients with hypercalcemia and renal stones, as asymptomatic PHPT may result in a devastating renal outcome.

Aim: To evaluate exposure to radiation during percutaneous nephrolithotomy (PCNL) by comparing balloon-type renal dilatation (BTRD) and amplatz-type renal dilatation (ATRD)., Materials and Methods: Retrospectively, 454 patients were documented and matched-pair analyses were performed. According to matched-paired criteria, in Group 1 (n = 78) BTRDs were used and in Group 2 (n = 78) ATRDs were used. Demographic, operative, and postoperative data including complications were recorded. Criteria for matched-pair analyses included age, gender, stone burden and localization, body mass index, presence of obstruction in intravenous urography, diabetes mellitus, previous extracorporeal shock wave lithotripsy and/or renal surgery even open and/or PCNL., Results: The mean follow-up was 11.9 ± 1.1 months, and mean age was 44.8 ± 13.7 years. Time to provide accessing into kidney, total time of exposure to X-ray, and time of exposure to X-ray until accessing into kidney were significantly lower in Group 1 than Group 2 (p < 0.003, 0.006, and 0.039, respectively)., Conclusions: BTRD may provide shorter exposure to radiation than ATRD for patients as well as operating room staff. Additionally, BTRD can provide rapid access into kidney than ATRD without significantly shorter operation time.

Purpose: To determine the effect of obesity on radiation exposure during simulated ureteroscopy., Methods: A validated anthropomorphic adult male phantom with a body mass index (BMI) of approximately 24 kg/m(2), was positioned to simulate ureteroscopy. Padding with radiographic characteristics of human fat was placed around the phantom to create an obese model with BMI of 30 kg/m(2). Metal oxide semiconductor field effect transistor (MOSFET) dosimeters were placed at 20 organ locations in both models to measure organ dosages. A portable C-arm was used to provide fluoroscopic x-ray radiation to simulate ureteroscopy. Organ dose rates were calculated by dividing organ dose by fluoroscopy time. Effective dose rate (EDR, mSv/sec) was calculated as the sum of organ dose rates multiplied by corresponding ICRP 103 tissue weighting factors., Results: The mean EDR was significantly increased during left ureteroscopy in the obese model at 0.0092 ± 0.0004 mSv/sec compared with 0.0041 ± 0.0003 mSv/sec in the nonobese model (P < 0.01), as well as during right ureteroscopy at 0.0061 ± 0.0002 and 0.0036 ± 0.0007 mSv/sec in the obese and nonobese model, respectively (P < 0.01). EDR during left ureteroscopy was significantly greater than right ureteroscopy in the obese model (P = 0.02)., Conclusions: Fluoroscopy during ureteroscopy contributes to the overall radiation dose for patients being treated for nephrolithiasis. Obese patients are at even higher risk because of increased exposure rates during fluoroscopy. Every effort should be made to minimize the amount of fluoroscopy used during ureteroscopy, especially with obese patients.

Background: Despite the increasing incidence of pediatric nephrolithiasis, there is little data quantifying the radiation exposure associated with treatment of this disease. In this study, pediatric patients with nephrolithiasis who were managed at a single institution were identified, and the average fluoroscopy time and estimated radiation exposure associated with their procedures were reported., Methods: Stone procedures performed on pediatric patients between 2005 and 2012 were retrospectively identified. Procedures were classified as primary ureteroscopy (URS), stent placement prior to ureteroscopy (SURS), percutaneous nephrolithotomy (PCNL), and bilateral ureteroscopy (BLURS). Patient demographic information, stone size, stone location, number of radiographic images, and fluoroscopy times were analyzed., Results: A total of 152 stone procedures were included in the final analysis (92 URS, 38 SURS, eight BLURS and 14 PCNL). Mean patient age at time of stone treatment was 15.94 ± 4.1 years. Median fluoroscopy times were 1.6 (IQR 0.8-2.4), 2.1 (IQR 1.6-3.0), 2.5 (IQR 2.0-2.9), and 11.7 (IQR 5.0-18.5) minutes for URS, SURS, BLURS and PCNL, respectively. There was a moderate correlation between stone size and fluoroscopy time (r = 0.33). When compared with ureteroscopic procedures, PCNL was associated with a significantly higher fluoroscopy time (11.7 vs 2.1 min, P < 0.001). The estimated median effective dose was 3 mSv for ureteroscopic procedures and 16.8 mSv for PCNL. In addition to radiation exposure during treatment, patients in this cohort were exposed to an average of one (IQR1-3) CT scan and three (IQR 1-8) abdominal X-rays. No new malignancies were identified during the limited follow-up period., Conclusions: Radiation exposure during treatment of pediatric stone disease is not trivial, and is significantly greater when PCNL is performed. Given the recommended maximum effective dose of 50 mSv in any one year, urologists should closely monitor the amount of fluoroscopy used, and consider the potential for radiation exposure when choosing the operative approach. Prospective studies are currently underway to elucidate precise dose measurements and localize sites of radiation exposure in children during stone treatment., (Copyright © 2015 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.)

Introduction: The management of urolithiasis in children differs from adults because of anatomic and metabolic abnormalities. At present, various minimally invasive and invasive treatment strategies have been recommended to treat urinary tract Stones, including shock wave lithotripsy (SWL), standard percutaneous nephrolithotomy (PNL), mini-PNL, retrograde intrarenal surgery (RIRS), micro-PNL, and a new technique termed ultra-mini PNL (UMP). UMP is a new method for the treatment of kidney stones. The main difference between UMP and standard PNL or mini-PNL lies in the small access sheath and in its design. A 9.5F pediatric compact cystoscope was used (Figure). A major advantage of UMP is that it provides similar stone-free rates when compared with standard PNL, with lower intrarenal pressure than micro-PNL., Objective: The aim of the study was to determine the applicability and safety of UMP in the treatment of pediatric kidney stones., Patients and Methods: We retrospectively reviewed the files of 39 kidney stones in children who had undergone UMP between May 2011 and October 2014. The indications for UMP included stones resistant to SWL, stones requiring repeated sessions of SWL, and stones size larger than 20 mm., Results: The study included 17 females and 22 males, with a mean age of 5.8 ± 4.6 years. The mean hemoglobin loss was 0.9 ± 0.6 mg/dL and none of the patients required a blood transfusion. The complication rate of the PNL procedure was 15.3% (n = 6). Complete clearance was achieved in 32 patients (82%) with UMP monotherapy, which increased to 34% (87.1%) 4 weeks after the operation., Discussion: Management of urolithiasis necessitates a balance between stone clearance and morbidity related to the procedure. SWL often leads to persistent residual stones. The developing RIRS can minimize the risks associated with bleeding and visceral injury, but sometimes the abnormal pelvicaliceal anatomy and poor imaging of the flexible ureteroscopy may impact its success rate and applications. It has been reported that PNL can be performed safely and effectively to achieve a higher stone-free rate; however, it has serious complications such as bleeding that requires blood transfusion in 11-14% of the cases with increased risk of kidney loss. The recent development of smaller sheaths allows tract formation with minimal damage to the renal parenchyma, thereby reducing procedure-related morbidity without diminishing its therapeutic efficacy., Conclusion: The most important advantage of this surgical technique that has been developed is similar stone-free rates to standard PNL and lower intrarenal pressure than micro-PNL. Our experience supports that UMP is safe and effective for the management of renal stones in children., (Copyright © 2015 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.)

This article presents the experience of applying 3D-computer simulation for treatment planning in patients with coral kidney stones. The impact of the kidney internal structure and the nephrolithiasis stage on the treatment results of the patients with staghorn stones are analyzed on the basis of authors' own experience. They note the usefulness of computer modeling in preoperative planning for improving the treatment results and preventing intraoperative complications.

Some patients with nephrolithiasis who become candidates for percutaneous nephrolithotomy (PCNL) have a single kidney. This poses a challenge for the physician regarding the safety and efficacy of this procedure for these patients. This study has aimed to evaluate the safety and efficacy of PCNL in these patients. Between 2002 and 2014, out of 10,800 cases who underwent PCNL in our centres, 412 had a single kidney. We recorded the results and complications in these patients. Out of 412 patients, 279 were men and 133 women. Their mean age was 46.4 years (range 19-71) and mean stone size was 26.5 mm (range 21-55); 161 of them had a functional single kidney, 36 were congenital, and the remaining 215 had undergone contralateral nephrectomy because of stones, trauma, infection or tumour. Comorbidities included 104 hypertensive, 66 diabetic, 65 morbidly obese, 56 uremic and 47 ischemic heart disease cases. The stone-free rate was 91.3% (376/412) on postoperative X-ray/sonography. However, 42 patients required ancillary measures. Complications include fever (T > 38.3 °C) in 34 cases (8.2%), bleeding requiring transfusion 19 cases (4.6%), UTI nine cases (2%), sepsis one case (0.2%), perinephric collection three cases (0.7%), hydro/pneumothorax two cases (0.4%), access failure in five morbidly obese cases (1.2%), pyonephrosis two cases (0.4%), myocardial infarction four cases (1%), transient increasing of blood urea nitrogen (BUN) and serum creatinine (Scr.) in four normal functioning kidney (1%) and eight uremic cases (1.9%), and two cases resulted in death (0.4%). PCNL seems a safe and effective option in cases of a single kidney, but it needs more attention in order to prevent even minor complications that can result in an anephric state.

Purpose: The goal of this study was to analyze the effect of stone composition on the efficacy of retrograde intrarenal surgery (RIRS) with kidney stones of 1-3 cm, 1-2 cm, and 2-3 cm in diameter., Methods: We undertook a retrospective analysis of 74 patients with kidney stones who underwent RIRS. The patients were divided into two groups based on stone composition: Group I (n=47) (calcium oxalate monohydrate and calcium phosphate) was the hard to fragment stone group and group II (n=27) (calcium oxalate dihydrate, magnesium ammonium phosphate, and uric acid) was the easy to fragment stone group. Forty-six patients with kidney stones 1 to 2 cm in diameter were divided into group A (n=30) (smaller than 20 mm, hard to fragment stones) and group B (n=16) (smaller than 20 mm, easy to fragment stones). Twenty-eight patients with stones 2 to 3 cm in diameter were divided into group C (n=17) (larger than 20 mm, hard to fragment stones) and group D (n=11) (larger than 20 mm, easy-to-crush stones)., Results: The stone clearance rates of group I and group II were 66.0% and 88.9%, respectively (P<0.05). The stone clearance rates of group A and group B were 73.3% and 100% (P<0.05). The stone clearance rates of group C and group D were 52.9% and 72.7%, respectively., Conclusion: Stone composition has a significant impact on the efficacy of RIRS in the management of 1 to 3 cm kidney stones. For 2-3 cm calcium oxalate dihydrate stones, uric acid stones, and magnesium ammonium phosphate stones, the outcome of RIRS treatment was relatively good, and RIRS is recommended.

Percutaneous renal access and removal of large renal calculi was first described nearly 40 years ago and has since become the gold standard in management of large and complex renal calculi. In this same time period, technological and medical advances have allowed this procedure to develop in improved efficacy and morbidity. The following review offers an update to new approaches to percutaneous renal access and imaging in the management of large and complex renal calculi.

Daily practice of a physician of any specialty is incomplete without an analysis of the data derived from the use of various imaging techniques. Over the past decade, there have been significant changes in the understanding of the clinical anatomy of the patient, which is largely the result of the introduction of modern computer technology in medicine.

Purpose: To describe our experience with percutaneous nephrolithotomy (PCNL) in patients with solitary kidneys and analyze factors that can impact on intra-operative bleeding and postoperative complications., Materials and Methods: We reviewed our stone database searching for patients with solitary kidney who underwent PCNL from Jan-05 through Oct-13. Demographic data, stone characteristics, and intra- and postoperative outcomes were recorded. Spearman correlation was performed to assess which variables could impact on bleeding and surgical complications. Linear and logistic regressions were also performed., Results: Twenty-seven patients were enrolled in this study. The mean age and BMI were 45.6 years and 28.8Kg/m(2), respectively; 45% of cases were classified as Guys 3 (partial staghorn or multiple stones) or 4 (complete staghorn) - complex cases. Stone-free rate was 67%. Eight (29.6%) patients had postoperative complications (five of them were Clavien 2 and three were Clavien 3). On univariate analysis only number of tracts was associated with increased bleeding (p=0.033) and only operative time was associated with a higher complication rate (p=0.044). Linear regression confirmed number of access tracts as significantly related to bleeding (6.3, 95%CI 2.2-10.4; p=0.005), whereas logistic regression showed no correlation between variables in study and complications., Conclusions: PCNL in solitary kidneys provides a good stone-free rate with a low rate of significant complications. Multiple access tracts are associated with increased bleeding.

Introduction: Clavien-Dindo classification system has been proposed to grade perioperative complications in percutaneous nephrolithotomy. The complications of this technique that have taken place in the last 2 years are reported in this paper according Clavien-Dindo classification., Materials and Methods: Between 2011 and 2012 a total of 255 percutaneous nephrolithotomy were performed at our center for stones more than 2 cm in size. In order to determine the incidence of complications classified in the modified Clavien-Dindo system, statistical analysis of the data obtained was carried out., Results: During the period analyzed, 255 percutaneous nephrolithotomy were performed in 249 patients, 41% of the right side, 57% of the left side and 2% bilateral and simultaneous. 137 and 112 patients were males and females, respectively. The most prevalent comorbidities were: hypertension (AHT) in 101 patients (40.6%), BMI>30 in 81 patients (32%), diabetes mellitus in 46 patients (18.5%) and coagulation abnormalities in 24 patients (9.6%). A total of 70 cases (27.4%) were distributed according to Clavien-Dindo classification: grade i, 8.4%, grade ii 8.4%, grade iiia 4.4%, grade iiib 6% grade iva .8%, grade ivb: 0% and grade v 0%., Conclusions: A graded classification scheme for reporting the complications of percutaneous nephrolithotomy is useful for monitoring and reporting outcomes. We propose a standardized use of this classification in order to make the results comparable among different centers performing the technique., (Copyright © 2014 AEU. Publicado por Elsevier España, S.L.U. All rights reserved.)

The increasing incidence of pediatric stone disease has coincided with significant advances in technology and equipment, resulting in drastic improvements in management. Miniaturization of both ureteroscopes and percutaneous nephrolithotomy (PCNL) equipment has facilitated access to the entirety of the urinary tract and has made ureteroscopy a first-line therapy option along with shock-wave lithotripsy for kidney and ureteral stones. Advances in PCNL have decreased patient morbidity while preserving stone clearance rates. In this review, the advances in operative approach for ureteroscopy and PCNL in children and its applicability to current surgical management of pediatric stone disease are discussed., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Introduction: Micropercutaneous nephrolithotomy (microperc) has been recently proposed in adult patients. We present our initial experience in children using a modified technical approach., Methods: After the retrograde positioning of a 5F catheter, a 4.85F metallic needle (1.9 mm) was used for direct percutaneous calyceal access under ultrasonographic and fluoroscopic guidance with the patient in supine Valdivia-modified position. Once a three-way connector was inserted to the needle, stone fragmentation was performed under direct vision using a 200 μm holmium:YAG laser fiber and a 0.9-mm high-resolution (10,000 pixels) optic flexible wire connected with the telescope, with intermittent saline infusion. The transureteral catheter was removed within 18 to 24 hours., Results: A total of five patients aged 18 months to 11 years (mean, 5.8 years) received microperc lithotripsy in a 6-month period. The mean stone size was 15.0 mm (± 2.5 mm). Conversion to retrograde intrarenal surgery was necessary in one case, due to stone migration and poor visibility. Moderate hydronephrosis was present in one kidney. The mean operative time was 56 minutes (± 23 minutes). The blood loss was insignificant (< 0.6 Hbg/dL) and postoperative discomfort was minimal. The mean hospital stay was 2.4 ± 0.6 days for four patients after the removal of ureteral catheter. The JJ stent was removed after 15 days in the last patient. The overall stone-free rate at 1 month was 100% and no ancillary procedures were required. Conclusions Microperc is a new cost-effective and time-saving technique that we demonstrated as safe and effective in minimally invasive procedure for lower pole and pelvic renal stones of small size. Indications and limits should be defined by multicenter randomized studies, comparing the former procedures., (Georg Thieme Verlag KG Stuttgart · New York.)

Nephrolithiasis is a frequent problem that can cause serious morbidity. When associated with an underlying metabolic disorder the recurrence rate is higher. Hypocitraturia is estimated to be present in 20-60% of cases. Several secondary causes are known. Potassium citrate is the primary treatment. In the case we present here we emphasise the need for metabolic screening, focussing on hypocitraturia, a less well-known cause of nephrolithiasis.

Objective: To analyze the patient- and procedure-related factors affecting the outcomes of percutaneous nephrolithotomy (PNL) in horseshoe kidneys (HSKs)., Methods: A retrospective analysis was done of patients with stones in HSKs treated with PNL in 3 referral centers between 1998 and 2013. Demographics, along with perioperative characteristics, were evaluated in detail as to whether or not they had an effect on the success and complication rates., Results: A total of 54 HSKs with calculi in 53 patients were treated with PNL. Mean stone size was 28.4 ± 19.6 mm (range, 10-120 mm). Fifty-three patients were treated through a single tract, and 1 patient required additional access. Access was directed to the upper calyx (n = 27), middle calyx (n = 17), and lower calyx (n = 10) through the intercostal (n = 23) and subcostal (n = 31) areas. Flexible nephroscopy was used in 18.5% of the procedures. Postoperative complications were observed in 9 (16.7%) of the procedures. Success rate was 66.7% after a single session of PNL and increased to 90.7% with additional treatments. Although patient demographics, preoperative imaging, and other operative measures did not have significant effect on the complication rate, stone complexity and multiplicity, in combination with flexible nephroscopy, were found to significantly affect the success rate (P = .026, P = .043, and P = .021, respectively). However, in multivariate analysis stone multiplicity was the only factor that affected success rate (P = .004)., Conclusion: Stone parameters play an important role in achieving stone-free status in HSKs. Use of flexible nephroscopy positively affects the success rate by allowing reaching the peripherally located calices., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Content: Management of primary hyperparathyroidism has evolved over the past two decades, yet impaired renal function has consistently been a surgical indication. This recommendation has been based upon the historical association between primary hyperparathyroidism and renal impairment, and a review of the literature is needed to determine whether such a recommendation is warranted., Evidence Acquisition and Synthesis: PubMed was utilized to identify English-language articles published between January 1990 and February 2014 using keywords related to hyperparathyroidism and renal function. The keywords were "primary hyperparathyroidism," "surgery," "parathyroidectomy," "kidney," "renal," "glomerular filtration rate," and "creatinine." Of the 1926 articles obtained with this search, all articles germane to the topic that quantified the relationship between primary hyperparathyroidism and renal function were included. All references within these articles were investigated for inclusion. When helpful, data tables were constructed to summarize the results succinctly., Conclusions: A secondary elevation of PTH levels has not been consistently shown to occur at the threshold currently indicated for surgical intervention. While renal impairment is seen with more significant disease, mild asymptomatic primary hyperparathyroidism has not been conclusively associated with renal impairment. Furthermore, there is no evidence to suggest that surgically curing primary hyperparathyroidism via a parathyroidectomy has any impact upon renal function.

Purpose of Review: Nephrolithiasis is a common systemic disease associated with both acute kidney injury (AKI) and chronic kidney disease (CKD). The purpose of this review is to discuss recent publications regarding nephrolithiasis-associated kidney damage, with an emphasis on AKI., Recent Findings: Nephrolithiasis is not a common cause of adult AKI (1-2% of cases), although it may be a more important factor in young children (up to 30%). The primary mechanism of nephrolithiasis-associated AKI is obstructive nephropathy, and factors on presentation with obstructive uropathy predict the likelihood of long-term renal recovery. Crystalline nephropathy is another potential pathway in certain circumstances that is often associated with a worse outcome. Recent studies have elucidated additional pathways whereby calcium oxalate crystals can cause acute injury, implicating innate immunity and intracellular inflammasome pathways. Several large cohort studies have demonstrated an independent association of nephrolithiasis with CKD and end-stage renal disease, although the effect size is modest. Urologic comorbidities, urinary infection, and shared underlying risk factors (e.g., diabetes, hypertension) all impact nephrolithiasis-associated CKD risk., Summary: Obstructive nephropathy and crystalline nephropathy both contribute to nephrolithiasis-associated AKI, although the latter appears to have a worse prognosis. Nephrolithiasis is an independent, albeit small, risk factor for CKD. Further study is needed to clarify the incidence and mechanisms of nephrolithiasis-associated AKI, and the relationship between nephrolithiasis-associated AKI and CKD.