Contemporary diagnosis and management of pelvi-ureteric junction obstruction.

Pelvi-ureteric junction obstruction (PUJO) is defined as a functionally significant impairment of the flow of urine from the kidney's renal pelvis into the proximal ureter. Symptomatically, the patient may experience flank pain, recurrent infections, stone formation, and impairment of renal function. Although many cases of intrinsic PUJO are diagnosed at birth, a minority of patients may present in adulthood with previously silent disease or develop secondary PUJO to other causes. PUJO is therefore broadly categorised into both primary and secondary PUJO. A wide array of diagnostic scans and tests are available to aid in diagnosing and monitoring patients with PUJO. In patients with compromised renal function or symptomatic PUJO that require intervention, minimally invasive techniques are the 'gold standard' for surgical intervention. This review will detail the endoscopic, laparoscopic, and robotic options available to the urologist practicing in 2021, including the use of autografts and other emerging technologies.

Frailty as predictor of complications in patients undergoing percutaneous nephrolithotomy (PCNL).

INTRODUCTION & OBJECTIVE: Surgical complications are difficult to predict, despite existing tools. Frailty phenotype has shown promise estimating postoperative risk among the elderly. We evaluate the use of frailty as a predictive tool on patients undergoing percutaneous renal surgery. METHODS: Frailty was prospectively analyzed using the Hopkins Frailty Index, consisting of 5 components yielding an additive score: patients categorized not frail, intermediate, or severely frail. Primary outcomes were complications during admission and 30-day complication rate. Secondary outcomes included overall hospital length of stay (LOS) and discharge location. RESULTS: A total of 100 patients recruited, of whom five excluded as they did not need the procedure. A total of 95 patients analyzed; 69, 10, and 16 patients were not frail, intermediate, and severely frail, respectively. There were no differences in blood loss, number of dilations, presence of a staghorn calculus, laterality, or location of dilation. Severely frail patients were likely to be older and have a higher American Society of Anesthesiologists score and Charlson comorbidity index. Patients of intermediate or severe frailty were more likely to exhibit postoperative fevers, bacteremia, sepsis, and require ICU admissions (P < 0.05). Frail patients had a longer LOS (P < 0.001) and tended to require skilled assistance when discharge (p < 0.0001). CONCLUSIONS: Frailty assessment appears useful stratifying those at risk of extended hospitalization, septic complications, and need for assistance following percutaneous renal surgery. Risks of sepsis, bacteremia, and post-operative hemorrhage may be higher in frail individuals. Preoperative assessment of frailty phenotype may give insight into treatment decisions and represent a modifiable marker allowing future trials exploring the concept of "prehabilitation".

A Two-Dimensional Manganese Gallium Nitride Surface Structure Showing Ferromagnetism at Room Temperature.

Practical applications of semiconductor spintronic devices necessitate ferromagnetic behavior at or above room temperature. In this paper, we demonstrate a two-dimensional manganese gallium nitride surface structure (MnGaN-2D) which is atomically thin and shows ferromagnetic domain structure at room temperature as measured by spin-resolved scanning tunneling microscopy and spectroscopy. Application of small magnetic fields proves that the observed magnetic domains follow a hysteretic behavior. Two initially oppositely oriented MnGaN-2D domains are rotated into alignment with only 120 mT and remain mostly in alignment at remanence. The measurements are further supported by first-principles theoretical calculations which reveal highly spin-polarized and spin-split surface states with spin polarization of up to 95% for manganese local density of states.

Stones in special situations.

There are several special situations in which urinary lithiasis presents management challenges to the urologist. An in-depth knowledge of the pathophysiology, unique anatomy, and treatment options is crucial in order to maintain good health in these patients. In this review, we summarize the current literature on the management of the following scenarios: bladder stones, stones in bowel disease, during pregnancy, in association with renal anomalies, with skeletal deformities, in urinary diversions, and in children.

Can Activities of Daily Living Predict Complications following Percutaneous Nephrolithotomy?

PURPOSE: Activities of daily living provide information about the functional status of an individual and can predict postoperative complications after general and oncological surgery. However, they have rarely been applied to urology. We evaluated whether deficits in activities of daily living could predict complications after percutaneous nephrolithotomy and how this compares with the Charlson comorbidity index and the ASA(®) (American Society of Anesthesiologists(®)) classification. MATERIALS AND METHODS: We retrospectively reviewed the records of all patients who underwent percutaneous nephrolithotomy between March 2013 and March 2014. Those with complete assessment of activities of daily living were included in analysis. Perioperative outcomes, complications and hospital length of stay were examined according to the degree of deficits in daily living activities. RESULTS: Overall 176 patients underwent a total of 192 percutaneous nephrolithotomies. Deficits in activities of daily living were seen in 16% of patients, including minor in 9% and major in 7%. Complications developed more frequently in those with vs without deficits in daily living activities (53% vs 31%, p = 0.029) and length of stay was longer (2.0 vs 4.5 days, p = 0.005). On multivariate logistic regression activities of daily living were an independent predictor of complications (OR 1.11, p = 0.01) but ASA classification and Charlson comorbidity index were not. CONCLUSIONS: Activities of daily living are easily evaluated prior to surgery. They independently predict complications following percutaneous nephrolithotomy better than the Charlson comorbidity index or the ASA classification. Preoperative assessment of daily living activities can help risk stratify patients and may inform treatment decisions.

Percutaneous nephrolithotomy in super obese patients (body mass index ≥ 50 kg/m²): overcoming the challenges.

OBJECTIVE: To analyse our experience with and the outcomes and lessons learned from percutaneous nephrolithotomy (PCNL) in the super obese (body mass index [BMI] ≥50 kg/m(2) ). PATIENTS AND METHODS: In this institutional review board approved study we retrospectively reviewed our PCNL database between July 2011 and September 2014 and identified all patients with a BMI ≥ 50 kg/m(2) . Patient demographics, peri-operative outcomes and complications were determined. Additionally, we identified a number of special PCNL considerations in the super obese that can maximize safe outcomes. RESULTS: A total of 21 PCNL procedures performed on 17 super obese patients were identified. The mean patient age was 54.8 years, the mean BMI was 57.2 kg/m(2) and the mean stone area was 1 037 mm(2) . Full staghorn stones were observed in six patients and partial staghorns in four patients. The mean operating time was 106 min and the mean haemoglobin decrease was 1.2 g/dL. The overall stone-free rate was 87%. There were four total complications: two Clavien grade II, one Clavien IIIb and one Clavien IVb. We identified several special considerations for safely preforming PCNL in the suber obese, including using extra-long nephroscopes and graspers, using custom-cut extra long access sheaths with suture 'tails' secured to easily retrieve the sheath, choosing the shortest possible access tract, readily employing flexible nephroscopes, placing nephroureteral tubes rather than nephrostomy tubes postoperatively, and meticulous patient positioning and padding. CONCLUSION: With appropriate peri-operative considerations and planning, PCNL is feasible and safe in the super obese. Stone clearance was similar to that reported in previous PCNL series in the morbidly obese, and is achievable with few complications.

Indications for adult circumcision: a contemporary analysis.

INTRODUCTION: Circumcision is the most common surgical procedure performed worldwide. However, there is a dearth of literature regarding medical indications for adult circumcisions. Here, we describe our experience with adult circumcision and contemporary demographics, indications and complications. MATERIALS AND METHODS: We reviewed all circumcisions performed in our institution between July 2008 and January 2015. Patient demographics, procedure indications and postoperative complications were recorded, and patients were grouped by age as either less than 50 years old or 50 years and older. RESULTS: A total of 202 charts were reviewed. The most common indications for circumcision were phimosis (46.5%), dyspareunia (17.8%), balanitis (14.4%), and concurrent phimosis and balanitis (8.9%). Older patients were more likely to undergo circumcision for concurrent phimosis and balanitis or cancer, whereas younger patients sought circumcision for dyspareunia. The complication rate was 3.5% and there was no significant difference in complication rates between the two age groups. CONCLUSION: Circumcision is performed in the adult population for a variety of reasons. Circumcision remains a safe surgical option for patient management with a low complication rate.

Native gallium adatoms discovered on atomically-smooth gallium nitride surfaces at low temperature.

In advanced compound semiconductor devices, such as in quantum dot and quantum well systems, detailed atomic configurations at the growth surfaces are vital in determining the structural and electronic properties. Therefore, it is important to investigate the surface reconstructions in order to make further technological advancements. Usually, conventional semiconductor surfaces (e.g., arsenides, phosphides, and antimonides) are highly reactive due to the existence of a high density of group V (anion) surface dangling bonds. However, in the case of nitrides, group III rich growth conditions in molecular beam epitaxy are usually preferred leading to group III (Ga)-rich surfaces. Here, we use low-temperature scanning tunneling microscopy to reveal a uniform distribution of native gallium adatoms with a density of 0.3%-0.5% of a monolayer on the clean, as-grown surface of nitrogen polar GaN(0001̅) having the centered 6 × 12 reconstruction. Unseen at room temperature, these Ga adatoms are strongly bound to the surface but move with an extremely low surface diffusion barrier and a high density saturation coverage in thermodynamic equilibrium with Ga droplets. Furthermore, the Ga adatoms reveal an intrinsic surface chirality and an asymmetric site occupation. These observations can have important impacts in the understanding of gallium nitride surfaces.

Factors associated with suicide in patients with genitourinary malignancies.

BACKGROUND: Approximately 70% of all suicides in patients aged >60 years are attributed to physical illness, with higher rates noted in patients with cancer. The purpose of the current study was to characterize suicide rates among patients with genitourinary cancers and identify factors associated with suicide in this specific cohort. METHODS: Patients with prostate, bladder, kidney, testis, and penile cancer were identified in the Surveillance, Epidemiology, and End Results database (1988-2010). Standardized mortality ratios (SMRs) and 95% confidence intervals (95% CIs) were calculated for each anatomic site. Multivariable logistic regression models generated odds ratios (ORs) for the identification of factors associated with suicide for each malignancy. RESULTS: There were 2268 suicides identified among 1,239,522 individuals with genitourinary malignancies observed for 7,307,377 person-years. The SMRs for patients with cancer were 1.37 for prostate cancer (95% CI, 0.99-1.86), 2.71 for bladder cancer (95% CI, 2.02-3.62), 1.86 for kidney cancer (95% CI, 1.32-2.62), 1.23 for testis cancer (95% CI, 0.88-1.73), and 0.95 for penile cancer (95% CI, 0.65-1.35). On multivariable analysis, male sex was found to be associated with odds of suicide among patients with bladder cancer (OR, 6.63) and kidney cancer (OR, 4.98). Increasing age was associated with suicide for patients with prostate, bladder, and testis cancer (OR range, 1.03-1.06). Distant disease was associated with suicide in patients with prostate, bladder, and kidney cancer (OR range, 2.82-5.43). Among patients with prostate, bladder, and kidney cancer, African American patients were less likely to commit suicide compared with white individuals (OR range, 0.26-0.46). CONCLUSIONS: Suicide in patients with genitourinary malignancies poses a public health dilemma, especially among men, the elderly, and those with aggressive disease. Clinicians should be aware of risk factors for suicide in these patients.

Does Peak Inspiratory Pressure Increase in the Prone Position? An Analysis Related to Body Mass Index.

PURPOSE: Percutaneous nephrolithotomy is commonly performed with the patient prone. There is concern that the prone position, especially in obese patients, negatively affects ventilation due to the restriction of chest compliance and respiratory mechanics. We analyzed the change in airway resistance between supine and prone positioning of patients undergoing percutaneous nephrolithotomy. MATERIALS AND METHODS: We retrospectively reviewed the intraoperative respiratory parameters of 101 patients who underwent prone percutaneous nephrolithotomy. Peak inspiratory pressure was assessed with the patient supine, at several time points after being turned prone and at the end of the case. The change in peak inspiratory pressure with time was calculated. Results were stratified based on body mass index and data were compared using the paired t-test and Spearman ρ. RESULTS: Of 101 patients 50 (50%) were obese (body mass index 30 kg/m(2) or greater). Median body mass index was 25.6 kg/m(2) in the nonobese cohort and 38.3 kg/m(2) in the obese cohort. Average peak inspiratory pressure while supine and prone was 18.0 and 18.5 cm H2O in the nonobese cohort, and 25.5 and 26.6 cm H2O, respectively, in the obese cohort. Obese patients had significantly higher peak inspiratory pressure in the supine and the prone positions relative to nonobese patients (p <0.0001). However, there was no change in peak inspiratory pressure from the supine to the prone position in either cohort. CONCLUSIONS: Obese patients have higher baseline peak inspiratory pressure regardless of position. However, prone positioning does not impact peak inspiratory pressure in either cohort. It remains a safe and viable option.

Evaluation and comparison of urolithiasis scoring systems used in percutaneous kidney stone surgery.

PURPOSE: Contemporary predictive tools for percutaneous nephrolithotomy outcomes include the Guy stone score, S.T.O.N.E. nephrolithometry and the CROES nephrolithometric nomogram. We compared each scoring system in the same cohort to determine which was most predictive of surgical outcomes. METHODS: We retrospectively reviewed the records of patients who underwent percutaneous nephrolithotomy between 2009 and 2012 at a total of 3 academic institutions. We calculated the Guy stone score, the S.T.O.N.E. nephrolithometry score and the CROES nephrolithometric nomogram score based on preoperative computerized tomography images. A single observer at each institution reviewed all images and assigned scores. Univariate and multivariate analysis was done to determine the most predictive scoring system. RESULTS: We enrolled 246 patients in study. In stone-free patients vs those with residual stones the mean Guy score was 2.2 vs 2.7, the mean S.T.O.N.E. score was 8.3 vs 9.5 and the mean CROES nomogram score was 222 vs 187 (each p <0.001). Logistic regression revealed that the Guy, S.T.O.N.E. nephrolithometry and CROES nomogram scores were significantly associated with stone-free status (p = 0.02, 0.004 and <0.001, respectively). The Guy and S.T.O.N.E. nephrolithometry scores were associated with estimated blood loss (p <0.0001 and 0.03) and length of stay (p = 0.03 and 0.009, respectively). The CROES nomogram did not predict estimated blood loss or length of stay. CONCLUSIONS: All scoring systems and the stone burden equally predicted stone-free status. The Guy and S.T.O.N.E. nephrolithometry scores were associated with estimated blood loss and length of stay. A single scoring system should be adopted to unify reporting.

Differences in 24-h urine composition between nephrolithiasis patients with and without diabetes mellitus.

OBJECTIVES: To examine the differences in 24-h urine composition between nephrolithiasis patients with and without diabetes mellitus (DM) in a large cohort of stone-formers and to examine differences in stone composition between patients with and without DM. PATIENTS AND METHODS: A retrospective review of 1117 patients with nephrolithiasis and a 24-h urine analysis was completed. Univariable analysis of 24-h urine profiles and multivariable linear regression models were performed, comparing patients with and without DM. A subanalysis of patients with stone analysis data available was performed, comparing the stone composition of patients with and without DM. RESULTS: Of the 1117 patients who comprised the study population, 181 (16%) had DM and 936 (84%) did not have DM at the time of urine analysis. Univariable analysis showed significantly higher total urine volume, citrate, uric acid (UA), sodium, potassium, sulphate, oxalate, chloride, and supersaturation (SS) of UA in individuals with DM (all P < 0.05). However, patients with DM had significantly lower SS of calcium phosphate and pH (all P < 0.05). Multivariable analysis showed that patients with DM had significantly lower urinary pH and SS of calcium phosphate, but significantly greater citrate, UA, sulphate, oxalate, chloride, SSUA, SS of calcium oxalate, and volume than patients without DM (all P < 0.05). Patients with DM had a significantly greater proportion of UA in their stones than patients without DM (50.2% vs 13.5%, P < 0.001). CONCLUSIONS: DM was associated with multiple differences on 24-h urine analysis compared with those without DM, including significantly higher UA and oxalate, and lower pH. Control of urinary UA and pH, as well as limiting intake of dietary oxalate may reduce stone formation in patients with DM.

Contemporary assessment of renal stone complexity using cross-sectional imaging.

Recently, several scoring systems have been proposed to predict outcomes of percutaneous nephrolithotomy, objectively and quantitatively assessing kidney calculi complexity using cross-sectional imaging. These scoring systems are promising new tools that can guide surgical decision making, predict surgical outcomes, counsel patients undergoing stone surgery, and improve standardized academic reporting in percutaneous kidney stone surgery. In this article, we review features of each of these systems, their similarities and differences, and their applicability in clinical practice and relevance in academic reporting.

Association of serum biochemical metabolic panel with stone composition.

INTRODUCTION: To determine the association of the basic metabolic panel with stone type. METHODS: The present study was a retrospective review of 492 stone formers with both stone composition analysis and basic metabolic panel available. Analysis of a basic metabolic panel across stone types was carried out using Fisher's exact test and analysis of variance. Multinomial logistic regression was used to predict stone type based on a basic metabolic panel. RESULTS: A total of 272 (55%) patients had predominantly calcium oxalate stones, 100 (21%) had uric acid stones, 93 (19%) had calcium phosphate stones, 16 (3%) had mixed stones and 11 (2%) had other types of stones. Uric acid stone formers had the highest serum glucose, blood urea nitrogen and creatinine levels. Calcium oxalate stone formers had the highest serum sodium. No significant differences in mean serum calcium levels across different stone types were identified. The predicted risk of uric acid stone over the other stone types increased with an increase in serum glucose and decreased with an increase in carbon dioxide levels. The predicted risk of calcium oxalate stones increased with an increase in serum sodium and chloride levels. The predicted risk of calcium phosphate and oxalate stones over the other stone types increased with an increase in serum calcium levels. The overall accuracy of the basic metabolic panel alone to predict stone type was 59%. CONCLUSION: A basic metabolic panel alone or in combination with 24-h urinalysis and demographics does not accurately predict stone type. However, it can be used in combination with other variables to predict stone composition.

Stenting for malignant ureteral obstruction: Tandem, metal or metal-mesh stents.

Extrinsic malignant compression of the ureter is not uncommon, often refractory to decompression with conventional polymeric ureteral stents, and frequently associated with limited survival. Alternative options for decompression include tandem ureteral stents, metallic stents and metal-mesh stents, though the preferred method remains controversial. We reviewed and updated our outcomes with tandem ureteral stents for malignant ureteral obstruction, and carried out a PubMed search using the terms "malignant ureteral obstruction," "tandem ureteral stents," "ipsilateral ureteral stents," "metal ureteral stent," "resonance stent," "silhouette stent" and "metal mesh stent." A comprehensive review of the literature and summary of outcomes is provided. The majority of studies encountered were retrospective with small sample sizes. The evidence is most robust for metal stents, whereas only limited data exists for tandem or metal-mesh stents. Metal and metal-mesh stents are considerably more expensive than tandem stenting, but the potential for less frequent stent exchanges makes them possibly cost-effective over time. Urinary tract infections have been associated with all stent types. A wide range of failure rates has been published for all types of stents, limiting direct comparison. Metal and metal-mesh stents show a high incidence of stent colic, migration and encrustation, whereas tandem stents appear to produce symptoms equivalent to single stents. Comparison is difficult given the limited evidence and heterogeneity of patients with malignant ureteral obstruction. It is clear that prospective, randomized studies are necessary to effectively scrutinize conventional, tandem, metallic ureteral and metal-mesh stents for their use in malignant ureteral obstruction.

The surgical spectacle: a survey of urologists viewing live case demonstrations.

OBJECTIVE: To evaluate perspectives of urologists viewing live case demonstrations (LCD) and taped case demonstrations (TCD). METHOD: A 15-question anonymous survey was distributed to attendees of the live surgery session at the American Urological Association 2012 national meeting (Atlanta) and the second International Challenges in Endourology meeting (Paris). RESULTS: Of 1000 surveys distributed, 253 were returned completed (response rate 25%). Nearly half of respondents were in the academic practice setting and nearly 75% were beyond training. Just over 30% had performed a LCD previously. The perceived benefit of an LCD was greater than unedited and edited videos (chi-squared P = 0.014 and P < 0.001, respectively). Nearly no one selected 'not helpful' and a few selected 'minimally helpful' for any of the three forms of demonstration. Most respondents identified that opportunity to ask questions (61%) and having access to the full unedited version (72%), two features inherent to LCD, improved upon the educational benefit of edited videos. Most (78%) identified LCD as ethical. However, those that did not perceived lower educational benefit from LCD (P = 0.019). A slim majority (58%) would allow themselves or a family member to be a patient of a LCD and the vast majority (86%) plan to transfer knowledge gained at the LCD session into their practice. CONCLUSIONS: Urologists who attended these LCD sessions identified LCDs as beneficial and applicable to their practice. LCDs are preferred over videos. The large majority considers LCD ethical, although not as many would volunteer themselves for LCD. Further studies are necessary to determine if there is actual benefit from LCD over TCD to patient care.

Energetic requirements of iridium(III) complex based photosensitisers in photocatalytic hydrogen generation.

A new family of Ir(III) complexes were synthesised and employed as light-induced hydrogen-production photosensitisers in aqueous systems, where hydrogen evolution was observed only when the PS* was reduced by the sacrificial agent, NEt3, signifying that a minimum potential difference of >0.2 V between E(PS*/PS(-)) and E(NEt3(+)/NEt3) is required for efficient hydrogen production [i.e., E(PS*/PS(-)) >1.19 V versus NHE]. The analytical method developed here is demonstrated to be useful for screening new photosensitisers for light-driven hydrogen generation.

Bilateral nephrolithiasis and upper tract transitional cell carcinoma in horseshoe kidney.

Nephroureterectomy is currently the criterion-standard treatment for high-grade upper tract urothelial carcinoma (UTUC). Current guidelines and expert opinions propose some exceptions to this approach based on patient characteristics, disease status, and function of the contralateral kidney. We present a rare case of a patient with horseshoe kidney, bilateral large nephrolithiasis, high-grade UTUC in one moiety, and relative parenchymal thinning of the contralateral side. The patient was treated with a percutaneous, minimally invasive, nephron sparing approach. The patient also had intracollecting system instillations of gemcitabine and docetaxel. Minimally invasive percutaneous resection of high-grade UTUC is a safe procedure in select cases. Current guidelines may not apply to all patients; unique scenarios with UTUC may require personalized decision-making and treatment at specialized centers.

Using 24-hour urinalysis to predict stone type.

PURPOSE: We determined the accuracy of 24-hour urinalysis in predicting stone type and identify the associations between 24-hour urine elements with stone type. MATERIALS AND METHODS: We performed a retrospective review of 503 stone formers with stone composition analysis and 24-hour urinalysis available. Analysis of 24-hour urine elements across stone types was performed using Fisher's exact test and ANOVA. Multinomial logistic regression was used to predict stone type based on 24-hour urinalysis. RESULTS: A total of 280 (56%) patients had predominantly calcium oxalate, 103 (20%) had uric acid, 93 (19%) had calcium phosphate, 16 (3%) had mixed and 11 (2%) had other stone types. There were several significant patient characteristics and 24-hour urinalysis differences across stone type groups. The statistical model predicted 371 (74%) calcium oxalate, 78 (16%) uric acid, 52 (10%) calcium phosphate, zero mixed and 2 (less than 1%) other stone types. The model correctly predicted calcium oxalate stones in 85%, uric acid in 51%, calcium phosphate in 31%, mixed in 0% and other stone types in 18% of the cases. Of the predicted stone types, correct predictions were 61%, 69%, 56% and 71% for calcium oxalate, uric acid, calcium phosphate and other stones types, respectively. The overall accuracy was 64%. Plots were used to explore the associations between each 24-hour urine element with each predicted stone type adjusted for all the others urinary elements. CONCLUSIONS: A 24-hour urinalysis alone does not accurately predict stone type. However, it may be used in conjunction with other variables to predict stone composition.

A nephrolithometric nomogram to predict treatment success of percutaneous nephrolithotomy.

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