Complications of Percutaneous Nephrolithotomy: Experience From a Tertiary Care Center.

Introduction Renal stones are mineral concretions in the pelvicalyceal system. Their prevalence and recurrence are increasing globally. Percutaneous nephrolithotomy (PCNL) is a minimally invasive procedure for the removal of kidney stones. It is a safer technique offering the highest stone-free rates. However, a few complications may still occur. We aimed to evaluate our experiences of PCNL and classify the complications as intraoperative, early postoperative, and late postoperative events. We also aimed to find the predictors of complications in PCNL. Methods A single-center prospective observational study was conducted from June 2021 to October 2022 where all patients who were >18 years old with radiopaque calculus in the kidney and underwent PCNL were included. Statistical analysis was performed using the IBM Statistical Package for Social Sciences (SPSS) software (IBM SPSS Statistics, Armonk, NY). A p-value of <0.05 was considered significant. Results Two hundred one patients including 137 males and 64 females participated in the study. The overall rate of complications was 21.9%. Most of the patients (16.4%) experienced minor complications of Clavien grades 1 and 2. A Clavien grade of >3 included major complications and was noted in 5.5% of patients. No mortality was seen in the postoperative period. Female patients (p = 0.028), a stone burden of >3 cm (p = 0.003), stones in multiple calyces (p = 0.001), hydronephrosis (p = 0.001), history of recently treated urinary tract infection (UTI) (p < 0.001), longer operative time (>91 minutes) (p < 0.001), Guy's stone scores (GSS) III and IV (p < 0.001), complex renal calculi (staghorn) (p = 0.002), and multiple punctures (p = 0.001) were associated with higher complication rates after PCNL. Conclusion Most PCNL-related complications are minor and resolve with conservative or minimally invasive management. However, there are certain complications that can limit the surgical outcome. The overall complication rate in the current study is similar to that reported in the literature. Bleeding was the most common intraoperative complication, whereas hematuria was the most common early postoperative complication. A stone burden of >3 cm, hydronephrosis, longer operative time, higher GSS, and multiple punctures can all affect the rate of complications.

Fully Automated Longitudinal Assessment of Renal Stone Burden on Serial CT Imaging Using Deep Learning.

Purpose: Use deep learning (DL) to automate the measurement and tracking of kidney stone burden over serial CT scans. Materials and Methods: This retrospective study included 259 scans from 113 symptomatic patients being treated for urolithiasis at a single medical center between 2006 and 2019. These patients underwent a standard low-dose noncontrast CT scan followed by ultra-low-dose CT scans limited to the level of the kidneys. A DL model was used to detect, segment, and measure the volume of all stones in both initial and follow-up scans. The stone burden was characterized by the total volume of all stones in a scan (SV). The absolute and relative change of SV, (SVA and SVR, respectively) over serial scans were computed. The automated assessments were compared with manual assessments using concordance correlation coefficient (CCC), and their agreement was visualized using Bland-Altman and scatter plots. Results: Two hundred twenty-eight out of 233 scans with stones were identified by the automated pipeline; per-scan sensitivity was 97.8% (95% confidence interval [CI]: 96.0-99.7). The per-scan positive predictive value was 96.6% (95% CI: 94.4-98.8). The median SV, SVA, and SVR were 476.5 mm3, -10 mm3, and 0.89, respectively. After removing outliers outside the 5th and 95th percentiles, the CCC measuring agreement on SV, SVA, and SVR were 0.995 (0.992-0.996), 0.980 (0.972-0.986), and 0.915 (0.881-0.939), respectively Conclusions: The automated DL-based measurements showed good agreement with the manual assessments of the stone burden and its interval change on serial CT scans.

External validation of Modified Seoul National University Renal Stone Complexity Score to predict outcome and complications of retrograde intrarenal surgery: a RIRSearch Group study.

INTRODUCTION: The Modified Seoul National University Renal Stone Complexity Score (S-ReSC) is a simple model based solely on stone location regardless of stone burden. The aims of this study were to validate S-ReSC for outcomes and complications of retrograde intrarenal surgery (RIRS) and to evaluate its predictive power against the stone burden. MATERIAL AND METHODS: Data of 1007 patients with kidney stones who had undergone RIRS were collected from our RIRSearch database. Linear-by-linear association, logistic regression, ANOVA/post hoc analysis and ROC curve (with Hanley and McNeil's test) were used for evaluation. The main outcomes were stone-free status and complications of RIRS. RESULTS: The overall stone-free rate was 76.8% (773/1007). Higher S-ReSC scores were related to lower stone-free rates and higher total, perioperative and postoperative complication rates (p<.001, p<.001, p=.008 and p<.001, respectively). S-ReSC score (p=.02) and stone burden (p<.001) were independent predictors of stone-free status. But stone burden (AUC = 0.718) had a more powerful discriminating ability than the S-ReSC score (AUC = 0.618). CONCLUSIONS: The S-ReSC score is able to predict not only stone-free status but also complications of RIRS. Although this location-only based scoring system has a fair discriminative ability, stone burden is a more powerful predictor of stone-free status after RIRS. An ideal scoring system aiming to predict outcomes of RIRS must include stone burden as a parameter.

Factors predicting duration and success of semirigid ureteroscopy for ureteral stones in different localizations / El papel diagnóstico de la proteína fijadora de ácidos grasos testiculares en la isquemia testicular: un estudio experimental controlado aleatorizado

Objetive: In this study, we aimed to determine the factors predicting the duration and successof semirigid ureteroscopy performed for the treatment ofureteral stones in different localizations.Materials and methods: Medical records of thepatients whom underwent semirigid ureteroscopy forurolithiasis in our centre between January 2015 and December 2019 were retrospectively reviewed. The studygroup composed of 170 patients and divided into threesubgroups; of which 54 in proximal ureter (31.8%), 51in the mid (30 %) and 65 (38.2%) in the distal ureter.Predictive factors of semirigid ureteroscopy duration andsuccess were determined by performance of correlationanalysis and multivariate analysis. Rresults: Overall stone-free rate was calculated as78.8%. Success rates for proximal, mid and distalureteral stones were 72.2% (39/54 patients), 74.5%(38/51 patients) and 87.7% (57/65 patients), respectively. Complications were present in 19 patients(11.2%). Multivariate analysis indicated that stone diameter and stone burden independently affected thestone-free rate. Statistically significant negative correlation was determined between success of the procedureand stone diameter, stone burden, impaction and moreproximal stone localization. While there was a statistically significant positive correlation between duration ofprocedure and stone burden, diameter, impaction, history of ipsilateral ureteroscopy and more proximal stonelocalization, there was negative correlation betweenduration of procedure and stone-free status.Conclusion: We conclude that stone diameter,stone burden, impaction and more proximal stone localization are common factors affecting both durationand success of semirigid ureteroscopy. In addition, stonesize and stone burden were determined as independentmarkers of stone-free status.(AU)

Objetivo: En este estudio determinamoslos factores predictores de la duración y el éxito de laureteroscopia semirígida realizada como tratamiento delas litiasis ureterales en diferentes localizaciones.Materiales y métodos: Revisamos retrospectivamente las historias clínicas de los pacientes que han sido sometidos a una ureteroscopia semirígida por litiasis ennuestro centro entre enero 2015 y diciembre 2019. Elgrupo de estudio está formado por 170 pacientes y dividido en 3 subgrupos: 54 con litiasis en uréter proximal(31,8%) 51 en medio (30%) y 65 (38,2%) en el uréterdistal. Los factores predictores de duración y éxito de laureteroscopia semirígida fueron determinados con análisis de correlación y multivariante.RESULTADOS: La tasa global libre de litiasis fue de78,8%. La tasa de éxito en uréter proximal, medio y distal fue de 72,2% (39/54 pacientes), 74,5% (38/51pacientes) y 87,7% (57/65 pacientes), respectivamente. Las complicaciones estuvieron presentes en 19 pacientes (11,2%). El análisis multivariante indicó que eldiámetro de la litiasis y el volumen afectaron de formaindependiente la tasa libre de litiasis. Una significaciónestadística negativa fue determinada entre el éxito delprocedimiento y el diámetro de la litiasis, volumen, impactación y localización proximal. Una significación estadística positiva entre la duración del procedimiento yel volumen de la litiasis, diámetro, impactación, previasureteroscopias y localización proximal. Se observó unacorrelación negativa entre la duración del procedimiento y el estado libre de litiasis.CONCLUSIÓN: Concluimos que el diámetro de la litiasis, volumen, impactación y localización proximal sonlos factores que afectan a la duración y el éxito de laureteroscopia semirígida. Además, el tamaño de la litiasis y el volumen fueron predictores independientes de latasa libre de litiasis.(AU)

Factors predicting duration and success of semirigid ureteroscopy for ureteral stones in different localizations. / Factores predictores de la duración y éxito de la ureteroscopia semirígida para litiasis ureterales en diferentes localizaciones.

OBJECTIVE: In this study, we aimed to determine the factors predicting the duration and successof semirigid ureteroscopy performed for the treatment of ureteral stones in different localizations. MATERIALS AND METHODS: Medical records of the patients whom under went semirigid ureteroscopy for urolithiasis in our centre between January 2015 and December 2019 were retrospectively reviewed. The study group composed of 170 patients and divided into three subgroups; of which 54 in proximal ureter (31.8%), 51 in the mid (30 %) and 65 (38.2%) in the distal ureter. Predictive factors of semirigid ureteroscopy duration and success were determined by performance of correlation analysis and multivariate analysis. RESULTS: Overall stone-free rate was calculated as 78.8%. Success rates for proximal, mid and distal ureteral stones were 72.2% (39/54 patients), 74.5% (38/51 patients) and 87.7% (57/65 patients), respectively. Complications were present in 19 patients (11.2%). Multivariate analysis indicated that stone diameter and stone burden independently affected the stone-free rate. Statistically significant negative correlation was determined between success of the procedure and stone diameter, stone burden, impaction and more proximal stone localization. While there was a statistically significant positive correlation between duration of procedure and stone burden, diameter, impaction, historyof ipsilateral ureteroscopy and more proximal stone localization, there was negative correlation between duration of procedure and stone-free status. CONCLUSION: We conclude that stone diameter, stone burden, impaction and more proximal stone localization are common factors affecting both duration and success of semirigid ureteroscopy. In addition, stone size and stone burden were determined as independent markers of stone-free status.

OBJETIVO: En este estudio determinamos los factores predictores de la duración y el éxito de la ureteroscopia semirígida realizada como tratamiento de las litiasis ureterales en diferentes localizaciones. MATERIALES Y MÉTODOS: Revisamos retrospectivamente las historias clínicas de los pacientes que han sido sometidos a una ureteroscopia semirígida por litiasis en nuestro centro entre enero 2015 y diciembre 2019. El grupo de estudio está formado por 170 pacientes y dividido en 3 subgrupos: 54 con litiasis en uréter proximal (31,8%) 51 en medio (30%) y 65 (38,2%) en el uréter distal. Los factores predictores de duración y éxito de la ureteroscopia semirígida fueron determinados con análisis de correlación y multivariante. RESULTADOS: La tasa global libre de litiasis fue de 78,8%. La tasa de éxito en uréter proximal, medio y distal fue de 72,2% (39/54 pacientes), 74,5% (38/51pacientes) y 87,7% (57/65 pacientes), respectivamente. Las complicaciones estuvieron presentes en 19 pacientes (11,2%). El análisis multivariante indicó que el diámetro de la litiasis y el volumen afectaron de forma independiente la tasa libre de litiasis. Una significación estadística negativa fue determinada entre el éxito del procedimiento y el diámetro de la litiasis, volumen, impactación y localización proximal. Una significación estadística positiva entre la duración del procedimiento y el volumen de la litiasis, diámetro, impactación, previas ureteroscopias y localización proximal. Se observó una correlación negativa entre la duración del procedimiento y el estado libre de litiasis. CONCLUSIÓN: Concluimos que el diámetro de la litiasis,volumen, impactación y localización proximal son los factores que afectan a la duración y el éxito de la ureteroscopia semirígida. Además, el tamaño de la litiasis y el volumen fueron predictores independientes de la tasa libre de litiasis.

Analysis of risk factors for pulmonary complications in patients undergoing Upper Pole Prone Percutaneous Nephrolithotomy (uPPCNL): A single center experience

INTRODUCTION@#To determine the risk factors contributing to pulmonary complications among patients who undergo upper pole prone percutaneous nephrolithotomy (uPPCNL). This will serve as a guide to urologists who utilize uPPCNL among their patients, so that they may monitor them more closely for these events.@*METHODS@#A retrospective chart review was done on all patients who underwent uPPCNL from January 2015 to December 2017. Patient characteristics (age, gender, BMI, co-morbidity) and stone demographics (Stone size, Guy’s Stone score, laterality, stone location) were summarized as well as intraoperative parameters inclusive of operative time, number of tracts, estimated blood loss, and length of hospital stay. Point biserial correlation and Pearson Chi-square for independent tests were used to identify the independent predictors of pulmonary complications.@*RESULTS@#Nine hundred ninety-two patients underwent uPPCNL during the study period. Fifty-two (5.2%) had pulmonary complications. Sixty-seven pulmonary complications were tallied because some had two complications at one time. The most common was pleural effusion 35(48%), followed by atelectasis in 16(30%), hospital-acquired pneumonia 14(27%) and acute respiratory distress syndrome 2(4%). Forty-one (78.8%) and 11(21.2%) required medical and surgical interventions, respectively. Higher Guy’s stone scores, larger stone size, and longer hospital stay were significant predictors for developing pleural effusion. Patients with higher preoperative serum creatinine and longer hospital stay were significantly associated with surgical management (p < 0.05).@*CONCLUSION@#The incidence of pulmonary complications after uPPCNL is low and only a minority need surgical management. When risk factors are present, these patients need to be monitored closely so that a timely intervention may be done to avoid life-threatening consequences.

Stone growth patterns and risk for surgery among children presenting with hypercalciuria, hypocitraturia and cystinuria as underlying metabolic causes of urolithiasis.

INTRODUCTION: Hypercalciuria, hypocitraturia and cystinuria are the most common underlying metabolic stone abnormalities in children. The present study compared stone growth patterns, stone burden, and the risk of stone-related surgery among these underlying metabolic conditions. METHODS: A retrospective cohort of 356 children with renal stones, followed from 2000 to 2015, was studied. Differences among metabolic groups were determined using Kruskal-Wallis test; the Scheffé-test was used for multiple comparisons to determine differences among single groups. Independent sample t-test was used when adequate, given the sample size, and Chi-squared test was used for categorical variables. Stone growth rates were calculated as differences in diameter divided by time elapsed between U/Ss (mm/year). Logistic regression was performed to assess the effect of initial stone size on the likelihood of surgery. RESULTS: Median stone size at presentation was significantly different among groups, with cystinuria being the group with the largest proportion of stones >10 mm, while patients with stones <5 mm were likely to have a normal metabolic workup (P < 0.05). Stones with a higher growth rate were found in the operative group, while slower growing stones were mostly managed conservatively (3.4 mm/year vs 0.8 mm/year, respectively; P = 0.014). However, stone growth rates were not significantly different among metabolic groups. On the other hand, the rate of new stone formation in cystinuric patients at their first follow-up was 30.4%, which was significantly higher than in patients with hypercalciuria (16.3%) or with a normal metabolic workup (17.2%; P < 0.05). Compared with stones <5 mm, stones measuring 5-10 mm were more than four times more likely to result in surgery, whereas the likelihood of surgery for 10-20 mm or >20 mm stones was almost 16 or 34 times, respectively (P < 0.001). CONCLUSIONS: It is believed that this is the first study to evaluate stone growth patterns, stone burden and surgical risk among children with hypercalciuria, hypocitraturia and cystinuria. Cystinuric patients presented with larger stones at the time of diagnosis, higher new stone formation rates, and were at higher risk of surgery. While no significant difference of growth rate was found among metabolic groups, stones with a higher growth rate were significantly more likely to result in surgical treatment than slower growing stones. Initial stone size, location of largest stone, previous urinary tract infection, and patient's metabolic type significantly influenced the likelihood of a surgical intervention. Better understanding of the natural history ultimately helps surgeons and clinicians defining prognosis, treatment, and prevention plans for pediatric urolithiasis.

Evaluation of CROES Nephrolithometry Nomogram as a Preoperative Predictive System for Percutaneous Nephrolithotomy Outcomes.

PURPOSE: Scoring systems have been devised to predict outcomes of percutaneous nephrolithotomy (PCNL). CROES nephrolithometry nomogram (CNN) is the latest tool devised to predict stone-free rate (SFR). We aim to compare predictive accuracy of CNN against Guy stone score (GSS) for SFR and postoperative outcomes. MATERIALS AND METHODS: Between January 2013 and December 2015, 313 patients undergoing PCNL were analyzed for predictive accuracy of GSS, CNN, and stone burden (SB) for SFR, complications, operation time (OT), and length of hospitalization (LOH). We further stratified patients into risk groups based on CNN and GSS. RESULTS: Mean ± standard deviation (SD) SB was 298.8 ± 235.75 mm2. SB, GSS, and CNN (area under curve [AUC]: 0.662, 0.660, 0.673) were found to be predictors of SFR. However, predictability for complications was not as good (AUC: SB 0.583, GSS 0.554, CNN 0.580). Single implicated calix (Adj. OR 3.644; p = 0.027), absence of staghorn calculus (Adj. OR 3.091; p = 0.044), single stone (Adj. OR 3.855; p = 0.002), and single puncture (Adj. OR 2.309; p = 0.048) significantly predicted SFR on multivariate analysis. Charlson comorbidity index (CCI; p = 0.020) and staghorn calculus (p = 0.002) were independent predictors for complications on linear regression. SB and GSS independently predicted OT on multivariate analysis. SB and complications significantly predicted LOH, while GSS and CNN did not predict LOH. CNN offered better risk stratification for residual stones than GSS. CONCLUSION: CNN and GSS have good preoperative predictive accuracy for SFR. Number of implicated calices may affect SFR, and CCI affects complications. Studies should incorporate these factors in scoring systems and assess if predictability of PCNL outcomes improves.

High prevalence of chronic kidney disease in a semi-urban population of Western India.

BACKGROUND: Globally there is an increase in incidence of chronic kidney diseases (CKDs). Diabetes mellitus (DM), hypertension and stone diseases are the major risk factors for CKD. We organized kidney disease screening camps in a semi-urban population of Gujarat, India on the occasion of World Kidney Day (WKD). METHODS: Voluntary participants from six towns were screened. Estimated glomerular filtration rate (eGFR) was calculated by the Modification of Diet in Renal Disease formula and CKD was defined as an eGFR <60 mL/min/1.73 m(2) or albuminuria ≥1+. Urogenital ultrasonography was performed with emphasis on stone burden. Participants with known diabetes, stone diseases, hypertension, kidney/liver/cardiac disease, hepatitis, HIV, transplant recipients, pregnant women and those <18 years were excluded from the study. RESULTS: Of the 2350 participants (1438 men), CKD was found in 20.93% and eGFR <60 mL/min/1.73 m(2) was noted in 8.29% of participants. The prevalence of CKD peaked after the seventh decade of life in both genders. There was no significant difference in the prevalence of CKD between coastal and non-coastal regions, however, obesity, hypertension and diabetes were more common in the coastal belt, whereas stone burden was greater in the non-coastal region. CONCLUSIONS: The prevalence of CKD in a semi-urban apparently healthy Indian population was higher than the reported prevalence in developed countries. Significant differences between regions point to the need to evaluate and correctregion-specific risk factors.

Do Hypertension, diabetes mellitus and obesity increase the risk of severity of nephrolithiasis?

OBJECTIVE: In this study we planned to investigate the relationship between presence of kidney stones and stone burden with hypertension (HT), diabetes mellitus (DM) and body mass index (BMI). METHODS: A total of 574 patients were included in the study. None of the patients had a history of stones. The 121 patients with kidney stone identified on ultrasound evaluation and the 453 patients with no stones were compared in terms of HT, BMI and DM. The stone burden of 121 patients with diagnosed stones was compared in terms of the same variables. RESULTS: Of the 121 patients with kidney stones 30 (24.7%) had HT, while 66 (14.5%) of the 453 patients without stones had HT (p=0.007). BMI values of those with and without stones were 27.2 ± 4.93 kg/m(2) and 25.29 ± 4.12 kg/m(2), respectively (p<0.001). Twenty-five (20.6%) of the patients with stones diagnosed by ultrasound had DM, while 49 (10.8%) of those without stones had DM (p=0.004). When comparing patients with and without kidney stones, logistic regression analysis revealed that DM (odds ratio [OR] 2.06, 95% confidence interval [CI] 1.17 to 3.63, p=0.013) and BMI (OR 1.08, CI 1.03 to 1.13, p=0.003) were independently associated with presence of stones. No significant relationship was found between the same variables and cumulative stone diameter (CSD) and stone surface area (SA) evaluated for stone burden. CONCLUSIONS: While diabetes mellitus, Hypertension and increased Body Mass Index may add to the possibility of stone formation, they did not affect stone burden.