Comparison of S.T.O.N.E and CROES nephrolithometry scoring systems for predicting stone-free status and complication rates after percutaneous nephrolithotomy: a single center study with 262 cases

Does success in percutaneous nephrolithotomy depend only on stone size? Analysis of the predictive capacity for success and complications of the current nephrolithometry scoring systems and their relationship with the stone surface

OBJECTIVE

To analyze the predictive capacity of the nephrolithometry scoring systems (GSS, STONE, CROES and S-ReSC) and stone surface regarding success and complications following percutaneous nephrolithotomy (PCNL).

METHODS

We studied 392 patients who had undergone PCNL in our center. Only patients with a non-contrast CT (n = 240) were finally included for analysis. The predictive capacities for success and complications of the different scoring systems were evaluated using ROC curves and their area under the curve (AUC).

RESULTS

Regarding success, the S-ReSC system had the highest predictive capacity with an AUC of 0.681 (95% CI 0.610-0.751), followed by the CROES with 0.667 (95% CI 0.595-0.738), the STONE with 0.654 (95% CI 0.579-0.728) and finally the GSS with 0.626 (95% CI 0.555-0.698). The stone surface as a single variable had an AUC of 0.641 (95% CI 0.565-0.718). As for complications, the S-ReSC had the highest AUC with 0.664 (95% CI 0.57-0.758), followed by STONE with 0.663 (95% CI 0.572-0.755), GSS with 0.626 (95% CI 0.555).-0.698) and CROES with 0.614 (95% CI 0.518-0.7). The stone surface alone had an AUC of 0.616 (95% CI 0.522-0.715).

CONCLUSION

The nephrolithometry scales analyzed show a moderate predictive capacity for success and complications in patients undergoing PCNL in our center. Moreover, stone surface as an independent variable demonstrates moderate predictive capacity for both outcomes.

Prediction of percutaneous nephrolithotomy outcomes and flexible ureteroscopy outcomes using nephrolithometry scoring systems

BACKGROUND

Kidney stones account for a high proportion of urological emergencies. The main objective of this paper is to evaluate the predictive ability of five scoring systems for overall stone-free status and postoperative complications after percutaneous nephrolithotomy and retrograde ureteroscopy.

MATERIALS AND METHODS

This study retrospectively analysed 312 cases of kidney stone patients between January 2021 and May 2022 at our centre. Multivariate logistic regression as well as ROC curves were applied to determine the ability to evaluate each scale to predict stone-free rates and postoperative complications.

RESULTS

179 patients have undergone PCNL. After multivariate logistic regression, the S.T.O.N.E score and history of ipsilateral renal surgery were predictive of stone-free status, and the predictive power of the S.T.O.N.E score was higher than that of history of ipsilateral renal surgery. Grade 1 complications were considered to be related to Guy's score and grade 2 complications were considered to be related to history of diabetes mellitus. 133 patients have undergone f-URS. After multivariate logistic regression analysis, the modified S-ReSC score, RUSS score, and R.I.R.S score were predictive of stone-free status, with the R.I.R.S score being the strongest predictor. Evidence of grade 2 complications was considered to be related to abnormal renal function.

CONCLUSION

For PCNL, the S.T.O.N.E score had the best efficacy in predicting stone-free status, and the Guy's score had the best efficacy in predicting postoperative complications; for f-URS, the R.I.R.S score had the best efficacy in predicting stone-free status, and no scoring system predicted postoperative complications.

Comparison of STONE Score, Guy's Stone Score, CROES Nomogram, and Seoul National University Renal Stone Complexity Score in Prognosticating Outcomes of Multiple-Tract Mini-Percutaneous Nephrolithotomy: A Retrospective Study

Objective  The objective of this study was to compare the STONE score (Size of the stone, Topography or location, degree of Obstruction of the urinary system, Number of stones, and Evaluation of Hounsfield units), Guy's stone score (GSS), Clinical Research Office of the Endourological Society (CROES) nomogram, and Seoul National University Renal Stone Complexity Score (RSCS) in prognosticating multiple tract mini-percutaneous nephrolithotomy (mPCNL) outcome. Methodology This descriptive retrospective analysis was carried out at the Urology Department, Lady Reading Hospital, Peshawar, Pakistan. Male and female patients in the age range of 18-70 years who underwent multiple tract mPCNL for renal stones from July 1, 2021, to June 30, 2023, were included in the analysis. Results  A total of 110 patients were registered. Stone-free status (SFS) was achieved in 78.2% (n=86), and complications were observed in 13.6% (n=15) patients. The odds ratio for STONE score, GSS, CROES scoring system, and RSCS for predicting the SFS was 7.093 (95%CI 2.40-20.89), 9.333 (95%CI 2.92-29.81), 11.70 (95%CI 2.56-53.38) and 3.450 (95%CI 1.25-9.53), respectively. Conclusion  Multiple tract mPCNL is a safe and effective technique for the management of renal stones, producing a high stone-free rate. This study demonstrated adequate efficacy and dependability of the four scoring systems in predicting SFS.

Stone-scoring systems for predicting complications in percutaneous nephrolithotomy: A systematic review of the literature

Objective

Percutaneous nephrolithotomy is a treatment of choice for larger stones of the upper urinary tract. Currently, several nephrolithometric nomograms for prediction of post-operative surgical outcomes have been proposed, although uncertainties still exist regarding their roles in the estimation of complications.

Methods

We conducted a systematic review on PubMed and Web of Sciences databases including English studies with at least 100 cases and published between January 2010 and December 2021. We identified original articles evaluating correlations between the Guy's stone score, the stone size (S), tract length (T), obstruction (O), number of involved calices (N), and essence or stone density (E) (S.T.O.N.E.), Clinical Research Office of the Endourological Society (CROES), and Seoul National University Renal Stone Complexity (S-ReSC) scores and post-operative complications in adult patients. We also included newly designed nomograms for prediction of specific complications.

Results

After an initial search of 549 abstracts, we finally included a total of 18 papers. Of them, 11 investigated traditional nephrolithometric nomograms, while seven newly designed nomograms were used to predict specific complications. Overall, 7316 patients have been involved. In total, 14 out of 18 papers are derived from retrospective single-center studies. Guy's stone score obtained correlation with complications in five, S.T.O.N.E. nephrolithometry score in four, while CROES score and S-ReSC score in three and two, respectively. None of the studies investigated minimally invasive percutaneous nephrolithotomy (PCNL) and all cases have been conducted in prone position. Considering newly designed nomograms, none of them is currently externally validated; five of them predict post-operative infections; the remaining two have been designed for thromboembolic events and urinary leakage.

Conclusion

This review presents all nomograms currently available in the PCNL field and highlights a certain number of concerns. Published data have appeared contradictory; more recent tools for prediction of post-operative complications are frequently based on small retrospective cohorts and lack external validations. Heterogeneity among studies has also been noticed. More rigorous validations are advisable in the future, involving larger prospective patients' series and with the comparison of different tools.

The Correlation Between STONE Nephrolithometry Score and Hemoglobin Drop in Patients Undergoing Percutaneous Nephrolithotomy

Objective

In this study, we aimed to determine the correlation between the STONE score [(S)ize of the stone, (T)opography or location, degree of (O)bstruction of the urinary system, (N)umber of stones, and (E)valuation of Hounsfield units] and postoperative hemoglobin drop in patients undergoing percutaneous nephrolithotomy (PCNL).

Methods

This was a prospective observational study and all adult patients aged 18-65 years undergoing unilateral, single-tract PCNL using 26 Ch. Amplatz sheath for renal calculi were included. The five variables of the STONE nephrolithometry score were calculated prior to the procedure. The stone-free rates were assessed on imaging at four weeks and complications were graded using the modified Clavien system.

Results

Of the 142 patients included, 75% were below 55 years of age. More than half of our patients were diabetic with more than 60% having a body mass index (BMI) above 25 kg/m². The mean STONE score was 7 with 33% having a high (>9) STONE score. The mean hemoglobin drop was 1.15 +0.92 g/dL with eight patients (5.63%) requiring transfusion and one (0.7%) requiring angioembolization; one patient required readmission for observation. Complete STONE clearance was achieved with PCNL alone in 78.2% of the patients. There was a significant correlation of hemoglobin drop with the STONE score, stone size, and preoperative creatinine clearance. Patients with a hemoglobin drop of >1 g/dL had a higher STONE score and mean stone size. The overall complication rate was significantly higher (10.5%) in patients with a hemoglobin drop of >1 g/dL as compared to those with a hemoglobin drop of <1 g/dL (2.8%).

Conclusion

Stone complexity as measured by the STONE score correlates with post-PCNL hemoglobin drop, stone clearance, and complication rates. The STONE score may be used for preoperative counseling and to evaluate the potential need for transfusion.

Study on risk factors, bacterial species, and drug resistance of acute pyelonephritis associated with ureteral stent after percutaneous nephrolithotomy

The purpose of this study is to explore the risk factors, bacterial species, and drug resistance of acute pyelonephritis (AP) associated with ureteral stent after percutaneous nephrolithotomy (PCNL) and to provide reference for clinical intervention. The clinical data of 415 patients with indwelling ureteral stent after PCNL from December 2016 to May 2019 were analyzed retrospectively. The patients were divided into infection group (n = 54) and non-infection group (n = 361) according to whether patients had AP. Patients' clinical data, blood and urine bacterial culture, and drug sensitivity were collected and analyzed. The incidence of AP associated with ureteral stent after PCNL was 13.01% and diabetes mellitus (P = 0.001), postoperative stone residue (P = 0.002), urinary leucocytes ≥ 100/HP (P = 0.018), positive urine culture results (P = 0.001), ureteral stent retention time ≥ 8 weeks (P = 0.004), and high S.T.O.N.E. score (P = 0.014) are independent risk factors for it. Escherichia coli (40.54%, 47.82%), Klebsiella pneumoniae (16.21%, 15.21%), Pseudomonas aeruginosa (10.81%, 4.34%), Enterococcus faecalis (21.6%, 19.56%), and epidermis Staphylococci (10.81%, 13.33%) are the main pathogens in blood and urine. The main sensitive drugs of pathogenic bacteria are imipenem, meropenem, tigecycline, piperacillin/tazobactam, ceftazidime, linezolid, teicoplanin, levofloxacin, vancomycin, tigecycline, etc., while levofloxacin, norfloxacin, penicillin G, first, and second-generation cephalosporins showed a strong drug resistance rate (> 70%). This study found that diabetes, postoperative stone residuals, urinary leukocytes ≧ 100 cells/HP, positive urine culture results, ureteral stent indwelling time ≧ 8 weeks, and high S.T.O.N.E. score were independent of AP associated with ureteral stent after PCNL risk factors and Escherichia coli is the main pathogenic bacteria and shows drug resistance.

Preoperative risk factors for complications of percutaneous nephrolithotomy

This study was conducted to evaluate preoperative risk factors for development of complications of percutaneous nephrolithotomy (PCNL). All consecutive patients aged ≥ 16 years who underwent PCNL during 2015 were retrospectively reviewed. Non-contrast CT (NCCT) was performed for all patients to evaluate stone complexity. The technique of PCNL was the same for all patients. Intra-operative and postoperative complications were recorded and classified based on modified Clavien system. The differences in preoperative data (patients, renal and stone characteristics including Guy's and STONE scores) between complicated and uncomplicated cases were compared using univariate and multivariate statistical analyses for detection of independent risk factors. The study included 1178 patients (61% were males). Mean age was 50 ± 12 years, and mean BMI was 30.7 ± 5.7 kg/m². Complicated group included 166 patients (14.1%). Independent risk factors on multivariate analysis were infected preoperative urine culture (RR: 2.098, P 0.001, 95%CI: 1.380-3.189), largest stones diameter 30 mm or more (RR: 2.481, P > 0.001, 95%CI: 1.697-3.627) and number of calyces affected by the stones (RR: 2.431, P 0.002, 95%CI: 1.400-4.222 for affection of two calyces and RR: 2.778, P 0.005, 95%CI: 1.357-5.684 for affection of three calyces). While two scoring systems (Guy's and STONE) were not predictive of complications after PCNL, preoperative risk factors were infected preoperative urine culture, distribution of the stones or stone branches in two or three calyceal groups and stone size 30 mm or more.

Guy's Stone Score as a Predictor for Stone-Free Rate and Complications in Percutaneous Nephrolithotomy: A Single-Center Report from a Stone Belt Country

OBJECTIVES

To evaluate Guy's Stone Score (GSS) as a grading system for the complexity of renal calculi before percutaneous nephrolithotomy (PCNL) and as a predictor for stone-free rate (SFR) and potential complications in the setting of a developing country with many cases of advanced complex stone disease.

PATIENTS AND METHODS

We performed a prospective study on 115 patients with renal stones who had PCNL between August 2017 and October 2018. Stone complexity was classified according to GSS using preoperative imaging. The rates of perioperative complications were assessed using the Clavien grading system, and the SFR was assessed in the 3rd postoperative week by abdominal X-ray and renal ultrasound. The χ2 and one-way ANOVA tests were used for statistical analysis. A p value ≤0.05 was considered significant.

RESULTS

The study included 115 patients (77 males) with a mean age of 50.2 (±13.3) years. Cases were classified according to GSS into 4 grades; there were 24 (20.9%) grade I, 48 (41.7%) grade II, 25 (21.7%) grade III, and 18 (15.7%) grade IV cases. There was a significant inverse correlation between GSS grade and SFR (p < 0.001). The rate of complications using the Clavien grading system were significantly higher in GSS grades III and IV (p = 0.002). So were the rates of blood transfusion, the need for >1 access tract, and the duration of hospitalization.

CONCLUSION

GSS is a simple and easily reproducible system to classify the complexity of renal stones. In our setting, it also proved an excellent tool to predict SFR, perioperative complications, and associated ancillary procedures. Ultimately, it can help surgeons and, above all, patients to make a more informed decision about their surgery.

The Impact of Stone Multiplicity on Surgical Decisions for Patients with Large Stone Burden: Results from ReSKU

Introduction: American Urological Association (AUA) guidelines recommend percutaneous nephrolithotomy (PCNL) for total stone burden greater than 20 mm, yet it is unclear if the number of stones affects adherence to this guideline. We aim to assess the impact of stone multiplicity on the choice of ureteroscopy (URS) vs PCNL as a first-line therapy for patients with high burden (>20 mm), and examine whether the AUA guideline-discordant care impacts patient outcomes. Materials and Methods: Data were collected from the Registry for Stones of the Kidney and Ureter (ReSKU) database, a prospectively collected registry of patients with stone disease. Multivariate logistic regression (MLR) was used to estimate the association between stone multiplicity and the decision to perform URS for high stone burden (>20 mm) patients. MLR was further used to estimate the association between performing URS and the following outcomes: stone-free rate, need for a second operation, and complications. Postoperative hospital stay was compared between patients receiving URS vs PCNL using Student's t-test. Results: One hundred twenty-five patients were included in this analysis. For patients with total stone burden exceeding 20 mm, those with more than three stones had roughly nine times the likelihood of undergoing URS over PCNL compared with patients with a single stone (adjusted odds ratio 9.21, confidence interval [95% CI] 2.55-40.58, p = 0.001). Stone-free rates, Clavien-Dindo scores, and frequency of second-look operations did not differ significantly between URS and PCNL patients. URS patients were discharged an average of 1.26 days earlier than patients who received PCNL (95% CI 0.72-1.81, p < 0.001). Discussion: Stone multiplicity strongly predicts which patients with stone burden >20 mm will undergo URS and who will undergo PCNL. These deviations from AUA guidelines do not appear to worsen patient outcomes. These results suggest that careful consideration of each patient may warrant deviation from guidelines.

Evaluation of three stone-scoring systems for predicting SFR and complications after percutaneous nephrolithotomy: a systematic review and meta-analysis

Background

Clinical studies assessing the feasibility and accuracy of three stone scoring systems’s (SSSs: Guy’s stone score, CROES nomogram and S.T.O.N.E nephrolithometry scoring system) have reported contradictory outcomes. This systematic evaluation was performed to obtain comprehensive evidence with regard to the feasibility and accuracy of three SSSs.

Methods

A systematic search of Embase, Pubmed, Medline, and the Cochrane Library was conducted to identify studies that compared three SSSs up to Mar 2018. Patients were categorized according to stone free (SF) and no-stone free (NSF), Outcomes of interest included perioperative variables, stone-free rate (SFR), and complications.

Results

Ten studies estimating three SSSs were included for meta-analysis. The results showed that SF patients had a significantly lower proportion of male (OR = 1.48, P = 0.0007), lower stone burden (WMD = -504.28, P < 0.0001), fewer No of involved calyces (OR = -1.23, P = 0.0007) and lower proportion of staghorn stone (OR = 0.33, P < 0.0001). Moreover, SF patients had significantly lower score of Guy score (WMD = -0.64, P < 0.0001), but, S.T.O.N.E. score (WMD = -1.23, P < 0.0001) and a higher score of CROES nomogram (WMD = 29.48, P = 0.003). However, the comparison of area under curves (AUC) of predicting SFR indicated that there was no remarkable difference between three SSSs. Nonetheless, Guy score was the only stone scoring system that predicted complications after PCNL (WMD = -0.29, 95% CI: − 0.57 to − 0.02, P = 0.03).

Conclusions

Our meta-analysis indicated that the three SSSs were equally, feasible and accurate for predicting SFR after PCNL. However, Guy score was the only stone scoring system that predicted complications after PCNL.

Electronic supplementary material

The online version of this article (10.1186/s12894-019-0488-y) contains supplementary material, which is available to authorized users.

Subcostal artery bleeding after percutaneous nephrolithotomy: a case report and literature review

Postoperative bleeding is a dangerous complication after percutaneous nephrolithotomy (PCNL). Pseudoaneurysm, arteriovenous fistula, and arterial laceration are the three most common causes of post-PCNL bleeding. Subcostal artery bleeding is a rare cause. We herein present a clinical case involving a 43-year-old man who presented with right renal complex calculi and was managed by PCNL in the prone position using an inferior calyceal puncture approach. Intermittent extreme bleeding occurred 1 day postoperatively, and immediate renal angiography was performed. However, we found no sign of a pseudoaneurysm, arteriovenous fistula, or arterial laceration. Another well-trained and experienced doctor also found no pseudoaneurysm, arteriovenous fistula, or arterial laceration. After adjusting the catheter position, subcostal artery bleeding finally appeared and was successfully controlled by coils. This finding indicates that subcostal artery damage is one cause of post-PCNL bleeding. We suggest that clinicians should carefully and patiently perform angiography and/or embolization to avoid misdiagnosis and mistreatment.

Comparison of STONE, CROES and Guy's nephrolithometry scoring systems for predicting stone-free status and complication rates after percutaneous nephrolithotomy in obese patients

In this study, we aim to evaluate the accuracy of STONE (stone size, tract length, obstruction, number of involved calyces, and essence/stone density), Clinical Research Office of the Endourological Society (CROES), and Guy's nephrolithometry scoring systems (NSS) in obese patients. The charts of patients who underwent percutaneous nephrolithotomy (PNL) between June 2008 and June 2016 were retrospectively analyzed. Calculations of the STONE, CROES, and Guy's NSS were performed by a resident who was well informed regarding each NSS. Patients were classified under nine scores according to STONE, four grades according to CROES, and four grades according to Guy's NSS. In total, 248 obese patients were enrolled in the study. Stone size was significantly higher in patients without stone-free status (p = 0.001). In patients who were stone-free and those with residual stones, the mean STONE score was 9.71 and 9.23 (p = 0.160), CROES was 172 and 129 (p = 0.001), and Guy's NSS was 1.67 and 2.75 (p = 0.001). Multivariate regression analysis identified the CROES and Guy's NSS were independent factors for PNL success in obese patients (p = 0.01 and p = 0.01, respectively). The CROES and Guy's NSS showed good accuracy with PNL success (AUC = 0.777 and AUC = 0.844, respectively). None of the three NSS systems were statically associated with a complication rate (p = 0.23 for STONE, p = 0.14 for CROES, and p = 0.51 for Guy's NSS). Our study demonstrated that CROES and Guy's NSS were independent predictors of stone-free rate following PNL in obese patients. Our study also revealed that three of the NSSs were not useful for predicting PNL complications in obese patients.

Comparison of CROES, S.T.O.N.E, and Guy's scoring systems for the prediction of stone-free status and complication rates following percutaneous nephrolithotomy in patients with chronic kidney disease

PURPOSE

To evaluate and compare the accuracy of S.T.O.N.E, Clinical Research Office of the Endourological Society (CROES), and Guy's stone score in patients with chronic kidney disease (CKD) following percutaneous nephrolithotomy (PNL).

METHODS

The charts of patients who had undergone a prone percutaneous nephrolithotomy from June 2006 to June 2016 were retrospectively analyzed. Patients accepted as stage 3 and higher according to chronic kidney disease epidemiology collaboration formula, were enrolled into the study. Calculation of the CROES, S.T.O.N.E, and Guy's scoring system (SS) was made as defined in original papers. Patients were categorized into four scores according to CROES, into nine scores according to S.T.O.N.E, and into four scores according to Guy's SS.

RESULTS

A total of 303 patients fulfilled the study inclusion criteria. The mean preoperative eGFR and creatinine levels were 47 mL/min and 1.55 mg/dL, respectively. In patients who were stone free and those with residual stones, the mean CROES SS was 179 and 137 (p < 0.001), the mean S.T.O.N.E score was 8.8 and 9.9 (p < 0.001), and the mean Guy's SS was 1.8 and 2.4 (p < 0.001), respectively. Multivariate regression analysis revealed CROES SS was the only scoring system, which had a predictive value for PNL outcome in patients with CKD (p = 0.011) and any of three SS were not useful for predicting PNL complications in patients with CKD.

CONCLUSION

Our study demonstrated the CROES SS was the only independent factor in the prediction of PNL outcome in CKD patients. Furthermore, three of the NSSs were not useful for predicting PNL complications in patients with CKD.