Prognostic Impact of Stone-Scoring Systems After Percutaneous Nephrolithotomy for Staghorn Calculi: A Single Center's Experience Over 10 Years

Clinical comparison of lateral supine position mini-percutaneous nephrolithotomy and anatrophic nephrolithotomy in the treatment of complete staghorn renal calculi

BACKGROUND

At present, the guidelines for urology recommend percutaneous nephrolithotomy (PCNL) as the preferred treatment for staghorn renal calculi (SRC). However, for complete SRC, it has been questioned by clinicians and patients due to high residual stone rate, complications, repeated hospitalizations and high treatment cost. Anatrophic nephrolithotomy (ANL) is a traditional and classic method for the treatment of SRC. Due to its high trauma and high technical requirements, it is difficult to carry out in primary hospitals, and gradually replaced by PCNL. The purpose of this study is to compare the efficacy of PCNL and ANL in the treatment of complete SRC.

METHODS

Overall, 238 patients with complete SRC were divided into mini-PCNL in lateral supine position group, (n = 190) and ANL group (n = 94) according to treatment for a retrospective cohort study. The calculi parameters, renal function index, comorbidities of calculi, surgical complications, length and frequency of hospitalization, treatment costs, results of postoperative satisfaction survey were compared between the two groups.

RESULTS

The risk of the residual stone rate after mini-PCNL in lateral supine position was 239 times (OR = 238.667, P < 0.0001), the number of residual stone 1.3 times (OR = 1.326, P < 0.0001), the amount of residual stone 2.2 times (OR = 2.224, P < 0.0001) that of ANL. The risk of the cost of initial treatment after mini-PCNL in lateral supine position was 3.3 times (OR = 3.273, P < 0.0001), the total cost of treatment 4 times (OR = 4.051, P < 0.0001), the total length of hospital stays 1.4 times (OR = 1.44, P < 0.0001) that of ANL, the incidence of postoperative renal atrophy was 2.2 times (OR = 2.171, P = 0.008) higher in the ANL than in the mini-PCNL in lateral supine position. Glomerular filtration rate (GFR) reduction after ANL was 1.4 times (OR = 1.381, P = 0.037) greater than that after mini-PCNL in lateral supine position at 24-month follow-up. The risk of the overall satisfaction of ANL was 58 times (OR = 57.857, P < 0.0001) higher than that of mini-PCNL in lateral supine position, the number of branches of staghorn greater than 8 is a high risk factor for the occurrence of residual stone after mini-PCNL in lateral supine position (OR = 353.137, P < 0.0001).

CONCLUSION

Although the risk of renal atrophy and decreased GFR after ANL is higher than that of mini-PCNL in lateral supine position, the efficacy of traditional ANL in the treatment of complete SRC was generally superior to that of mini-PCNL in lateral supine position. Moreover, number of branches of staghorn greater than 8 are the preferred ANL for complete SRC.

TRIAL REGISTRATION

ChiCTR2100047462. The trial was registered in the Chinese Clinical Trial Registry; registration date: 19/06/2021.

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.

Comparison of percutaneous nephrolithotomy and retrograde intrarenal surgery outcomes for kidney stones larger than 2 cm from Guy's stone scoring system perspective

OBJECTIVE

To compare surgical outcomes of percutaneous nephrolithotomy (PNL) and retrograde intrarenal surgeries (RIRS) as a result of kidney stones larger than 2 cm, together with Guy's stone scores (GSS).

MATERIALS AND METHODS

The data of 811 patients with stone sizes 2-6 cm were operated using PNL (n = 361) and RIRS (n = 450) reviewed retrospectively. GSS were graded 1, 2, 3 or 4 according to the computed tomography findings. Stone-free rate (SFR), operation times, length of hospital stay (LOHS) and Clavien complications (CC) were recorded.

RESULTS

Although mean operative times were significantly longer in the RIRS group than the PNL group in GSS grades 1, 2 and 3 (P < .001), it was similar between the two groups in GSS grade 4 (P = .186). SFRs in the PNL and RIRS group were 90.3% and 58.4% on post-operative 10th day (P < .001), and it raised up to 95.3% and 81.6% after secondary interventions (P < .001). Significantly higher SFRs observed in the PNL group in GSS grades 1, 2 and 3 categories. On postoperative 10th day, the SFRs were similar in both GSS grade 4 categories (P = .06). LOHS was longer in the PNL group (P < .001). Although LOHS was significantly longer only in GSS grade 3 (P = .043) and GSS grade 4 (P < .001) in the PNL group, it was similar in GSS grade 1 and 2 between groups. Clavien complications increased in line with GSS in the PNL group (P < .001), but the difference did not differ between GSS grade 3 and 4.

CONCLUSION

SF of PNL in a single session and short operation time seems to be significant especially in GSS grades 1, 2 and 3 category stones. Although the number of patients in the GSS 4 group is very small to claim this, RIRS might be considered as an alternative to PNL in a special group of patients such as GSS grade 4 because of its lower complication rates and shorter LOHS.

Staghorn renal stones: what the urologist needs to know

Patients with staghorn renal stones are challenging cases, requiring careful preoperative evaluation and close follow-up to avoid stone recurrence. In this article we aim to discuss the main topics related to staghorn renal stones with focus on surgical approach. Most of staghorn renal stones are composed of struvite (magnesium ammonium phosphate) and are linked to urinary tract infection by urease-producing pathogens. Preoperative computed tomography scan and careful evaluation of all urine cultures made prior surgery are essential for a well-planning surgical approach and a right antibiotics choice. Gold standard surgical technique is the percutaneous nephrolithotomy (PCNL). In cases of impossible percutaneous renal access, anatrophic nephrolithotomy is an alternative. Shockwave lithotripsy and flexible ureteroscopy are useful tools to treat residual fragments that can be left after treatment of complete staghorn renal stone. PCNL can be performed in supine or prone position according to surgeon's experience. Tranexamic acid can be used to avoid bleeding. To check postoperative stone-free status, computed tomography is the most accurate imaging exam, but ultrasound combined to KUB is an option. Intra-operative high-resolution fluoroscopy and flexible nephroscopy have been described as an alternative for looking at residual fragments and save radiation exposure. The main goals of treatment are stone-free status, infection eradication, and recurrence prevention. Long-term or short-term antibiotic therapy is recommended and regular control imaging exams and urine culture should be done.

Preoperative imaging in staghorn calculi, planning and decision making in management of staghorn calculi

Objective

Staghorn calculi present a particular and challenging entity of stone morphology. Treatment is associated with lower stone-free rates and higher complication rates compared to non-staghorn stones. In this review we looked for the most relevant data on preoperative imaging and access planning to help decision making for percutaneous surgery with this complex condition.

Methods

We conducted a PubMed search of publications in the past 2 decades that include relevant information on the planning for management of staghorn stones. Non-contrast computerized tomography (NCCT) is indeed the standard imaging tool for percutaneous nephrolithotomy (PCNL); additional tools such as three-dimensional computed tomography (CT) reconstruction of the staghorn calculus may help plan access in complex cases. Ultrasound guided percutaneous access may be considered for staghorn stones when planning upper pole access in kidney malposition or complex intrarenal anatomy or with complex body habitus. Wideband doppler ultrasound and real-time virtual sonography can assist. New technologies to improve kidney access such as Uro Dyna-CT or electromagnetic sensor have been reported, but have not shown utilization in staghorn cases. Staghorn morphometry-based prediction algorithms may predict the number of tract(s) and stage(s) for PCNL monotherapy. Lower pole access can be equally effective as upper pole when planning for staghorn and complex stones, with significantly less complications rate; Stone-Tract length-Obstruction-Number of involved calyces-Essence of stone density (STONE) nephrolithometry seems to be the best system to predict outcomes of PCNL in staghorn cases. There is a growing trend of endoscopic combined intrarenal surgery (ECIRS) in concordance with PCNL to treat larger stones. Conservative management of staghorn calculi is an undesired option, but can be an alternative for a carefully selected group of high-risk patients.

Conclusion

Staghorn stones may lead to deterioration of renal function and life-threatening urosepsis. This entity should be managed aggressively with planning ahead for surgery using the different tools available as the cornerstone for a successful outcome.

Morphometry scores: Clinical implications in the management of staghorn calculi

Due to their large size, rapid growth, and attendant morbidity, staghorn calculi are complex clinical entities that impose significant treatment-related challenges. Moreover, their relative heterogeneity-in terms of both total stone burden and anatomic distribution-limits the ability to standardize their characterization and the reporting of surgical outcomes. Several morphometry systems currently exist to define the volumetric distribution of renal stones, in general, and to predict the outcomes of percutaneous nephrolithotomy; however, they fall short in their applicability to staghorn stones. In this review, we aim to discuss the clinical utility of morphometry systems and the influence of pelvicalyceal anatomy on the management of these complex calculi.

Predicting the Postoperative Outcome of Percutaneous Nephrolithotomy with Machine Learning System: Software Validation and Comparative Analysis with Guy's Stone Score and the CROES Nomogram

Purpose: To validate the output of a machine learning-based software as an intelligible interface for predicting multiple outcomes after percutaneous nephrolithotomy (PCNL). We compared the performance of this system with Guy's stone score (GSS) and the Clinical Research Office of Endourological Society (CROES) nomogram. Patients and Methods: Data from 146 adult patients (87 males, 59%) who underwent PCNL at our institute were used. To validate the system, accuracy of the software for predicting each postoperative outcome was compared with the actual outcome. Similarly, preoperative data were analyzed with GSS and CROES nomograms to determine stone-free status as predicted by these nomograms. A receiver operating characteristic (ROC) curve was generated for each scoring system, and the area under the ROC curve (AUC) was calculated and used to assess the predictive performance of all three models. Results: Overall stone-free rate was 72.6% (106/146). Forty of 146 patients (27.4%) were scheduled for 42 ancillary procedures (extracorporeal shockwave lithotripsy [SWL] [n = 31] or repeat PCNL [n = 11]) to manage residual renal stones. Overall, the machine learning system predicted the PCNL outcomes with an accuracy ranging between 80% and 95.1%. For predicting the stone-free status, the AUC for the software (0.915) was significantly larger than the AUC for GSS (0.615) or CROES nomograms (0.621) (p < 0.001). Conclusion: At the internal institutional level, the machine learning-based software was a promising tool for recording, processing, and predicting outcomes after PCNL. Validation of this system against an external dataset is highly recommended before its widespread application.

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.

Mortality from kidney stone disease (KSD) as reported in the literature over the last two decades: a systematic review

INTRODUCTION

Current trends show a rising incidence of kidney stone disease (KSD) globally, with a lifetime risk of 10% and increasing hospital admissions. However, it is not perceived as a life-threatening condition and there are no publications examining its mortality rate. The aim of this review was to report on the number of KSD mortalities in the literature from the past two decades, identify risk factors, and to summarize their key learning points.

METHODS

A search was conducted for full-text English language articles that reported on KSD associated mortality, following intervention or conservative treatment, published between 1999 and 2017, using PubMed, MEDLINE, EMBASE, Scopus, CINAHL, Clinicaltrials.gov, Google Scholar and The Cochrane Library. Study quality and risk of bias assessment was undertaken using a validated critical appraisal tool from the Joanna Briggs Institute.

RESULTS

Of the 2786 articles identified, 34 were included. Of the total number of reported mortalities (2550), 21% were related to intervention. Sepsis was the leading cause of mortality. Risk factors identified were patients with multiple co-morbidities, spinal cord injury or neurogenic bladder and high stone burden. The main recommendations suggested were to treat pre-operative UTI or use prophylactic antibiotics and to reduce operative duration. The included studies were of moderate to good quality.

CONCLUSION

Pre-procedural optimization of the patients is the key to avoiding KSD mortality, and care should be taken in patients with multiple co-morbidities. Surgeons should meticulously plan for patients with high stone burden to reduce their operative time, as mortality can be procedural related.

Predictability and Practicality of Image-Based Scoring Systems for Patient Assessment and Outcome Stratification During Percutaneous Nephrolithotomy: a Contemporary Update

Preoperative nomograms offer systematic and quantitative methods to assess patient- and stone-related characteristics and their impact on successful treatment and potential risk of complication. Discrepancies in the correlation of perioperative variables to patient outcomes have led to the individual development, validation, and application of four independent scoring systems for the percutaneous nephrolithotomy: Guy's stone score, S.T.O.N.E. nephrolithometry, Clinical Research Office of the Endourology Society nomogram, and Seoul National University Renal Stone Complexity. The optimal nomogram should have high predictive ability, be practically integrated into clinical use, and be widely applicable to urinary stone disease. Herein, we seek to provide a contemporary evaluation of the advantages, disadvantages, and commonalities of each scoring system. While the current data is insufficient to conclude which scoring system is destined to become the gold standard, it is crucial that a nephrolithometric scoring system be incorporated into common practice to improve surgical planning, patient counseling, and outcome assessment.

External validation and comparison of the scoring systems (S.T.O.N.E, GUY, CROES, S-ReSC) for predicting percutaneous nephrolithotomy outcomes for staghorn stones: A single center experience with 160 cases

The aim of this study was validation and comparison of stone scoring systems (S.T.O.N.E, GUY, CROES, S-ReSC) used to predict postoperative stone-free status and complications after percutaneous nephrolithotomy (PCNL) for staghorn stones. A total of 160 patients who had staghorn renal stones and underwent PCNL between January 2012 and August 2015 were included in the current retrospective study. Guy, S.T.O.N.E., S-ReSC (Seoul National University Renal Stone Complexity) and CROES (Clinical Research Office of the Endourological Society) nephrolithometry scores were calculated for each patient, and their potential association with stone-free status, operative and fluoroscopy time, and length of hospital stay (LOS) were evaluated. Postoperative complications were graded according to the modified Clavien classification, and the correlation of scoring systems with postoperative complications was also investigated. The mean CROES, S.T.O.N.E, Guy and S-ReSC scores were 143.5 ± 33.6, 9.7 ± 1.6, 3.5 ± 0.5 and 6.2 ± 2.0 respectively. The overall stone-free rate was 59%. All scoring systems were significantly correlated with stone-free status in univariate analysis. However, Guy and S-ReSC scores were the only significant independent predictor in multivariate analysis. And all four nomograms failed to predict complication rates. Current study demonstrated that Guy and S-ReSC scoring systems could effectively predict postoperative stone-free status for staghorn stones. However all four scoring systems failed to predict complication rates.

A prospective randomized comparison among SWL, PCNL and RIRS for lower calyceal stones less than 2 cm: a multicenter experience : A better understanding on the treatment options for lower pole stones

PURPOSE

To prospectively evaluate the efficacy and safety of RIRS, SWL and PCNL for lower calyceal stones sized 1-2 cm.

MATERIALS AND METHODS

Patients with a single lower calyceal stone with an evidence of a CT diameter between 1 and 2 cm were enrolled in this multicenter, randomized, unblinded, clinical trial study. Patients were randomized into three groups: group A: SWL (194 pts); group B: RIRS (207 pts); group C: PCNL (181 pts). Patients were evaluated with KUB radiography (US for uric acid stones) at day 10 and a CT scan after 3 months. The CONSORT 2010 statement was adhered to where possible. The collected data were analyzed.

RESULTS

The mean stone size was 13.78 mm in group A, 14.82 mm in group B and 15.23 mm in group C (p = 0.34). Group C compared to group B showed longer operative time [72.3 vs. 55.8 min (p = 0.082)], fluoroscopic time [175.6 vs. 31.8 min (p = 0.004)] and hospital stay [3.7 vs. 1.3 days (p = 0.039)]. The overall stone-free rate (SFR) was 61.8% for group A, 82.1% for group B and 87.3% for group C. The re-treatment rate was significantly higher in group A compared to the other two groups, 61.3% (p < 0.05). The auxiliary procedure rate was comparable for groups A and B and lower for group C (p < 0.05). The complication rate was 6.7, 14.5 and 19.3% for groups A, B and C, respectively.

CONCLUSIONS

RIRS and PCNL were more effective than SWL to obtain a better SFR and less auxiliary and re-treatment rate in single lower calyceal stone with a CT diameter between 1 and 2 cm. RIRS compared to PCNL offers the best outcome in terms of procedure length, radiation exposure and hospital stay. ISRCTN 55546280.

Comparison of Guy’s vs S.T.O.N.E. nephrolithometry scoring systems in predicting the success rate of PCNL

Introduction and objective:

The aim of the present study was to compare the accuracy of the Guy’s and S.T.O.N.E. scoring systems in predicting percutaneous nephrolithotomy (PCNL) outcomes.

Methods:

This prospective study was carried out in the Department of Urology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, between August 2013 and September 2015 in collaboration with the Department of Radiodiagnosis and Imaging. A total of 100 cases of renal calculi operated on with PCNL were considered in the study on the basis of CT morphodensitometry. The study was approved by the institute’s ethical committee. Guy’s and S.T.O.N.E. scoring systems were calculated. Regression analysis and ROC curves were performed.

Results:

A total of 100 PCNLs were operated on. The overall stone-free rate was 90% with a complication rate of 17%. When compared to patients with residual fragments, stone-free patients had significantly lower Guy’s grade (3.5 vs 2; p < 0.001) and S.T.O.N.E. score (9.1 vs 7.5; p = 0.023). Logistic regression analysis showed that both Guy’s and S.T.O.N.E. systems were significantly associated with stone-free status, OR 0.96 ( p < 0.001) and OR 0.94 ( p < 0.001), respectively. Furthermore, both scoring systems were significantly associated with estimated blood loss ( p = 0.02 and p = 0.004). There was good correlation between both scoring systems and operative time ( r = 0.2, p < 0.002 and r = 0.3, p < 0.002) and length of hospital stay ( r = 0.1, p = 0.002 and r = 0.2, p < 0.002). There were significant associations between both scoring systems and complications ( p < 0.001 and p = 0.004). There was no significant difference in the areas under the curves for the Guy’s and S.T.O.N.E. scoring systems (0.96 (95% CI 0.92–0.99) vs 0.94 (95% CI 0.89–1.001); p < 0.001).

Conclusion:

Both Guy’s and S.T.O.N.E scoring systems have comparable accuracies in predicting post-PCNL stone-free status. Other factors not included in either scoring system may need to be incorporated in the future to increase their accuracy.