Nephrolithometry Scoring System Research Articles

A comparison of S.T.O.N.E nephrolithometry scoring system, Guy's stone score, and Seoul National University Renal Stone Complexity (S-ReSC) in predicting mini-PCNL stone-free rate.

The main goal of the study is to evaluate the three stone scoring systems (S.T.O.N.E nephrolithometry scoring system (STONE), Guy's stone score (GSS) and Seoul National University Renal Stone Complexity (S-ReSC)) for the stone-free rate (SFR) of mini-PCNL. We retrospectively analyzed 72 patients who received mini-PCNL from February 2018 to October 2020. The SFR, complication rates, hospitalization days and recurrence rates were analyzed using three stone scoring systems. The result showed statistical significance in the association between scoring system and stone-free (STONE: OR 95%CI 0.409 (0.221-0.759), p = 0.0045; S-ReSC OR 95%CI 0.633 (0.401-0.999), p = 0.0497), but not GSS (OR 95%CI 0.776 (0.397-1.516), p = 0.4581). After adjusting the potential confounding factors, the area under curve (AUC) of STONE, GSS, and S-ReSC was 0.86, 0.78, and 0.81, respectively, and Akaike information criterion (AIC) of STONE, GSS, and S-ReSC was 64.65, 74.89, and 69.92, respectively. The accuracy rate of STONE, GSS, and S-ReSC was 0.81, 0.75, and 0.79, respectively. There was no statistically difference of predicting stone recurrence (p = 0.46, 0.53, 0.86), complications (p = 0.74, 0.51, 0.16) and hospitalization days (p = 0.77, 0.86, 0.87) in STONE, GSS, and S-ReSC, respectively. In conclusion, both the STONE and S-ReSC stone scoring systems are viable for predicting the SFR following mini-PCNL, especially after variable adjustment with the STONE system demonstrating superiority over S-ReSC.

Evaluation of the STONE nephrolithometry score in predicting surgical outcomes of percutaneous nephrolithotomy: results of a prospective study at a university hospital

Objective: One of the popular advances in percutaneous nephrolithotomy (PCNL) includes nephrolithometry classification systems. It enables better patient counseling, surgery planning, outcome evaluation, and uniform academic reporting. The STONE nephrolithometry is a validated quantitative scoring system that is undervalued in clinical settings, and this study evaluates the scoring system's ability to predict the outcome of PCNL surgery. Methodology: From January 2017 to June 2018, a total of 102 PCNL patients were studied prospectively. The STONE score was derived from a preoperative non-contrast computed tomography (NCCT) scan which was used to evaluate stone-free status at 4 weeks followup. Results: The STONE nephrolithometry scoring system predicted stone-free rate (SFR) following PCNL surgery with an accuracy of 88%. The statistical cut off level of the STONE score of 8 was superior for predicting SFR. Individual variables such as stone size, degree of pelvicalyceal obstruction, number of calyceal involvement, and stone density were found to have a significant correlation with STONE score, although there was no statistically significant correlation between SFR and tract length (p=0.81). The score was divided into three categories: low complexity score 5-6 (SFR-58.7%), moderate complexity score 7-8 (SFR-40%), and high complexity score 9-13 (SFR- 1.2%). The STONE score had excellent inter-observer reliability and reproducibility (p=<0.001). Conclusions: The STONE score was a simple and easy to apply tool for predicting the stone complexity and stone clearance after PCNL. The STONE score had no statistically significant correlation with postoperative complications. Furthermore, it demonstrated high inter-observer reliability and reproducibility.

Correlation of the S.T.O.N.E. Score with surgical outcomes of Percutaneous Nephrolithotomy in an academic hospital

Introduction: Percutaneous nephrolithotomy (PCNL) is the best option for the treatment of patients with large kidney stones. The S.T.O.N.E score system takes measurements of objective parameters from preoperative tomography into account, and aims to provide the surgical team with a preliminary assessment of the complexity of each case, allowing the surgeon to more accurately predict the final results of PCNL. However, adequate studies that confirm its results and effectiveness are so far lacking. Hence, our objective was to correlate the S.T.O.N.E. nephrolithometry scoring system to the actual surgical outcomes achieved in a cohort of patients undergoing PCNL, in an academic hospital.Patients e Methods: We retrospectively reviewed the charts of 277 consecutive patients who underwent percutaneous nephrolithotomy from 2014 to 2019 in our academic hospital. Only those patients with all radiological images available for review were included in this cohort. The S.T.O.N.E nephrolithotomy score was calculated based on the preoperative computed tomography (CT) scans and then correlated with stone-free rate (SFR), postoperative complications (PC) in accordance with the Clavien-Dindo system, length of hospital stay (LHS) and operative time (OT). Results: A total of 193 PCNLs were included. Mean age was 50.7 years (25-82); 56% of patients were female, and the right side was slightly more affected (51.8%). The mean S.T.O.N.E. score for the entire cohort was 8.45, but for patients with residual stone after PCNL, this figure was actually higher, at 9.4 (p <0.01). The overall SFR after an initial procedure was 51.8%, with logistic regression analysis showing that the number of involved calyces and stone size were significantly correlated with stone-free status (p<0.001). Mean LHS (3.47 days) and OT (117.9 mins) also significantly correlated with S.T.O.N.E. score (p<0.001). The overall complication rate after the primary procedure was 16.6% (of which 68.8% were grade I or II), and there were no complications Grades IVb or V. There was no significant correlation between complications and the S.T.O.N.E. score (p=0.37). Conclusion: The S.T.O.N.E nephrolithometry score was significantly associated with stone free status, operative time and length of hospital stay, although not with occurrence of complications.

Reliability and Validity of S.T.O.N.E Nephrolithometry Scoring System in Predicting Peri-operative Complications after Percutaneous Nephrolithotomy for Renal Stones

Reliability and Validity of S.T.O.N.E Nephrolithometry Scoring System in Predicting Peri-operative Complications after Percutaneous Nephrolithotomy for Renal Stones

Comparison between OPEN STONE SURGERY vs PERCUTENOUS NEPHROLITHOTOMY in Management of Renal Stones By Using S.T.O.N.E Nephrolithometry Scoring System

Abstract Background In spite of Percutaneous nephrolithotomy (PCNL) became the first-line treatment option for patients with large and complex renal stones, there still remains a need of using open stone surgery (OSS) for removal of stones as a second or third line of treatment option. To date, 3 scoring systems have been proposed utilizing different metrics including the Guy’s Stone Score, S.T.O.N.E. nephrolithometry and the Clinical Research Office of the Endourological Society (CROES) nomogram, and that used to assess and estimate the treatment success rate. Aim of the Work To evaluate and compare between OSS and PCNL in the management of renal stones by using the S.T.O.N.E. nephrolithometry scoring system to predict and assess the stone free rate and the correlation with peri-operative complications in that two procedures. Patients and Methods A total 100 patients who need surgical intervention for renal stones were treated with OSS (35 pa ents) and PCNL (65 pa ents) from January 2019 ll the end of October 2019, were invited to participate in the present study. This was a multicenter, comparative, prospective cohort controlled study. This study was controlled by the standard results recorded in the previous literatures. Only adult(>18 ys. Old) patients with renal stone size ≥ 20mm were involved in the study. Peri-operative and follow-up data included stone free rate and complications were collected for all patients and were compared between both procedures. S.T.O.N.E nephrolithometry scoring systems was applied to preoperative non-contrast computed tomography(CTUT) for all cases and compared the results of both procedures. Stone-free rate was diagnosed using early postoperative kidney, ureter, bladder X-rays(KUB) and another CTUT on the postoperative day30. Results There was a significant difference between the PCNL group and the OSS group in the primary stone free rate (90% and 97.5% respec vely, p-value=0.021), peri-operative major complications (3% and 14.3% respectively, p-value=0.033), opera ve me (123.46 ± 34.61 and 175.71 ± 55.10 respec vely, p-value=0.000) and postopera ve hospital stay (3.52 ± 0.84 and 5.23 ± 1.00 respec vely, p-value=0.000), while there was no significant difference in the intra-opera ve bleeding requiring blood transfusion (10.8% and 14.3% respec vely, pvalue=0.124). S.T.O.N.E score showed a significant difference between PCNL and OSS groups ( 7 (6-11) and 10 (7-12) respectively, p-value=0.000) and it also had a significant rela on with the outcome SFR (p-value=0.000) a er both PCNL and OSS(r= -0.581 and r= -0.567 respec vely), the higher the score, the lower the SFR and the higher the possibility of OSS choice. While this score had on relation with the peri-operative complications. Conclusion The S.T.O.N.E. nephrolithometry score was predictive of the stone-free status in both surgical procedures (PCNL and OSS) and can be used as an formal guidance for surgical planning and patient counseling. This score would be classified into two categories “low” score range from 5 to 8 recommend PCNL procedure with expec ng SFR of 88% to 97% and “high” score range from 9 to 12 recommend Open Stone Surgery with expec ng SFR of 90% to 96%, to reach the most acceptable results for each procedures to sa sfy the patient and the doctor. The S.T.O.N.E score was not associated with the peri-operative complications in both procedures.

Reliability and validity of "S.T.O.N.E" nephrolithometry scoring system to predict the stone-free rate after percutaneous nephrolithotomy.

Objective:The objective was to assess the reliability and validity of “S.T.O.N.E” nephrolithometry scoring system to predict the stone-free rate (SFR) after percutaneous nephrolithotomy (PNL).Methods:A total of 123 patients with unilateral radiopaque stones ≥2 cm were included in the study. According to S.T.O.N.E score, five parameters available from preoperative computed tomography (CT) without contrast were measured: stone size (S), tract length (T), obstruction (O), number of involved calices (N), and essence of stone (E). The Stone free rates evaluated within one month postoperatively by plain X-ray and/or CT scan without contrast.Results:The mean S.T.O.N.E. score in this study was 7.4 in stone-free (SF) group and 9.3 in residual stone group (P = 0.0001). Patients with SF comprised 82.1% after the first PNL, whereas 17.9% had significant residual stones >4 mm. Postoperative complications were 8%. The most common complications were bleeding requiring transfusion. The size of stone (P = 0.002) and number of calices involved (P = 0.001) had a statistically significant difference between patients with residual stones, other components were not. There was a statistically significant difference between non-SF and SF according to the hospital stay (P = 0.002).Conclusion:This score predicted the clearance after PNL. The size of calculi and number of calices involved statistically affected the stone clearance, whereas other S.T.O.N.E scoring parameters were not. There was a statistically significant difference between SF and residual stones groups according to the hospital stay (P = 0.0001).

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

BackgroundClinical 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.MethodsA 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.ResultsTen 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).ConclusionsOur 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.

Predicting the results of percutaneous nephrolithotomy with S.T.O.N.E. nephrolithometry scoring system

Predicting the results of percutaneous nephrolithotomy with S.T.O.N.E. nephrolithometry scoring system

Comparison of the most popular methods for predicting stonefree rate after percutaneous nephrolithotomy

BACKGROUND: The Guy’s stone score, S.T.O.N.E. nephrolithometry, CROES nomogram, and S-ReSC scoring system have recently been externally validated as effective predictors of stone-free rate after percutaneous nephrolithotomy.OBJECTIVE: We describe herein the advantages of identifying the most accurate scale and propose its standardized use.MATERIALS AND METHODS: We analyzed 188 patients that underwent percutaneous nephrolithotomy for kidney stones within the time frame of October 2010 and July 2015 at a tertiary care referral center. Preoperative and postoperative non-contrast computed tomography scans were used in all patients to compare the four scoring systems, using the strict criterion of absolute absence of residual stone as the stone-free rate.RESULTS: The overall stone-free rate was 57.9%. All scoring systems presented a statistically significant stone-free rate (p&lt;0.001). Only the Guy’s stone score had no correlation with postoperative complications. The four scoring systems had similar accuracy, none of them were more predictive for stone-free rate than the other, and there was no significant difference in the areas under the curve between them (p=0.2). In addition, each scale had a correlation with operative time and length of hospital stay.CONCLUSIONS: The four scales analyzed were excellent predictors for stone-free rate. They had similar receiver operating characteristic curves and areas under the curve, with no significant differences between them. However, the Guy’s stone score presented the best predictive capacity and the S-ReSC scoring system was the best method for predicting complications. It is up to the urologic community to decide which evidence-based scale is the most suitable. Meanwhile, the need for a standardized method continues to grow. KEYWORDS: Stone-free rate; Percutaneous nephrolithotomy; CROES; S-ReSC, S.T.O.N.E.; Guy’s stone score

Comparison of the most popular methods for predicting stonefree rate after percutaneous nephrolithotomy

BACKGROUND: The Guy’s stone score, S.T.O.N.E. nephrolithometry, CROES nomogram, and S-ReSC scoring system have recently been externally validated as effective predictors of stone-free rate after percutaneous nephrolithotomy.OBJECTIVE: We describe herein the advantages of identifying the most accurate scale and propose its standardized use.MATERIALS AND METHODS: We analyzed 188 patients that underwent percutaneous nephrolithotomy for kidney stones within the time frame of October 2010 and July 2015 at a tertiary care referral center. Preoperative and postoperative non-contrast computed tomography scans were used in all patients to compare the four scoring systems, using the strict criterion of absolute absence of residual stone as the stone-free rate.RESULTS: The overall stone-free rate was 57.9%. All scoring systems presented a statistically significant stone-free rate (p&lt;0.001). Only the Guy’s stone score had no correlation with postoperative complications. The four scoring systems had similar accuracy, none of them were more predictive for stone-free rate than the other, and there was no significant difference in the areas under the curve between them (p=0.2). In addition, each scale had a correlation with operative time and length of hospital stay.CONCLUSIONS: The four scales analyzed were excellent predictors for stone-free rate. They had similar receiver operating characteristic curves and areas under the curve, with no significant differences between them. However, the Guy’s stone score presented the best predictive capacity and the S-ReSC scoring system was the best method for predicting complications. It is up to the urologic community to decide which evidence-based scale is the most suitable. Meanwhile, the need for a standardized method continues to grow. KEYWORDS: Stone-free rate; Percutaneous nephrolithotomy; CROES; S-ReSC, S.T.O.N.E.; Guy’s stone score

Evaluation and comparison of SHA.LIN, S.T.O.N.E nephrolithometry scoring system and Guy's stone score in predicting the accuracy of the percutaneous nephrolithotomy(PCNL) outcomes

Objective To compared the accuracy of the SHA.LIN, S. T.O.N.E. nephrolithometry scoring system and Guy's stone score in the same cohort and to determine which was most predictive of percutaneous nephrolithotomy(PCNL) outcomes. Methods A retrospective analysis was conducted of clinical data of 123 patients with nephrolithiasis undergoing PCNL from June 2011 and June 2015 in two hospitals. The SHA.LIN nephrolithometry score , the S. T.O.N.E. score and the Guy's stone score based on preoperative computerized tomography images were calculated. A single observer reviewed all images and assigned scores. Logistic and linear regression analysis were performed and Receiver operating characteristic (ROC) curves were drawn to determine the most predictive scoring system. Results The stone free rate was 76.4%(94/123) and postoperative complications occurred in 33(26.8%) cases.In stone-free patients vs. those with residual stones the mean SHA.LIN nephrolithometry score was 8.2 vs. 11.8, the mean S. T.O.N.E. score was 7.3 vs. 8.6 and the mean Guy's stone score was 2.4 vs.3.0 (each P=0.000). Logistic regression revealed that SHA.LIN nephrolithometry score, S. T.O.N.E. score and the Guy's stone score were significantly associated with stone-free status (each P=0.000) and postoperative complications(P<0.05). The SHA.LIN nephrolithometry score was associated with operation time and estimated blood loss (P=0.000 and 0.011). S. T.O.N.E. score and Guy's stone score were associated with operation time (P=0.000 and 0.006, respectively). All scoring systems did not predict length of stay. There was significant difference in the areas under the curves(AUC) for the SHA.LIN vs. S. T.O.N.E. scoring system [0.924(95%CI 0.874-0.975)vs. 0.795(95%CI 0.698-0.891), P=0.001] and for the SHA.LIN nephrolithometry score vs Guy's stone score [0.924(95%CI 0.874-0.975) vs. 0.701(95%CI 0.592-0.811), P<0.000]. Conclusion All scoring systems have comparable accuracies and the predictive accuracy of the SHA.LIN scoring system is more precise than the S. T.O.N.E. score and the Guy's score in predicting post-PCNL stonefree status and postoperative complications. Key words: Kidney calculi; Nephrostomy, percutaneous; Classification; Prognosis; Perioperative period

The S.T.O.N.E. nephrolithometry scoring system: How valid is it?

The S.T.O.N.E. nephrolithometry scoring system: How valid is it?

External validation of the S.T.O.N.E. nephrolithometry scoring system.

We perform external validation of the S.T.O.N.E. nephrolithometry scoring system for the preoperative assessment of percutaneous nephrolithotomy (PCNL) outcomes. After obtaining institutional review board approval, all PCNLs performed from 2009 to 2013 at a tertiary referral centre were reviewed. The S.T.O.N.E. score was calculated and correlated with stone-free status, estimated blood loss (EBL), operative time, length of hospital stay (LOS), and postoperative complications. A total of 155 PCNLs were included, with 100 (64.5%) males and 55 (35.5%) females. The mean age was 54.9 ± 1.2 years (range: 17-85), with a mean body mass index of 26.9 ± 0.5 kg/m(2) (range: 17.2-51). The mean S.T.O.N.E. score was 7.67 ± 0.1 (range: 5-12), with a mean stone size of 609.8 ± 48.4 mm(2) (range: 250-4030), a mean Hounsfield unit of 887.7 ± 25.3 (range: 222-1766), a mean tract length of 97.3 ± 1.9 mm (range: 53-175), a mean operative time of 100.1 ± 2.8 min (range: 60-240), and a mean LOS of 4.2 ± 0.3 days (range: 1-18). The overall stone-free rate after the primary procedure was 71.6%. The S.T.O.N.E. score significantly affected stone-free status (p = 0.001) and EBL (p = 0.003). There was significant correlation between the S.T.O.N.E. score and operative time (r = 0.4; p < 0.001) and LOS (r = 0.3; p = 0.001). Therefore, the higher the S.T.O.N.E. score, the longer the operative time, the higher the EBL, the longer the LOS, and the lower the chance of being stone-free. The overall complication rate after the primary procedure was 15.5%, which did not correlate with the S.T.O.N.E. score (p = 0.9). Although this study externally validates the S.T.O.N.E. scoring system, its accuracy is comparable to stone size and number of involved calyces in predicting stone-free status post-PCNL.

Prediction of single procedure success rate using S.T.O.N.E. nephrolithometry surgical classification system with strict criteria for surgical outcome.

To evaluate the S.T.O.N.E. nephrolithometry scoring system for percutaneous nephrolithotomy using computerized tomography (CT) imaging with strict criteria for stone clearance. We analyzed a cohort of 122 patients who consecutively underwent primary percutaneous nephrolithotomy from July 2010 to March 2012 at our university-based referral hospital. All patients routinely have preoperative and postoperative CT imaging for stone burden determination. Primary outcome (residual stone) was scored as 0-2, 3-4, and >4 mm. All S.T.O.N.E. nephrolithometry parameters were recorded and scored as per published definition. The t test was used for continuous variables, and the chi-square testing or the Fisher exact test (when counts were small) was used for categorical covariates. S.T.O.N.E. score correlation with stone-free status was analyzed by logistic regression. Nephrolithometry score ranged from 5 to 13 with a mean of 9.5. Postoperative CT for residual stone showed 67 (54.9%), 26 (21.3%), and 29 (23.8%) patients had 0-2, 3-4, and >4 mm residual stone, respectively. Mean nephrolithometry scores for residual stone of 0-2, 3-4, and >4 mm were 8.87, 9.73, and 10.79 respectively (P <.0001). There were 11 (9.8%) complications. With use of strict CT imaging criteria for assessment of residual stone status, the S.T.O.N.E. scoring system is reproducible and predictive of treatment success. Further investigation is required to both validate this model and to determine if other predictive parameters will improve it as a predictive model.

Interobserver Reliability and Reproducibility of S.T.O.N.E. Nephrolithometry for Renal Calculi

To assess the reliability of the S.T.O.N.E. (stone size [S], tract length [T], obstruction [O], number of involved calices [N], and essence or stone density [E]) nephrolithometry scoring system by testing its reproducibility between different observers. Preoperative images of 58 patients who underwent percutaneous nephrolithotomy (PCNL) were reviewed. Medical students, urology residents, one fellow, and a urology attending independently reviewed all images and scored the renal stones. Interobserver reliabilities of the total score for all categories and each component were evaluated by the intraclass correlation (ICC) and a κ coefficient. The interobserver reliability for the total score demonstrated high correlations for all components and total score (ICC=S, T, O, N, E and total 0.80, 0.97, 0.89, 0.84, 0.91, and 0.87, respectively). κ rates for individual components between two medical students were 0.36, 1, 0.31, 0.45, 0.33, and 0.30 for the S, T, O, N, E components and total score, respectively. κ values between the two urology residents were 0.71, 1, 0.92, 0.79, 0.93, and 0.67 for S, T, O, N, E components and total score, respectively. κ values between the urology fellow and an attending physician were 0.95, 1, 0.88, 0.94, 0.89, and 0.87 for S, T, O, N, E components and total score, respectively. P value for all the scoring components was <0.05, indicating that the estimated κ was not a result of chance. The S.T.O.N.E. nephrolithometry has excellent interobserver reliability. Quantifying the S and N metrics was the most challenging and least reliable. Standardized protocols to measure these components should be considered to improve accuracy and reproducibility of the scoring system.

1535 S.T.O.N.E. NEPHROLITHOMETRY: A NOVEL SCORING SYSTEM FOR KIDNEY CALCULI – INTEROBSERVER RELIABILITY AND REPRODUCIBILITY

You have accessJournal of UrologyStone Disease: SWL, Ureteroscopy or Percutaneous Stone Removal (I)1 Apr 20131535 S.T.O.N.E. NEPHROLITHOMETRY: A NOVEL SCORING SYSTEM FOR KIDNEY CALCULI – INTEROBSERVER RELIABILITY AND REPRODUCIBILITY Zhamshid Okhunov, Alberto Perez Lansac DeLorca, Ashleigh Menhadji, Achim Lusch, and Jaime Landman Zhamshid OkhunovZhamshid Okhunov Orange, CA More articles by this author , Alberto Perez Lansac DeLorcaAlberto Perez Lansac DeLorca Orange, CA More articles by this author , Ashleigh MenhadjiAshleigh Menhadji Orange, CA More articles by this author , Achim LuschAchim Lusch Orange, CA More articles by this author , and Jaime LandmanJaime Landman Orange, CA More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2013.02.3025AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES The S.T.O.N.E. nephrolithometry scoring system has been recently developed to predict outcomes of percutaneous nephrolithotomy (PCNL) and for standardized academic reporting. The nephrolithometry score consists of 5 components measured from preoperative computer tomography (CT) images (Table 1). The objective of this study was to assess the reliability of the scoring system by testing its reproducibility between different observers. METHODS Methods: Interobserver reliability was assessed reviewing CT images of 32 randomly selected subjects that underwent PCNL. Axial and coronal CT images were available for all patients. One medical student, one fellow and one urology attending independently reviewed all images and scored the renal stones. Interobserver reliabilities of the total score for all categories were evaluated by the intraclass correlation coefficient (ICC). Interobserver variability was calculated for each of the 5 components using a Kappa coefficient. RESULTS The interobserver reliability of the total score demonstrated high correlations (ICC = 0.836). Concordance rates for individual components among the 3 observers were 68%, 96%, 99%, 81%, and 93% for the S, T, O, N, and E components, respectively. The corresponding Kappa values for each of these 5 components are shown in table 2. No statistical difference was observed between the total score assigned by the three observers. CONCLUSIONS The S.T.O.N.E. nephrolithometry scoring system showed good interobserver reliability. Quantifying the S (stone volume) component was the most challenging and least reliable of the 5 components. This discrepancy might affect the total nephrolithomety score. Standardized protocols to measure the stone volume should be considered to improve accuracy and reproducibility of the scoring system. Table 1. A summary of S.T.O.N.E. Nephrolithometry scoring system. Variables/Scores 1 2 3 4 Stone Size (mm2) 0-399 400-799 800-1599 ≥1600 Tract length ≤100 >100 Obstruction none severe Number of calyces 1 -2 calyces 3 calyces Staghorn stone Essence (HU) ≤950 >950 HU-Hounsfield Units Table 2. Interobserver reliability of five components of the scoring system using the Kappa coefficient. Scoring system components Kappa coefficient (SD) S 0.43 (0.07) T 0.71 (0.03) O 0.68 (0.04) N 0.45 (0.08) E 0.82 (0.02) - Kappa Interpretation: 0-poor agreement; 0.0-0.2-slight agreement; 0.21-0.4-fair agreement; 0.41-0.6-moderate agreement; 0.61-0.8-substantial agreement; 0.81-1.00-almost perfect agreement. - SD-standard deviation. © 2013 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 189Issue 4SApril 2013Page: e629 Peer Review Report Advertisement Copyright & Permissions© 2013 by American Urological Association Education and Research, Inc.MetricsAuthor Information Zhamshid Okhunov Orange, CA More articles by this author Alberto Perez Lansac DeLorca Orange, CA More articles by this author Ashleigh Menhadji Orange, CA More articles by this author Achim Lusch Orange, CA More articles by this author Jaime Landman Orange, CA More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

1532 PREDICTION OF SINGLE PROCEDURE SUCCESS RATE USING S.T.O.N.E. NEPHROLITHOMETRY SURGICAL CLASSIFICATION SYSTEM WITH STRICT CRITERIA FOR SURGICAL OUTCOME

You have accessJournal of UrologyStone Disease: SWL, Ureteroscopy or Percutaneous Stone Removal (I)1 Apr 20131532 PREDICTION OF SINGLE PROCEDURE SUCCESS RATE USING S.T.O.N.E. NEPHROLITHOMETRY SURGICAL CLASSIFICATION SYSTEM WITH STRICT CRITERIA FOR SURGICAL OUTCOME Arash Akhavein, Carl Henriksen, and Vincent G Bird Arash AkhaveinArash Akhavein Gainesville, FL More articles by this author , Carl HenriksenCarl Henriksen Gainesville, FL More articles by this author , and Vincent G BirdVincent G Bird Gainesville, FL More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2013.02.3022AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Percutaneous nephrostolithomy (PCNL) is a commonly employed surgical modality for treatment of large and complex urinary stones. Instruments for outcome prediction have limitations relating to clinical utility, ease of use, and lack of validation. The S.T.O.N.E. nephrolithometry scoring system was recently introduced by Okhunov et al as a more practical method. We evaluate this scoring system in a recent PCNL cohort using computerized tomography (CT) imaging with strict criteria for stone clearance as a measure of surgical outcome. METHODS We maintain an institutional review board approved prospective database of all patients undergoing stone surgery by a single surgeon. Inclusion criteria included primary PCNL and availability of pre- and post-operative CT imaging. Technique for PCNL involves percutaneous access at time of procedure and stone removal by means of both rigid and flexible nephroscopy. Repeat CT is done on post-operative day 1-14. Residual stone is scored as 0-2 mm, 3-4 mm, and >4 mm. Stone size, tract length, obstruction (hydronephrosis), number of calyces with stone, and essence (CT attenuation value) are recorded and scored as according to Okhunov et al. Statistical analysis was performed using t test for continuous variables and chi square testing for categorical covariates. Final score and stone free analysis was analyzed with logistic regression. RESULTS 117 patients were available for analysis. Table 1 summarizes the results. Gender distribution and mean age were 56 M vs 61 F and 56.7 yrs. Nephrolithometry score ranged from 6 to 12. Postoperative CT for residual stone showed 88 (75%) and 29 (25%) patients had 0-4 mm, and >4 mm residual stone respectively. There were 12 (10%) complications, most commonly fever. No patients required perioperative blood transfusion. Mean nephrolithometry score for residual stone 0-4 mm and >4 mm were 8.9 and 10.3 respectively (logistic regression p<0.0001). CONCLUSIONS With use of strict CT imaging criteria for assessment of residual stone status, the S.T.O.N.E. scoring system is reproducible and predictive of treatment success. Further investigation is required to both validate this model and to determine if other predictive parameters will improve it as a predictive model. © 2013 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetailsCited ByLabadie K, Okhunov Z, Akhavein A, Moreira D, Moreno-Palacios J, del Junco M, Okeke Z, Bird V, Smith A and Landman J (2018) Evaluation and Comparison of Urolithiasis Scoring Systems Used in Percutaneous Kidney Stone SurgeryJournal of Urology, VOL. 193, NO. 1, (154-159), Online publication date: 1-Jan-2015. Volume 189Issue 4SApril 2013Page: e627-e628 Advertisement Copyright & Permissions© 2013 by American Urological Association Education and Research, Inc.MetricsAuthor Information Arash Akhavein Gainesville, FL More articles by this author Carl Henriksen Gainesville, FL More articles by this author Vincent G Bird Gainesville, FL More articles by this author Expand All Advertisement Advertisement PDF DownloadLoading ...

1702 NEPHROLITHOMETRY: A NOVEL SURGICAL CLASSIFICATION SYSTEM FOR RENAL STONES

You have accessJournal of UrologyStone Disease: New Technology/SWL, Ureteroscopic or Percutaneous Stone Removal II1 Apr 20121702 NEPHROLITHOMETRY: A NOVEL SURGICAL CLASSIFICATION SYSTEM FOR RENAL STONES Zhamshid Okhunov, Martin Lesser, Justin Friedlander, Brian Duty, Arvin George, Arun Shrinivasan, Arthur Smith, and Zeph Okeke Zhamshid OkhunovZhamshid Okhunov New Hyde Park, NY More articles by this author , Martin LesserMartin Lesser New Hyde Park, NY More articles by this author , Justin FriedlanderJustin Friedlander New Hyde Park, NY More articles by this author , Brian DutyBrian Duty New Hyde Park, NY More articles by this author , Arvin GeorgeArvin George New Hyde Park, NY More articles by this author , Arun ShrinivasanArun Shrinivasan New Hyde Park, NY More articles by this author , Arthur SmithArthur Smith New Hyde Park, NY More articles by this author , and Zeph OkekeZeph Okeke New Hyde Park, NY More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2012.02.1639AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Percutaneous nephrolithotomy (PCNL) is the minimally invasive treatment modality for complex kidney calculi. Instruments currently available to predict PCNL outcomes are cumbersome and of limited clinical utility. We proposed a novel standardized scoring system (SS) to predict outcomes of PCNL. The SS was previously validated with 52 patients undergoing PCNL and was found to be predictive of stone free rates (SFR) and radiation time (RT). In this study we evaluated the predictive value of each variable included in the SS in a larger cohort of patients who underwent PCNL. METHODS Five reproducible variables available from preoperative non-contrast computed tomography (CT) were measured, including stone volume (SV), stone density (SD), number of involved calyces, presence of hydronephrosis, and skin-to-stone distance (SSD). Scoring for each variable is outlined in Table 1. Comparisons of categories were made using the Wilcoxon rank sum test or Kruskal-Wallis test. Logistic regression was used to measure the association between variables. Table 1. Nephrolithometry scoring system. Variables/Scores 1 2 3 Stone volume (mm2) ≤225 225-900 >900 Stone density (HU) >900 >900 Hydronephrosis No/mild Severe Skin to stone distance (mm) ≤115 >115 Number of calyces Pelvis only, or 1 calyx involved Pelvis + >2 calyces Staghorn RESULTS A total of 137 patients were included. Demographic, clinical, and operative data are included in Table 2. SFR after first procedure was 80%. There were 18 (13.3%) complications. The most frequent complications were sepsis and bleeding. In a model predicting SFR, SV (p<0.0001), calyces (p<0.0001), greater number of calyces or staghorn calculi (SC) (p<0.0001), and pelvis involvement (p<0.004) were individually significantly associated with SFR. In a multivariable model, only SV and calyces were associated with SFR (p<0.0001). In a model predicting complications, SV (p<0.018) and SC (p<0.0318) were associated with complications. In a multivariate analysis, only SV was associated with complications (p=0.003). Table 2. Demographic, clinical, and operative data Gender (male/female) 74/63 Hydronephrosis (yes/no) 55/82 Position (prone/supine) 130/7 Mean (Range) Age (years) 55(16-77) BMI (kg/m2) 30 (15-48) Stone density (HU) 950(236-2345) Skin to stone distance (mm) 117 Operative time (minutes) 97.5(50-180) Estimated blood loss (ml) 230(50-400) Fluoroscopy time (minutes) 6.10(1.5-23.5) Length of stay (days) 2.9(2-10) Number (%) Complications 18(13.3) Stone free rate 80% CONCLUSIONS Nephrolithometry score can be used to successfully predict success of PCNL. Reproducible, standardized parameters obtained from CT can be used for preoperative patient counseling, surgical planning and for evaluation of surgical outcomes across institutions within the medical literature. © 2012 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 187Issue 4SApril 2012Page: e687 Advertisement Copyright & Permissions© 2012 by American Urological Association Education and Research, Inc.MetricsAuthor Information Zhamshid Okhunov New Hyde Park, NY More articles by this author Martin Lesser New Hyde Park, NY More articles by this author Justin Friedlander New Hyde Park, NY More articles by this author Brian Duty New Hyde Park, NY More articles by this author Arvin George New Hyde Park, NY More articles by this author Arun Shrinivasan New Hyde Park, NY More articles by this author Arthur Smith New Hyde Park, NY More articles by this author Zeph Okeke New Hyde Park, NY More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...