Outcomes Of Percutaneous Nephrolithotomy Research Articles

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

122 - Outcome and clinical complications of percutaneous nephrolithotomy

122 - Outcome and clinical complications of percutaneous nephrolithotomy

Comparison of Complications and Surgical Outcomes of Percutaneous Nephrolithotomy with and Without Nephrostomy: A Double-Blind Randomized Controlled Trial

Comparison of Complications and Surgical Outcomes of Percutaneous Nephrolithotomy with and Without Nephrostomy: A Double-Blind Randomized Controlled Trial

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.

Supine Percutaneous Nephrolithotomy in the Galdako-Modified Valdivia Position: A High-Volume Single Center Experience.

To describe the technique and outcomes of supine percutaneous nephrolithotomy (PCNL) in the Galdako-modified Valdivia position. Prospective data were collected from 303 patients undergoing PCNL in the Galdako-modified Valdivia position at our institution between 2007 and 2015. We report our technique with outcomes of operative times, stone-free rate (SFR), and complications. A total of 202 solitary stones with a mean size of 17.19 ± 5.82 mm, 42 stones in multiple calices, and 57 staghorns were treated. Mean operative time was 79.79 ± 35.72 minutes. A total of 244/303 (80.5%) patients had clearance or <2 mm stone on postoperative CT. Minor complications (Clavien-Dindo Classification [CDC] 1-2) occurred in 59 (19.5%) cases and major complications (CDC ≥3) occurred in 22 (7.3%) cases. Five (1.7%) cases required postoperative blood transfusion for bleeding complications. We demonstrate that PCNL in a high-volume center to be safe and efficacious in the Galdalko-modified Valdivia position. We show equivalent SFR and complication rates to large studies of prone PCNL, with potential to decrease operative time. In particular, supine position is optimum for obese or high-risk patients with complex stone disease, because of ease of positioning and lower theoretical risk of anesthetic complications.

Effects of body mass index on the outcomes of percutaneous nephrolithotomy.

ABSTRACTObjective To examine the the effect of body mass index (BMI) on PNL results and complications with a large number of patients.Materials and Methods A total of 958 patients were included in the study, who underwent percutaneous nephrolithotomy in our clinic between 2008 and 2015. Patients were divided into 2 groups according to their body mass index. Patients with a BMI < 30 kg/m2 were classified as group 1 (n:676) and patients with a BMI ≥ 30 kg/m2 were classified as group 2 (n:282). Achieving stone-free status or having residual stones of ≤ 4 mm were considered as operational success.Results The mean age was 47.9 years for group 1 and 48.9 years for group 2 patients. At postoperative first month CT analysis, residual stone was not observed in 466 patients (69%) of group 1 and 20 (72%) patients of group 2. There was no significant difference between the groups in terms of stone-free status (p=0.348). There was no significant difference between two groups complications. Also, there was no difference between the groups for requiring additional intervention (p=0.924). No other complications were observed in the patients.Conclusions BMI does not affect the outcomes of percutaneous nephrolithotomy as well as complication rate.

Skin to calyx distance is not a predictive factor for miniaturized percutaneous nephrolithotomy outcomes.

ABSTRACTObjective To evaluate the predictive value of the distance from skin to calyx (SCD) on the outcome and complication rates of patients undergoing mPNL.Materials and Methods Patient’s charts, who had undergone mPNL between June 2012 and June 2015, were analyzed retrospectively. Patients who had a preoperative computerized tomography (CT) were enrolled into the study. Two separateurologists evaluated the CT scans and calculated the SCD defined as the distance between the skin and surface/lateral edge of the calyx, which was the preferred site of entry for percutaneous access. The average value of the two measurements was included inthe final analysis to avoid bias. The mean SCD was 75mm. According to the median SCD value, patients were divided into two groups: group 1 (SCD ≤75) and group 2 (SCD >75).Results A total of 140 patients and 130 patients were enrolled in groups 1 and 2, respectively. The mean operation time and the mean fluoroscopy time was significantly longer in group 2 (p:0.004 vs. p:0.021). The rate of blood transfusion was significantly higher in group 1 (6 patients). None of patientsin group 2required blood transfusion (p:0.017). Stone-free status after a single session of mPNL was 67.1% in group 1 and 75.4% in group 2 (p:0.112). After additional procedures, stone-free rates increased to 84.3% and 85.4% in group 1 and group 2, respectively (p:0.802).Conclusion Our study demonstrated that longer SCD was not a predictive factor for stone-free rates after mPNL. However, SCD over 75mm was associated with longer operation time and fluoroscopy time with lower rates of transfusion.

Factors determining perioperative complications of percutaneous nephrolithotomy: A single center perspective

ObjectiveTo determine factors affecting perioperative complications of percutaneous nephrolithotomy (PCNL) at a tertiary care academic center. Patients and methodsData from medical records of all patients who had undergone PCNL and matched the selection criteria in a tertiary care center between March 2010 and March 2015 were retrospectively reviewed. The demographic data, stone parameters, and stone free rate were addressed. Factors affecting perioperative complications of PCNL were evaluated and classified according to the modified Clavien classification (MCC) using different statistical methods. ResultsA total of 518 patients undergoing 575 PCNL procedures were enrolled in this study. Complications were detected in 148 patients (28.6%); the most serious complication was peri-operative bleeding in 53 patients (10.2%), which required conversion to open surgery in 12 cases (2.3%). Mortality occurred in 2 patients (0.4%). Grade I, II, IIIa, IIIb, IVa, IVb, V complications represented (14.1%), (15.4%), (7.5%), (2.3%), (0.6%), (0%), (0.4%), respectively. Complications of PCNL were significantly associated with tract numbers, tract location, method of stone extraction, and surgeon experience (P<0.05), while gender, stone shape and location, stone burden, degree of hydronephrosis, pervious surgery, position of PCNL (supine vs. prone) and comorbidity did not impact perioperative complications (P>0.05). ConclusionPerioperative complications of PCNL were significantly affected by surgeon experience, number of PCNL tracts, accessed calyx as well as method of stone extraction. However, patient gender, stone characteristics (configuration, location and burden), degree of hydronephrosis, pervious renal surgery, surgical position (supine vs. prone) did not impact the outcome of PCNL.

Contemporary Trends in Utilization and Perioperative Outcomes of Percutaneous Nephrolithotomy in the United States from 2003 to 2014.

To investigate the contemporary trends and perioperative outcomes of percutaneous nephrolithotomy (PCNL) by using a population-based cohort. Using the Premier Healthcare Database, we identified 225,321 patients in whom kidney/ureteral calculi were diagnosed and who underwent PCNL at 447 different hospitals across the United States from 2003 to 2014. Outcomes included 90-day postoperative complications (as classified by the Clavien-Dindo system), prolonged hospital length of stay, operating room time, blood transfusions, and direct hospital costs. Temporal trends were quantified by estimated annual percentage change (EAPC) by using least-squares linear regression analysis. Multivariable logistic regression was performed to identify predictors of outcomes. PCNL utilization rates initially increased from 6.7% (2003) to 8.9% (2008) (EAPC: +5.60%, p = 0.02), before plateauing at 9.0% (2008-2011), and finally declining to 7.2% in 2014 (EAPC: -4.37%, p = 0.02). Overall (Clavien ≥1) and major complication (Clavien ≥3) rates rose significantly (EAPC: +12.2% and +16.4%, respectively, both p < 0.001). Overall/major complication and blood transfusion rates were 23.1%/4.8% and 3.3%, respectively. Median operating room time and 90-day costs were 221 minutes (interquartile range [IQR] 4) and $12,734 (IQR $9419), respectively. Significant predictors of overall complications include higher Charlson comorbidity index (CCI) (CCI ≥2: odds ratio [OR] 2.08, p < 0.001) and more recent year of surgery (2007-2010: OR 3.20, 2011-2014: OR 4.39, both p < 0.001). Higher surgeon volume was significantly associated with decreased overall (OR 0.992, p < 0.001) and major (OR 0.991, p = 0.01) complications. Our contemporary analysis shows a decrease in the utilization of PCNL in recent years, along with an increase in complication rates. Numerous patient, hospital, and surgical characteristics affect complication rates.

Safety and Efficacy of Percutaneous Nephrolithotomy in Patients with Severe Skeletal Deformities.

Treatment of renal calculi in patients with severe skeletal deformities can be challenging. We present our experience in order to provide an assessment of technical difficulties, associated complications, and outcomes of percutaneous nephrolithotomy (PCNL) as a treatment option in this special patient group. Our study included eight patients treated with PCNL for renal stones. All had severe skeletal deformities including six with severe kyphoscoliosis, one with osteogenesis imperfecta, and another withrickets. After pre-operative evaluation the procedure was performed under fluoroscopic and/or ultrasonic guidance. In all but one case, PCNL was performed with the patient in the prone position. Silicone rolls and soft padded bolsters were used to obtain the best positioning for the procedure. Clearance rates and complications were assessed. Complete stone-free rate was achieved in six patients (75%) after first-PCNL. The two patients with residual stones underwent a second-look PCNL, after which one was completely cleared. The overall completestone-free rate after second PCNL was 87%. Only minor complications were seen in two patients (25%). We found PCNL to be safe and effective for managing kidney stones in patients with severe skeletal deformities.

Current clinical scoring systems of percutaneous nephrolithotomy outcomes.

Percutaneous nephrolithotomy has become the preferred treatment modality for patients with large renal calculi. The technique provides excellent stone clearance, but complication rates are higher than those of minimally invasive techniques, such as ureteroscopy and shockwave lithotripsy. Guy's stone score, S.T.O.N.E. nephrolithometry, the CROES nomogram, and S-ReSC are contemporary scoring systems introduced to provide standardized grading of stone complexity and outcomes of percutaneous stone surgery. Guy's stone score is easy to apply and has been validated in multiple studies. The S.T.O.N.E. score is based on factors determined through CT imaging, which is the currently preferred imaging modality for patients with nephrolithiasis. The CROES nomogram was developed from data in a large multicentre database and has high statistical power. Determination of the S-ReSC score relies on stone location only, providing a simple approach to grading disease complexity. Each system has advantages and disadvantages, but several studies suggest that their ability to predict stone-free rate is comparable. The optimal system should have a high predictive ability, should be simple to use and should be widely applicable. Additional studies are required to evaluate patient clinical factors that influence stone complexity and are predictive of outcomes. A future unified scoring system might incorporate the strengths of each currently available system and optimize care of patients with nephrolithiasis.

Feasibility of Pure Ultrasonography Guided Percutaneous Nephrolithotomy in Flank Position

Background: Although percutaneous nephrolithotomy is most commonly performed with fluoroscopic access, yet, phobia and risks of radiation exposure are 2 important dilemmas. Herein the feasibility of flank position ultrasound guided percutaneous nephrolithotomy for management of renal stones was assessed. Methods: Between September 2012 and June 2016, 250 cases (134 males and 116 females) with renal stone underwent ultrasonography-guided percutaneous nephrolithotomy under lateral decubitus position. The exclusion criteria were active urinary tract infection and bleeding status. The peri-operative surgical outcomes were recorded and analyzed. Results: The mean age of patients was 42.0 ± 13.4 years. Twelve patients were children under 12 years old. Mean size of the stones was 4.2 ± 1.1 cm (range from 2.5 to 5.3 cm). Mean access and operative times were 15.5 ± 2.3 and 68 ± 14.5 minutes, respectively. In 45% of patients, superior calyx was selected for access. History of previous open stone surgery was obtained in 24 cases. Early complete stone free rate (SFR) was 68%, and after auxiliary procedures (SWL and TUL), this increased to 88%. The mean hemoglobin reduction was 1.9 ± 0.9 gr/dL. Blood transfusion was needed in 6 cases (2.4%). Prolonged or delay hemorrhage did not occur in any of the patients. One patient was complicated by moderate degree of pneumothorax and managed with chest tube insertion. Solid or viscus abdominal organ injury had not happened. Conclusions: This study suggested that the feasibility and outcomes of ultrasonography-guided percutaneous nephrolithotomy are comparable with the standard fluoroscopic approach. Also flank position can facile this procedure.

Prediction of Pediatric Percutaneous Nephrolithotomy Outcomes Using Contemporary Scoring Systems.

We evaluate the applicability of contemporary percutaneous nephrolithotomy scoring systems in pediatric patients and compare their predictive power regarding postoperative outcomes. We retrospectively analyzed the records of 125 children who were diagnosed with renal calculi and underwent percutaneous nephrolithotomy between March 2011 and April 2016. Predictive scores, which consisted of Guy's Stone Score, S.T.O.N.E. (stone size, tract length, obstruction, number of involved calyces and essence/stone density) nephrolithometry and CROES (Clinical Research Office of the Endourological Society) nomogram, were calculated for all patients included in the study. Patient demographics, stone-free rate and complications were all analyzed and are reported. Median Guy's Stone Score was 2 (IQR 2 to 3) in patients with residual stones (group 1) and 2 (1 to 2) in those who were stone-free (group 2). Median respective CROES nomogram scores were 215 (IQR 210 to 235) and 257 (240 to264), and S.T.O.N.E. nephrolithometry scores were 8 (7 to 9) and 5 (5 to 6, all p<0.0001). S.T.O.N.E. score demonstrated the greatest accuracy in predicting stone-free rate. Guy's Stone Score was significantly correlated with complications but the CROES and S.T.O.N.E. scores were not significantly correlated with complications. The scoring systems analyzed could be used to predict success of percutaneous nephrolithotomy in the pediatric setting. However, further studies are needed to formulate modifications for use in children. The main variables in the scoring systems, ie stone burden, tract length and case volume, were measured using records from adult patients. Besides these variables, the relatively small pelvicalyceal system and higher incidence of anatomical malformations in children could potentially affect percutaneous nephrolithotomy outcomes.

Surgical outcomes of percutaneous nephrolithotomy in 3402 patients and results of stone analysis in 1559 patients.

To report our experience of a series of percutaneous nephrolithotomy (PCNL) procedures in a single centre over 18years in terms of patient and stone characteristics, indications, stone clearance and complications, along with the results of chemical analysis of stones in a subgroup. We retrospectively analysed the outcomes of PCNL in 3402 patients, who underwent the procedure between 1997 and 2014, obtained from a prospectively maintained database. Data analysis included patients' age and sex, laboratory investigations, imaging, punctured calyx, duration of operation, volume of irrigation fluid, radiation exposure time, blood transfusion, complications and stone-free status at 1-month follow-up. For the present analysis, outcomes in relation to complications and success were divided in two eras, 1997-2005 and 2006-2014, to study the differences. Of the 3402 patients, 2501 (73.5%) were male and 901 (26.5%) were female, giving a male:female ratio of 2.8:1. Staghorn (partial or complete) calculi were found in 27.5% of patients, while 72.5% had non-staghorn calculi. Intracorporeal energy sources used for stone fragmentation included ultrasonography in 917 patients (26.9%), pneumatic lithoclast in 1820 (53.5%), holmium laser in 141 (4.1%) and Lithoclast® master in 524 (15.4%). In the majority of patients (97.4%) a 18-22-F nephrostomy tube was placed after the procedure, while 69 patients (2.03%) underwent tubeless PCNL. The volume of the irrigation fluid used ranged from 7 to 37 L, with a mean of 28.4L. The stone-free rate after PCNL in the first era studied was 78%, vs 83.2% in the second era, as assessed by combination of ultrasonography and plain abdominal film of the kidney, ureter and bladder. The complication rate in the first era was 21.3% as compared with 10.3% in the second era, and this difference was statistically significant. Stone analysis showed pure stones in 41% and mixed stones in 58% of patients. The majority of stones consisted of calcium oxalate. This is the largest series of PCNL reported from any single centre in Pakistan, where there is a high prevalence of stone disease associated with infective and obstructive complications, including renal failure. PCNL as a treatment method offers an economic and effective option in the management of renal stone disease with acceptable stone clearance rates in a resource-constrained healthcare system.

Effects of previous unsuccessful extracorporeal shockwave lithotripsy treatment on the performance and outcome of percutaneous nephrolithotomy

ObjectiveTo evaluate the effects of previous unsuccessful extracorporeal shockwave lithotripsy (ESWL) treatment on the performance and outcome of percutaneous nephrolithotomy (PCNL). Patients and methodsOf 1625 PCNL procedures performed in our clinic, 393 renal units with similar stone burden and number of accesses was included in the present study. We categorised the study patients into two groups according to whether they underwent ESWL within 1year prior to PCNL or not. Accordingly, Group 1 comprised 143 (36.3%) ESWL-treated patients and Group 2 comprised 250 (63.7%) non-ESWL-treated patients. ResultsResidual stones were detected in 36 (25.1%) of the ESWL-treated patients (Group 1) and in 60 (24%) of non-ESWL-treated patients (Group 2). There were no statistically significant differences between the groups for length of hospital stay (LOS), nephrostomy tube removal time, and the presence of residual stones. When we evaluated the groups for both the preoperative and postoperative haemoglobin (Hb) drop and blood transfusion rate, manifest Hb declines and more transfusions were required in the ESWL-treated patients (both P=0.01). ConclusionsIn our study, previous ESWL treatment had no influence on the PCNL stone-free rate, operation time, incidence of postoperative complications, and LOS, in patients with similar stone burdens. However, bleeding during PCNL was more prevalent in the ESWL-treated patients, so close attention should be paid to bleeding in patients who have been pretreated with ESWL.

Outcomes of percutaneous nephrolithotomy versus open stone surgery for patients with staghorn calculi

ObjectivesAdvances in shock wave lithotripsy and endourological procedures have markedly limited the need for open surgery in the treatment of renal stones. We retrospectively compared the clinical outcomes of percutaneous nephrolithotomy (PNL)-based therapy with open stone surgery (OSS) to treat staghorn stones. Materials and methodsHospital and office charts, operative records, and radiographic studies of all patients undergoing OSS (Group 1, 11 patients) and PNL (Group 2, 61 patients) for the treatment of large staghorn calculi from 2007 to 2013 were reviewed. Only patients with stones ≥ 10 cm2 in area were included. Patient characteristics, stone burden, indications, and surgical outcomes between the two procedures were compared. Stone-clearance was confirmed using postoperative kidney, ureter, bladder X-rays. ResultsThere were no differences between the two groups in patient demographics, stone size, estimated blood loss, and mean renal function level change, however, there were statistically significant differences in mean operative time (282.1±54.5 minutes vs. 156.6±41.2 minutes, p<0.001), mean hospital stay (10.3±1.8 days vs. 6.2±2.7 days, p<0.001), postoperative stone-clearance rate (97.5% vs. 76.1±23.9%, p<0.001), and number of procedures per patient (1.6 vs. 2.8, p<0.001) between the OSS and PNL group. ConclusionBoth OSS and PNL are viable options for the management of staghorn stones. Considering the lower postoperative complication rate and need for auxiliary treatment, we suggest that OSS is more suitable for staghorn stones with large burdens. OSS should still be considered as a valid treatment for patients with complex staghorn calculi, although PNL is a less invasive treatment option in most cases.

CORRELATION BETWEEN S.T.O.N.E NEPHROLITHOMETRY SCORING IN PREDICTING FREE-STONE RATE AFTER PERCUTANEOUS NEPHROLITHOTOMY

Objective: To investigate free-stone rate after Percutaneous Nephrolithotomy (PNL) using S.T.O.N.E nephrolitometry scoring system, with regards of stone size (S), skin-to-stone distance (T), obstruction degree (O), number of calyx involved (N), and stone density (E) in Non Contrast CT Scan (NCCT). Material &amp; methods: This is an analytic observational study on patients with renal stones undergoing PNL. All patients underwent NCCT before and after PNL; each variables was measured and counted for a total score. Post-operative evaluation was done using NCCT. Results: Thirty patients met inclusion criteria, 19 (63.3%) were stone-free, and 11 (36.7%) were with residual stone. Among the five variables, stone size (p=0.005), number of calyx involved (p=0.002) affected the outcome of surgery, while skin-to-stone distance, obstruction degree, and stone density did not. The overall total score of S.T.O.N.E nephrolithometry is correlated with the outcome of PNL (p=0.001). Conclusion: S.T.O.N.E nephrolithometry is a simple scoring system, while it is also easy to use, and can be used to predict the free-stone rate after PNL.

Artificial Neural Network System to Predict the Postoperative Outcome of Percutaneous Nephrolithotomy.

To construct, train, and apply an artificial neural network (ANN) system for prediction of different outcome variables of percutaneous nephrolithotomy (PCNL). We calculated predictive accuracy, sensitivity, and precision for each outcome variable. During the study period, all adult patients who underwent PCNL at our institute were enrolled in the study. Preoperative and postoperative variables were recorded, and stone-free status was assessed perioperatively with computed tomography scans. MATLAB software was used to design and train the network in a feed forward back-propagation error adjustment scheme. Preoperative and postoperative data from 200 patients (training set) were used to analyze the effect and relative relevance of preoperative values on postoperative parameters. The validated adequately trained ANN was used to predict postoperative outcomes in the subsequent 254 adult patients (test set) whose preoperative values were serially fed into the system. To evaluate system accuracy in predicting each postoperative variable, predicted values were compared with actual outcomes. Two hundred fifty-four patients (155 [61%] males) were considered the test set. Mean stone burden was 6702.86 ± 381.6 mm3. Overall stone-free rate was 76.4%. Fifty-four out of 254 patients (21.3%) required ancillary procedures (shockwave lithotripsy 5.9%, transureteral lithotripsy 10.6%, and repeat PCNL 4.7%). The accuracy and sensitivity of the system in predicting different postoperative variables ranged from 81.0% to 98.2%. As a complex nonlinear mathematical model, our ANN system is an interconnected data mining tool, which prospectively analyzes and "learns" the relationships between variables. The accuracy and sensitivity of the system for predicting the stone-free rate, the need for blood transfusion, and post-PCNL ancillary procedures ranged from 81.0% to 98.2%.The stone burden and the stone morphometry were among the most significant preoperative characteristics that affected all postoperative outcome variables and they received the highest relative weight by the ANN system.

545 - Value of CROES, S.T.O.N.E nomograms and Guy’s stone score as preoperative predictive system for percutaneous nephrolithotomy (PCNL) outcomes

545 - Value of CROES, S.T.O.N.E nomograms and Guy’s stone score as preoperative predictive system for percutaneous nephrolithotomy (PCNL) outcomes

547 - Can Guy’s and S.T.O.N.E. scores predict the outcome of percutaneous nephrolithotomy in children?

547 - Can Guy’s and S.T.O.N.E. scores predict the outcome of percutaneous nephrolithotomy in children?