Trends in Percutaneous Nephrolithotomy Use and Outcomes in the United States

The value of IL-6, PCT, qSOFA, NEWS, and SIRS to predict septic shock after Percutaneous nephrolithotomy

BACKGROUND

There are numerous methods available for predicting sepsis following Percutaneous Nephrolithotomy. This study aims to compare the predictive value of Quick Sequential Organ Failure Assessment (qSOFA), Systemic Inflammatory Response Syndrome (SISR), National Early Warning Score (NEWS), interleukin-6 (IL-6), and procalcitonin (PCT) for septicemia.

METHODS

Patients who underwent percutaneous nephrolithotomy were included in the study and divided into a control group and a septic shock group. The effectiveness of qSOFA, SIRS, NEWS, Interleukin-6, and Procalcitonin was assessed, with Receiver Operating Characteristic curves and Area Under the Curve used to compare the predictive accuracy of these four indicators.

RESULTS

Among the 401 patients, 16 cases (3.99%) developed septic shock. Females, elderly individuals, and patients with positive urine culture and positive nitrite in urine were found to be more susceptible to septic shock. PCT, IL-6, SIRS, NEWS, qSOFA, and surgical time were identified as independent risk factors for septic shock. The cutoff values are as follows: qSOFA score > 0.50, SIRS score > 2.50, NEWS score > 2.50, and IL-6 > 264.00 pg/ml. Among the 29 patients identified by IL-6 as having sepsis, 16 were confirmed to have developed sepsis. The qSOFA identified 63 septicemia cases, with 16 confirmed to have developed septicemia; NEWS identified 122 septicemia cases, of which 14 cases actually developed septicemia; SIRS identified 128 septicemia patients, with 16 confirmed to have developed septicemia. In terms of predictive ability, IL-6 (AUC 0.993, 95% CI 0.985 ~ 1) demonstrated a higher predictive accuracy compared to qSOFA (AUC 0.952, 95% CI 0.928 ~ 0.977), NEWS (AUC 0.824, 95% CI 0.720 ~ 0.929) and SIRS (AUC 0.928, 95% CI 0.888 ~ 0.969).

CONCLUSIONS

IL-6 has higher accuracy in predicting septic shock after PCNL compared to qSOFA, SIRS, and NEWS.

RIRS with FV-UAS vs. MPCNL for 2-3-cm upper urinary tract stones: a prospective study

To observe the efficacy and safety of retrograde intrarenal surgery (RIRS) combined with flexible vacuum-assisted ureteral access sheath (FV-UAS) and minimally invasive percutaneous nephrolithotomy (MPCNL) in patients with 2-3 cm upper urinary tract stones. A total of 160 patients with 2-3 cm upper urinary tract stones were prospectively randomized into 2 groups-80 in the FV-UAS group and 80 cases as control in the MPCNL group. The stone-free rates (SFRs) at different times (postoperative 1st day and 4th week) were considered as the primary outcome of the study. The secondary end points were operative time, hemoglobin decrease, postoperative hospital stay, and operation-related complications. There was no obvious difference between the two groups in patient's demographics and preoperative clinical characteristics (all P > 0.05). Postoperative data showed that mean decrease in hemoglobin level was less in FV-UAS group than that in MPCNL group (5.3 vs. 10.8 g/L, P < 0.001). Postoperative hospital stay in FV-UAS group was more shorten than that in MPCNL group (2.7 vs. 4.9 days, P < 0.001). There was no statistical significance between the two groups in SFRs during postoperative 1st day and 4th week (both P > 0.05). However, in terms of the rates of bleeding and pain, MPCNL group were both significantly higher than FV-UAS group (6.2 vs. 0.0%, P = 0.023; 16.2 vs. 2.5%, P = 0.003; respectively). Our study showed that RIRS with FV-UAS, a new partnership to treat 2-3 cm upper urinary tract stones, was satisfying as it achieved a high SFR rate and a low rate of complications. This method was safe and reproducible in clinical practice.

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.

Management of nephrolithiasis in the Middle East over a recent decade: A systematic review

Nephrolithiasis is a prevalent issue around the globe, particularly in hot climates such as Saudi Arabia. This analysis's objectives were to investigate the characteristics of kidney stones in Eastern Saudi Arabia and to provide the following findings: urinary stone composition, gender and age distribution, seasonal variations in stone formation, coexisting diseases linked to stone development, and urinary stone incidence. With comparisons to European and American populations, the primary risk factors for nephrolithiasis in Asian populations are to be determined through this systematic review and meta-analysis. We synthesized data from 13 geographically different studies using a thorough literature search through PubMed, ScienceDirect, and ResearchGate following the Preferred Reporting Items of Systematic Reviews and Meta-Analyses criteria. Potential targets for specialized public health programs were highlighted by the elucidation of differences in health-care-seeking behavior and disparities in health-care access. The results of this systematic analysis give doctors, researchers, and policymakers a thorough understanding of the condition of nephrolithiasis care in Saudi Arabia today. In addition, to maximize the care of nephrolithiasis in this particular group, this review identifies information gaps and highlights the necessity of context-specific guidelines and future research initiatives. All things considered, this systematic review addresses the unique possibilities and problems that exist within the Saudi Arabian health-care sector while also adding to the worldwide conversation on nephrolithiasis.

Infectious Complications, Healthcare Resource Use, and Medical Costs Associated with Delays in Percutaneous Nephrolithotomy Among Patients with Stone Disease and Ureteral Stent Placement

Purpose: The relationship between ureteral stent duration before percutaneous nephrolithotomy (PCNL) and infectious complications, admissions, imaging, and medical costs was evaluated. Materials and Methods: Patients who underwent PCNL within 6 months of ureteral stent placement were identified from commercial claims, categorized by time to treatment (0-30, 31-60, and >60 days), and followed 1-month post-PCNL. The effect of delayed treatment on inpatient admissions, infectious complications (pyelonephritis/sepsis), and imaging utilization was evaluated with logistic regression. A generalized linear model evaluated the effect of delayed treatment on medical costs. Results: Among 564 patients with PCNL and meeting the inclusion criteria (mean age 50; 55% female; 45% from South), mean (standard deviation) time to surgery was 48.8 (41.8) days. Less than half (44.3%; n = 250) underwent PCNL within 30 days of ureteral stent placement, 27.0% (n = 152) between 31 and 60 days, and 28.7% (n = 162) >60 days. Time to PCNL was significantly associated with inpatient admissions (>60 vs ≤30 days odds ratio [OR] 1.97, 95% confidence interval [CI] 1.29-3.01, p = 0.0016), infectious complications (>60 vs ≤30 days OR 2.43, 95% CI 1.55-3.81, p = 0.0001), imaging utilization (31-60 vs ≤30 days OR 1.56, 95% CI 1.02-2.38, p = 0.0383; >60 vs ≤30 days OR 2.01, 95% CI 1.31-3.06, p = 0.0012), and medical costs (31-60 vs ≤30 days OR 1.27, 95% CI 1.08-1.49, p = 0.0048; >60 vs ≤30 days OR 1.46, 95% CI 1.24-1.71, p < 0.0001). Conclusions: Compared with PCNL within 30 days, patients undergoing PCNL >30 days after ureteral stent placement had increased likelihood of infectious complications, resource use, and medical costs. These results may inform health care resource utilization and PCNL prioritization.

Can we identify the risk factors for SIRS/sepsis after percutaneous nephrolithotomy? A meta‑analysis and literature review

With the increase in percutaneous interventions such as percutaneous nephrolithotomy (PCNL) for renal lithiasis, infectious complications are becoming more frequent. The present study performed a systematic Medline and Embase databases search, using the following words: 'PCNL' [MeSH Terms] AND ['sepsis' (All Fields) OR 'PCNL' (All Fields)] AND ['septic shock' (All Fields)] AND ['urosepsis' (MeSH Terms) OR 'Systemic inflammatory response syndrome (SIRS)' (All Fields)]. Because of the technological advances in endourology, articles published between 2012 and 2022 were searched. Of the 1,403 results of the search, only 18 articles, representing 7,507 patients in which PCNL was performed, met the criteria to be included in the analysis. All authors applied antibiotic prophylaxis to all patients and, in some cases, the infection was treated preoperatively in those with positive urine cultures. According to the analysis of the present study, the operative time has been significantly longer in patients who developed SIRS/sepsis post-operatively (P=0.0001) with the highest heterogeneity (I²=91%) compared with other factors. Patients with a positive preoperative urine culture had a significantly higher risk of developing SIRS/sepsis following PCNL (P=0.00001), OD=2.92 (1.82, 4.68) and there was also a high degree of heterogeneity (I²=80%). Performing a multi-tract PCNL also increased the incidence of postoperative SIRS/sepsis (P=0.00001), OD=2.64 (1.78, 3.93) and the heterogeneity was a little smaller (I²=67%). Diabetes mellitus (P=0.004), OD=1.50 (1.14, 1.98), I²=27% and preoperative pyuria (P=0.002), OD=1.75 (1.23, 2.49), I²=20%, were other factors that significantly influenced postoperative evolution. A total of two factors analyzed, body mass index and patient's age, did not influence the outcome, P=0.45, I²=58% and P=0.98, I²=63%.

Evaluating outcomes of patient-centered enhanced recovery after surgery (ERAS) in percutaneous nephrolithotomy for staghorn stones: An initial experience

Objective

To evaluate the outcomes of patient-centered enhanced recovery after surgery (ERAS) in -percutaneous nephrolithotomy (PCNL) for staghorn stones.

Patients and methods

A retrospective analysis of 106 patients with staghorn calculi who underwent PCNL treatment at the Third Xiangya Hospital from October 01, 2018 to September 30, 2021 was performed. The patients were divided into the ERAS group (n = 56) and traditional group (n = 50). The ERAS program focused on a patient-centered concept, with elaboration on aspects, such as patient education, nutritional support, analgesia, body warming, early mobilization, nephrostomy tube removal, and strict follow-up.

Results

The total stone free rate and total complication rate were similar in both groups. The visual analogue scale (VAS) 6 h after surgery, ambulation off bed time, indwelling fistula time, indwelling catheter time, and postoperative hospital stays were lower in the ERAS group than in the traditional group (P < 0.05). The multiple session rate in the ERAS group (19, 28.57%) was lower than that in the traditional group (30, 60%) (P = 0.007). The 1-year stone recurrence rate in the ERAS group (7, 17.5%) was lower than that in the traditional group (14, 38.9%) (P = 0.037).

Conclusion

The patient-centered ERAS in PCNL for staghorn stones accelerated rehabilitation by relieving postoperative pain, shortening hospitalization time, accelerating early ambulation, and reducing multiple session rate and 1-year stone recurrence rate, which have socioeconomic benefits.

The value of postoperative HLA-DR expression and high mobility group box 1 level in predictive diagnosis of sepsis in percutaneous nephrolithotomy surgery

OBJECTIVE

To analyze the value of postoperative human leukocyte antigen-DR (HLA-DR) expression and high mobility group box 1 (HMGB1) level in predictive diagnosis of postoperative sepsis for patients with percutaneous nephrolithotomy (PCNL) surgery.

METHODS

The present prospective observational study included 387 patients with renal calculus who received PCNL surgery from January 2017 to October 2020 in our hospital. After exclusion criteria, 33 patients with sepsis and 78 patients with no sepsis remained. All patients received PCNL surgery. Sepsis definition is according to the third international consensus definitions for sepsis and septic shock (Sepsis-3). The data of the HMGB1, c-reactive protein (CRP), interleukin-6 (IL-6), procalcitonin (PCT) and HLA-DR expression were collected within admission and 24 h and 72 h after surgery. Postoperative HMGB1 levels and HLA-DR expression at 24 h and 72 h were respectively compared between the two groups using t test. ROC cure was used to analyze the value of postoperative HLA-DR expression and HMGB1 level in predictive diagnosis of sepsis.

RESULTS

The positive rate of urine culture and the time of hospitalization time in patients with sepsis were significantly higher than those in patients with no sepsis. Sepsis group had higher levels of HMGB1 at post-24 h ((93.07 ± 11.37) ng/mL vs (75.41 ± 4.85) ng/mL), p < 0.05) and 72 h ((96.58 ± 12.12) ng/mL vs (81.16 ± 8.86) ng/mL), p < 0.05) than nosepsis group. Meanwhile, sepsis group had lower expression of HLA-DR at post-24 h ((50.01 ± 7.42) % vs (69.32 ± 10.58) %), p < 0.05) and 72 h ((54.85 ± 9.45) % vs (69.98 ± 11.00) %), p < 0.05) than non-sepsis group. ROC analysis showed that the HLA-DR expression at postoperative 24 h had highest predictive value in the diagnosis of sepsis, the AUC of HLA-DR was 0.934, cutoff value 56.19%, with sensitivity 89.7%, specificity 81.8%.

CONCLUSION

Postoperative HLA-DR and HMGB1 can both be used as a predictive diagnosis of sepsis for patients with renal calculus received PCNL surgery. HighlightsSepsis group had higher levels of high mobility group box 1 at post-24 h and 72 h than nosepsis group.Sepsis group had lower expression of HLA-DR at post-24 h and 72 h than nosepsis group.Postoperative HLA-DR and HMGB1 can both be used as a predictive diagnosis of sepsis for patients with renal calculus received PCNL surgery.

Changing Trends in Surgical Management of Nephrolithiasis among Young Adults: A 15-Year Population-Based Study

Background: Increases in obesity and diabetes rates among all ages have led to a greater prevalence of nephrolithiasis worldwide. We aimed to explore the changing trends in surgical management of nephrolithiasis in young adults over a 15 year period. Methods: We reviewed medical records of military personnel for information on the diagnosis and care of nephrolithiasis before and during active service between 2007−2021, divided into three 5 year periods: 2007−2011, 2012−2016, and 2017−2021. Demographic, clinical, radiological, and surgical data were retrieved for the analysis of changing trends. Results: The records of 1,117,692 recruits yielded 7383 (0.66%) with stone-related surgeries, of whom 1885 were operated during military service. Their median age was 19.6 years (interquartile range [IQR] 16.8−21.2), 829 (70%) were males, and the cohort’s median body mass index was 23.6 (IQR 17.3−26.1). There was a dramatic decline in shock wave lithotripsy (SWL) prevalence (35.1%, 10.4%, and 4.4%, respectively) with a continually increasing prevalence of ureteroscopy (URS)/retrograde intrarenal surgery (RIRS) (62.7%, 88.5%, and 94.6%, p = 0.01). Percutaneous nephrolithotomy (PCNL) procedures have become nearly extinct over time (0.8% in 2017−2021). The number of median-sized stones treated by URS/RIRS increased (7.5 mm, 8.2 mm, and 9.7 mm, p = 0.044), but not those treated by SWL/PCNL. The median length of medical leave for URS/RIRS and PCNL decreased significantly (7 vs. 4 days, p = 0.05 and 10 vs. 6 days, p = 0.036, respectively), with no comparable change for SWL. There was a substantial decline in ancillary procedures in the URS/RIRS groups (9%, 6.8%, and 3.1%, p < 0.01), but not in the SWL/PCNL groups. Conclusions: Advancements in technology and surgical training are leading to the extinction of SWL and the adoption of URS/RIRS as the new standard of care for nephrolithiasis among young adults.

Factors Affecting Transfusion during Percutaneous Nephrolithotomy: A Retrospective Study of 665 Cases

Objective

This study was designed to evaluate the aspects that affect transfusion following percutaneous nephrolithotomy (PCNL). Patients and Methods. From 2016 to 2019, 665 patients underwent PCNL for the removal of renal calculi at our center (Department of Urology, Shanghai Xu-hui Central Hospital). Complications, including hemorrhages, have been reported. Twenty-three patients (3.5%) have received a blood transfusion, and 12 (1.9%) patients were treated with hyper-selective embolization. We focused on the influencing factors related to postoperative blood transfusion. The factors analyzed were age, sex, hypertension, diabetes, serum creatinine level, preoperative hemoglobin, and the use of anticoagulants or antiplatelet medications; renal and stone factors (i.e., previous surgery, abnormal anatomy, stone side, stone burden, and stone type); and surgical features (i.e., access number, the calyx of puncture, and stone-free rate). These data were analyzed for the presence of bleeding.

Results

Among individual factors, preoperative hemoglobin level (p < 0.001) and urinary infections (p < 0.001) were significantly correlated with blood transfusion. Among renal and stone factors, only a history of open surgery was significantly correlated with blood transfusion (p < 0.05). Stone type or stone burden did not correlate with transfusion. Furthermore, no statistically significant correlation was found between surgical features and bleeding, and a lower stone-free rate was reported for the transfusion group.

Conclusion

The obtained results demonstrated that PCNL is a safer surgical procedure in a high-volume center; however, anemic conditions, infections, and history of open surgery will significantly increase the transfusion rate following PCNL.

THE FUNCTIONAL STATE OF THE RENAL PARENCHYMA AFTER VARIOUS VIDEO ENDOSURGICAL METHODS OF TREATMENT OF PATIENTS WITH LARGE AND COMPLEX KIDNEY STONES

The work is based on the analysis of literature data devoted to the problem of preserving the functional state of the kidneys with various video endoscopic methods of surgical treatment of large and complex kidney stones. The purpose of the review is to highlight the likelihood of deterioration in the functional state of the kidneys in the postoperative period. A detailed analysis of postoperative outcomes in various minimally invasive methods of treatment of patients with large and complex kidney stones was carried out, with an overview of the possibility of using dynamic nephroscintigraphy as a method of objectively assessing the functional state of the kidneys.

Utility of Frailty Assessment in Urologic Stone Surgery: A Review of the Literature

Introduction & Objective As life expectancy continues to rise, the prevalence of frailty is also increasing. The idea of frailty and its effect on the operative patient has been previously studied, but not regularly incorporated into routine practice. We present a review on frailty metrics in the literature, validated assessment methods, and simplified screening tools, to better predict and optimize patient outcomes. Methods An online Pubmed search was conducted by 3 authors (TA, TB, MM) for all frailty, frailty assessment, and pre-operative risk assessment. Only English publications were included in the analysis. Full text analysis was then conducted by all three authors to validate the data. Results An abundance of literature was found on frailty. Even though some methods are validated as very effective for assessing frailty, they may be time consuming and require a specialist. various quick screening methods are also present, many already validated, and should be utilized by urologist more regularly. Conclusions Multiple studies demonstrate the relationship between frailty and surgical patients' outcome. Many quick, office based, validated tools to screen for frailty are described, and should be incorporated into our practice in appropriate patients. Future research is now focused on the concept of "prehabilitation" to improve patient frailty status in the pre-operative setting, and consequently operative outcomes.

Current Trends in Percutaneous Nephrolithotomy in China: A Spot Survey

OBJECTIVE

To describe trends in the procedure of percutaneous nephrolithotomy (PCNL) in China to identify training needs.

METHODS

A spot survey with 36 questions, which revealed demographic data, patterns of PCNL practice, and opinions regarding specific clinical cases, was administered to Chinese urologists during the 17th National Urological Urolithiasis Symposium held in Dandong in 2018.

RESULTS

Out of 400 participants, 221 responses to the survey were received. PCNL was performed by 80.5% of the participants, and 70.2% of them were senior clinicians. It was found that 91% used the prone decubitus in training programs and 27.6% the modified supine, and 46.6% were apprenticeship trained for PCNL, while 5.6% trained during their residency. The prone position was the preferred decubitus, even for obese patients. All of the urologists established their own access, 93.7% used ultrasonography guidance alone, 70.7% used ultrasonic and/or pneumatic lithotripters, and 29.2% used laser. When exiting the kidney, 73.8% placed a nephrostomy tube whereas 26.2% used the tubeless technique. For postoperative follow-up, 51.3% used computed tomography (CT) or ultrasonography plus kidney-ureter-bladder (KUB) to monitor the results of procedures, while 45% used KUB alone. Colonic injury was reported by 8.9%. Average hospital stays of >3 days were reported for 81.2% of procedures.

CONCLUSION

Chinese urologists obtain their own access during PCNL, with ultrasonic guidance in most cases, and almost a half of them are apprenticeship trained. They prefer the prone position, use fascial dilators, and place a nephrostomy tube when exiting the kidney. Most urologists follow the official management guidelines in special cases. Skilled use of urological ultrasound examination, flexible nephroscopy, postoperative CT, tubeless procedures in selected patients, and urology residency training are recommended for PCNL practice.

Frailty as predictor of complications in patients undergoing percutaneous nephrolithotomy (PCNL)

INTRODUCTION & OBJECTIVE

Surgical complications are difficult to predict, despite existing tools. Frailty phenotype has shown promise estimating postoperative risk among the elderly. We evaluate the use of frailty as a predictive tool on patients undergoing percutaneous renal surgery.

METHODS

Frailty was prospectively analyzed using the Hopkins Frailty Index, consisting of 5 components yielding an additive score: patients categorized not frail, intermediate, or severely frail. Primary outcomes were complications during admission and 30-day complication rate. Secondary outcomes included overall hospital length of stay (LOS) and discharge location.

RESULTS

A total of 100 patients recruited, of whom five excluded as they did not need the procedure. A total of 95 patients analyzed; 69, 10, and 16 patients were not frail, intermediate, and severely frail, respectively. There were no differences in blood loss, number of dilations, presence of a staghorn calculus, laterality, or location of dilation. Severely frail patients were likely to be older and have a higher American Society of Anesthesiologists score and Charlson comorbidity index. Patients of intermediate or severe frailty were more likely to exhibit postoperative fevers, bacteremia, sepsis, and require ICU admissions (P < 0.05). Frail patients had a longer LOS (P < 0.001) and tended to require skilled assistance when discharge (p < 0.0001).

CONCLUSIONS

Frailty assessment appears useful stratifying those at risk of extended hospitalization, septic complications, and need for assistance following percutaneous renal surgery. Risks of sepsis, bacteremia, and post-operative hemorrhage may be higher in frail individuals. Preoperative assessment of frailty phenotype may give insight into treatment decisions and represent a modifiable marker allowing future trials exploring the concept of "prehabilitation".

Trends of percutaneous nephrolithotomy in Saudi Arabia

Objective:

The objective of the study was to present the current practice patterns on percutaneous nephrolithotomy (PCNL) in Saudi Arabia and to compare it with the international patterns and to observe the adherence to the guidelines.

Materials and Methods:

A survey consisting of 28 questions was sent to urologists working in Saudi Arabia using a Google Forms questionnaire. The questioner covered most aspects of performing PCNL starting from preparing the patient till discharging him.

Results:

One hundred and thirty-two replied to the survey. Almost 70.2% performed PCNL and 59.1% of them learned PCNL during residency. The access was obtained by the urologists in 80.3% from the participants, 68.2% of them uses fluoroscopic guidance for the puncture. The majority (80.3%) perform PCNL in the prone position. Nearly 69.7% use the balloon dilators and 16.7% use the Amplatz dilators. For kidney drainage, 60.6% place a nephrostomy tube and a double-J stent (DJ stent) together and 4.5% perform tubeless PCNL (DJ stent only). About 45.5% stated that the introduction of flexible ureteroscopy decreased the rate of doing PCNL for >20%.

Conclusions:

Data obtained from a group of urologists in Saudi Arabia showed that the majority of urologists practicing in Saudi Arabia perform PCNL. They usually learn PCNL during residency. We observe that the majority of urologists attach to the original patterns in PCNL, i.e., they predominantly prefer the prone position and use fluoroscopy to gain the PCNL access. Furthermore, the data showed that new trends in PCNL did not gain a lot of momentum as few practices miniaturized PCNL and tubeless PCNL. The majority use balloon dilators and combined ultrasonic/pneumatic lithotripters. The complication rate encountered by the participants is concomitance with the published international figures. The introduction of flexible ureteroscopy highly decreased the rate of doing PCNL for most urologists.

Performance of SOFA, qSOFA and SIRS to predict septic shock after percutaneous nephrolithotomy

OBJECTIVE

The new clinical criteria termed SOFA and qSOFA were demonstrated to be more accurate than SIRS in screening patients at high risk of sepsis. We aim to evaluate the ability of SOFA, qSOFA and SIRS to predict septic shock after PCNL.

PATIENTS AND METHODS

Consecutive patients undergoing PCNL were included to assess the performance of SOFA, qSOFA and SIRS in predicting septic shock, the AUC of ROC curve and decision curve analysis were used, and the optimal cutoff values and their achieving time were calculated.

RESULTS

Of the 431 included patients, 12 (2.7%) cases developed septic shock. Compared with non-septic shock patients, patients with septic shock were more likely to be female, have positive history of urine culture and higher urine leukocyte count, and show increased postoperative serum creatinine, PCT and decreased leukocyte. The optimal cutoff of SOFA, qSOFA and SIRS was > 2, > 0 and > 1, respectively. All of the 12 patients with verified septic shock met SOFA and SIRS criteria, while only 11 cases met qSOFA criterion. SOFA had the identical highest sensitivity (100%) and greater specificity (87% vs. 81%) than SIRS. qSOFA had higher specificity (92%) than both SOFA and SIRS at the expense of lower sensitivity (92%). The AUC of SOFA (0.973) to predict septic shock was greater than that of qSOFA (0.928) and SIRS (0.935). When combined with SIRS, SOFA outperformed qSOFA for discrimination of septic shock (AUC 0.987 vs. 0.978). Decision curve analysis indicated SOFA was clearly superior to both qSOFA and SIRS with a higher net benefit and net reduction in intervention. The qSOFA achieved the best time-based predictive efficiency, with the shortest median time to meet its cutoff, followed by SOFA and SIRS.

CONCLUSION

The performance of SOFA in predicting septic shock after PCNL was slightly greater than qSOFA and SIRS. The comprehensive application of various criteria is recommended to assist early detection of septic shock following PCNL.

Effects of Tranexamic Acid on Bleeding and Hemoglobin Levels in Patients with Staghorn Calculi Undergoing Percutaneous Nephrolithotomy: Randomized Controlled Trial

Background:

The incidence of renal hemorrhage during percutaneous nephrolithotomy (PCNL) is high. We sought to evaluate the effects of tranexamic acid (TXA) on bleeding and hemoglobin levels of patients with staghorn calculi treated with PCNL.

Methods:

In a double-blind clinical trial, 120 patients with staghorn calculi candidated for PCNL in Alzahra Hospital between January 2014 and November 2017, Isfahan, Iran, were classified into two groups in terms of the stone size (>4 cm and <4 cm). The patients in both groups were then randomly assigned to receive either 1 g of TXA intravenously or normal saline. (The generation of random numbers was done by computer.) Thus, there were four groups of 30 patients each. The transfusion rate, the mean volume of blood loss, the operative duration, and the hemoglobin level were compared between the intervention and control groups for each stone-size category. Statistical analysis was performed using SPSS, version 19. The paired and independent t test and the Pearson coefficient correlation were used, and a P value less than 0.05 was considered statistically significant.

Results:

The mean volume of blood loss was significantly higher in the control group patients than in those receiving TXA, in both stone-size categories (P<0.001). There was no significant difference in the postoperative hemoglobin level between the intervention and control groups, in both stone-size categories (P=0.26 and P=0.10, respectively). In addition, the mean volume of blood loss increased significantly with an increase in the operative duration (P<0.001).

Conclusion:

TXA reduced the risk of bleeding during and after PCNL and attenuated the drop in the hemoglobin level in the postoperative period. Longer operative procedures were associated with an increase in the bleeding volume.

Trial Registration Number: IRCT20180209038673N1

Postoperative Emergency Department Visits After Urinary Stone Surgery: Variation Based on Surgical Modality

Introduction: Urinary stone disease is responsible for more than 1 million emergency department (ED) visits annually. There is increasing regulatory and cost pressure to reduce unplanned episodes of care, particularly after elective surgery. However, the frequency of ED visits in the early postoperative period after different modalities of stone surgery is not well characterized. We aimed at describing rates of postoperative ED visits after percutaneous nephrolithotomy (PCNL), ureteroscopy (URS), and extracorporeal shockwave lithotripsy (SWL). Methods: The Agency for Healthcare Research and Quality's Healthcare Cost and Utilization Project (HCUP) state databases for Florida (2010-2012), Iowa (2010-2012), California (2010-2011), and New York (2006-2012) were used to identify patients undergoing PCNL, URS, or SWL. The HCUP State Emergency Department Database was used to identify postoperative ED visits in the first 30 days after surgery. Rates of postoperative ED visits were compared across surgery types with chi-square and multivariate logistic regression. Results: A total of 321,899 patients undergoing stone surgery during the study period were identified, including 151,006 (46.9%) URS, 128,040 (39.8%) SWL, and 42,853 (13.3%) PCNL. PCNL had the highest rate of 30-day postop ED visits (13.2%), followed by URS (10.6%) and SWL (7.5%; p < 0.0001). On multivariate logistic regression adjusting for baseline clinical and sociodemographic characteristics, both PCNL (odds ratio [OR] 1.62, 95% confidence interval [CI] 1.56-1.69) and URS (OR 1.33, 95% CI 1.30-1.37) were independently associated with increased risk of postop ED visit when compared with SWL. Conclusion: Among kidney stone surgeries, PCNL has the highest rate of 30-day postoperative ED visits, whereas SWL has the lowest. Postoperative ED visits are an important outcome for both patients and surgeons, and observed differences across surgical modalities should be incorporated into the preoperative shared decision-making process.

Percutaneous Nephrolithotomy in Children: Analysis of Nationwide Hospitalizations and Short-Term Outcomes for the United States, 2001-2014

OBJECTIVE

To describe population-wide utilization rates and outcomes of percutaneous nephrolithotomy (PCNL) in the management of pediatric upper urinary tract calculi (UUTC).

PATIENTS AND METHODS

Patients <18 years with a diagnosis of UUTC, who underwent PCNL between 2001 and 2014 were identified from the National Inpatient Sample database. Annual PCNL rates, based on the at-risk population for each year, were estimated, and change in utilization rate was analyzed using negative binomial regression. Perioperative outcomes, hospital length of stay (LOS), and costs were determined; continuous and categorical variables were analyzed using nonparametric tests and Chi-squared tests, respectively. Trends tests and multivariable analyses (MVAs) were also performed where appropriate.

RESULTS

An estimated 3206 pediatric PCNL procedures were performed. Mean annual PCNL rate increased significantly relative to 2001 (incidence rate ratio = 1.40; 95% confidence interval 1.15-1.71, p = 0.001). Proportion of PCNL as a fraction of all inpatient surgical procedures for UUTC also significantly increased over time, from 15.7% in 2001 to 26.4% in 2014 (p < 0.0001). Complications overall occurred in 20.7% of cases, with a significantly rising rate over time period (p < 0.0001). Complication rates were similar across hospital types and geographic regions. Median hospitalization cost was significantly higher for the West than for each of the other regions (p < 0.05 in each case). Median LOS was also highest for the West (4 days vs 3 days for each of the other regions). In MVA, significant predictors of both increased LOS and costs included black race, comorbidities of hypertension, diabetes, coagulopathy and neurologic disease, hospitalization in the South, and presence of complications. Race, gender, comorbidities, and treatment year were among the predictors of complications.

CONCLUSIONS

PCNL utilization in the management of pediatric UUTC has significantly increased since 2001, with an associated increase in complication rates, although major complications were uncommon. Regional variations in costs and LOS were evident.

Percutaneous Nephrolithotomy in the 80 Years of Age and Older Population

OBJECTIVE

To evaluate feasibility of percutaneous nephrolithotomy (PCNL) for complex nephrolithiasis in patients 80 years of age and older compared to younger individuals.

METHODS

From an institutional IRB-approved database, 1,647 patients were identified who underwent PCNL from 1999 to 2019. Patients were stratified by age: group 1 (20-59), group 2 (60-79), and group 3 (>80). Statistics were performed using chi-square and ANOVA to compare outcomes.

RESULTS

Of the 1,647 patients, median age was 46, 66, and 83, respectively (P <0.0001). Three patients within group 3 were 90 or older. Females made up 54%, 46%, 56% of patients (P = 0.02). Average stone size with SD was 2.6 ± 2.2, 2.5 ± 2.3, 2.2± 1.9 cm for each group (P = 0.06). Mean preoperative hemoglobin (Hgb) was significantly lower in the 80+ group (13.8, 13.4, 13.1 g/dL, P <.0001). Change in Hgb was not significantly different. There were more Clavien II-IV complications (10.4, 14.4, 28.8%; P = 0.02) and transfusions (2.3, 4.7, 10.2%; P <0.001) in the elderly. The most common complications in the 80+ group were bleeding related (10.1%). No difference in readmission rates or ICU admissions was noted.

CONCLUSION

PCNL is feasible in the extremely elderly; however with a higher rate of complications and longer hospitalizations. No long-term sequelae or deaths in the 80 and older cohort were seen. This study allows us to appropriately counsel older patients on a realistic postoperative course and supports use of PCNL as the best means of long-term survival.

Advances in laser technology and fibre-optic delivery systems in lithotripsy

The flashlamp-pumped, solid-state holmium:yttrium-aluminium-garnet (YAG) laser has been the laser of choice for use in ureteroscopic lithotripsy for the past 20 years. However, although the holmium laser works well on all stone compositions and is cost-effective, this technology still has several fundamental limitations. Newer laser technologies, including the frequency-doubled, double-pulse YAG (FREDDY), erbium:YAG, femtosecond, and thulium fibre lasers, have all been explored as potential alternatives to the holmium:YAG laser for lithotripsy. Each of these laser technologies is associated with technical advantages and disadvantages, and the search continues for the next generation of laser lithotripsy systems that can provide rapid, safe, and efficient stone ablation. New fibre-optic approaches for safer and more efficient delivery of the laser energy inside the urinary tract include the use of smaller-core fibres and fibres that are tapered, spherical, detachable or hollow steel, or have muzzle brake distal fibre-optic tips. These specialty fibres might provide advantages, including improved flexibility for maximal ureteroscope deflection, reduced cross section for increased saline irrigation rates through the working channel of the ureteroscope, reduced stone retropulsion for improved stone ablation efficiency, and reduced fibre degradation and burnback for longer fibre life.

The evolution of percutaneous nephrolithotomy: Analysis of a single institution experience over 25 years

INTRODUCTION

Over time, the incidence of nephrolithiasis has risen significantly, and patient populations have become increasingly complex. Our study aimed to determine the impact of changes in patient demographics on percutaneous nephrolithotomy (PCNL) outcomes.

METHODS

A retrospective analysis of a prospectively collected database was carried out from 1990-2015. Patient demographics, comorbidities, stone and procedure characteristics were analyzed. Multivariate logistic regression was used to evaluate differences in operative duration, complications, stone-free rate, and length of stay.

RESULTS

A total of 2486 patients with a mean age of 54±15 years, body mass index (BMI) of 31±8, and stone surface area of 895±602 mm² were analyzed; 47% of patients had comorbidities, including hypertension (22%), diabetes mellitus (14%), and cardiac disease (13%). Complication rate was 19%, including a 2% rate of major complications (Clavien grade III-V). There was a statistically significant increase in patient age, BMI, and comorbidities over time, which was correlated with an increased complication rate (odds ratio [OR] 1.15; p=0.010). The overall transfusion rate was 1.0% and remained stable (p=0.131). With time, both OR duration (mean Δ 16 minutes; p<0.001) and hospital length of stay (mean Δ 2.4 days; p<0.001) decreased significantly. Stone-free rate of 1873 patients with available three-month followup was 87% and decreased significantly over time (OR 1.09; p<0.001), but was correlated with an increased use of computed tomography (CT) scans for followup imaging.

CONCLUSIONS

Despite an increasingly complex patient population, PCNL remains a safe and effective procedure with a high stone-free rate and low risk of complications.

Laser Endoscopic X-Ray-Guided Intrarenal Tract: Comparison Among Renal Access Modalities in the Porcine Kidney

Introduction and Objectives: Laser endoscopic X-ray-guided intrarenal tract (LEXIT) is a recently described holmium laser retrograde access technique for creating percutaneous access during a percutaneous nephrolithotomy. We compared bleeding, ease of access, and the time to achieve access for each of the following three modalities: LEXIT, retrograde Lawson puncture wire, and antegrade 18-gauge nephrostomy needle access in the porcine kidney. Methods: Eight pigs underwent an average of five nephrostomy accesses per kidney under simultaneous laparoscopic vision at 5 mm Hg insufflation pressure. Data collected included: access time (seconds), bleeding intensity (scale: 1 [no bleeding] - 10 [severe bleeding]), bleeding duration (seconds), accuracy of caliceal entry, and surgeon comfort with the technique (scale: 1 [very easy] - 10 [very difficult]). Results: A total of 64 nephrostomy accesses were obtained. The speed of nephrostomy access with LEXIT was significantly faster than the nephrostomy needle and Lawson wire (p < 0.001). Bleeding intensity (p = 0.002) and severity (p = 0.001) were lower with the Lawson puncture wire, followed by LEXIT and then by the nephrostomy needle. LEXIT was rated as easier in acquiring access within the upper pole (p = 0.003) and interpolar calices (p < 0.001). Histopathology demonstrated no difference in parenchymal damage between LEXIT and nephrostomy needle (p = 0.18); however, LEXIT was associated with significantly increased peri-tract thermal injury, although within a narrow focus of 1.6 mm (p < 0.01). Conclusion: Among the three renal access techniques, LEXIT provided the fastest access times and greatest ease of access specifically for upper pole and interpolar calices. Also, bleeding with LEXIT was significantly less compared with the standard antegrade nephrostomy needle access. Histopathological analysis demonstrated that the holmium laser resulted in focal thermal tissue effects similar in range to the blunt tissue trauma caused by the 18-gauge nephrostomy needle.

Contemporary best practice in the management of staghorn calculi

Staghorn calculi are complex renal stones that occupy the majority of the renal collecting system. These stones are associated with high morbidity and can lead to recurrent urinary tract infections, urosepsis, renal deterioration, and death if left untreated. Managing patients with staghorn calculi can be challenging. Fortunately, advances in technology and endourology techniques have enabled urologists to effectively treat these stones with minimal morbidity to the patient. This article describes the contemporary best practices in the initial evaluation, management, and follow up of patients with staghorn calculi to help the practicing urologist navigate this complex condition.

Mini Versus Standard Percutaneous Nephrolithotomy: The Impact of Sheath Size on Intrarenal Pelvic Pressure and Infectious Complications in a Porcine Model

OBJECTIVE

To determine how sheath and endoscope size affect intrarenal pelvic pressures and risk of postoperative infectious complications comparing "Mini" vs "Standard" percutaneous nephrolithotomy (PCNL).

MATERIALS AND METHODS

Uropathogenic Escherichia coli were grown and 10⁹ of them were instilled into the porcine renal pelvis through retrograde access for 1 hour. Percutaneous access utilized a 14/16F 20 cm ureteral access sheath for the Mini arm and a 30F sheath for the Standard arm. Nephroscopy was simulated utilizing either an 8/9.8F semirigid ureteroscope or 26F nephroscope for 1 hour while intrarenal pelvic pressure was continuously monitored. Blood and tissue cultures of kidney, liver, and spleen biopsies were plated and incubated and positive cultures were confirmed with polymerase chain reaction.

RESULTS

Intrapelvic pressures were higher in the Mini group, 18.76 ± 5.82 mm Hg vs 13.56 ± 5.82 mm Hg (p < 0.0001). Time spent above 30 mm Hg was greater in the Mini arm, 117.0 seconds vs 66.1 seconds (p = 0.0452). All pigs had positive kidney tissue cultures whereas spleen cultures were positive in 100% and 60% of pigs in the Mini and Standard arms, respectively (p = 0.0253); 90% and 30% had positive liver tissue culture in the Mini and Standard arms, respectively (p = 0.0062). Blood cultures were positive in 30% of pigs in the Mini arm compared with none in the Standard arm (p = 0.0603).

CONCLUSION

Mini-PCNL was associated with higher intrarenal pressures and higher risk of end organ bacterial seeding in the setting of an infected collecting system. This suggests a higher potential for infectious complications in a clinical setting.

Recent surgical treatments for urinary stone disease in a Korean population: National population-based study

OBJECTIVES

To provide surgical treatment trends for urinary stone disease in Korea.

METHODS

We analyzed medical service claim data of surgical treatments to urinary stone disease submitted by medical service providers from the Health Insurance Review and Assessment Service from 2009 to 2016.

RESULTS

There was a significantly increasing trend among outpatients and inpatients for urinary stone disease from 2009 to 2016 (R²  = 0.643, P = 0.017; R²  = 0.575, P = 0.029). The number of shock wave lithotripsy for treating urinary stone disease increased by 16% from 89 553 in 2009 to 104 013 in 2016 (R²  = 0.684). The number of ureteroscopic lithotripsy increased by 97% from 6106 in 2009 to 12 057 in 2016 (R²  = 0.99). The number of flexible ureteroscopic lithotripsy increased by 16-fold from 219 in 2009 to 3712 in 2016 (R²  = 0.756). The number of percutaneous nephrolithotomy increased by 99.7% from 919 in 2009 to 1835 in 2016 (R²  = 0.987). The use of non-contrast and contrast-enhanced computed tomography in the diagnostic codes for urinary stone disease increased by 394.8% and 263.3% from 2009 to 2016, respectively (R²  = 0.83; R²  = 0.967). Conversely, the use of intravenous pyelography decreased 26.2% over the same period (R²  = 0.945).

CONCLUSIONS

Outpatient and inpatient procedures for urinary stone disease have increased over the past 8 years in Korea. Shock wave lithotripsy is the most widely used treatment modality for urinary stone disease, and endoscopic surgical procedures are rapidly being implemented. There has been a steep increase in the use of computed tomography, whereas conventional intravenous pyelography is declining.

Comparison of Scoring Systems in Predicting Success of Percutaneous Nephrolithotomy

Background:

Scoring systems are useful to inform the patients about the success and complication rates of the operation prior the surgery.

Aims:

To determine the applicability of the popular scoring systems (Guy’s, stone size, tract length, obstruction, number of involved calices, and essence/stone density and Clinical Research Office of the Endourological Society) by means of examining preoperative data of patients treated with percutaneous nephrolithotomy.

Study Design:

Cross sectional study.

Methods:

We retrospectively reviewed files of the patients who had undergone percutaneous nephrolithotomy in our center between 2011 and 2015. Excluded from the study were patients aged <18 years, and those who were not assessed preoperatively with computed tomography. Preoperative computed tomography images of all patients were assessed by a single observer, and patients were graded based on three scoring system. Demographic data were analyzed along with perioperative data (operation, fluoroscopy, length of hospital stay, changes in hematocrit values, location, and number of access sites, stone-free and complication rates).

Results:

A total of 298 patients who had been treated with 300 procedures were enrolled into the study. Mean age, stone burden, number of stones, and density were 48.1±12.9 years, 663.5±442.8 mm², 1.8±1.1 and 888.3±273 HU respectively. Scores of the cases based on Guy’s, stone size, tract length, obstruction, number of involved calices, and essence/stone density, and Clinical Research Office of the Endourological Society scoring system were calculated as 2, 7.6, and 222.1 points respectively. 81.6% of the patients were stone-free. Complications were detected in 30 (9.9%) patients. Based on receiver operating characteristic curve analysis a positive correlation was detected between success rate and scoring systems, i.e., Guy’s (p=<0.001, r=-0.309), stone size, tract length, obstruction, number of involved calices, and essence/stone density (p=<0.001, r=-0.295), and Clinical Research Office of the Endourological Society (p=<0.001, r=0.426). The Clinical Research Office of the Endourological Society scoring system had the highest predictive value. The sensitivity rates rates for Guy’s, Clinical Research Office of the Endourological Society and Stone scoring system were as 78.78%, 80% and 82.34% respectively.

Conclusion:

All of scoring systems predicted correctly the success of the percutaneous nephrolithotomy procedures. The Clinical Research Office of the Endourological Society scoring system had the highest predictive value.

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.

The Influence of Super-Mini Percutaneous Nephrolithotomy on Renal Pelvic Pressure In Vivo

OBJECTIVE

Renal pelvic pressure (RPP) is expected to rise during percutaneous procedures. A very small tract size was expected to bring high RPP, and super-mini percutaneous nephrolithotomy (SMP) uses a 14F sheath, which is even smaller than that used in mini-percutaneous nephrolithotomy, so the RPP in SMP was more worrisome. Interestingly, the sheath had suction, which aimed to decrease the RPP, so we measured the RPP in an in vivo model to explore the relationship of implying negative pressure through the sheath with the RPP.

METHODS

Seventy-four consecutive patients were enrolled for RPP measurement during SMP between April 2016 and July 2017. Prospective RPP measurements were recorded using the MINDRAY-PM9000 monitor by connecting its baroceptor of the invasive blood pressure channel to a retrogradely inserted renal pelvic open-ended ureteric catheter. RPP data were collected each second by a computer program. All data were evaluated statistically with SPSS 13.0 software.

RESULTS

During SMP with a 14F irrigation-suction sheath, the average RPP was 19.51 ± 5.83 mm Hg. The median accumulative time of RPP ≥30 mm Hg was 55 (3-345) seconds. Postoperative fever was recorded in four patients (5.4%). A receiver operating characteristic -curve analysis showed that when suction pressure was set to 0.03 Mpa (≈230 mm Hg), irrigation pressure between 200 and 250 mm Hg, and the irrigation flow to 320 mL/minute, the accumulative high RPP was more likely <50 seconds, and the sensitivity and specificity were 75.0% and 66.7%, respectively.

CONCLUSIONS

The RPP in SMP remains <30 mm Hg. Controlling the pressures as well as the flow of irrigating saline is important for the safety and efficiency of percutaneous procedures.

Metabolic evaluation guidelines in patients with nephrolithiasis: Are they being followed? Results of a national, multi-institutional, quality-assessment study

INTRODUCTION

The significant cost burden of kidney stones underscores the importance of best clinical practice in kidney stone management. We evaluated adherence to kidney stone metabolic evaluation guidelines in a Canadian population and the interest of patients with regard to prevention.

METHODS

A questionnaire based on Canadian Urological Association (CUA) best practice guidelines was designed. Patients presenting for extracorporeal shockwave lithotripsy treatment (ESWL) were administered this questionnaire to evaluate risk factors of stone disease and assess the use of metabolic evaluations. Patients were asked if they received explanations about their results and if they were interested in kidney stone prevention.

RESULTS

We identified 530 patients at five academic institutions; 79.4% had at least one indication to receive a metabolic evaluation (high-risk stone formers), which increased to 96.6% if first-time stone formers whom reported an interest in metabolic evaluation were included. However, only 41.1 % of these patients had a metabolic evaluation. Endourologists ordered metabolic evaluation more often than other referring urologists (63.6% vs. 36.5%; p<0.001). Furthermore, urologists ordered metabolic evaluations more often than other prescribing physicians (68.9% vs. 31.1%; p<0.001). Sixty-two percent of patients received explanations about their metabolic evaluation results and 77.5% understood them. Regarding prevention, 84.1% and 83.8% were interested in more explanations and in following a diet or taking a medication, respectively.

CONCLUSIONS

Adherence to CUA metabolic evaluation guidelines is suboptimal and could be improved by urologists referring patients for ESWL. Communication between physician and patient may not be adequate. The majority of stone formers are interested in kidney stone prevention.

Current trends of percutaneous nephrolithotomy in a developing country

Introduction

To present the current practice patterns on percutaneous nephrolithotomy (PCNL) in a developing country.

Materials and Methods

A survey was offered to Brazilian urologists during the II International Endourology Symposium held in Sao Paulo, in 2015. The first seven questions were related to demographic data while the 20 remaining were directed to urologists who performed PCNL.

Results

From 250 participants, 100 replied to the survey, 81% performed PCNL and 60.4% of performers had been in practice for less than 15 years. Eighty-one percent were trained in the prone position and 64% in supine. PCNL was learned during the residency in 66.7% and 2.5% had fellowship training. Prone position was the preferred decubitus for simple or complex calculi, though for obese patients there was no difference. Younger surgeons prefer supine while older surgeons prefer prone. The access was obtained by the surgeon in all cases, 96.3% use fluoroscopy and 3.7% prefer ultrasonography. Forty-seven percent use ultrasonic lithotripters and 4.1% laser. For kidney drainage, 71.6% place a nephrostomy tube. Double J stent is left in 77%. The postoperative image method was CT for 50%. Colonic injury was reported by 25%, predominantly in the senior group without statistically difference between positions.

Conclusions

From a selected group of urologists, we observe that Brazilian urologists usually gain their own access for PCNL guided by fluoroscopy. They predominantly prefer the prone position, use fascial dilators, ultrasonic lithotripters and place a nephrostomy tube when exiting the kidney. Fellowship programs, ultrasonography, flexible nephoscopy and tubeless procedures could be encouraged.

Comparison of two different renal access techniques in one-stage percutaneous nephrolithotomy: triangulation versus eye of the needle

BACKGROUND

Two primary methods used to create appropriate percutaneous renal access under fluoroscopic guidance are the triangulation technique (TT) and the "eye of the needle" (EN) technique. To the best of our knowledge, no study has yet compared the EN versus TT renal access methods that precede one-stage dilatation during percutaneous nephrolithotomy (PCNL).

OBJECTIVES

Compare effects of renal access techniques on the stone-free rate of one-stage PCNL, and the influence on outcomes.

DESIGN

Retrospective cross-sectional study.

SETTINGS

Tepecik Training and Research Hospital, Turkey.

PATIENTS AND METHODS

The records of patients with renal stones larger than 2 cm in diameter who underwent PCNL in our hospital between January 2008 and September 2017 were retrieved. Patients who had undergone one-stage PCNL with the EN renal access technique (EN group) were compared with patients who had undergone one-stage PCNL with the TT renal access technique (TT group).

MAIN OUTCOME MEASURES

Operative time, stone size, access location, stone side, length of hospital stay, Hounsfield unit (HU), fluoroscopy time, change in hemoglobin level, complications (modified Clavien classification) and stone-free rate.

SAMPLE SIZE

195.

RESULTS

Of 272 records, 195 met inclusion criteria. The one-stage PCNL stone-free rate and other outcomes did not differ significantly between the EN (n=91, 46.7%) and TT groups (n=104, 53.3%).

CONCLUSION

According to our study, renal access for one-stage PCNL can be achieved using either the EN or TT technique. The renal access technique used does not independently affect the complication rate.

LIMITATIONS

Retrospective, small sample size, and no comparison of body mass index.

CONFLICT OF INTEREST

None.

A contemporary lower pole approach for complete staghorn calculi: outcomes and efficacy

PURPOSE

Percutaneous nephrolithotomy (PCNL) is the preferred surgical treatment for staghorn stones. Two approaches are commonly employed to gain access into the collecting system which consists of either an upper pole (UP) approach or lower pole (LP) approach. However, opinions vary on which approach offers the best access and outcome. In this study, we aim to challenge the traditional paradigm that staghorn stones are most effectively treated through a prone UP approach. We herein report our institutional experience using a prone LP access in PCNL for patients with complete staghorn stones.

METHODS

Data were prospectively collected over 3 years on 473 PCNL procedures, of which 76 patients had complete staghorn calculi (five or more calyces). Operative and peri-operative outcomes were analyzed to compare a modified LP approach with the more widely accepted UP approach.

RESULTS

A total of 59/76 (77.6%) patients had LP access. There was no difference in the ability of completing the surgery utilizing a single tract as opposed to multiple tracts (74.6% of LP patients vs. 76.5% of UP patients). Stone-free rates for LP and UP access were similar (74.5 versus 70.5%, respectively; p = 0.760. Complication rates were lower for LP access vs. UP access (3.4 vs. 23.5%, p = 0.02) with two pulmonary complications in the UP group. Overall median operative time was not significantly different between LP and UP access (112.0 vs. 126.0 min, p = 0.486).

CONCLUSIONS

Prone LP access demonstrated similar efficacy with decreased morbidity in patients with complete staghorn calculi compared to prone UP access.

National Imaging Trends after Percutaneous Nephrolithotomy

PURPOSE

Followup imaging after percutaneous nephrolithotomy serves to detect postoperative complications, residual fragments and silent hydronephrosis. However, the timing and optimal imaging modality remain poorly defined. We describe imaging use patterns after percutaneous nephrolithotomy.

MATERIALS AND METHODS

In the MarketScan® database we identified patients 17 to 64 years old who underwent percutaneous nephrolithotomy between 2007 and 2014. Imaging modalities were identified by CPT, and ICD-9 and 10 codes, and tracked for 1 year after percutaneous nephrolithotomy. The modalities included computerized tomography, renal ultrasound, abdominal x-ray and intravenous pyelogram. Cumulative longitudinal use patterns were characterized and the association with demographic factors was assessed by the chi-square test.

RESULTS

Of the 6,495 patients included in analysis 29% and 15% had undergone no postoperative imaging by 3 and 12 months, respectively. While abdominal x-ray was the most common modality at 3, 6 and 12 months, performed in 46%, 53% and 62% patients, respectively, nearly 50% underwent computerized tomography by 1 year. Of these patients 34% underwent computerized tomography within 3 months, which was done within the first 3 days in 69%. During the study period renal ultrasound use increased by 13% while computerized tomography and abdominal x-ray use remained relatively stable. Female gender, residence in the Northeast, no health maintenance organization status and treatment in a metropolitan statistical area were independently associated with higher rates of renal ultrasound on multivariate analyses (p <0.05).

CONCLUSIONS

Among insured adults national imaging patterns vary following percutaneous nephrolithotomy. Many patients do not receive any followup imaging while approximately half undergo computerized tomography within a year. Imaging patterns may be evolving with the increased use of ultrasound.

Outcomes of more than 1 000 percutaneous nephrolithotomies and validation of Guy's stone score

OBJECTIVE

To present the experience with percutaneous nephrolithotomy (PCNL) at a high-volume Brazilian centre and to evaluate Guy's stone score (GSS) as a predictor of success and complications in PCNL.

PATIENTS AND METHODS

We prospectively evaluated patients who underwent PCNL between June 2011 and October 2016. Indications for PCNL included renal stones >2 cm in size and stones <2 cm in size in which first-line techniques had failed. All patients underwent a complete preoperative evaluation, including non-contrast-enhanced abdominal computed tomography (CT). Stone complexity was assessed using GSS. Success was defined as the absence of fragments >2 mm on CT on postoperative day 1. Complications were classified according to the Clavien grade.

RESULTS

A total of 1 066 PCNLs were performed on 891 patients. In all, 20.2% were classified as GSS1, 27.4% as GSS2, 35.0% as GSS3, and 17.4% as GSS4. The mean operating time was 108.44 min, and the mean fluoroscopy time was 13.57 min. The overall immediate success rate based on postoperative day 1 CT was 43.8%. Complications occurred in 14.9% of cases, and the mean length of hospital stay was 54.55 h. Stratifying patients according to GSS, success rate was inversely proportional to the calculus complexity: GSS1: 87.9%; GSS2: 62.1%; GSS3: 44.0%; and GSS4: 24.3% (P < 0.001). Higher GSS categories were significantly correlated with the number of puncture tracts (P < 0.001), operating time (P < 0.001), fluoroscopy time (P < 0.001), blood transfusion rate (P < 0.001), complications (P < 0.001) and length of stay (P < 0.001).

CONCLUSION

In a high-volume centre, PCNL was a reliable surgical technique, with low morbidity and short hospital stay. GSS was confirmed to be a very useful tool for predicting the outcomes of PCNL, and its use should be encouraged.

Elevated Renal Pelvic Pressures during Percutaneous Nephrolithotomy Risk Higher Postoperative Pain and Longer Hospital Stay

PURPOSE

Renal pelvic pressure may vary during percutaneous nephrolithotomy. We sought to determine the relationship of postoperative pain to endoscope caliber, renal pelvic pressure and hospital stay.

MATERIALS AND METHODS

We reviewed the records of 20 percutaneous nephrolithotomies done under ureteroscopic guidance with renal pelvic pressure monitoring. The ureteroscope working channel was connected to a pressure transducer and used to determine renal pelvic pressure at baseline, when irrigating with a 26Fr rigid nephroscope and a 16Fr flexible nephroscope, and during suction. Patient demographics, operative characteristics, Likert pain scores and length of hospital stay were compared as stratified by average renal pelvic pressure. The Mann-Whitney U and Fisher exact tests were used with p <0.05 considered significant.

RESULTS

A total of 220 measurements were recorded in 20 patients undergoing single access percutaneous nephrolithotomy. Mean patient age was 55.2 years (range 20 to 77) and mean body mass index was 32.4 kg/m² (range 18 to 53.3). Rigid nephroscopy resulted in significantly higher average renal pelvic pressure than flexible nephroscopy (30.3 vs 12.9 mm Hg, p = 0.007). Average renal pelvic pressure was 30 mm Hg or greater in 7 patients (35%) undergoing rigid nephroscopy and in none (0%) undergoing flexible nephroscopy (p <0.01). Patients exposed to an average renal pelvic pressure of 30 mm Hg or greater during rigid nephroscopy had significantly higher average pain scores (p = 0.004) and longer hospital stays (p = 0.04) than patients with renal pelvic pressure less than 30 mm Hg. Average renal pelvic pressure 30 mm Hg or greater during rigid nephroscopy was also associated with a longer skin to calyx distance (105.5 vs 79.7 mm, p = 0.03).

CONCLUSIONS

Knowledge of the factors that influence renal pelvic pressure and methods to control pressure extremes may improve patient outcomes during percutaneous nephrolithotomy.

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

PURPOSE

To investigate the contemporary trends and perioperative outcomes of percutaneous nephrolithotomy (PCNL) by using a population-based cohort.

MATERIALS AND METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Burden of Urolithiasis: Trends in Prevalence, Treatments, and Costs

CONTEXT

The recent evolution of management options for urolithiasis has presented a unique dilemma for the modern urologist. A comprehensive understanding of epidemiological trends along with current provider preferences in treating urinary stones would be beneficial.

OBJECTIVE

To review trends in the prevalence, treatments, and costs of urolithiasis worldwide.

EVIDENCE ACQUISITION

A literature review was performed using the MEDLINE database, the Cochrane Library Central search facility, Web of Science, and Google Scholar between 1986 and 2016. Keywords used for the search were "urolithiasis" and "prevalence; treatment; and cost".

EVIDENCE SYNTHESIS

The incidence and prevalence of urinary stones are rising around the world, including regions that have historically had low rates of urolithiasis. Common theories explaining this trend involve climate warming, dietary changes, and obesity. Shockwave lithotripsy (SWL) has been the preferred mode of treatment since its introduction in the 1980s. However, ureteroscopy (URS) has become increasingly popular for small stones regardless of location because of lower recurrence rates and costs. Developing countries have been slower to adopt URS technology and continue to use percutaneous nephrolithotomy at a steady rate.

CONCLUSIONS

URS has recently challenged SWL as the treatment modality preferred for small upper urinary tract stones. In some cases it is less expensive but still highly effective. As the burden of stone disease increases worldwide, appropriate selection of stone removal therapies will continue to play an important role and will thus require further investigation.

PATIENT SUMMARY

Urinary stones are becoming more prevalent. Recent advances in technology have improved the management of this disease and have decreased costs.

Percutaneous Nephrolithotomy Increases the Risk of New-onset Hypertension: A Nationwide 6-Year Follow-up Study

OBJECTIVE

To determine whether percutaneous nephrolithotomy or ureteroscopic lithotripsy leads to the development of hypertension, using the Taiwan National Health Insurance database.

METHODS

Data were sourced from the Longitudinal Health Insurance Database (LHID2000) of Taiwan, Republic of China, compiled by the Taiwan National Health Insurance database from 1996 to 2010. Percutaneous nephrolithotomy and ureteroscopic lithotripsy were studied as time-dependent covariates in a Cox proportional hazard model to estimate the hazard ratio for the effect of new-onset hypertension.

RESULTS

A total of 2552 patients were included, with 232 PNL percutaneous nephrolithotomy, 1160 ureteroscopic lithotripsy patients, and 1160 comparison patients. There was a significant difference between the incidence of new-onset hypertension between the percutaneous nephrolithotomy and comparison groups (adjusted hazard ratio 1.48, 95% confidence interval 1.13-1.95, P = .005). The percutaneous nephrolithotomy group also had a higher incidence of new-onset hypertension than the ureteroscopic lithotripsy group (adjusted hazard ratio 1.39, 95% confidence interval 1.06-1.83, P = .018). The incidence rate of new hypertension during the follow-up period was 44.5 per 1000 person-years in the percutaneous nephrolithotomy group, 33.0 per 1000 person-years in the ureteroscopic lithotripsy group, and 30.2 per 1000 person-years in the comparison group.

CONCLUSION

An association exists between nephrolithiasis patients who were treated with percutaneous nephrolithotomy and subsequent hypertension diagnosis. Although the exact mechanisms for this phenomenon are not clear, patients who undergo percutaneous nephrolithotomy may need close monitoring of blood pressure during postoperative follow-up.

The Effect of Obesity on Perioperative Outcomes Following Percutaneous Nephrolithotomy

OBJECTIVES

To test if obesity predisposes to higher rates of adverse outcomes after percutaneous nephrolithotomy (PCNL).

MATERIALS AND METHODS

Within the Nationwide Inpatient Sample (NIS), we identified patients treated with PCNL between 1998 and 2010 for kidney stones. We examined the temporal trends in PCNL use and charges among obese and nonobese patients. We then tested the effect of obesity on perioperative complications, transfusions, length of stay (LOS), and total hospital charges (THCs). LOS and THCs were defined as a continuous variable and were also dichotomized according to the 75th percentile into prolonged LOS (pLOS) and increased THCs (iTHCs). Then, multivariable models were fitted.

RESULTS

Overall, a weighted sample of 90,529 individuals treated with PCNL between 1998 and 2010 was examined. Of those patients, 9300 were obese (10.3%). The proportion of PCNLs performed in obese patients increased throughout the years from 7.4% to 16.7% (p < 0.001). Overall complication rates were 21.6% vs 22.0% (p = 0.3) and transfusion rates were 4.3% vs 4.0% (p = 0.1) for obese and nonobese patients, respectively. Obese patients had fewer genitourinary complications (13.4% vs 15.0%, p < 0.001), but had higher rates of sepsis (1.7% vs 1.3%, p = 0.009) as well as respiratory (3.0% vs 2.5%, p = 0.002) and vascular complications (0.3% vs 0.2%, p = 0.007). Conversely, pLOS (20.9% vs 18.8%, p < 0.001) and iTHCs (30.8% vs 24.4%, p < 0.001) were more frequently recorded in obese patients. In multivariable analyses, obesity was neither associated with higher rates of overall complications (odds ratio [OR], p = 0.3) nor with higher rates of transfusions (p = 0.3). However, obesity was associated with pLOS (OR: 1.21, p = 0.002) as well as iTHCs (OR: 1.17, p = 0.002).

CONCLUSIONS

PCNL in obese patients did not result in higher rates of individual complications or transfusions. However, it resulted in higher rates of pLOS and iTHCs.

Trends in urological stone disease: a 5-year update of hospital episode statistics

OBJECTIVE

To provide a 5-year follow-on update on the changes in prevalence and treatment of upper urinary tract (UUT) stone disease in England.

METHODS

Data from the Hospital Episode Statistics (HES) website (http://www.hesonline.nhs.uk) were extracted, summarised, analysed, and presented.

RESULTS

The total number of UUT stone hospital episodes increased slightly from 83 050 in 2009-2010 to 86 742 in 2014-2015 (4.4% increase). The use of shockwave lithotripsy (SWL) for treating all UUT stones remained stable over the 5-year study period following a significant increase in previous years. There was a 49.6% increase in the number of ureteroscopic stone treatments from 12 062 in 2009-2010 to 18 055 in 2014-2015. Increase in ureterorenoscopy (flexible ureteroscopy) showed the most rapid increase from 3 267 to 6 631 cases in the 5-year study period (103% increase). The gap between the total number of ureteroscopies and SWL treatments continues to narrow. Open stone surgery continued to decline with only 30 reported cases in 2014-2015. Due to the continued rapid increase in the number of ureteroscopies performed, treatment for stone disease has continued to increase significantly in comparison to other urological activity.

CONCLUSION

This study provides an update on the changing landscape of the management of UUT stones in England. It shows a sustained high prevalence of stone disease commensurate with levels in other developed countries. This study reveals a trend in the last 5 years to surgically intervene on a higher proportion of patients with stones. As in other countries, there is a significant increase in the use of ureteroscopy (particularly intrarenal flexible ureteroscopy) in England. These data have important implications for work-force planning, training, service delivery, and research in the field of urolithiasis.

Salvage Percutaneous Nephrolithotomy: Analysis of Outcomes following Initial Treatment Failure

PURPOSE

Percutaneous nephrolithotomy has high potential for morbidity or failure. There are limited data regarding risk factors for failure and to our knowledge no published reports of surgical outcomes in patients with prior failed attempts at percutaneous stone removal.

MATERIALS AND METHODS

We identified patients referred to 3 medical centers after prior failed attempts at percutaneous nephrolithotomy. A retrospective chart review was performed to analyze reasons for initial failure and outcomes of salvage percutaneous nephrolithotomy. Outcomes were compared to those in a prospectively maintained database of more than 1,200 patients treated with a primary procedure.

RESULTS

Salvage percutaneous nephrolithotomy was performed in 31 patients. Unsuitable access to the stone was the reason for failure in 80% of cases. Other reasons included infection, bleeding and inadequate instrument availability in 6.5% of cases each. Compared to patients who underwent primary percutaneous nephrolithotomy those treated with salvage were more likely to have staghorn calculi (61.3% vs 31.4%, p <0.01) and a larger maximum stone diameter (3.7 vs 2.5 cm, p <0.01), and require a secondary procedure (65.5% vs 42.1%, p <0.01). There was no significant difference between the cohorts in the remaining demographics or perioperative outcomes. All patients were deemed completely stone free except one who elected observation for a 3 mm nonobstructing fragment.

CONCLUSIONS

Despite the more challenging nature and prior unsuccessful attempts at treatment, the outcomes of salvage percutaneous nephrolithotomy were no different from those of primary percutaneous nephrolithotomy when performed by experienced surgeons.