Comparison of stone-free rates following shock wave lithotripsy, percutaneous nephrolithotomy, and retrograde intrarenal surgery for treatment of renal stones: A systematic review and network meta-analysis

Tip bendable suction ureteral access sheath versus traditional sheath in retrograde intrarenal stone surgery: an international multicentre, randomized, parallel group, superiority study

Background

Retrograde intrarenal surgery (RIRS) is the main treatments for upper urinary tract stones. The Ureteral Access Sheath (UAS) serves as a supplementary tool, facilitating direct kidney access during RIRS. High quality of evidence comparing tip bendable suction ureteral access sheath (S-UAS) with traditional UAS in RIRS for the treatment of renal and ureteral stones is lacking. The purpose of the study is to compare the efficacy and safety of S-UAS with traditional UAS in RIRS for the treatment of renal or ureteral stones ≤30 mm.

Methods

An international, multicenter, and superiority randomized controlled trial included 320 intention-to-treat patients across 8 medical centers in China, the Philippines, Malaysia and Turkey from August 2023 to February 2024. The inclusion criteria were patients ≥18 years old with renal or ureteral stones ≤30 mm. RIRS was performed using either S-UAS or traditional UAS. The primary outcome was the immediately stone-free rate (SFR). Secondary outcomes included SFR 3 months after operation, operating time, hospital stay, auxiliary procedures, complications (using the Clavien-Dindo grading system), and improvement in the Quality of Life (QoL) score. Differences between proportions [risk difference (RD)]/means [mean difference (MD)] and 95% confidence intervals (CI) were presented. This study is registered at ClinicalTrials.gov: NCT05952635.

Findings

The S-UAS group demonstrated a significantly higher immediately SFR (81.3% versus 49.4%; RD 31.9%; 95% CI 22.5%-41.7%; p = 0.004) compared to the traditional UAS group, as determined by the one-side superiority test. Additionally, the S-UAS group exhibited a higher SFR at 3 months post-operation (87.5% versus 70.0%; RD 17.5%; 95% CI 8.7%-26.3%; p < 0.001), lower postoperative fever rate (RD -11.9%; 95% CI -18.7% to -4.9%; p < 0.001), reduced use of stone baskets (RD -70.6%; 95% CI -77.8% to -63.5%; p < 0.001), and better QoL improvement (MD 7.25; 95% CI 2.21-12.29; p = 0.005). No statistically significant differences were observed in operation time, hospital stay, or the need for second-stage RIRS.

Interpretation

In RIRS for upper urinary tract stones ≤30 mm, S-UAS exhibited superior performance compared to traditional UAS, demonstrating higher SFR, reduced postoperative fever rate, and improved QoL outcomes. S-UAS emerges as a prudent and advantageous alternative to traditional UAS for RIRS.

Funding

National Natural Science Foundation of China and Guangdong Province, and Zhejiang Medicine and Health Program.

Impact of frailty on perioperative outcomes following percutaneous nephrolithotomy in older persons: evidence from the US Nationwide Inpatient Sample

To evaluate the impact of frailty on perioperative outcomes of older patients undergoing PCNL, utilizing the US Nationwide Inpatient Sample (NIS) database. Data of hospitalized patients ≥ 60 years who received PCNL were extracted from the 2010 to 2020 NIS database, and included demographics, clinical, and hospital-related information. Patients were assigned to low (< 5), medium (5-15), and high frailty risk (> 15) groups based on the hospital frailty risk score (HFRS). Associations between frailty risk and perioperative outcomes including total hospital cost were determined using population-weighted linear and logistic regression analyses. Data of 30,829 hospitalized patients were analyzed (mean age 72.5 years; 55% male; 78% white). Multivariable analyses revealed that compared to low frailty risk, increased frailty risk was significantly associated with elevated in-hospital mortality (adjusted odds ratio (aOR) = 10.70, 95% confidence interval (CI): 6.38-18.62), higher incidence of unfavorable discharge (aOR = 5.09, 95% CI: 4.43-5.86), prolonged hospital length of stay (LOS; aOR = 7.67, 95% CI: 6.38-9.22), increased transfusion risk (aOR = 8.05, 95% CI: 6.55-9.90), increased total hospital costs (adjusted Beta = 37.61, 95% CI: 36.39-38.83), and greater risk of complications (aOR = 8.52, 95% CI: 7.69-9.45). Frailty is a significant prognostic indicator of adverse perioperative outcomes in older patients undergoing PCNL, underscoring importance of recognizing and managing frailty in older patients.

Related factors of perioperative low body temperature and incidence of postoperative shivering in patients undergoing complex percutaneous nephrolithotomy and the effect analysis of composite insulation nursing intervention

This study aimed to analyze the factors associated with intraoperative hypothermia and postoperative shivering rates in patients undergoing complex percutaneous nephrolithotomy (PCNL) and investigate the effects of combined insulation nursing intervention. A total of 168 patients were included, with 103 patients in the control (Ctrl) group receiving routine care and 65 patients in the nursing (Nur) group receiving combined insulation nursing intervention measures. General information, surgical data, temperature, intraoperative hypothermia incidence, postoperative shivering, and complication rates were statistically analyzed between the two groups. Patient temperature, blood pressure, and blood gas indicators including pH value, bicarbonate, and lactate levels were recorded at admission (T0), before anesthesia (T1), 30 min after spinal-epidural combined anesthesia (T2), 60 min (T3), 90 min (T4), 120 min (T5), and postoperatively (T6). The results demonstrated that the average intraoperative temperature of patients in the Nur group was significantly higher than that of the Ctrl group (P < 0.001), and their incidence of hypothermia was significantly lower than that of the Ctrl group (P < 0.01). Additionally, the Nur group exhibited shorter recovery time (18.36 ± 3.58 min), extubation time (28.01 ± 3.12 min), and length of hospital stay (8.45 ± 2.14 days) compared to the Ctrl group (P < 0.05). The incidence of postoperative shivering was 4.62 %, significantly lower than that of the Ctrl group (P < 0.001). Multifactorial analysis revealed that age ≥60 years, stone diameter ≥3.0 cm, irrigation volume ≥3000 mL, nursing intervention measures, and surgical duration were the main factors influencing the occurrence of intraoperative hypothermia. Age ≥60 years, nursing intervention measures, surgical duration, and intraoperative temperature<36 °C are identified as major risk factors for postoperative shivering. This indicates that specialized nursing care and combined insulation nursing intervention measures in patients undergoing complex percutaneous nephrolithotomy contribute to reducing the incidence of intraoperative hypothermia and postoperative shivering. It is recommended to promptly address the risk factors associated with hypothermia and shivering during and after surgery to mitigate the risk of perioperative complications.

Percutaneous nephrolithotomy for adult renal transplant de novo graft lithiasis: a single center analysis and systematic review of the literature

INTRODUCTION/OBJECTIVE

Graft stones in renal transplant recipients pose a unique challenge, finding effective interventions to ensure optimal graft function and patient well-being. Various methods of stone clearance have been described for graft stones, including percutaneous nephrolithotomy (PCNL). While PCNL is a promising approach for managing graft stones, specific outcomes and associated characteristics for this approach have not been comprehensively evaluated before. This study aims to evaluate the safety and efficacy of the use of PCNL as the primary intervention of graft stones by assessing stone-free rates (SFR), treatment impact on graft function, and perioperative complications.

METHODS

A retrospective clinical audit was performed for all transplants performed in a single center from 2007 to 2022, which included all graft lithiasis patients who were treated with PCNL. Both perioperative parameters and post-operative outcomes were collected. In addition, a systematic review including articles from MEDLINE, Embase, Web of Science yielded 18 full-text articles published between 1/1/2000 and 15/11/2023. The results pertaining to patients who underwent PCNLs for graft stones were cross-referenced and thoroughly evaluated. The review encompassed a comprehensive analysis of clinical data, postoperative outcomes, and procedural details. The protocol for the systematic review was prospectively registered on PROSPERO (CRD42023486825).

RESULTS

In our center, 6 graft lithiasis patients were treated with PCNL. The initial SFR was 83.3%. SFR at 3 months and 1 year were both 100.0%. SFR at 3 years was 66.7%. Other centers reported initial SFR of 82.6-100.0% (interquartile range). SFR at 3 months, 1 year, 3 years was not well reported across the included studies. Incidence of graft lithiasis ranged from 0.44%-2.41%. Most common presentations at diagnosis were oliguria/anuria/acute kidney injury and asymptomatic. Reported complications included blood loss, transient hematuria, high urine output, sepsis, and damage to surrounding structures. The most commonly reported metabolic abnormalities in transplant lithiasis patients included hyperuricemia and hyperparathyroidism.

CONCLUSION

PCNL is a practical and efficient choice for addressing graft lithiasis, demonstrating excellent stone clearance and minimal perioperative complications. These findings show the importance of PCNL as a primary intervention in this complex patient population.

Comparative Analysis of Super-Mini Percutaneous Nephrolithotomy and Retrograde Intrarenal Surgery for the Management of Renal Calculi ≤2 cm Among Somali Population

Background: Limited data have explored the efficacy of super-mini percutaneous nephrolithotomy (SMP) and retrograde intrarenal surgery (RIRS) in managing ≤2 cm renal calculi. This study aims to comprehensively evaluate the safety and effectiveness of SMP compared with RIRS. Methods: This prospective cohort study investigated 210 patients with renal calculi (≤2 cm) undergoing SMP or RIRS, randomly recruited over 4 years. In total, 51.4% underwent SMP and 48.6% underwent RIRS. Results: The mean patient age was 31.3 ± 14.7 years; 56.7% were men, mean stone size of 1.3 ± 0.28 cm, and stone hardness of 1190.1 ± 352.83 Hounsfield units. Pearson's correlation indicated negative correlations for SMP with hospital stays (r = -0.138, p = 0.046), operating time (r = -0.519, p < 0.001), and stone-free rate (SFR) (r = -0.161, p = 0.020); and a positive correlation with a postoperative ureteral catheter (r = +0.389, p < 0.001). With regard to RIRS, the study shows a positive correlation with hospital stay (r = +0.138, p = 0.046), operating time (r = +0.519, p < 0.001), and SFR (r = +0.161, p = 0.020); and a negative correlation with postoperative ureteral catheter (r = -0.389, p < 0.001). Logistic regression, using SMP as the reference, RIRS was associated with β = +0.31, and 1.20 (95% confidence interval [CI], 1.14-1.27, p ≤ 0.001) risk of operation duration and β = +0.37, 1.44 (95% CI, 1.00-2.07, p = 0.047) risk of longer hospital stay. Conclusion: This study investigates the suitability of SMP and RIRS for treating renal calculi ≤2 cm. SMP demonstrated superior efficacy with significantly shorter operating times and reduced hospital stays, suggesting potential advantages for managing lower volume renal stones.

Determining the Stone Free Rate of Retrograde Intrarenal Surgery. Which Radiological Technique? RIRSearch Study Group

OBJECTIVE

To evaluate the sensitivity and specificity of ultrasonography (USG) and kidney ureter bladder radiography (KUB) for the determination of stone-free status of retrograde intrarenal surgery (RIRS) according to different stone-free status definitions.

MATERIALS AND METHODS

The patients who underwent RIRS between September 2021 and September 2022 were prospectively included in the study. All patients underwent a KUB radiography, urinary system USG and noncontrast abdominal tomography at the postoperative first month of the surgery. The sensitivity, specificity, negative predictive factor, and positive predictive factor of USG and KUB on evaluating the stone-free rate were analyzed according to different stone-free status definitions.

RESULTS

A total of 178 patients were included in the study. The stone-free rates according to stone-free definitions as; residual stone <4 mm, <2 mm and no residual stone were 79.2%, 64.0%, and 56.7%, respectively. According to its definition as a residual stone <4 mm, the sensitivity and specificity of USG were 64.9% and 84.3%, respectively. The sensitivity of USG was 57.1% and 52.5% as the definitions were residual stone <2 mm and no residual stone, respectively. Addition of KUB to USG slightly increased the sensitivity but did not change the specificity.

CONCLUSION

USG had high specificity but low sensitivity for evaluating stone-free status after RIRS and addition of KUB did not increase the diagnostic efficacy. Although USG may be used in daily practice, it may overestimate the stone-free status and noncontrast abdominal tomography must be used during the clinical trials to document the exact stone-free rates of RIRS.

Extracorporeal shock wave lithotripsy: retrospective study on possible predictors of treatment success and revisiting the role of non-contrast-enhanced computer tomography in kidney and ureteral stone disease

Extracorporeal shock wave lithotripsy (ESWL) is a safe and efficient treatment option for urinary stone disease. The overall stone-free rate (SFR) varies significantly. This study aimed to assess the influence of stone size, location, stone density, and skin-to-stone distance (SSD), on the outcome of ESWL. We assessed whether pre-treatment non-contrast-enhanced CT scan (NCCT) confers significant advantages compared to kidney-ureter-bladder film (KUB) only. We reviewed the medical records of 307 cases (165 men, 142 women) with renal and ureteral stones treated consecutively at our institution with ESWL between 2020 and 2023. 44 of these underwent a NCCT. The outcome of ESWL was defined in two ways: visible stone fragmentation on KUB, and the need for further treatment. Overall success of fragmentation was 85% (261 patients). 61% of patients (n = 184) didn't need any further treatment. Stone size and location correlated significantly with treatment outcomes regarding the need for further treatment (p = 0.004) and stone fragmentation (p = 0.016), respectively. Unlike mean SSD (p = 0.462), the mean attenuation value (MAV) significantly correlated with the need for retreatment (p = 0.016). MAV seems to be a better predictor of treatment success (AUC of the ROC curve: 0.729), compared to stone size (AUC: 0.613). The difference between groups (with and without NCCT) in both treatment outcomes did not reach statistical significance. During decision-making, information regarding SSD and MAV can be useful in more dubious scenarios. However, it appears that their inclusion doesn't provide substantial advantages when compared to relying solely on KUB.

Is the Mayo Adhesive Probability Score Predictive in Patients Undergoing Percutaneous Nephrolithotomy?

Introduction: Mayo Adhesive Probability (MAP) score was developed as a means to predict the presence of adherent perinephric fat. Our aim was to determine the predictive value of the MAP score on surgical outcomes in patients undergoing standard adult percutaneous nephrolithotomy (PCNL). Materials and Methods: We retrospectively analyzed the data from 130 renal units that underwent PCNL between January 2022 and 2023. MAP scores 0-2 were classified as low, whereas MAP scores 3-5 were classified as high. The impact of the MAP score on perioperative and postoperative outcomes was studied. All statistical analyses were performed using SPSS 24.0 for Windows. Results: The median age of the patients at the time of surgery was 48 (21) years, with a female-to-male ratio of 1:1.82. The median MAP score was 2 (2), with 43.8% of patients falling into the high MAP score group. Advanced age, hypertension history, low estimated glomerular filtration rate (eGFR) levels, and low renal parenchymal thickness were significantly higher in the high MAP score group (P = .010, P = .004, P = .001, and P = .005, respectively). Female patients had a significantly higher MAP score of 0 (P = .021). Operation time, postoperative hematocrit decrease, blood transfusion rate, postoperative fever rate, hospitalization, and stone-free rates were comparable between the low and high MAP score groups (P = .535, P = .209, P = .313, P = .289, P = .281, and P = .264, respectively). Gender and eGFR levels were shown to be significant predictors of a MAP ≥3 (P = .004 and P = .003, respectively). Conclusion: The present study showed that the MAP score groups had similar perioperative and postoperative results. Low eGFR levels and the male gender were associated with MAP score ≥3. To determine the predictive MAP score value for PCNL outcomes, more prospective studies are needed.

The significance of clinically insignificant residual fragments after percutaneous nephrolithotomy: an analysis into the relevance of complete stone clearance

PURPOSE

After treatment for kidney stones, residual fragments with a diameter of ≤ 4 mm are traditionally referred to as 'clinically insignificant residual fragments'. We hypothesize that patients with these fragments are at an increased risk for stone-related morbidity, such as complaints, hydronephrosis, and stone regrowth, when compared to stone-free patients. This study aimed to investigate the relevance of complete stone clearance in surgical treatment of urolithiasis.

METHODS

We conducted a single-center retrospective cohort study. Patients who underwent percutaneous nephrolithotomy between 2015 and 2020 were included if a CT-scan was available within 6 months after the procedure, and the follow-up duration was at least 1 year. The stone-free status at the end of the first stone episode during the study period was categorized as fully stone-free, not stone-free with small residual fragments (≤ 4 mm) and not stone-free with large residual fragments (> 4 mm). Follow-up data were collected, including stone-related events and re-intervention rates.

RESULTS

A total of 103 subjects were included with a median follow-up of 21.4 months. Stone-related events occurred in 10 (29.4%) of the fully stone-free subjects, 20 (58.8%) of the subjects with small residual fragments and 25 (71.4%) of the subjects with large residual fragments. The stone-related event-free survival per subgroup resulted in a significantly different survival distribution in a log rank test (p = 0.008).

CONCLUSION

A complete stone-free status seems to be of fundamental importance for decreasing stone-related morbidity. Further developments and research should focus on optimizing the full clearance of stone material during PCNL.

Percutaneous nephrolithotomy vs retrograde intrarenal surgery for renal stones: a Cochrane Review

OBJECTIVES

To assess the effects of percutaneous nephrolithotomy (PCNL) vs retrograde intrarenal surgery (RIRS) for the treatment of renal stones in adults.

METHODS

We performed a comprehensive search of the Cochrane Library, MEDLINE, Embase, three other databases, trials registries, other sources of the grey literature, and conference proceedings up to 23 March 2023. We applied no restrictions on publication language or status. Screening, data extraction, risk-of-bias assessment, and certainty of evidence (CoE) rating using the Grading of Recommendations Assessment, Development and Evaluations (GRADE) approach were done in duplicate by two independent reviewers. This co-publication focuses on the primary outcomes of this review only.

RESULTS

We included 42 trials that met the inclusion criteria. Stone-free rate (SFR): PCNL may improve SFRs (risk ratio [RR] 1.13, 95% confidence interval [CI] 1.08-1.18; I2 = 71%; 39 studies, 4088 participants; low CoE). Major complications: PCNL probably has little to no effect on major complications (RR 0.86, 95% CI 0.59-1.25; I2 = 15%; 34 studies, 3649; participants; moderate CoE) compared to RIRS. Need for secondary interventions: PCNL may reduce the need for secondary interventions (RR 0.31, 95% CI 0.17-0.55; I2 = 61%; 21 studies, 2005 participants; low CoE) compared to RIRS.

CONCLUSION

Despite shortcomings in most studies that lowered our certainty in the estimates of effect to mostly very low or low, we found that PCNL may improve SFRs and reduce the need for secondary interventions while not impacting major complications. Ureteric stricture rates may be similar compared to RIRS. We expect the findings of this review to be helpful for shared decision-making about management choices for individuals with renal stones.

Comparison of percutaneous nephrolithotomy and flexible ureterorenoscopy in the treatment of single upper ureteral calculi measuring 1 to 2 centimeters: a retrospective study

PURPOSE

To compare the efficacy and safety of micropercutaneous nephrolithotomy (MPCNL) and flexible ureteroscopy (FURS) in the treatment of single upper ureteral calculi measuring 1 to 2 centimeters.

METHODS

This study is a retrospective analysis that combines a review of medical records with an outcomes management database. A total of 163 patients who underwent MPCNL and 137 patients who had FURS were identified between January 2017 and December 2021. Demographic data, operation time, hospitalization time, stone-free rate, and complication rate were collected and analyzed.

RESULTS

Preoperative general data of sex, age, BMI, serum creatinine, time of stone existence, stone hardness, stone diameter, preoperative hydronephrosis, and preoperative infection of the MPCNL group have no statistically significant difference with that of the FURS group. All MPCNL or FURS operations in both groups were successfully completed without any instances of reoperation or conversion to another surgical procedure. Patients who underwent MPCNL had a considerably reduced operation time (49.6 vs. 72.4 min; P<0.001), but a higher duration of hospitalization (9.1 vs. 3.9 days; P<0.001) compared to those who underwent FURS. The stone-free rate in the MPCNL group was superior to that of the FURS group, with a percentage of 90.8% compared to 71.5% (P<0.001). There was no statistically significant disparity in the rate of complications between the two groups (13.5% vs. 15.3%; P = 0.741).

CONCLUSION

Both MPCNL and FURS are viable and secure surgical choices for individuals with solitary upper ureteral calculi measuring 1 to 2 cm. The FURS procedure resulted in a shorter duration of hospitalization compared to MPCNL. However, it had a comparatively lower rate of successfully removing the stones and required a longer duration for the operation.There were no substantial disparities observed in the complication rate between the two groups.FURS is the preferable option for treating uncomplicated upper ureteral calculi, whereas MPCNL is the preferable option for treating complicated upper ureteral calculi.Prior to making treatment options, it is crucial to take into account the expertise of surgeons, the quality of the equipment, and the preferences of the patient.

TRIAL REGISTRATION

No.

Assessment of Hounsfield Units and Factors Associated with Fragmentation of Renal Stones by Extracorporeal Shock Wave Lithotripsy: A Computerized Tomography Study

The success rate of extracorporeal shock wave lithotripsy (ESWL) is influenced by various factors, including stone density, and is determined through computed tomography scans in terms of Hounsfield units (HU).

MATERIALS AND METHODS

This retrospective single-center study was conducted in the King Fahad Hospital. Sixty-seven adult patients with renal and ureteric stones were selected randomly and enrolled in the study. Their ages ranged from 20 to 69 years. The patients were examined with non-contrast enhancement (NCCT) to assess the HU of their stones and were consequently treated with ESWL.

RESULTS

Of the 67 patients, 37.3% had stones that were completely fragmented, while 62.7% had stones that were partially fragmented. The HU, location of the stone, multiplicity of the stone, and patient age were found to be significant factors contributing to stone fragility (p-values < 0.05). The HU data were found to have a positive significant linear correlation with serum calcium (r = 0.28, p-value = 0.036), while serum acid had a negative correlation (r = -0.55, p-value < 0.001). Thus, the probability of calcium-containing stone formation increases with increased HU. In contrast, uric acid stone formation likely develops with decreasing HU with serum uric acid. Renal stones in patients with diabetes mellitus and hypertension were not completely fragmented compared to those without clinical history.

CONCLUSIONS

Mean HU, location of the stone, laterality, stone status, and the number of ESWL sessions are the most significant factors affecting stone fragility. CT attenuation values can predict the composition of stones from serum calcium and uric acid examinations. Hypertension and diabetes mellitus are risk factors for renal stone fragmentation.

Single Specialty-Operated Renal Stone Removal: Initial Experience from 3 Interventional Radiology Centers

This retrospective analysis of the feasibility and safety of percutaneous renal stone removal using single-use flexible ureteroscopes was conducted at 3 academic centers. Twelve patients (58% men) underwent 14 percutaneous renal stone removal procedures between December 2021 and March 2023. All patients experienced symptom improvement and resolution of obstruction after stone removal. The procedural success rate was 92%. Only 1 patient required an additional stone removal procedure. No major adverse events occurred during or after the procedures. The percutaneous nephrostomy removal rate was 92%, with a median tube removal time of 5 weeks. The median procedural and pulsed fluoroscopy times were 106.5 and 16.3 minutes, respectively. Preliminary findings demonstrated that percutaneous renal stone removal using single-use endoscopes by interventional radiologists is feasible and safe.

Technological innovations in shock wave lithotripsy

INTRODUCTION

Since 1980, extracorporeal shock wave lithotripsy (SWL) has been employed in the treatment of urolithiasis, offering noninvasive alternatives to surgical techniques. In addition to being limited by the size and location of the stones, its efficacy is influenced by several factors. Despite the advancement of other surgical techniques, SWL could maintain its position with new improvements. Our objective is to review the existing literature on the latest advances in the extracorporeal treatment of lithiasis.

MATERIAL AND METHODS

A non-systematic literature review was carried out from 2017 to 2023 to obtain 26 articles on three different emerging technologies in extracorporeal lithotripsy: Burst Wave Lithotripsy (BWL), Histotripsy, and Microbubble Lithotripsy (ML).

RESULTS

The BWL uses sinusoidal bursts of US waves delivered at lower and higher frequencies than conventional SWL. Its mechanism of action generates a higher quality fragmentation (fine fragments) instead of generating tensile stresses for stone fracture resulting in larger fragments, as in traditional SWL. Studies in pigs and humans have shown effective fragmentation with a good safety profile. Based on High Intensity Focused Ultrasound (HIFU) technology, histotripsy fragments tissue through cavitation. Good in vitro results have been shown, but the formation of microbubbles between the stone and ultrasound waves hinders the progress of this technique. Microbubble Lithotripsy (ML) combines microbubbles and ultrasound for safe and effective stone fragmentation. In vitro and pig results are promising. This technique can help optimize treatments and reduce energy levels.

CONCLUSIONS

Technological innovation is not only being applied to endourological techniques, but also to ESWL. New techniques such as BWL, histotripsy and ML are promising, with good results in the research phase.

Percutaneous nephrolithotomy versus retrograde intrarenal surgery for treatment of renal stones in adults

BACKGROUND

Kidney stones (also called renal stones) can be a source of pain, obstruction, and infection. Depending on size, location, composition, and other patient factors, the treatment of kidney stones can involve observation, shock wave lithotripsy, retrograde intrarenal surgery (RIRS; i.e. ureteroscopic approaches), percutaneous nephrolithotomy (PCNL), or a combination of these approaches.

OBJECTIVES

To assess the effects of percutaneous nephrolithotomy (PCNL) versus retrograde intrarenal surgery (RIRS) for the treatment of renal stones in adults.

SEARCH METHODS

We performed a comprehensive search of the Cochrane Library, MEDLINE, Embase, Scopus, and two trials registries up to 23 March 2023. We applied no restrictions on publication language or status.

SELECTION CRITERIA

We included randomized controlled trials that evaluated PCNL (grouped by access size in French gauge [Fr] into three groups: ≥ 24 Fr [standard PCNL], 15-23 Fr [mini-PCNL and minimally invasive PCNL], and < 15 Fr [ultra-mini-, mini-micro-, super-mini-, and micro-PCNL]) versus RIRS.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies and extracted data from the included studies. Our primary outcomes were stone-free rate, major complications, and need for secondary interventions. Our main secondary outcomes were unplanned medical visits to emergency/urgent care or outpatient clinic, length of hospital stay, ureteral stricture or injury, and quality of life. We performed statistical analyses using a random-effects model. We rated the certainty of evidence using GRADE criteria. We adopted a minimally contextualized approach with predefined thresholds for minimal clinically important differences (MCIDs).

MAIN RESULTS

We included 42 trials assessing the effects of PCNL versus RIRS in 4571 randomized participants. Twenty-two studies were published as full-text articles, and 20 were published as abstract proceedings. The average size of stones ranged from 10.1 mm to 39.1 mm. Most studies did not report sources of funding or conflicts of interest. The main results for the most important outcomes are summarized below. Stone-free rate PCNL compared with RIRS may improve stone-free rates (risk ratio [RR] 1.13, 95% confidence interval [CI] 1.08 to 1.18; I2 = 71%; 39 studies, 4088 participants; low-certainty evidence). Based on 770 participants per 1000 being stone-free with RIRS, this corresponds to 100 more (62 more to 139 more) stone-free participants per 1000 with PCNL (an absolute difference of 10%, where the predefined MCID was 5%). Major complications PCNL compared with RIRS probably has little or no effect on major complications (RR 0.86, 95% CI 0.59 to 1.25; I2 = 15%; 34 studies, 3649 participants; moderate-certainty evidence). Based on 31 complications in the RIRS group, this corresponds to six fewer (13 fewer to six more) major complications per 1000 with PCNL (an absolute difference of 0.6%, where the predefined MCID was 2%). Need for secondary interventions PCNL compared with RIRS may reduce the need for secondary interventions (RR 0.31, 95% CI 0.17 to 0.55; I2 = 61%; 21 studies, 2005 participants; low-certainty evidence). Based on 222 secondary interventions in the RIRS group, this corresponds to 153 fewer (185 fewer to 100 fewer) secondary interventions per 1000 with PCNL (an absolute difference of 15.3%, where the predefined MCID was 5%). Unplanned medical visits No studies reported unplanned medical visits. Length of hospital stay PCNL compared with RIRS may extend length of hospital stay (mean difference 1.04 days more, 95% CI 0.27 more to 1.81 more; I2 = 100%; 26 studies, 2804 participants; low-certainty evidence). This effect size is greater than the predefined MCID of one day. Ureteral stricture or injury PCNL compared with RIRS may have little or no effect on the occurrence of ureteral strictures (RR 0.93, 95% CI 0.39 to 2.21; I2 = 0%; 13 studies, 1574 participants; low-certainty evidence). Based on 14 ureteral strictures in the RIRS group, this corresponds to one fewer (nine fewer to 17 more) ureteral strictures per 1000 with PCNL (an absolute difference of 0.1%, where the predefined MCID was 2%). Quality of life No studies reported quality of life.

AUTHORS' CONCLUSIONS

Based on a large body of evidence from 42 trials, we found that PCNL compared with RIRS may improve stone-free rates and may reduce the need for secondary interventions, but probably has little or no effect on major complications. PCNL compared with RIRS may have little or no effect on ureteral stricture rates and may increase length of hospital stay. We found no evidence on unplanned medical visits or participant quality of life. Because of the considerable shortcomings of the included trials, the evidence for most outcomes was of low certainty. Access size for PCNL was less than 24 Fr in most studies that provided this information. We expect the findings of this review to be helpful for shared decision-making about management choices for individuals with renal stones.

Prospective Randomized Trial of Antibiotic Prophylaxis Duration for Percutaneous Nephrolithotomy in Low-Risk Patients

Introduction and Objective: Postoperative infection and sepsis account for the most common complications following percutaneous nephrolithotomy (PCNL), as high as 14% in low-risk patients. Although the American Urological Association (AUA) recommends perioperative antibiotics for 24 hours or less for PCNL, practice patterns vary regarding duration of antibiotic therapy. We aimed to compare the efficacy of 24-hour antibiotic coverage vs short-course protocol of antibiotic prophylaxis for PCNL. Materials and Methods: Low-risk patients with a sterile preoperative urine culture undergoing PCNL were prospectively randomized to antibiotics for up to 24 hours after procedure (24Hr) or continued until external urinary catheters were removed (CR) study groups. Patients were given a first generation cephalosporin, or ciprofloxacin in patients with penicillin allergy. Exclusion criteria included age <18 years, receiving antibiotics immediately before the procedure, history of urosepsis, presence of indwelling catheter >1 week, multistage procedure, immunosuppression, pregnancy, multiple antibiotic allergies, and patients who are breastfeeding. Results: Ninety-eight patients were randomized to either 24Hr (n = 49) or CR (n = 49). Mean duration of antibiotic administration was 20.6 and 34.0 hours in the 24Hr and CR groups (p = 0.04), respectively. Age, comorbidities, stone size, operative time, number of punctures, dilations, and proportion of "tubeless" procedures were similar between groups. There were no differences in febrile episodes, rates of systemic inflammatory response syndrome, bacteremia, or culture-proven postoperative urinary tract infection between the 24Hr and CR groups. Overall complication rates were similar between groups. In a subgroup analysis which excluded "tubeless" patients (24 and 29 patients in 24Hr and CR groups, respectively), no differences were seen in postoperative outcomes. Conclusions: In a randomized, prospective study, we found that a 24-hour protocol for antibiotic prophylaxis is not associated with increased risk of infection-related events compared to giving antibiotics until external catheters are removed in patients with low infectious risk undergoing PCNL. Clinicaltrials.gov: NCT02579161.

Application of ultrasound imaging in the treatment of urinary tract stones

Urinary tract stones are a common clinical condition that affect millions of individuals worldwide. The management of these stones has evolved significantly over the past 70 years, and ultrasound imaging has emerged as a valuable tool for diagnosis, treatment planning, and follow-up. This review aims to provide an overview of the application of ultrasound imaging in the treatment of urinary tract stones, highlighting its advantages, limitations, and current advancements in the field.

Residual fragment size following retrograde intrarenal surgery: a critical evaluation of related variables

Given the limited data on the predictive factors of residual kidney stone size after flexible ureteroscopy (fURS), this study aims to investigate the variables affecting residual stone size. The medical records of 642 patients without complications being treated for kidney stones with fURS between July 2014 and May 2022 were reviewed retrospectively, and the information of the 170 patients in whom residual stones were found was recorded. In addition to patient-specific factors and stone characteristics, length of postoperative hospital stay, postoperative fever, and preoperative antiaggregant use were evaluated. Of the 170 patients ultimately included in the study. The mean age was 51.56 (± 14.70). The mean stone size was 14.01 mm (± 5.75), the mean residual stone size was 7.04 mm (± 2.51), and the mean stone density was 829 Hounsfield units (± 395.06). The mean infundibulopelvic angle (IPA) was 49.37º (± 15.37), and 41.2% of the stones were non-opaque. The mean parenchymal thickness was 22.88 mm (± 5.55). 34 patients were on antiaggregant therapy. Preoperative stone size increases in stone density and decreases in IPA were found to be correlated with increase residual stone size (p < 0.001, p < 0.001, and p < 0.001, respectively). In addition, larger residual stones were observed after the fURS procedure in patients using anticoagulants and those without hydronephrosis (p = 0.02 and p = 0.016, respectively). Use of reliable predictive factors to forecast residual stone size after fURS may help to inform those treated and enable urologists to design rational surgical strategies.

Extracorporeal shock wave lithotripsy (ESWL) versus percutaneous nephrolithotomy (PCNL) or retrograde intrarenal surgery (RIRS) for kidney stones

BACKGROUND

Nephrolithiasis is a common urological disease worldwide. Extracorporeal shock wave lithotripsy (ESWL) has been used for the treatment of renal stones since the 1980s, while retrograde intrarenal surgery (RIRS) and percutaneous nephrolithotomy (PCNL) are newer, more invasive treatment modalities that may have higher stone-free rates. The complications of RIRS and PCNL have decreased owing to improvement in surgical techniques and instruments. We re-evaluated the best evidence on this topic in an update of a Cochrane Review first published in 2014.

OBJECTIVES

To assess the effects of extracorporeal shock wave lithotripsy compared with percutaneous nephrolithotomy or retrograde intrarenal surgery for treating kidney stones.

SEARCH METHODS

We performed a comprehensive search in CENTRAL, MEDLINE, Embase, and ClinicalTrials.gov with no restrictions on language or publication status. The latest search date was 6 December 2022.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) and quasi-RCTs that compared ESWL with PCNL or RIRS for kidney stone treatment.

DATA COLLECTION AND ANALYSIS

Two review authors independently classified studies, extracted data, and assessed risk of bias. Our primary outcomes were treatment success rate at three months (defined as residual fragments smaller than 4 mm, or as defined by the study authors), quality of life (QoL), and complications. Our secondary outcomes were retreatment rate, auxiliary procedures rate, and duration of hospital stay. We performed statistical analyses using a random-effects model and independently rated the certainty of evidence using the GRADE approach.

MAIN RESULTS

We included 31 trials involving 3361 participants (3060 participants completed follow-up). Four trials were only available as an abstract. Overall mean age was 46.6 years and overall mean stone size was 13.4 mm. Most participants (93.8%) had kidney stones measuring 20 mm or less, and 68.9% had lower pole stones. ESWL versus PCNL ESWL may have a lower three-month treatment success rate than PCNL (risk ratio [RR] 0.67, 95% confidence interval [CI] 0.57 to 0.79; I2 = 87%; 12 studies, 1303 participants; low-certainty evidence). This corresponds to 304 fewer participants per 1000 (397 fewer to 194 fewer) reporting treatment success with ESWL. ESWL may have little or no effect on QoL after treatment compared with PCNL (1 study, 78 participants; low-certainty evidence). ESWL probably leads to fewer complications than PCNL (RR 0.62, 95% CI 0.47 to 0.82; I2 = 18%; 13 studies, 1385 participants; moderate-certainty evidence). This corresponds to 82 fewer participants per 1000 (115 fewer to 39 fewer) having complications after ESWL. ESWL versus RIRS ESWL may have a lower three-month treatment success rate than RIRS (RR 0.85, 95% CI 0.78 to 0.93; I2 = 63%; 13 studies, 1349 participants; low-certainty evidence). This corresponds to 127 fewer participants per 1000 (186 fewer to 59 fewer) reporting treatment success with ESWL. We are very uncertain about QoL after treatment; the evidence is based on three studies (214 participants) that we were unable to pool. We are very uncertain about the difference in complication rates between ESWL and RIRS (RR 0.93, 95% CI 0.63 to 1.36; I2 = 32%; 13 studies, 1305 participants; very low-certainty evidence). This corresponds to nine fewer participants per 1000 (49 fewer to 48 more) having complications after ESWL.

AUTHORS' CONCLUSIONS

ESWL compared with PCNL may have lower three-month success rates, may have a similar effect on QoL, and probably leads to fewer complications. ESWL compared with RIRS may have lower three-month success rates, but the evidence on QoL outcomes and complication rates is very uncertain. These findings should provide valuable information to aid shared decision-making between clinicians and people with kidney stones who are undecided about these three options.

Treatment of 2-4 cm kidney stones: multicentre experience. Comparison of safety, efficacy, and costs of percutaneous nephrolithotomy and retrograde intrarenal surgery

Introduction

The objective of this study is to compare the safety and efficacy, through the stone-free rate (SFR), as well as the costs, between retrograde intrarenal surgery (RIRS) and percutaneous nephrolithotomy (PCNL), for 2-4 cm kidney stones.

Material and methods

We analysed the data relating to RIRS and PCNL performed in 3 reference centres for kidney stones, in the period between 1/2019 and 12/2021. The total number of procedures was 130 (63 RIRS and 67 PCNL). We defined SFR as the absence of lithiasic fragments or stones <3 mm. Results were compared between 2 groups depending on the stone size: 2-3 cm stones (group 1) and >3 cm stones (group 2).

Results

The duration of RIRS was 90 minutes for group 1 and 115 minutes for group 2, and for PCNL it was 135 minutes for group 1 and 145 minutes for group 2. RIRS had shorter duration with a significant difference in group 1 (p = 0.000014). SFR for RIRS was 78% for group 1 and 21% for group 2, and for PCNL it was 92% for group 1 and 81% for group 2. Therefore, there is a statistically significant difference, which is more evident for 3 cm and multiple stones (p = 0.0057 for group 1, p = 0.000146 for group 2). The difference in costs was estimated by calculating the expected costs for a single surgical procedure and the estimated cost per day for ordinary hospitalization.

Conclusions

2-4 cm stones can be safely treated with both RIRS and PCNL, but RIRS should not be chosen as an option for stones >3 cm, except in selected cases. PCNL remains the gold standard for the treatment of complex stones, especially for stones >3 cm. Risk of postoperative complications is higher in PCNL, even if this difference is not great. The costs associated with RIRS, even when recalculating with the need for new treatments, remain cheaper.

Progress in the study of biomarkers for early prediction of systemic inflammatory response syndrome after percutaneous nephrolithotomy

Urolithiasis is a common and frequent disease in urology. Percutaneous nephrolithotomy (PCNL) is preferred for the treatment of upper urinary tract stones and complicated renal stones &gt;2 cm in diameter, but it has a higher rate of postoperative complications, especially infection, compared with other minimally invasive treatments for urinary stones. Complications associated with infection after percutaneous nephrolithotomy include transient fever, systemic inflammatory response syndrome (SIRS), and sepsis, which is considered one of the most common causes of perioperative death after percutaneous nephrolithotomy. In contrast, SIRS serves as a sentinel for sepsis, so early intervention of SIRS by biomarker identification can reduce the incidence of postoperative sepsis, which in turn reduces the length of stay and hospital costs for patients. In this paper, we summarize traditional inflammatory indicators, novel inflammatory indicators, composite inflammatory indicators and other biomarkers for early identification of systemic inflammatory response syndrome after percutaneous nephrolithotomy.

Hydrostatic pressure of the renal pelvis as a radiation-free alternative to fluoroscopic nephrostogram following percutaneous nephrolithotomy

Background

We evaluated the hydrostatic pressure of the renal pelvis (RPP) as a radiation-free alternative to fluoroscopic nephrostogram to assess ureteral patency after percutaneous nephrolithotomy (PCNL).

Methods

Retrospective non-inferiority study analyzing 248 PCNL-patients (86 female (35%) and 162 males (65%)) between 2007 and 2015. Postoperatively, RPP was measured using a central venous pressure manometer in cmH2O. The primary endpoint was to assess RPP depending on the patency of the ureter and the nephrostomy tube removal. Secondary, the upper limit of normal RPP of $$\le$$ ≤ 20 cmH2O was assessed as an indicator of an unobstructed patency.

Results

The median procedure duration was 141 min (112–171.5) with a stone free rate of 82% (n = 202). RPP was significantly higher in patients with obstructive nephrostogram with 25.0 mmH2O (21.0–32.0) versus 20.0 mmH2O (16.0–24.0; p < 0.001). The pressure was lower in successful nephrostomy removal with 18 cmH2O (15–21) versus 23 cmH2O (20–29) in the leakage group (p < 0.001). The analysis of a cut-off of $$\le$$ ≤ 20 cmH2O showed a sensitivity of 76.9% (95% CI [60.7%; 88.9%]) and a specificity of 61.5% (95% CI [54.6%; 68.2%]). The negative predictive value was 93.4% (95% CI: [87.9%; 97.0%]) and the positive predictive value 27.3% (95% CI [19.2%; 36.6%]). The accuracy of the model showed an AUC = 0.795 (95% CI [0.668; 0.862]).

Conclusion

The hydrostatic RPP seems to allow a bedside evaluation of ureteral patency after PCNL.

Effect of ureteric access sheath on outcomes of retrograde intrarenal surgery for renal stone disease: a randomized controlled trial

BACKGROUND

The need of ureteric access sheath (UAS) in retrograde intrarenal surgery (RIRS) has been controversial for gaining high success in terms of stone free rate (SFR), reducing operative times and complications. There has been lack of high level of evidence in the literature on this topic.

MATERIALS AND METHODS

This prospective randomized controlled trial (RCT) was conducted in the Department of Urology, PGIMER, Chandigarh from July 2019 to Dec 2021. The effect of UAS on the outcome of RIRS (SFR, operative time and complications) for renal stone disease was assessed. Ninety patients were randomized into two groups: 41 patients in Group 1 (RIRS with UAS) and 40 patients in Group 2(RIRS without UAS) were finally analyzed after exclusion. All the patients underwent preoperative double J stent placement at least 10 days prior to the definitive procedure. Operative time was recorded and postoperative pain was assessed by visual analogue scale(VAS) at 6 and 24 h postoperatively. Complications and emergency visits were recorded up to one month post procedure. SFR was assessed at 1 month using noncontrast CT KUB. Success was defined as absence of any residual fragment more than 3 mm in maximum diameter.

RESULTS

Demographic parameters (age, body mass index, and comorbidities) and preoperative parameters (stone burden, proportion of recurrent stone formers and proportion of patients with inferior calyceal stones) were comparable between the two groups. Operative times (45.49 vs 48.38 min; p - 0.484) and VAS scores at 6 and 24 h post-op (p - 0.577) were also comparable between Group 1 and Group 2. SFR was comparable in Group 1 and Group 2 (78.05% vs 80%, p - 0.829). Postoperative complications were higher in the UAS group, but not statistically significant (4.88% vs 0%; p - 0.157).

CONCLUSION

The use of UAS during RIRS is not associated with improved SFR. RIRS can be performed safely without the use of UAS and without increasing postoperative complications.

Comparison of Low-Power vs High-Power Holmium lasers in pediatric RIRS outcomes

OBJECTIVES

to compare the outcomes of using low-power (up to 30W) vs high-power (up to 120W) holmium lasers in retrograde intrarenal surgery (RIRS) in children and to analyse if lasering techniques and the use of access sheath have any influence on the outcomes.

METHODS

We retrospectively reviewed data from 9 centres of children who underwent RIRS with holmium laser for the treatment of kidney stones between January 2015 and December 2020. Patients were divided into two groups: high-power and low-power holmium laser. Clinical, perioperative variables and complications were analysed. Outcomes were compared between groups using Student's T-test for continuous variables, and Chi-square and Fisher's exact test for categorical variables. A multivariable logistic regression analysis model was also performed.

RESULTS

314 patients were included. A high-power and low-power holmium laser was used in 97 and 217 patients, respectively. Clinical and demographic variables were comparable between both groups, except for stone size where the low-power group treated larger stones (mean 11.11 mm vs 9.70 mm; p 0.018). In the high-power laser group, a reduction in surgical time was found (mean 64.29 min vs 75.27 min; p 0.018) with a significantly higher stone-free rate (SFR) (mean 81.4% vs 59%; p <0.001). We found no statistical differences in complication rates. The multivariate logistic regression model showed lower SFR in the low-power holmium group, especially with larger (p = 0.011) and multiple stones (p < 0.001).

CONCLUSION

Our real-world pediatric multicenter study favours high-power holmium laser and establishes its safety and efficacy in children.  .

Quality of life of patients treated for kidney stones 10-20mm in diameter in terms of the type of operation performed: A qualitative study

INTRODUCTION

Urolithiasis is a common chronic disease whose effect on patients' quality of life (QOL) is considerable but depends on the treatment received, differing between types of surgery. Intrarenal stones can be treated with different techniques: extracorporeal shock wave lithotripsy (ESWL), flexible ureteroscopy (fURS), and mini percutaneous nephrolithotomy (mini-PCNL), with proportional success and complication rates. The aim of this study was to qualitatively explore the impact of the different techniques on patients' QOL and understand their experiences of treatment choices.

METHODS

Patients treated for medium-sized kidney stones (10-20mm in diameter) were interviewed in a semi-structured manner. The interview data were transcribed and analyzed by theme according to consolidated criteria for reporting qualitative research (COREQ) guidelines.

RESULTS

Data saturation was achieved after interviewing 15 patients. The mean interview time was 34min (standard deviation (SD), 6.8min). The mean patient age was 54 years (SD, 9.5 years). Eight patients underwent ESWL, 10 were treated with fURS, and 8 underwent mini-PCNL. Twenty-seven subthemes were coded and regrouped into eight major themes, namely: no sense of choice in the decision-making process for eleven patients; extremely negative experiences of double-J stents for fourteen patients; concern about the risk of recurrence or treatment failure for thirteen patients; complicated hygiene and dietary recommendations for nine patients; technique-dependent postoperative outcomes; relatively well-tolerated operations for thirteen patients; a poor experience of sick leave, often because of a double-J stent; different views regarding future operations. In fact, a third of patients would choose the most effective treatment, a third would choose the simplest procedure and the last third would trust their urologist. Patients' experiences of these operations are variable.

CONCLUSION

Urologists must support their patients by presenting the different treatment options with clear, appropriate, and unbiased information. This should ensure patients take part in treatment decisions as part of a personalized treatment plan.

LEVEL OF EVIDENCE: 3

Knowledge-map analysis of percutaneous nephrolithotomy (PNL) for urolithiasis

Percutaneous nephrolithotomy (PNL) has been used in the treatment of urolithiasis for more than 20 years. However, bibliometric analysis of the global use of PNL for urolithiasis is rare. We retrieved the literatures on PNL and urolithiasis from Web of science core collection database. VOSviewer was used to analyze keywords, citations, publications, co-authorship, themes, and trend topics. A total of 3103 articles were analyzed, most of which were original ones. The most common keywords were "percutaneous nephrology" and "urolithiasis", both of which were closely related to "ureteroscopy". Journal of Urology and Zeng Guohua from the First Affiliated Hospital of Guangzhou Medical University were the most published journal and author in this field. The most productive country was the United States, and its closest partners were Canada, China, and Italy. The five hot topics were the specific application methods and means, risk factors of urolithiasis, the development of treatment technology of urolithiasis, the characteristics, composition, and properties of stones, and the evaluation of curative effect. This study aimed to provide a new perspective for PNL treatment of urolithiasis and provided valuable information for urologic researchers to understand their research hotspots, cooperative institutions, and research frontiers.

Can additional variables be used to predict stone-free rates following retrograde intrarenal surgery? Anticoagulants and parenchyma thickness: a detailed examination

The purpose of this article is to identify the factors that predict the success of retrograde intrarenal surgery (RIRS), with a focus on the effect of renal parenchymal thickness and anticoagulant use on stone-free rates. From February 2014 to April 2022, cases of kidney stones treated with RIRS at our clinic were retrospectively screened. The study included 642 cases meeting all inclusion and exclusion criteria. The patients who were observed to be stone free after a single session of RIRS were assigned to Group F, while those with residual fragments were assigned to Group R. Group F comprised 472 patients, while Group R included 170 patients. The two groups have compared certain preoperative and postoperative laboratory and radiological parameters. The infundibulopelvic angle was significantly more acute in Group R (45.63 ± 16.25 vs. 49.28 ± 15.36, p = 0.011) while patients in Group F tended to have thicker parenchyma (27.39 ± 8.38 vs. 22.88 ± 5.56, p < 0.001). In our analysis of multivariate logistic regression, stone size (OR: 1.074, 1.037-1.113; p < 0.001), lower calyceal location (OR: 0.550, 95% CI 0.364-0.831; p = 0.005), multiple numbers of stones (OR 0.254, 95% CI 0.166-0.389; p =  < 0.001), the value of parenchymal thickness (OR 0.911, 95% CI 0.882-0.941; p =  < 0.001) and more importantly use of anticoagulants/antiplatelets (OR 0.557, 95% CI 0.333-0.933; p = 0.026) appeared to be independent predictors of stone-free status after RIRS. Further evaluation of the data revealed that the cut-off value of the renal parenchymal thickness for an effective stone-free status in a ROC curve analysis was 24.5 with 62.9% sensitivity and 56.8% specificity (area under curve value: 0.654 [95% CI 0.608-0.699, p < 0.001]). The endourologist may be able to make more informed decisions by evaluating renal parenchymal thickness in addition to patient-related factors like anticoagulant use, which we find significantly affects outcomes, along with the stone and renal anatomy-related factors.

Comparison of dusting and fragmentation methods in the flexible ureteroscopic treatment of kidney lower calyx stones

To compare the long-term stone-free status of patients who underwent fragmentation of stones followed by active basketing versus stone dusting and spontaneous passage following flexible ureteroscopic treatment for lower calyceal stones. The dusting or fragmentation methods were randomly assigned to patients who were scheduled to undergo RIRS for only renal lower calyceal stones between February 2019 and May 2022, prospectively. Stone-free rates were determined after 3 months by non-contrast computed tomography and patient demography; preoperative and postoperative follow-up data of both groups were evaluated comparatively. While the fragmentation method was applied in 32 patients, the dusting method was applied in the remaining 31 cases. The two groups did not differ significantly regarding the demographic data and laboratory findings. Mean stone size was similar in both groups of cases. Operation time was significantly longer for fragmentation (93.23 ± 27.20 vs 78.43 ± 30.08, p = 0.045) and evaluation of the success rates after 3 months did show that patients in the dusting group had a higher rate of stone-free status when compared with the other group of cases (65.6 vs 87.1%, p = 0.043). Lastly, postoperative fever rates were not significantly different between the two groups (12.5 vs 9.7%, p = 0.518). Our findings showed that dusting the lower calyceal stones during fURS would reveal higher stone-free rates during long-term follow-up periods, and the mean operation time will be shorter in these patients.

Validation of the Trifecta Scoring Metric in Vacuum-Assisted Mini-Percutaneous Nephrolithotomy: A Single-Center Experience

Background: Scoring metrics to assess and compare outcomes of percutaneous nephrolithotomy (PCNL) are needed. We aim to evaluate prevalence and predictors of trifecta in a cohort of patients treated with vacuum-assisted mini-percutaneous nephrolithotomy (vmPCNL) for kidney stones. Methods: Data from 287 participants who underwent vmPCNL were analysed. Patients’ and stones’ characteristics as well as operative data were collected. Stone-free was defined as no residual stones. The modified Clavien classification was used to score postoperative complications. Trifecta was defined as stone-free status without complications after a single session and no auxiliary procedures. Descriptive statistics and logistic regression models tested the association between predictors and trifecta outcome. Results: After vmPCNL, 219 (76.3%) patients were stone-free, and 81 (28.2%) had postoperative complications (any Clavien). Of 287, 170 (59.2%) patients achieved trifecta criteria. Patients who achieved trifecta status had smaller stone volume (p < 0.001), a higher rate of single stones (p < 0.001), shorter operative time (p < 0.01), and a higher rate of single percutaneous tract (p < 0.01) than −trifecta patients. Trifecta status decreased with the number of calyces involved, being 77.1%, 18.8%, and 4.1% in patients with 1, 2, or 3 calyces with stones, respectively (p < 0.001). Multivariable logistic regression analysis showed that stone volume (OR 1.1, p = 0.02) and multiple calyces being involved (OR 2.8 and OR 4.3 for two- and three-calyceal groups, respectively, all p < 0.01) were independent unfavourable risk factors for trifecta after accounting for age, BMI, gender, operative time, and number of access tracts. Conclusions: Trifecta status was achieved in 6 out of 10 patients after vmPCNL. Stone distribution in multiple calyceal groups and stone volume were independent unfavourable risk factors for trifecta.

Flexible Ureterorenoscopy Versus Shockwave Lithotripsy for Kidney Stones ≤2 cm: A Randomized Controlled Trial

BACKGROUND

No clear recommendations are available on whether retrograde intrarenal surgery (RIRS) via flexible ureterorenoscopy or shockwave lithotripsy (SWL) should be preferred for kidney stones ≤2 cm, except for lower-pole stones.

OBJECTIVE

To compare outcomes between RIRS and SWL.

DESIGN, SETTING, AND PARTICIPANTS

This was a single-center randomized controlled trial from March 2015 to May 2018. Patients with a single 6-20-mm kidney stone were enrolled (NCT02645058).

INTERVENTION

Patients were randomized to RIRS or SWL.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary endpoint was the single-procedure stone-free rate (SFR) at 1 mo. Two levels of success were set: fragments ≤4 mm (SFR-4) and no residual fragments (SFR-0). Secondary endpoints were the SFR at 6 mo and 1 yr and rates of complications and further treatments.

RESULTS AND LIMITATIONS

A total of 138 patients underwent treatment (70 RIRS vs 68 SWL). In comparison to SWL, RIRS SFR results were higher at 1 mo (SFR-4 70.0% vs 45.6%; p = 0.004; SFR-0 50.0% vs 26.5%; p = 0.004) and 6 mo (SFR-4 79.7% vs 63.6%; p = 0.038; SFR-0 59.4% vs 40.9%; p = 0.032). There was no difference in SFR measures between the groups at 1 yr (SFR-4 p = 0.322; SFR-0 p = 0.392). Overall complications were comparable (p = 0.207), but the complication rate for stones >10 mm was higher for the SWL group (p = 0.021). The need for further treatment was comparable (p = 0.368). In terms of patient satisfaction, 86.8% and 77.1% of patients would choose SWL and RIRS again, respectively (p = 0.24).

CONCLUSIONS

RIRS achieved better SFRs in comparison to SWL at 1 and 6 mo, but not at 1 yr. The RIRS complication rate was lower for stones >10 mm. SWL remains a viable alternative, especially for 6-10-mm stones, providing comparable results to RIRS in the long term.

PATIENT SUMMARY

We compared outcomes for the treatment of kidney stones ≤2 cm with two techniques: flexible ureteroscopy, in which a flexible telescope is passed through the urethra and bladder to reach the ureter between the bladder and kidney; and shockwave lithotripsy, in which shockwaves are applied to the skin over the location of the kidney stone. Ureteroscopy achieved better stone-free results at 1 and 6 months, but not at 1 year.

The Clinical Efficacy and Safety of Extracorporeal Shock Wave Lithotripsy in the Treatment of Patients with Urinary Calculi

Objective

To evaluate the clinical efficacy of extracorporeal shock wave lithotripsy (ESWL) for urinary calculi and precautions of postoperative complications.

Methods

90 patients with urinary calculi at our hospital were randomly recruited between July 2019 and July 2020 and were allocated (1 : 1) to receive either ESWL (observation group) or conventional surgery (control group). Clinical efficacy was the primary endpoint, whereas adverse events were the secondary endpoint.

Results

The operation time, early activity time, and hospitalization time of the observation group were significantly lower than those of the control group (P < 0.05). ESWL resulted in less postoperative pain in patients versus conventional surgery (P < 0.05). ESWL was associated with a significantly higher total clinical efficacy (97.78%) versus conventional surgery (82.22%) (P < 0.05). The eligible patients given ESWL had a lower incidence of complications (11.12%) versus those given conventional surgery (31.12%) (P < 0.05).

Conclusion

Hematuria prevention requires precise localization of stones as well as adjustment of pulse energy and the number of impacts due to stone changes. Precautions against renal colic necessitate complete comminution of stones intraoperatively, more postoperative water intake, moderate exercise, or injection of antispasmodic drugs and cathartics for pain relief. Nausea and vomiting precautions require preoperative recording of previous medical history and corresponding treatment, intraoperative real-time adjustment of voltage pulse frequency, and duration depending on the magnitude of intraoperative reaction. Urinary tract infection prevention requires preoperative prevention and proper postoperative anti-infection and anti-inflammatory treatment, along with enough water intake and bed rest. Other precautions include thorough comminution of the calculi, proper anti-infection and anti-inflammatory treatment, no early exercise or excessive activity after surgery, and proper postoperative care. ESWL is effective in treating patients with urinary calculi with a simple, safe, and quick operation and a low incidence of adverse events, as it effectively reduces the incidence of complications, accelerates the recovery of patients and improves their quality of life.

Modified shockwave propulsion lithotripsy improves the lower pole renal stone clearance

The shockwave lithotripsy is an established modality for the treatment of urinary stone disease. The aim of the study was to present our modified shockwave lithotripsy (SWL) technique, a shockwave propulsion lithotripsy (SWPL) technique, for the treatment of lower pole renal stones and compare its clinical outcomes with the standard SWL technique. An evaluation of a prospectively collected database including 168 patients divided into two groups and treated with ultrasound-guided SWL (n = 80) and SWPL (n = 88) were included in our study. The data were collected between January 2016 and December 2021. Patients older than 18 years old with single lower pole stones sized up to 2 cm were included in the study. SWPL was associated with significant higher SFR compared to standard SWL (85.2 vs. 62.5%, p = 0.001) and required less applied shockwaves (2151 vs. 2502, p = 0.001). Most of the patients in both groups underwent only one SWL session. Overall, a 7.1% complication rate (12 out of 168 patients) was reported, with no difference between groups. In conclusion, our proposed SWPL technique was aimed to overcome difficulties associated with the gravity and anatomic specificities of the lower pole, increased SFR and decreased the need for additional treatment.

Mini-track, mini-nephroscopy, mini-ultrasonic probe percutaneous nephrolithotomy and its initial clinical application

Background

To assess the outcome of the mini-track, mini-nephroscopy, mini ultrasonic probe percutaneous nephrolithotomy for upper ureteral and kidney stones.

Methods

We collected data of 53 patients (55 kidney units) who underwent mini-track, mini-nephroscopy, mini-ultrasonic probe percutaneous nephrolithotomy between September 2020 and March 2021. The study included single and upper ureteral stones from 12 kidneys, multiple stones from 28 kidneys, and staghorn stones from 15 kidneys.

Results

The mean operative duration was 50.6 min, ranging from 15 to 200 min, whereas the mean lithotripsy and stone removal time was 17.2 min (3–45 min). Moreover, the mean postoperative length of stay was 4.0 days (1–7 days). Besides, the stone-free rate (SFR) of discharge was 89.1% (49/55). The mean hemoglobin drop was 15.3 mg/dL, ranging 1–32 mg/dL. Out of the total cases, only 4 of them displayed minor complications. The outcomes of < 40 mm versus ≥ 40 mm calculi were compared by performing subgroup analysis. The results demonstrated a longer operation duration (65.2 vs. 40.2 min), higher complication rate (13.0% vs. 3.3%), and lower SFR in the ≥ 40 mm calculi subgroup.

Conclusions

In summary, mini-track, mini-nephroscopy, mini-ultrasonic probe percutaneous nephrolithotomy is an effective and safe method to treat patients with upper ureteral and kidney calculi. This is especially significant for the stone size of 20–40 mm, demonstrating excellent SFR and a lower complication rate.

Urologists are optimistic surgeons: prevalence and predictors of discordance between intraoperative stone-free rate and cross-sectional imaging evaluation after vacuum-assisted mini-percutaneous nephrolithotomy

Purpose

To assess how accurate are urologists in predicting stone-free status (SFS) after vacuum-assisted mini-PCNL (vamPCNL) compared to computed tomography (CT) and clinical predictors of discordant SFS.

Methods

Data from 235 patients who underwent vamPCNL were analysed. Patient’s demographics, stones’ characteristics and operative data were recorded. SFS was evaluated intraoperatively by the treating urologist (iSFS) and with non-contrast CT 3 months after vamPCNL (ctSFS). SFS was defined as no residual stones. Stone complexity was scored with the Guy’s score. Descriptive statistics and logistic regression models were used to identify clinical factors associated with discordant SFS (namely iSFS not confirmed at CT).

Results

iSFS and ctSFS were 88.5% and 65.5%, respectively, with 54 (23%) cases resulting in discordant evaluation of SFS between the surgeon and CT imaging. Patients with discordant SFS had larger stone volume (p < 0.001), higher rate of multiple stones (p = 0.03) and higher rate of multiple calyceal groups affected by stones (p < 0.001) than those with concordant SFS. The use of flexible ureteroscopes to look for residual stones after lithotripsy was more frequently reported in cases with concordant SFS (p = 0.001). Multivariable logistic regression analysis revealed that stones in > 2 calyceal groups (OR 10.2, p < 0.001), Guy’s score II (OR 5.8, p < 0.01) and not using flexible ureteroscopes after lithotripsy (OR 2.9, p = 0.02) were independent predictors of discordant SFS.

Conclusion

One out of five patients is erroneously considered SF after vamPCNL. Urologist should carefully evaluate patients with multiple calyceal stones and consider using flexible ureteroscopes to complete lapaxy of migrated fragments in order to improve their prediction of SFS.

Endoscopic Combined Intrarenal Surgery vs Percutaneous Nephrolithotomy for Large and Complex Renal Stone: A Systematic Review and Meta-Analysis

Background: Managing complex and large renal stones with percutaneous nephrolithotomy (PCNL) is difficult because of the likelihood of residual stones and multiple access. Endoscopic combined intrarenal surgery (ECIRS) is introduced as an improvement to the procedure to manage stones in one session. The objective of this systematic review and meta-analysis is to compare the efficacy and safety between ECIRS and PCNL for treating large and complex renal stones. Materials and Methods: We conducted a systematic review in the Embase, Scopus, and MEDLINE databases based on the 2020 Preferred Reporting Items for Systematic Review and Meta-Analyses guideline. Eligible studies comprised both randomized and nonrandomized studies comparing ECIRS and PCNL. Results: A total of five nonrandomized studies and one randomized controlled trial were included. The analysis was divided into two subgroups based on the PCNL type, a conventional PCNL (cPCNL) and a mini-PCNL (mPCNL). The one-step stone-free rate (SFR) of ECIRS were significantly higher compared with both the cPCNL (odds ratio [OR] 5.14, 95% confidence interval [CI] 2.54 to 10.4, p < 0.001) and mPCNL (OR 4.27, 95% CI 2.57-7.1, p < 0.001). There were no significant differences in mean operative time and hemoglobin drop between both groups (p > 0.05). The use of auxiliary procedures was significantly higher in both PCNL groups compared with the ECIRS group (OR 0.19, 95% CI 0.13-0.30, p < 0.001). The overall complication rate of ECIRS was lower compared with PCNL (OR 0.43, 95% CI 0.21-0.85, p = 0.02), especially urosepsis, in which the incidence was lower compared with cPCNL (OR 0.14, 95% CI 0.02-0.78, p = 0.02), but not mPCNL (p > 0.05). Conclusion: ECIRS is an effective and safe treatment particularly for large and complex nephrolithiasis, with significantly higher one-step SFR, a lower necessity for auxiliary procedures, and a lower complication rate compared with PCNL.

Comparison of the Efficacy and Complications of Soft Ureteroscopy Lithotripsy and Percutaneous Nephrolithotomy in the Treatment of Urinary Calculi: A Systematic Review and Meta-analysis

Objective

To systematically evaluate the efficacy and complications of soft ureteroscopic lithotripsy (SUL) and percutaneous nephrolithotomy (PCNL) in the treatment of urinary calculi and to provide evidence-proof medicine basis for the popularization and application of flexible ureteroscopic lithotripsy.

Methods

PubMed, EMBASE, ScienceDirect, Cochrane Library, China knowledge Network Database (CNKI), China VIP Database, Wanfang Database, and China Biomedical Literature Database (CBM) were searched for randomized controlled trials (RCT) related to soft ureteroscopic lithotripsy and percutaneous nephrolithotomy in the treatment of urinary calculi from Jan. 2010 to Mar. 2022. The bias risk of each included literature was assessed according to the standard of Cochrane manual 5.1.0. The collected data were meta-analyzed by RevMan 5.4 statistical software.

Results

Ultimately, 6 RCT (a total of 794 samples) were included for meta-analysis. Heterogeneity test results of stone clearance rate were chi² = 2.44, df = 5, P = 0.79 > 0.05, and I² = 0%, indicating none obvious heterogeneity among the included research data. The test of WMD was Z = 2.11 (P = 0.03). It could be considered that compared with PCNL in the treatment of urinary calculi, SUL had a higher stone clearance rate in patients with urolithiasis. Secondly, heterogeneity test of operation time was chi² = 184.95, df = 5, P < 0.00001, and I² = 97%. The results of heterogeneity test of intraoperative blood loss displayed chi² = 645.47, df = 5, P < 0.00001, and I² = 99%. Then, heterogeneity test results of postoperative hospital stay existed chi² = 57.37, df = 5, P < 0.00001, and I² = 91% with an obvious heterogeneity. According to the results of this analysis, it could be considered that compared with PCNL in the treatment of urolithiasis, the operation time of SUL in the treatment of urolithiasis was longer, but the amount of intraoperative bleeding and postoperative hospital stay was significantly reduced. The results of heterogeneity of stress index level NE showed as chi² = 0.32, df = 2, P = 0.85 > 0.05, and I² = 0%, and COR was chi² = 1.09, df = 1, P = 0.30 > 0.05, and I² = 8%. It showed that there was no obvious heterogeneity. The heterogeneity of ACTH was chi² = 390.36, df = 2, P < 0.00001, and I² = 99%, suggesting obvious heterogeneity. The test of combined effect dose WMD was Z = 21.90, 4.50, and 15.42, (P < 0.00001). It could be considered that there was a statistical difference in the WMD of stress response between patients with urinary calculi treated by soft ureteroscope and percutaneous nephrolithotomy, indicating that the stress response of patients with urinary calculi treated with SUL is less than that of PCNL. For the heterogeneity test of serum creatinine level, NE showed chi² = 0.78, df = 2, P = 0.68 > 0.05, and I² = 0% without obvious heterogeneity, and the combined effect dose WMD is analyzed by random effect model. The test of combined effect dose WMD was Z = 4.22 (P < 0.00001). It can be considered that the improvement of serum creatinine level in patients with urolithiasis treated with SUL was better than that of PCNL. The results of heterogeneity test on the safety of operation are as follows: chi² = 13.76, df = 5, P = 0.02, and I² = 64%, indicating obvious heterogeneity among the included research data. The combined effect dose of WMD was Z = 5.53 (P < 0.00001). This could be considered that soft ureteroscopic lithotripsy had higher safety and less postoperative complications than percutaneous nephrolithotomy in the treatment of urinary calculi. An inverted funnel chart was used to analyze the publication bias of the study with stone clearance rate as the outcome index. The results showed that the figure was not completely symmetrical and the Egger's test showed that the figure was P = 0.0005 < 0.001. It was suggested that there may be a certain degree of publication bias.

Conclusion

PCNL and SUL can achieve higher stone clearance rate in the treatment of renal calculi. However, SUL has the advantages of less intraoperative bleeding, short stress reaction and postoperative hospital stay, less damage to renal function, and low incidence of complications, which is beneficial to the rapid recovery of patients after operation. More studies with higher methodological quality and longer intervention time are needed to further verify.

The comprehensive complication index as a tool for reporting the burden of complications after mini-percutaneous nephrolithotomy: is it time to leave the Clavien–Dindo classification behind?

Purpose

To validate the comprehensive complication index (CCI) for mini-percutaneous nephrolithotomy (mPCNL).

Methods

Data from 287 patients who underwent mPCNL were analyzed. Complications after mPCNL were classified using both the CCI and the Clavien–Dindo classification (CDC). Descriptive statistics and linear/logistic regression analyses detailed the association between clinical predictors and mPCNL outcomes.

Results

After mPCNL, 83 (28.9%) patients had complications, of which 12 (4.2%) patients with multiple complications had a higher CCI score compared to the traditional CDC system accounting only for the highest grade. The CCI enabled a more accurate prediction of length of stay (LOS) than CDC (CCI: r = 0.32; p < 0.01 vs. CDC: r = 0.26; p = 0.01). Patients with multiple complications had higher stone volume (p = 0.02), longer operative time and LOS (all p < 0.01). A higher rate of post-operative hospital readmission (33.3% vs. 9.9%, p = 0.02) and lower rate of stone free (33.3% vs. 64.7%, p = 0.04) were found in patients with multiple complications than in those with single complication. Linear regression analysis revealed that multiple complications were associated with longer LOS (p < 0.001) after accounting for BMI and stone volume. Similarly, having multiple complications was associated with fivefold higher risk of readmission (p = 0.02).

Conclusion

The CCI is a valuable metric for assessing post-operative complications after mPCNL. The cumulative CCI is a better predictor of LOS than the CDC for mPCNL. Minor complications not captured by the highest CDC score are relevant since patients with multiple complications have longer LOS and higher rate of readmission than those with single ones.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00345-022-04045-9.

External validation of the T.O.HO. score as predictor of success after retrograde intrarenal surgery

Background

To assess the effectiveness of T.O.HO. (Tallness, Occupied lesion, Houndsfield unit evaluation) score in predicting the retrograde intrarenal surgery (RIRS) success and to validate this scoring system.

Methods

The age, sex, previous stone surgery, hospitalization, surgery duration, postoperative complication, stone length, stone location, stone density, stone number, lateralization, presence of hydronephrosis, and presence of preoperative stent datas of 611 patients who underwent RIRS in our clinic between January 2013 and January 2021 were retrospectively assessed. The patients were divided into two groups as successful and unsuccessful. The T.O.HO scores of all patients were calculated.

Results

The success rate was 72.5%. Compared to the unsuccessful group, stone length and stone density were lower, surgery duration was shorter and there were less lower pole stones in the successful group (p < 0.001). No significant difference was found between the two groups in terms of the other parameters. The T.O.HO. score was significantly lower in the successful group compared to the unsuccessful group (p < 0.001). According to the multivariate logistic regression analysis, stone length (OR: 0.905; 95% Cl: 0.866–0.946; p < 0.001), lower pole location (OR: 0.546; 95% Cl: 0.013–0.296; p < 0.001), stone density (OR: 0.999; 95% Cl: 0.998–1; p = 0.044) and the T.O.HO. score (OR: 0.684; 95%Cl: 0.554–0.844; p < 0.001) were found as the independent risk factors for RIRS success. ROC curve analysis showed that the T.O.HO. score could predict the RIRS success with 7.5 cut-off point (AUC: 0.799, CI: 0.76–0.839; p < 0.001).

Conclusion

The T.O.HO. score can predict RIRS success with a high rate of accuracy.

Intravenous Pyelogram (IVP)-Based Guy’s Stone Score (GSS) Utility for Prediction of Outcomes of Upper Pole Access Percutaneous Nephrolithotomy (PCNL)

Background: Renal stone disease is a very common disease, and its lifetime prevalence is 1 - 15%, with a gradual rise in incidence and disease prevalence. There are significant financial implications of its management. Nowadays, for big (typically > 2 cm) renal and upper ureteric stones, PCNL is widely regarded as the first-line treatment. Because most of the intrarenal collecting systems can be accessed by superior calyceal puncture in PCNL, good stone clearance can be achieved. The “Guy’s Stone Score” is a useful technique for categorizing the complexity of PCNL. Objectives: This study aimed to evaluate the role of Guys Stone Score based on KUB and intravenous urography to predict the success rate, grading, and complexity of PCNL, which are performed via the upper pole access. Methods: The present prospective, non-randomized observational study was undertaken in the Department of Urology and Renal transplantation, SCBMCH, Cuttack, from 1st November 2017 to 31st October 2019. A total of 104 patients were enrolled in the study in whom PCNL was performed through superior calyceal puncture, based on preoperative intravenous pyelogram. The Guy's Stone Score was calculated, and the complexity of the procedure was graded using radiological studies, then the outcome was determined accordingly. Results: In this study, 59.6% of the patients had immediate success among them 29.0% had grade 3, and 6.5% had grade 4 GSS. Moreover, 38.4% of the patients had clinically significant residual fragments among them, 75.0% had grade 4, and 20.0% had grade 3 GSS.23% of the patients underwent REDO-PCNL and 11.5% of the patients underwent necessary procedure of ESWL. Conclusions: The present study shows that an intravenous pyelogram-based Guy’s Stone Score (GSS) is an easy-to-use tool in predicting the early success rate and potential difficulties and complications in PCNL performed through superior calyceal puncture.

Retrograde Intrarenal Surgery Versus Miniaturized Percutaneous Nephrolithotomy for Kidney Stones >1cm: A Systematic Review and Meta-analysis of Randomized Trials

CONTEXT

Although miniaturized percutaneous nephrolithotomy (mPCNL) and retrograde intrarenal surgery (RIRS) are both options for treating >1cm kidney stones, controversies exist on whether one is more effective and safer than the other.

OBJECTIVE

To systematically appraise randomized trials comparing the effectiveness and safety of mPCNL and RIRS for treating >1cm kidney stones.

EVIDENCE ACQUISITION

A systematic search on PubMed/Medline, Web of Science, Embase, and ClinicalTrials.gov was conducted in August 2020 following the Preferred Reporting Items for Systematic Review and Meta-analyses (PRISMA). Randomized trials comparing mPCNL and RIRS for >1cm kidney stones, and reporting stone-free rate (SFR), hemoglobin drop, transfusion rate, length of hospital stay (LOS), and/or complications, were included.

EVIDENCE SYNTHESIS

Eight studies compared mPCNL and RIRS, but one was not included due to its high risk of bias. SFR was higher for mPCNL (RR: 1.06 [95% coefficient interval {CI}, 1.01-1.10], p=0.008). Hemoglobin drop was higher for mPCNL (mean difference [MD]: 0.35 [95% CI, 0.05-0.65] g/dl, p=0.02); however, transfusion rates were similar (p=0.44). Complication rate was similar between mPCNL and RIRS (p=0.39), and the LOS was higher for mPCNL (MD: 1.11 [95% CI, 0.06-2.16] d, p=0.04). A subgroup analysis of lower pole stones showed that SFR was higher for mPCNL (RR: 1.09 [95% CI, 1.00-1.19], p=0.05).

CONCLUSIONS

Both approaches are effective and safe. Among these approaches, mPCNL has a higher SFR than RIRS for overall >1cm renal and lower pole stones, but longer LOS, and a higher hemoglobin drop that does not translate into higher transfusion rates. Complications are comparable.

PATIENT SUMMARY

Randomized trials have evaluated whether miniaturized percutaneous nephrolithotomy (mPCNL) or retrograde intrarenal surgery is more effective and safer for treating >1cm stones. After comparing the stone-free rate, hemoglobin drop, transfusion rate, length of hospital stay, and complications between both the approaches, mPCNL was found to be slightly more effective, but both were equally safe.

Obesity-related indices and its association with kidney stone disease: a cross-sectional and longitudinal cohort study

Obesity increases the risk of several diseases, including kidney stone disease (KSD). The study aimed to explore the relationship between KSD and various obesity-related indices. A total of 121,605 participants in the Taiwan Biobank from December 2008 to February 2020 were analyzed. The association between self-reported history of KSD and eight obesity-related indices, including body mass index (BMI), waist circumference (WC), waist-to-height ratio (WHtR), waist-to-hip ratio (WHR), abdominal volume index (AVI), body roundness index (BRI), conicity index, and triglyceride glucose index was examined in cross-sectional analysis; additionally, the risk of developing kidney stones was analyzed in a longitudinal cohort of 25,268 participants without KSD at baseline, which was a subset of the main cohort. Of all participants, 77,904 (64.1%) were female. Overall, 10.7% of males and 4.0% of females had KSD. Multivariate-adjusted logistic regression showed that all obesity-related indices were significantly associated with KSD. During a mean follow-up of 47 months, kidney stones occurred in 642 (2.5%) participants, and after adjusting for confounders, the risk of developing kidney stones was higher in participants with higher BMI, WC, WHtR, WHR, AVI and BRI. BMI, WC, WHtR, WHR, AVI, and BRI were found to be associated with a higher prevalence of kidney stones as well as development of incident kidney stones, which could be used as predictive factors for development of KSD in clinical practice.

Counter-Irrigation as a Novel Technique versus the Standard Technique in Percutaneous Nephrolithotomy: A Prospective Randomized Trial

OBJECTIVE

This study aimed to evaluate the efficacy of our counter-irrigation technique versus the standard technique in percutaneous nephrolithotomy (PCNL) by assessment of the stone-free rate after the procedures and its safety in terms of comparing the intraoperative time, Hb deficit, blood transfusion, length of hospital stay, auxiliary procedures, and perioperative complications with that of the standard one.

METHODS

This prospective randomized trial was conducted on patients with renal stone 2-3 cm in diameter without contraindications to PCNL. The patients were randomized into group A in which the counter-irrigation technique has been performed and group B who were managed by the standard technique. The preoperative characteristics including demographic data and stone parameters were compared between both groups. The primary outcome was the stone-free rate assessed by noncontrast spiral CT after 3 months. The secondary outcome included intraoperative time, Hb deficit, blood transfusion, hospital stay, auxiliary procedure required, and rate of complications.

RESULTS

Forty-eight patients were included in this study. Overall, no significant difference was observed between both groups regarding preoperative characteristics, Hb deficit, and complication rate. Operative time was significantly shorter in group B (p = 0.001). None of our patients required blood transfusion. The stone-free rates at 3 months were significantly better in group A (95% for group A and 70% for group B, p = 0.04).

CONCLUSIONS

Our results indicate that our counter-irrigation technique has lower stone migration with subsequent significantly better stone-free rate versus the standard technique. We can recommend this technique as a potentially valid option for cases with large stone burden when the access to the upper calyx is feasible to minimize significant residual fragments.

Mini-percutaneous nephrolithotomy versus shock wave lithotripsy for the medium-sized renal stones

INTRODUCTION

The aim of this study was to assess the clinical outcomes of mini-percutaneous nephrolithotomy (Miniperc) and shock wave lithotripsy (SWL) for medium-sized renal stones.

EVIDENCE ACQUISITION

A literature search was performed in February 2020 using the Pubmed, Web of Science and Embase. The outcome measurements between two procedures were stone-free rates (SFR), complication rates, operative time, hospitalization stay time, re-treatment rate, auxiliary procedures rate and efficiency quotient. Results were pooled by Review Manager version 5.3 software.

EVIDENCE SYNTHESIS

Seven studies on 936 patients (N.=471 for SWL and N.=465 for Miniperc) were included. Miniperc was associated with a higher SFR (OR: 0.25; P<0.00001). In addition, we performed a subgroup analyses for pediatric renal stones and lower pole stones, pooled results also favored Miniperc for higher SFR. SWL was associated with higher auxiliary procedure (OR: 3.32; P<0.00001), higher re-treatment rate (OR: 19.19; P<0.00001) and lower EQ (OR: 0.18; P=0.0003) compared with Miniperc. Besides, SWL was associated with a lower complication rate (OR: 0.36; P=0.0001), shorter operative time (WMD: -34.01; P<0.00001), fluoroscopy time (WMD: -134.48; P<0.00001) and hospital time (WMD: -49.11; P<0.00001) compared with Miniperc.

CONCLUSIONS

Miniperc offers a significantly higher SFR, lower auxiliary procedure and re-treatment rate, but SWL was associated with fewer complications.

The Effect of Shock Wave Lithotripsy on Male and Female Sexual Dysfunction in Patients with Proximal Ureteral Stones

INTRODUCTION

This study aims to investigate the effects of shock wave lithotripsy (SWL) treatment for proximal ureteral stones on the sexual functions of patients of both genders.

METHODS

In this prospective study, 30 female and 72 male patients who had received SWL treatment for proximal ureteral stones in our clinic between August 2019 and October 2020 were evaluated. CT, creatinine, urinary analysis, and culture were performed during the initial consultation for all patients. Information regarding the age, BMI, and stone burden of the patients was recorded. Male patients answered the International Index of Erectile Function-5 (IIEF-5) questionnaire, and female participants answered the Female Sexual Function Index (FSFI) 3 times: pre-procedural and post-procedural first and third month. CT was repeated on the first month, and any residues were noted.

RESULTS

The mean IIEF-5 scores of the male patients were 23.11 ± 8.11 prior to surgery, and it decreased to 19.74 ± 7.65 in the first month and 23.88 ± 9.23 in the third, p = 0.001. The mean FSFI scores of female patients were 18.2 ± 9.9, which decreased to 12.8 ± 6.12 in the first month and 17.8 ± 8.66 in the third, p = 0.001. Univariate analysis revealed that the patients' age (male: p = 0.004 and female: p = 0.008) and BMI (male: p = 0.044 and female: p = 0.027) were related to the poorer scores for both genders. However, there were not any significant findings regarding stone burden (male: p = 0.054 and female: p = 0.078).

CONCLUSIONS

The possibility of developing temporary sexual dysfunction should be taken into account for patients who are candidates for SWL treatment. As the patient's age and BMI increase, SWL-related sexual dysfunction becomes more severe.

Cost-effectiveness of Retrograde Intrarenal Surgery, Standard and Mini Percutaneous Nephrolithotomy, and Shock Wave Lithotripsy for the Management of 1-2cm Renal Stones

OBJECTIVE

To perform a cost-effectiveness evaluation comparing the management options for mid-size (1-2cm) renal stones including percutaneous nephrolithotomy (PCNL), retrograde intrarenal surgery (RIRS), and shockwave lithotripsy (SWL).

METHODS

A Markov model was created to compare cost-effectiveness of PCNL, mini-PCNL, RIRS, and SWL for 1-2cm lower pole (index patient 1) and PCNL, RIRS, and SWL for 1-2 cm non-lower pole (index patient 2) renal stones. A literature review provided stone free, complication, retreatment, secondary procedure rates, and quality adjusted life years (QALYs). Medicare costs were used. The incremental cost-effectiveness ratio (ICER) was compared with a willingness-to-pay(WTP) threshold of $100,000/QALY. One-way and probabilistic sensitivity analyses were performed.

RESULTS

At 3 years, costs for index patient 1 were $10,290(PCNL), $10,109(mini-PCNL), $5,930(RIRS), and $10,916(SWL). Mini-PCNL resulted in the highest QALYs(2.953) followed by PCNL(2.951), RIRS(2.946), and SWL(2.943). This translated to RIRS being most cost-effective followed by mini-PCNL(ICER $624,075/QALY) and PCNL(ICER $946,464/QALY). SWL was dominated with higher costs and lower effectiveness. For index patient 2, RIRS dominated both PCNL and SWL. For index patient 1: mini-PCNL and PCNL became cost effective if cost ≤$5,940 and ≤$5,390, respectively. SWL became cost-effective with SFR ≥75% or cost ≤$1,236. On probabilistic sensitivity analysis, the most cost-effective strategy was RIRS in 97%, mini-PCNL in 2%, PCNL in 1%, and SWL in 0% of simulations.

CONCLUSION

For 1-2cm renal stones, RIRS is most cost-effective. However, mini and standard PCNL could become cost-effective at lower costs, particularly for lower pole stones.

Clinical Comparison of Mini-Percutaneous Nephrolithotomy with Vacuum Cleaner Effect or with a Vacuum-Assisted Access Sheath: A Single-Center Experience

Purpose: To compare outcomes of two different miniaturized percutaneous nephrolithotomy (PCNL) techniques: minimally invasive PCNL (MIP) with the vacuum cleaner effect and vacuum-assisted mini-PCNL (vmPCNL). Materials and Methods: Data from 104 (66.7%) patients who underwent vmPCNL and 52 (33.3%) patients who underwent MIP at a single tertiary referral academic center between January 2016 and December 2019 were analyzed. Patient demographics and peri- and postoperative data were recorded, and propensity score matching was performed. Descriptive statistics and linear regression models were used to identify variables associated with operative time (OT) and patient effective dose. Logistic regression analyses were used to identify factors associated with infectious complications and stone-free (SF) status. Results: Patient demographics and stone characteristics were comparable between groups. vmPCNL was associated with shorter OT (p < 0.001), fluoroscopy time, and patient effective dose (4.2 mSv vs 7.9 mSv; p < 0.001). A higher rate of infectious complications was found in the MIP group (25.0% vs 7.7%, p < 0.01). Linear regression analysis showed that stone volume, multiple stones, and MIP procedure (all p values ≤0.02) were associated with longer OT. Similarly, OT and the MIP procedure (p ≤ 0.02) were associated with higher patient effective dose. Logistic regression analysis revealed that the stone volume, positive preoperative bladder urine culture, and MIP procedure (all p values ≤0.02) were associated with postoperative infectious complications. vmPCNL was not associated with the SF rate. Conclusions: Mini-PCNL performed with continuous active suction is associated with lower rates of infectious complications, shorter OT, and lower patient effective dose than MIP.

Disposable versus Reusable Ureteroscopes: A Prospective Multicenter Randomized Comparison

Purpose

To compare reusable and disposable flexible ureteroscopes in terms of efficacy and safety for patients undergoing Retrograde Intrarenal Surgery (RIRS).

Patients and Methods

Patients with a renal stone eligible for RIRS were enrolled in this multicenter, randomized, clinical trial study. Patients were randomized into two groups: group A (90 patients) underwent RIRS with a reusable flexible ureteroscope and group B (90 patients) were treated with a disposable one.

Results

The patients’ demographics, stone features and pre-operative urine cultures were comparable between the groups. The Stone Free Rates (SFRs) were not significantly different (86.6% and 90.0% for group A and group B, respectively, p=0.11) and the mean cost for each procedure was comparable (2321 € in group A vs 2543 € in group B, p=0.09). However, the days of hospitalization and of antibiotic therapy were higher in group A (p ≤ 0.05). The overall complication rate in group A was 8.8% whilst in group B it was 3.3% (p ≤ 0.05); in particular, group A exhibited a greater number of major complications (Clavien score IIIa-V). The overall postoperative infection rate was 16.6% in group A and 3.3% in group B (p ≤ 0.05). Furthermore, none of the patients in group B developed urosepsis or had a positive blood culture, while 3 patients in group A did (p<0.05).

Conclusion

The use of disposable ureteroscopes is characterized by significantly lower post-operative complications and infection rates, while having comparable costs and SFRs vis à vis reusable ureteroscopes. Clinical Trial Registration Number: ISRCTN92289221.

Evaluation of Patient Treatment Preferences for 15 to 20 mm Kidney Stones: A Conjoint Analysis

Introduction and Objective: Ureteroscopy (URS) and percutaneous nephrolithotomy (PCNL) are standard treatments for intermediate-size (15-20 mm) kidney stones but differ in their postoperative recovery, stone-free rates, and complication risks. We aimed to evaluate what affects patient treatment preferences. Methods: Patients with urinary stone disease completed a choice-based conjoint analysis exercise assessing four treatment attributes associated with URS and PCNL. A sensitivity analysis using a market simulator was performed, and the relative importance of each attribute was calculated. Differences in treatment preferences by demographic subgroup were assessed. Results: A total of 58 patients completed the conjoint analysis exercise. Stone-free rate was the most important treatment attribute, while the length of hospital stay and cosmesis were less important. Overall, sensitivity analysis based on market simulation scenarios predicted an almost equal preference for URS (52.4%) compared with PCNL (47.6%) for treatment of an intermediate-size stone. Older patients (>65 years old) expressed their stronger preferences for lower infection rates and shorter hospital stays, and were more likely to prefer URS (67.2%, 95% confidence interval [CI]: 52% to 82.5%) compared with younger patients (20-34 years old) (20.3%, 95% CI: 0% to 41.5%) who preferred higher procedure success rates and fewer repeat procedures. Conclusion: Conjoint analysis predicts nearly equal patient preference for URS or PCNL for the treatment of intermediate-size kidney stones. Older patients prefer the lower urinary tract infection risk and shorter hospital stay associated with URS, while younger patients prefer higher stone-free rates associated with PCNL. These results can help guide urologists in counseling patients and improve the shared decision-making process.