Ultrasound-guided renal puncture followed by endoscopically guided tract dilatation vs standard fluoroscopy-guided percutaneous nephrolithotomy for non-opaque renal stones; a randomized clinical trial.

This study was designed to evaluate the non-inferiority of ultrasound puncture followed by endoscopically guided tract dilatation compared to the standard fluoroscopy-guided PCNL. Forty patients with non-opaque kidney stones eligible for PCNL were randomly divided into two groups. The standard fluoroscopy-guided PCNL using the Amplatz dilator was performed in the XRAY group. In the SONO group, the Kidney was punctured under an ultrasound guide followed by tract dilatation using a combination of the Amplatz dilator based on the tract length and an endoscopically guided tract dilatation using a bi-prong forceps in cases of short-advancement. The primary outcome was successful access. In 90% of cases in the XRAY and 95% in the SONO group access dilatation process was performed uneventfully at the first attempt (p = 0.5). In 45% of cases in the SONO group, bi-prong forceps were used as salvage for short-advancement. In one case in the X-ray group over-advancement occurred. One month after surgery, the stone-free rate on the CT-scan was 75% for the X-ray group and 85% for the SONO group (p = 0.4). There were no significant differences in operation time, hospitalization duration, transfusion, or complication rates between the two groups. We conclude that ultrasound-guided renal puncture, followed by endoscopically guided tract dilatation can achieve a high success rate similar to X-ray-guided PCNL while avoiding the harmful effects of radiation exposure and the risk of over-advancement.

Comparison of supine-prone percutaneous nephrolithotomy methods in the treatment of kidney stones in pediatric patients: prospective randomized study.

Mini-PCNL is one of the most effective surgical methods in the treatment of kidney stones in pediatric patients. In this study, we aimed to compare PCNL in the supine-prone position in pediatric patients (especially operation time, postop complications, hospital stay and stone-free rates).We conducted our study in a randomized and prospective manner. Patients with lower pole stones larger than 1 cm, stones larger than 1.5 cm in the pelvis, upper pole, midpole or multiple locations, and patients who did not respond to ESWL or whose family that preferred mini-PCNL to be the primary treatment were included in the study. Patients with any previous kidney stone surgery, patients with coagulation disorders and patients with retrorenal colon were excluded from the study. Between 2021 and 2023, a total of 144 patients underwent PCNL. 68 of these patients had supine PCNL and 76 prone PCNL. Postoperative Clavien grade1 complication occurred in a total of 7 patients in the prone position; Clavien grade1 complication occurred in 1 patient in the supine position. The mean operation time for prone PCNL was 119.88 ± 28.32 min, and the mean operative time for supine PCNL was 98.12 ± 14.97 the mean hospitalization time in prone PCNL was 3.56 ± 1.12 days, and 3.00 ± 0.85 days in supine PCNL. In conclusion, supine PCNL is a safe and effective method in the treatment of pediatric kidney stones and postoperative complications were observed to be less; the operation time and hospital stay were shorter in supine PCNL.

Comparison of safety and efficacy of tubeless vs. conventional mini percutaneous nephrolithotomy in patients with Escherichia coli bacteriuria.

To evaluate the safety and efficacy of tubeless percutaneous nephrolithotomy (PCNL) in patients with Escherichia coli (E. coli) bacteriuria. We conducted a retrospective review of 84 patients with E. coli bacteriuria who underwent PCNL. Patients were divided into two groups according to whether a nephrostomy tube is placed at the end of the procedure. Preoperative clinical data, surgical outcomes, and postoperative complications were compared. Then, regression analysis of factors predicting success rate of PCNL in patients with E. coli bacteriuria was performed. After PCNL, residual fragments ≤ 4 mm were considered as success. At baseline, the two groups were similar with regard to age, gender, BMI, underlying disease, hydronephrosis, stone characteristics, and urinalysis. Postoperative fever occurred in 1 patient (3.8%) in the tubeless PCNL group, and in 5 patients (8.6%) in the conventional PCNL group (p > 0.05). There were no significant differences in terms of successful rate, decrease in hemoglobin, pain scores, blood transfusion, and hospitalization expenses. However, the tubeless PCNL group had significantly shorter operative time (60 vs. 70 min, p = 0.033), indwelling time of catheter (2 vs. 4 days, p < 0.001), and hospital stays (3 vs. 5 days, p < 0.001) than the conventional PCNL group. In the analysis of factors predicting success, the stone diameter, stone burden, and operative time were associated with success rate of PCNL. It is safe and effective to perform tubeless PCNL in patients with E. coli bacteriuria. Compared to conventional PCNL, tubeless PCNL accelerates patient recovery and shortens hospital stays.

Prone vs supine percutaneous nephrolithotomy: does position affect renal pelvic pressures?

The purpose of this study was to measure and compare renal pelvic pressure (RPP) between prone and supine percutaneous nephrolithotomy (PCNL) in a benchtop model. Six identical silicone kidney models were placed into anatomically correct prone or supine torsos constructed from patient CT scans in the corresponding positions. A 30-Fr renal access sheath was placed in either the upper, middle, or lower pole calyx for both prone and supine positions. Two 9-mm BegoStones were placed in the respective calyx and RPPs were measured at baseline, irrigating with a rigid nephroscope, and irrigating with a flexible nephroscope. Five trials were conducted for each access in both prone and supine positions. The average baseline RPP in the prone position was significantly higher than the supine position (9.1 vs 2.7 mmHg; p < 0.001). Similarly, the average RPP in prone was significantly higher than supine when using both the rigid and flexible nephroscopes. When comparing RPPs for upper, middle, and lower pole access sites, there was no significant difference in pressures in either prone or supine positions (p > 0.05 for all). Overall, when combining all pressures at baseline and with irrigation, with all access sites and types of scopes, the mean RPP was significantly higher in the prone position compared to the supine position (14.0 vs 3.2 mmHg; p < 0.001). RPPs were significantly higher in the prone position compared to the supine position in all conditions tested. These differences in RPPs between prone and supine PCNL could in part explain the different clinical outcomes, including postoperative fever and stone-free rates.

Bilateral Single-session PCNL with Minimally Invasive Technique in Pediatric Nephrolithiasis.

PURPOSE: To assess outcomes of bilateral single-session percutaneous nephrolithotomy (PCNL) with minimally invasive techniques in pediatric population. MATERIALS AND METHODS: From August 2015 to July 2021, 45 children (including 12 infants) were treated with bilateral single-session PCNL, which included miniPCNL (12-16-Fr) and Microperc (4.8-Fr). Patient, stone and operation-related characteristics, stone-free rate (SFR) and complication rate (CR) were compared using ANOVA. Independent predictors were determined using multivariate linear regression. RESULTS: The mean stone burden was 3.2 cm in sum diameter for both kidneys. For bilateral kidneys, the mean operative time was 61.6min and SFR was 93.3%; CR was 53.3%, of which complications of Clavien grade 1 and 2 accounted for 46.7%. Bilateral Microperc, bilateral miniPCNL and Microperc plus miniPCNL was performed in 19, 14 and 12 children respectively. Both irrigation volume and postoperative stay were less in groups with Microperc. Both SFRs and CRs were satisfactory for the three groups. Self-limiting hematuria represented the most common complication of all cases (33.3%), especially in groups with miniPCNL. The stone burden was the only independent predictor for operative time (P < .001) and the postoperative complication (P = .008). Children with older age (P = .009), higher body mass index (P = .016) or a higher stone burden (P < .001) received larger irrigated fluid volume. Microperc was associated with less irrigated fluid volume (P = .001). Children with Clavien grade 3 complications (P = .004) spent prolonged postoperative hospital stay. CONCLUSION: With favourable SFR and acceptable CR, bilateral single-session PCNL with minimally invasive techniques might be an effective and safe procedure for pediatric nephrolithiasis.

Flank versus prone position in percutaneous nephrolithotomy: a meta-analysis of randomized controlled studies.

The objective of this study is to assess the safety and efficacy of the flank position in percutaneous nephrolithotomy (PCNL). We searched PubMed, Embase, SCOPUS, the Cochrane database libraries, and the Chinese Biomedical Literature Database, and randomized controlled trials (RCTs) assessing PCNL in flank position are included in this meta-analysis. The related trials met the inclusion criteria were analyzed using RevMan 5.4. Seven randomized controlled trials were included, involving a total of 587 patients. We found that there was a lower decrease in hemoglobin levels in the flank position group compared to prone-position group (mean difference [MD] = - 0.15, 95% confidence interval (CI) - 0.22 to - 0.08, P < 0.00001). Moreover, our meta-analysis demonstrated no significant differences between groups regarding stone-free rate (relative risk [RR] = 1.00, 95% CI 0.93 to 1.06, P = 0.92), operative time(MD = 0.76, 95% CI - 5.31 to 6.83, P < 0.00001), hospital stay (MD = 0.03, 95% CI - 0.32 to 0.32, P < 0.00001), and complications Clavien grade I (RR = 1.01, 95% CI 0.98 to 1.05, P = 0.54), Clavien grade II (RR = 1, 95% CI 0.97 to 1.02, P = 0.78), and Clavien grade III (RR = 1, 95% CI 0.98 to 1.03, P = 0.77). The use of flank position for PCNL is associated with reduced hemoglobin change without an increase in complications. This positioning technique can be considered safe for patients with nephrolithiasis and may be particularly suitable for high-risk individuals such as those who are obese or have decreased cardiopulmonary function. However, further randomized trials are needed to confirm these findings.

Analysis of factors affecting intraoperative hemorrhage during percutaneous nephrolithotomy and establishment of nomogram model.

Intraoperative hemorrhage is an important factor affecting intraoperative safety and postoperative patient recovery in percutaneous nephrolithotomy (PCNL). This study aimed to identify the factors that influence intraoperative hemorrhage during PCNL and develop a predictive nomogram model based on these factors.A total of 118 patients who underwent PCNL at the Department of Urology, The Affiliated Huai'an No.1 People's Hospital of Nanjing Medical University from January 2021 to September 2023 was included in this study. The patients were divided into a hemorrhage group (58 cases) and a control group (60 cases) based on the decrease in hemoglobin levels after surgery. The clinical data of all patients were collected, and both univariate analysis and multivariate logistic regression analysis were conducted to identify the independent risk factors for intraoperative hemorrhage during PCNL. The independent risk factors were used to construct a nomogram model using R software. Additionally, receiver operating characteristic (ROC) curves, calibration curves and decision curve analysis (DCA) were utilized to evaluate the model.Multivariate logistic regression analysis revealed that diabetes, long operation time and low psoas muscle mass index (PMI) were independent risk factors for intraoperative hemorrhage during PCNL (P < 0.05). A nomogram model was developed incorporating these factors, and the areas under the ROC curve (AUCs) in the training set and validation set were 0.740 (95% CI: 0.637-0.843) and 0.742 (95% CI: 0.554-0.931), respectively. The calibration curve and Hosmer-Lemeshow test (P = 0.719) of the model proved that the model was well fitted and calibrated. The results of the DCA showed that the model had high value for clinical application.Diabetes, long operation time and low PMI were found to be independent risk factors for intraoperative hemorrhage during PCNL. The nomogram model based on these factors can be used to predict the risk of intraoperative hemorrhage, which is beneficial for perioperative intervention in high-risk groups to improve the safety of surgery and reduce the incidence of postoperative complications.

[Colon injury during percutaneous nephrolithotomy (clinical case, literature review)].

Urolithiasis occupies one of the leading places in terms of the frequency of requests for urgent urological care and emergency hospitalization in specialized departments. Percutaneous surgery for urolithiasis, like any of the surgical methods, is associated with a number of specific and non-specific complications. Of course, the frequency of occurrence is dominated by hemorrhagic and inflammatory complications. But damage to the colon is quite rare and amounts to 0.3-0.4%. Focusing on the literature data, it is possible to identify risk factors for colon damage and clinical manifestations of this complication. Given the small clinical experience, both in the world and in the domestic literature, there is no recommendatory base for the management of patients with colon damage during percutaneous interventions. Publications available for analysis indicate the possibility of both an operative approach with the removal of a colostomy and conservative management of patients with such complications. The article presents a clinical observation of successful conservative management of a patient with damage to the descending colon during percutaneous nephrolithotomy. An assessment of risk factors for colon damage in this patient was given. Imaging methods are presented that confirm the presence of this complication and the resulting recovery during the follow-up examination.

Radiation exposure of patients during endourological procedures.

PURPOSE: Considering the existing gaps in the literature regarding patient radiation dose (RD) and its associated risks, a systematic review of the literature on RD was conducted, focusing on percutaneous nephrolithotomy (PCNL), extracorporeal shock wave lithotripsy (SWL), and ureteroscopy (URS). METHODS: Two authors conducted a literature search on PubMed, Web of Science, and Google Scholar to identify studies on RD during endourological procedures. Two thousand two hundred sixty-six articles were screened. Sixty-five publications met the inclusion criteria using the PRISMA standards. RESULTS: RD was generally highest for PCNL, reaching levels up to 33 mSv, 28,700 mGycm2, and 430.8 mGy. This was followed by SWL, with RD reaching up to 7.32 mSv, 13,082 mGycm2, and 142 mGy. URS demonstrated lower RD, reaching up to 6.07 mSv, 8920 mGycm2, and 46.99 mGy. Surgeon experience and case load were inversely associated with RD. Strategies such as optimizing fluoroscopy settings, implementing ultrasound (US), and following the ALARA (As Low As Reasonably Achievable) principle minimized RD. CONCLUSIONS: This is the first systematic review analyzing RD, which was generally highest during PCNL, followed by SWL and URS. There is no specific RD limit for these procedures. Implementation of strategies such as optimizing fluoroscopy settings, utilizing US, and adhering to the ALARA principle proved effective in reducing RD. However, further research is needed to explore the factors influencing RD, assess their impact on patient outcomes, and establish procedure-specific reference levels for RD.

Exploring the Risk Factors for Deep Vein Thrombosis after Percutaneous Nephrolithotomy.

BACKGROUND: Deep vein thrombosis (DVT), a frequent complication following percutaneous nephrolithotomy (PCNL), may lead to severe conditions like pulmonary embolism. Current knowledge on postoperative DVT risk factors is, however, limited. The aim of our study was to investigate the risk of DVT after PCNL. METHODS: A retrospective study was conducted on patients who underwent PCNL from March 2020 to March 2023 at our institution. Patient demographics and clinical data, including, DVT-specific information, preoperative labs, and surgical details, was evaluated. RESULTS: One hundred patients were included. Thirty-two (20 males, 12 females, mean age 52.5 ± 7.4 years) developed lower limb DVT post-surgery, while the remaining 68 (48 males, 20 females, mean age 51.1 ± 5.5 years) had no DVT symptoms. Analysis revealed significant correlations between hyperlipidemia, operating time, postoperative bed rest duration, D-dimer level on the first day after surgery, Caprini risk assessment model (RAM) score, and DVT risk. D-dimer on the first day after percutaneous nephrolithotomy, postoperative bed rest time and Caprini RAM scores were independent risk factors for DVT after PCNL. Sex, age, hypertension status, diabetes status and smoking and drinking habits were not significantly associated with DVT risk. CONCLUSIONS: D-dimer on the first day after PCNL, postoperative bed rest time and Caprini RAM scores were independent risk factors for DVT after PCNL.

Efficacy of Flexible Ureteroscopy Lithotripsy and Percutaneous Nephrolithotomy in the Treatment of Patients with Kidney Stones and Their Impact on Inflammatory Response and Renal Function.

BACKGROUND: Kidney stones are one of the most common benign diseases in urology. As technology updates and iterates, more minimally invasive and laparoscopic surgeries with higher safety performance appear. This paper explores the effectiveness of retrograde intrarenal surgery (RIRS) and percutaneous nephrolithotomy (PCNL) in treating kidney stones, focusing on their effects on inflammatory responses and renal function. METHODS: We conducted a retrospective analysis of 200 patients with kidney stones treated in our hospital between June 2019 and June 2023. 100 patients who underwent RIRS were included in the RIRS group. Another 100 patients who underwent PCNL treatment were included in the PCNL group. The intraoperative blood loss, operation duration, and hospitalization time of the two groups of patients were recorded and compared. The enzyme-linked immunosorbent assay (ELISA) was used to detect the levels of inflammatory factors in the serum of the two groups of patients: [serum amyloid A (SAA), interleukin-6 (IL-6) and high-sensitivity C-reactive protein (CRP)] and renal function index [blood urea nitrogen (BUN), creatinine (Scr) and serum cystatin (Cys-c)]. The two groups of patients were recorded separately: Postoperative complications and stone-free rate. RESULTS: Operation duration was longer for the RIRS group than the PCNL group, which exhibited significantly less intraoperative blood loss and shorter hospital stays (p < 0.05). Before surgery, there was no statistically significant difference in the serum levels of SAA, IL-6, and CRP between the two groups of patients (p > 0.05). On the first day after surgery, the serum SAA levels in both groups were lower than before surgery, IL-6 and CRP levels were higher than before surgery, and the serum levels of SAA, IL-6, and CRP in the RIRS group were significantly lower than those in the PCNL group. The difference was statistically significant (p < 0.05). Before surgery, there was no statistically significant difference in the serum BUN, Scr, and Cys-c levels between the two groups of patients (p > 0.05). On the first day after surgery, the serum BUN, Scr, and Cys-c levels of the two groups of patients were significantly higher than those before surgery. The serum BUN, Scr, and Cys-c levels of the RIRS group were significantly lower than those of the PCNL group, and the difference was statistically significant (p < 0.05). Both surgical methods have sound stone-clearing effects regarding long-term stone clearance rates 1 month and 3 months after surgery (p > 0.05). PCNL had a better stone clearance rate on the 2nd postoperative day (p < 0.05). The incidence of postoperative complications in the RIRS group was significantly lower than that in the PCNL group, and the difference was statistically significant (p < 0.05). CONCLUSION: For kidney stones ≤2 cm, PCNL showed higher stone clearance rates on the second postoperative day. However, RIRS and PCNL demonstrated adequate long-term stone clearance at 1 and 3 months post-surgery. Both surgical methods are safe and effective, and RIRS is safer than PCNL. Compared with PCNL, RIRS is a new method of kidney stone operation, which has less trauma to the patient's body and fewer complications after the operation, speeding up the recovery process of the patient.

Construction and validation of the nomogram predictive model for post-percutaneous nephrolithotomy urinary sepsis.

OBJECTIVE: This study aimed to construct and validate a simple and accurate clinical nomogram for predicting the occurrence of post-percutaneous nephrolithotomy sepsis, aiming to assist urologists in the early identification, warning, and early intervention of urosepsis, and to provide certain evidence-based medicine basis. METHODS: This study included patients who underwent PCNL surgery due to kidney or upper ureteral stones at the Department of Urology, Affiliated Hospital of Zunyi Medical University, from January 2019 to September 2022. This study utilized univariate and multivariate logistic regression analysis to screen and evaluate the risk factors for sepsis and construct a predictive model. An evaluation was performed using the receiver operating characteristic curve, calibration curve, and decision curve analysis curve. All statistical analyses were conducted using R version 4.2. RESULTS: A total of 946 patients who underwent post-PCNL were included in this study, among whom 69 patients (7.29%) developed post-PCNL urinary sepsis. Multiple-factor logistic regression analysis identified four independent risk factors associated with post-PCNL urinary sepsis, including positive urinary nitrite (OR = 5.9, P < 0.001), positive urine culture (OR = 7.54, P < 0.001), operative time ≥ 120 min (OR = 20.93, P = 0.0052), and stone size ≥ 30 mm (OR = 13.81, P = 0.0015). The nomogram model demonstrated good accuracy with an AUC value of 0.909, and in the validation cohort, the AUC value was 0.922. The calibration curve indicated a better consistency between the predictive line chart and the actual occurrence of post-PCNL urinary sepsis. The decision curve analysis curve showed favorable clinical utility. CONCLUSION: Preoperative positive urine culture, positive urinary nitrite, operative time ≥ 120 min, and stone size ≥ 30 mm are independent risk factors for developing post-PCNL urinary sepsis. The constructed line chart based on these factors effectively assesses the risk of urinary sepsis in patients after PCNL.

Transient ureteral obstruction after mini-percutaneous nephrolithotomy is associated with stone volume and location: results from a single-center, real-life study.

PURPOSE: To evaluate the rate of and predictors of ureteral obstruction after mini-percutaneous nephrolithotomy (mPCNL) for kidney stones. METHODS: We analyzed data from 263 consecutive patients who underwent mPCNL at a single tertiary referral academic between 01/2016 and 11/2022. Patient's demographics, stone characteristics, and operative data were collected. A nephrostomy tube was placed as the only exit strategy in each procedure. On postoperative day 2, an antegrade pyelography was performed to assess ureteral canalization. The nephrostomy tube was removed if ureteral canalization was successful. Descriptive statistics and logistic regression models were used to identify factors associated with a lack of ureteral canalization. RESULTS: Overall, median (IQR) age and stone volume were 56 (47-65) years and 1.7 (0.8-4.2) cm3, respectively. Of 263, 55 (20.9%) patients showed ureteral obstruction during pyelography. Patients without ureteral canalization had larger stone volume (p < 0.001), longer operative time (p < 0.01), and higher rate of stones in the renal pelvis (p < 0.01) than those with normal pyelography. Length of stay was longer (p < 0.01), and postoperative complications (p = 0.03) were more frequent in patients without ureteral canalization. Multivariable logistic regression analysis revealed that stone volume (OR 1.1, p = 0.02) and stone located in the renal pelvis (OR 2.2, p = 0.04) were independent predictors of transient ureteral obstruction, after accounting for operative time. CONCLUSION: One out of five patients showed transient ureteral obstruction after mPCNL. Patients with a higher stone burden and with stones in the renal pelvis are at higher risk of inadequate ureteral canalization. Internal drainage might be considered in these cases to avoid potential complications.

Risk of Systemic Inflammatory Response Syndrome Following Preoperative Glucocorticoids Administration in Patients After Percutaneous Nephrolithotomy: A Retrospective Cohort Study.

INTRODUCTION: Systemic inflammatory response syndrome (SIRS) is one of the most serious complications in patients undergoing percutaneous nephrolithotomy (PCNL). Although glucocorticoids are increasingly used during PCNL, few studies have been concerned about the association between glucocorticoids and postoperative SIRS. The study aims to explore whether preoperative use of glucocorticoids is associated with SIRS after PCNL. METHODS: A total of 1259 patients who underwent PCNL between January 2015 and April 2021 were enrolled in the retrospective cohort study. Risk factors for post-PCNL SIRS were identified by univariate and multivariate regression analysis. To further explore the association between preoperative administration of glucocorticoids and SIRS, 113 pairs of patients were matched for the confounding factors using propensity score matching (PSM) analysis. The odds ratios (OR) and 95 % confidence intervals (CI) for the above variables were analyzed. RESULTS: The incidence of SIRS after PCNL was 9.6 % (121/1259) and the patients who suffered from postoperative SIRS had longer hospital stays and higher hospital costs (all p < 0.05). Multivariate logistic regression analysis indicated that female, preoperative leukocyte count, insertion of central vein catheter, serum albumin, preoperative high-sensitive C-reactive protein/albumin ratio, preoperative transfusion, preoperative administration of glucocorticoids were independent risk factors for SIRS (all p < 0.05). After minimization, the effects of confounding factors by PSM, preoperative administration of glucocorticoids was significantly correlated with SIRS in patients after PCNL (OR=2.44, 95 %CI: 1.31-4.55, p = 0.005). CONCLUSION: Preoperative administration of glucocorticoids is an independent risk factor for SIRS in patients undergoing PCNL.

Systemic inflammatory response syndrome (SIRS) is a frequent and severe complication in patients underwent percutaneous nephrolithotomy (PCNL), which can be challenging to diagnose early, potentially leading to delayed treatment. Identifying SIRS risk factors and promptly treating high-risk patients is crucial. Glucocorticoids are commonly used to prevent SIRS in clinical practice, and this study aims to investigate whether preoperative glucocorticoid administration is associated with SIRS after PCNL. In total, 1259 patients underwent PCNL and were enrolled in the study. The study utilized both propensity score matching (PSM) analysis and regression analysis to identify risk factors for post-PCNL SIRS. The incidence of SIRS after PCNL was 9.6 % in the study and patients with postoperative SIRS had longer hospital stays and higher hospital costs. After minimizing the potential influence of confounding factors through the use of PSM, we found a significant association between the preoperative use of glucocorticoids and the occurrence of SIRS in patients undergoing PCNL. Based on our analysis, we can conclude that the preoperative administration of glucocorticoids represents an independent risk factor for the development of SIRS in these patients.

Vacuum-assisted mini-percutaneous nephrolithotomy is associated with lower rates of infectious complications compared to vacuum-cleaner procedure in patients at high risk for infections: a single-center experience.

PURPOSE: To evaluate the impact of vacuum-assisted mini-percutaneous nephrolithotomy (vamPCNL) vs. vacuum-cleaner mPCNL (vcmPCNL) on the rate of postoperative infectious complications in a cohort of patients with high risk factors for infections. METHODS: We retrospectively analysed data from 145 patients who underwent mPCNL between 01/2016 and 12/2022. Patient's demographics, stones characteristics and operative data were collected. vamPCNL and vcmPCNL were performed based on the surgeon's preference. High-risk patients were defied as having ≥ 2 predisposing factors for infections such as a history of previous urinary tract infections, positive urine culture before surgery, stone diameter ≥ 3 cm, diabetes mellitus and hydronephrosis. Complications were graded according to modified Clavien classification. Descriptive statistics and logistic regression models were used to identify factors associated with postoperative infectious complications. RESULTS: vamPCNL and vcmPCNL were performed in 94 (64.8%) and 51 (35.2%) cases, respectively. After surgery, infectious complications occurred in 43 (29.7%) participants. Patients who developed infectious complications had larger stone volume (p = 0.02) and higher rate of multiple stones (p = 0.01) than those who did not. Infectious complications occurred more frequently after vcmPCNL than vamPCNL (55.9% vs. 44.1%. p = 0.01) in high-risk patients. Longer operative time (p < 0.01) and length of stay (p < 0.01) were observed in cases with infectious complications. At multivariable logistic regression analysis, longer operative time (OR 1.1, p = 0.02) and vcmPCNL (OR 3.1, p = 0.03) procedures were independently associated with the risk of infectious complications post mPCNL, after accounting for stone volume. CONCLUSION: One out of three high-risk patients showed infectious complications after mPCNL. vamPCL and shorter operative time were independent protective factors for infections after surgery.

Is supine a preferred position for percutaneous nephrolithotomy in the pediatric age group? A randomized controlled study.

BACKGROUND: The aim is to evaluate supine versus prone position in mini-percutaneous nephrolithotomy in pediatric renal urolithiasis management. METHODS: A randomized controlled trial was constructed to evaluate supine versus prone position in pediatric PCNL. Seventy pediatric patients with a stone burden ≥1.5 cm were randomized into two groups. RESULTS: Sixty-three patients were available for evaluation in our study with no significant difference in the perioperative demographic data. The supine group showed a shorter operation time of 43.9 min compared to 73.5 min in the prone group. The stone-free rate was higher in the supine group, with a 93.9% SFR compared to 83.3% in the prone group. The supine group showed a shorter hospital stay of 2.0±1.0 days, compared to 3.20±1.56 days in the prone group. No significant difference was seen in the perioperative complication rate and fluoroscopy time between both groups. CONCLUSIONS: Supine mini-percutaneous nephrolithotomy is safe and effective in managing pediatric renal stones, with a higher stone-free rate, less operative time, and less hospital stay compared to the prone position.

PCNL vs. two staged RIRS for kidney stones greater than 20 mm: systematic review, meta-analysis, and trial sequential analysis.

INTRODUCTION: Percutaneous nephrolithotomy (PCNL) is considered the gold standard treatment for kidney stones greater than 20 mm. However, retrograde intrarenal surgery (RIRS) may achieve the same stone-free rate with repeated procedures, and potentially fewer complications. This study aimed to compare the efficacy and safety of PCNL and two-staged RIRS. EVIDENCE ACQUISITION: We conducted a systematic search in PubMed, Embase, Scopus, Cochrane, and Web of Science for studies comparing PCNL and RIRS for kidney stones greater than 20mm. The primary outcome is stone-free rate (SFR) of PCNL and RIRS (repeated once if needed). Secondary outcomes were SFR of PCNL versus RIRS (single procedure), operative time, hospital stay, need for auxiliary procedures, and complications. We performed a subgroup analysis for randomized trials, non-randomized trials, and patients with solitary kidney. We performed a trial sequential analysis for the main outcome. EVIDENCE SYNTHESIS: We included 31 articles, with 1987 patients in the PCNL and 1724 patients in RIRS. We confirmed the traditional result that after a single procedure PCNL has a higher SFR. We also found that comparing the SFR of PCNL and RIRS, repeated up to two times if needed, no difference in SFR was observed. Surprisingly, only 26% (CI95 23%-28%) of the patients required a second RIRS. In the trial sequential analysis, the last point of the z-curve was within futility borders. We observed that PCNL has a higher incidence of complications (RR=1.51; CI95 1.24, 1.83; P<0.0001; I2=28%), specifically CD2 (RR=1.82; CI95 1.30, 2.54; P=0.0004; I2=26%) and longer hospital stay (MD 2.57; 2.18, 2.96; P<0.00001; I2-98%). No difference was observed regarding operative time. CONCLUSIONS: RIRS repeated up to two times is equivalent to PCNL in terms of the SFR and may have the same safety.

Comparison of safety and efficacy of different positions in percutaneous nephrolithotomy: a network meta-analysis.

OBJECTIVES: Various new positions for percutaneous nephrolithotomy (PCNL) were proposed to reduce the limitations of the traditional position. This study was aimed to evaluate the efficacy and safety of the different PCNL positions. METHODS: PubMed, Embase, Web of Science, and the Cochrane Library were searched for relevant randomized controlled trials (RCTs) up to 18 April 2023. The authors collected five common surgical positions used for PCNL: oblique supine position (OSP), supine position (SP), flank position (FP), split-leg oblique supine/flank position (SLP), and prone position (PP). Paired and network meta-analysis were conducted to compare relevant outcomes, including complications, operative time, stone-free rates, hospital stay, and hemoglobin loss among these different positions. RESULTS: The study included 17 RCTs with a total of 1841 patients. The result demonstrated that SLP significantly outperformed in terms of decreasing operation time (FP vs SLP MD- MD-41.65; OSP vs SLP MD 28.97; PP vs SLP MD 34.94), hospital stay, and hemoglobin loss. Ranking probabilities showed SLP had highest stone-free rate. Prone position was more likely to occur complications than others. Based on SMAA model, the benefit-risk analysis suggested the SLP was the optimal position in PCNL. CONCLUSIONS: For PCNL, the split-leg, flank, supine, and OSPs are as secure as the prone position. Further RCTs are necessary to confirm the outstanding safety and efficacy of split-leg position. Besides, the position should be selected regard for the patient's demands, the surgeon's preference and learning curve.

A novel post-percutaneous nephrolithotomy sepsis prediction model using machine learning.

OBJECTIVES: To establish a predictive model for sepsis after percutaneous nephrolithotomy (PCNL) using machine learning to identify high-risk patients and enable early diagnosis and intervention by urologists. METHODS: A retrospective study including 694 patients who underwent PCNL was performed. A predictive model for sepsis using machine learning was constructed based on 22 preoperative and intraoperative parameters. RESULTS: Sepsis occurred in 45 of 694 patients, including 16 males (35.6%) and 29 females (64.4%). Data were randomly segregated into an 80% training set and a 20% validation set via 100-fold Monte Carlo cross-validation. The variables included in this study were highly independent. The model achieved good predictive power for postoperative sepsis (AUC = 0.89, 87.8% sensitivity, 86.9% specificity, and 87.4% accuracy). The top 10 variables that contributed to the model prediction were preoperative midstream urine bacterial culture, sex, days of preoperative antibiotic use, urinary nitrite, preoperative blood white blood cell (WBC), renal pyogenesis, staghorn stones, history of ipsilateral urologic surgery, cumulative stone diameters, and renal anatomic malformation. CONCLUSION: Our predictive model is suitable for sepsis estimation after PCNL and could effectively reduce the incidence of sepsis through early intervention.

Is traditional stone clinic the optimal use of NHS resources?

There is no clear guidance on the efficacy of stone follow-up. NICE have been unable to make recommendations with current published evidence. The aim of this study was to understand the patient journey resulting in surgical intervention, and whether traditional stone follow-up is effective. A retrospective review of patients undergoing ureteroscopy (URS) or percutaneous nephrolithotomy (PCNL) over a 3 year period identified 471 patients who underwent these procedures to treat stone disease. Records were interrogated for the following: symptoms, mechanism of booking, reason for intervention, stone size, stone location, risk factors and previous follow-up. Of 471 patients who underwent intervention, 168 were booked from stone clinic follow-up (36%). Of these, 96% were symptomatic and 4% were asymptomatic. When risk factors were removed, this figure was reduced to 1%. Sepsis rate for emergency admissions differs between those followed up (13%) versus new presentations (19)%. There was no statistically significant difference in the outpatient imaging frequency between patients booked from an emergency admission (80% having imaging every 6 months) and those from the clinic (82%). Our Hospital provides on average 650 stone clinic appointments a year with a cost of £93,000. Given the low rate of intervention in patients with asymptomatic renal stones, a symptomatic, direct-access emergency stone clinic could be a better model of care and use of NHS resources. Urgent research is required in this area to further assess if this is the case.