Initial Clinical Experience With a Novel Robotically Assisted Platform for Combined Mini-Percutaneous Nephrolithotomy and Flexible Ureteroscopic Lithotripsy.

PURPOSE: We sought to evaluate the technical feasibility of performing a combined robotically assisted mini-percutaneous nephrolithotomy (PCNL) and flexible ureteroscopy (URS) procedure by a single urologist using the MONARCH Platform, Urology (Johnson & Johnson MedTech, Redwood City, California). MATERIAL AND METHODS: In this prospective, first-in-human clinical trial, 13 patients underwent robotically-assisted PCNL for renal calculi at the University of California-Irvine, Department of Urology. Successful completion of the procedure was assessed as the primary endpoint. Postoperative adverse events were monitored for 30 days following the completion of the procedure. Stone ablation efficiency was evaluated on postoperative day 30 with low-dose 2-3 mm slice CT scans. Patients were classified according to the maximum length of their residual stone fragments as either absolute stone-free (Grade A), < 2 mm remnants (Grade B), or 2.1-4.0 mm remnants (Grade C). RESULTS: The combined robotic mini-PCNL and URS procedure was successfully completed in 12 of 13 procedures. No robotic device-related adverse events occurred. Preoperative stone burden was quantified by both maximum linear measurement (median 32.8 mm) as well as by CT-based volume (median 1645.9 mm3). Using the unique robotically assisted targeting system, percutaneous access was gained directly through the center of the renal papilla in a single pass in all cases. Median operative time was 187 minutes (range: 83-383 minutes). On postoperative day 30, a 98.7% (range: 72.9%-100.0%) volume reduction was achieved, with 5 Grade A (38.5%), 1 Grade B (7.7%), and 2 Grade C (15.4%). Three patients experienced complications (2 grade 1 and one grade 2 Clavien-Dindo). CONCLUSIONS: Our preliminary investigation demonstrates the safety, efficacy, and feasibility of a unique robotic-assisted combined mini-PCNL and URS platform.

Tranexamic acid for percutaneous nephrolithotomy: an abridged Cochrane review.

OBJECTIVE: To assess the effects of tranexamic acid (TXA) in individuals with kidney stones undergoing percutaneous nephrolithotomy (PCNL). PATIENTS AND METHODS: We performed a literature search of Cochrane Library, PubMed (including MEDLINE), Embase, Scopus, Global Index Medicus, trials registries, grey literature, and conference proceedings. We included randomised controlled trials (RCTs) that compared treatment with PCNL with administration of TXA to placebo (or no TXA) for patients aged ≥18 years. Two review authors independently classified studies and abstracted data. Primary outcomes were blood transfusion, stone-free rate (SFR), thromboembolic events (TEE). We rated the certainty of evidence (CoE) according to the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach using a minimally contextualised approach with pre-defined thresholds for minimally clinically important differences (MCID). RESULTS: We included 10 RCTs assessing the effect of systemic TXA in PCNL vs placebo (or no TXA). Eight studies were published as full text. Based on an adjusted baseline risk of blood transfusion of 5.7%, systemic TXA may reduce blood transfusions (risk ratio [RR] 0.45, 95% confidence interval [CI] 0.27-0.76). Based on an adjusted baseline SFR of 75.7%, systemic TXA may increase SFR (RR 1.11, 95% CI 0.98-1.27). There is probably no difference in TEEs (risk difference 0.001, 95% CI -0.01 to 0.01). Systemic TXA may increase adverse events (AEs) (RR 5.22, 95% CI 0.52-52.72). Systemic TXA may have little to no effect on secondary interventions (RR 1.15, 95% CI 0.84-1.57). The CoE for most outcomes was assessed as low or very low. CONCLUSIONS: Based on a body of evidence of 10 RCTs, we found that systemic TXA in PCNL may reduce blood transfusions, major surgical complications, and hospital length of stay, as well as improve the SFR; however, it may increase AEs. These findings should inform urologists and their patients in making informed decisions about the use of TXA in the setting of 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.

Exploring the competency of the comprehensive complication index over the clavien-dindo classification in standard percutaneous nephrolithotomy: a call for better complication reporting.

PURPOSE: The Comprehensive Complication Index (CCI) was introduced in 2013 to overcome the limitations of the Clavien-Dindo Classification (CDC) in grading postoperative complications. The objective of this study to assess the predictive value of the CDC and the CCI for postoperative course in patients undergoing standard adult percutaneous nephrolithotomy (PCNL). METHODS: A retrospective analysis of 320 renal units that underwent standard PCNL between July 2021 - April 2023 was conducted. The CDC and CCI systems assessed complications occurring within the first 30 days after surgery. A second CCI score was calculated only on the highest CDC grade, and this score was referred to as the noncumulative CCI. A comparative analysis was conducted to determine the predictive efficacy of both evaluation methods regarding the postoperative course. RESULTS: The postoperative complication rate was 23.1% (74/320). Eight patients (2.5%) experienced multiple complications, resulting in a higher total CCI score than the noncumulative CCI (p = 0.010). Correlation analysis revealed that the CCI correlated with the length of hospital stay (LOS) more precisely than the noncumulative CCI (CCI: r = 0.335; p = 0.004 vs. noncumulative CCI: r = 0.325; p = 0.005). Compared with patients with a single complication, those with multiple complications had similar demographics, preoperative stone characteristics, and intraoperative features. CONCLUSION: Cumulative CCI proves to be a more effective predictor of LOS and complication burden in standard PCNL than CDC. Hence, using CCI to evaluate complications after PCNL may be a more appropriate approach.

Risk factors and prediction model for postoperative complications in patients with struvite stones after percutaneous nephrolithotomy and flexible ureteroscopy.

OBJECTIVE: To analyze the risk factors for complications in patients with struvite stones following percutaneous nephrolithotomy (PCNL) or flexible ureteroscopy (fURS), and to establish a nomogram for postoperative complications in patients following PCNL. METHODS: A retrospective analysis was conducted on patients with struvite stones after PCNL and fURS at the Department of Urology, Peking University People's Hospital, from January 2012 to March 2022. The common pathogens and antimicrobial susceptibilities in preoperative midstream urine culture were analyzed. Logistic regression analyses were used to evaluate the risk factors. Receiver-operating characteristic (ROC) curve, calibration plots, and decision curve analysis (DCA) were used to assess the discrimination, accuracy, and practicability of the nomogram. RESULTS: 332 patients with struvite stones received one-stage PCNL or fURS, including 243 cases of PCNL and 89 cases of fURS. 72 patients (21.69%) developed postoperative complications. The most common pathogens in preoperative urine cultures were Escherichia coli, Proteus mirabilis, and Enterococcus faecalis. Multivariate logistic regression analysis showed that preoperative hemoglobin (OR = 0.981, P = 0.042), staghorn stone (OR = 4.226, P = 0.037), and positive preoperative midstream urine culture (OR = 2.000, P = 0.043) were independent risk factors for postoperative complications in patients following PCNL. The nomogram showed good performance in discrimination, accuracy, and applicability. CONCLUSION: Preoperative hemoglobin, staghorn stone, and positive preoperative midstream urine culture were independent risk factors for postoperative complications in patients with struvite stones following PCNL. A nomogram was developed to predict the probability of postoperative complications.

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.

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.

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.

Feasibility of stereotactic optical navigation for needle positioning in percutaneous nephrolithotomy.

BACKGROUND: This study assessed the feasibility of acquiring single-attempt access to the pelvicalyceal system during percutaneous nephrolithotomy (PCNL) using stereotactic optical navigation combined with cone-beam CT (CBCT) imaging. METHODS: Patients with a PCNL indication were prospectively included in this IRB approved study. After sterile preparation, fiducial markers were attached to patients' skin. An initial intraprocedural CBCT scan was acquired, on which the urologist planned the needle trajectory using the navigation software. After verifying that no critical structures were crossed, the needle guide was aligned with the plan. A needle was manually inserted through the needle guide to the indicated depth and a second CBCT scan was performed for needle position confirmation. Both, scanning and needle insertion, were performed under apnea. The study evaluated technical success, accuracy, procedure time, complication rate, and radiation dose. RESULTS: Between June 2022 and April 2023, seven patients were included. In all patients, the navigation system allowed safe puncture. However, the technical success rate was only 29%. In 42% of the cases, pelvicalyceal access was achieved by a small manual adjustment. In the remaining 29%, the needle was retracted and positioned per clinical standard. The average deviation between the needle and target was 5.9 ± 2.3 mm. The average total procedure time was 211 ± 44 min. The average radiation exposure was 6.4 mSv, with CBCT scanning contributing to 82% of this exposure. CONCLUSIONS: The optical navigation system facilitated safe needle insertion but did not consistently ensure accurate one-attempt needle positioning for PCNL. Real-time visualization and trajectory correction may improve the technical success rate.

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.

Ureteral stent after PCNL: is leaving the threads through the percutaneous tract safe and better tolerated?

OBJECTIVE: To assess safety, urinary symptoms, and feasibility of JJ stent removal with exteriorized threads through the percutaneous tract after percutaneous nephrolithotomy (PCNL). MATERIALS AND METHODS: Prospective, transversal, comparative, experimental, randomized 1-to-1 cohort study in 52 patients who underwent "tubeless" PCNL from October 2020 to November 2022. Group A with threads through the urethra and Group B through the percutaneous tract. The validated USSQ (Ureteral Stent Symptom Questionnaire) was applied in the Urology office a week after the procedure, and the JJ stent was withdrawn by pulling the threads. Hemoglobin and urine culture, and pre- and post-surgery were evaluated. RESULTS: There is a statistically significant difference in favor of group B when comparing urinary symptoms (p = 0.008), body pain (p = 0.009), and general condition (p = 0.042), mainly for non-urgency incontinence, frequency of analgesic use, and dysuria. There were significant differences between groups (p = 0.028, p = 0.026, p = 0.027, respectively). There is no association with urinary infections (p = 0.603) nor an increased risk of bleeding (p = 0.321). CONCLUSION: The removal of the JJ stent with exteriorized threads through the percutaneous tract after PCNL in the office is a feasible and safe procedure if it is removed before 8 days and has better tolerance regarding the urinary symptoms.

Clinical study of UMP and RIRS in 1.0-2.0 cm diameter renal/upper ureteral calculi.

BACKGROUND: The purpose of this study was to compare the efficacy and safety of Ultra-mini-percutaneous nephrolithotomy (UMP) and Retrograde intrarenal surgery (RIRS) for renal/upper ureteral calculi in 1.0-2.0 cm diameter. METHODS: From October 2017 to October 2022, the surgical treatment of patients with renal/upper ureteral calculi in 1.0-2.0 cm diameter who were admitted to our hospital was retrospectively analyzed. They were divided into two groups, the UMP group (sixty-two cases) and the RIRS group (one hundred and nine cases), according to the different surgical methods. Baseline data includes general information, stone size, location, CT value, hydronephrosis, creatinine level, etc. RESULTS: Intraoperative blood loss was 33.6 ± 8.5 ml in the UMP group was significantly more than 4.3 ± 0.7 ml in the RIRS group (P < 0.05). Intraoperative renal pelvis pressure of UMP group 10.5 ± 1.3 mmHg was significantly lower than RIRS group 23.6 ± 5.6 mmHg (P < 0.05). The incidence of postoperative infection was higher in the RIRS group (thirteen cases [11.93%]), and one case ([1.61%]) in the UMP group (P < 0.05). Routine CT scans on the second day and two months after surgery showed that the stone clearance rates in the UMP group were 87.1% and 93.5%, respectively, higher than those in the RIRS group (69.7% and 79.8%, respectively; P < 0.05). CONCLUSION: UMP has the advantage of a higher stone-free rate but a higher risk of injury and bleeding. The advantages of RIRS include less trauma, less bleeding, and faster recovery, but lower stone-free rates and a higher risk of infection.

A meta analysis of the lateral decubitus position and prone position percutaneous nephrolithotomy.

Objective To analyzed the safety and efficacy of percutaneous nephrolithotomy (PCNL) in lateral decubitus position and prone position for upper ureteral calculi. Methods Databases including PubMed, Springer, ScienceDirect, Wiley Online Library, CNKI, CSPD and VIP were searched for clinical controlled studies involved with lateral decubitus position and prone position PCNL from their establishment to November 2023.Studies were enrolled according to inclusion and exclusion criteria. the dates were compared by Review Manager 5.4 software. Results seven studies were eligible, including 807 cases. The Meta-analysis showed that, blood loss and perioperative complication rate of lateral decubitus position PCNL group were significantly different from those of the prone position PCNL group (P < 0.05). There was no significant difference between the two groups regarding hospital time, operative time, channel establishment time and stone-free rate (P>0.05).Conclusions The lateral decubitus position can reduce blood loss and perioperative complication rate. The lateral decubitus position PCNL is safe and effective for upper ureteral calculi which was deserved clinical popularizing use.

Incidence of metabolic syndrome in patients with unilateral or bilateral staghorn renal stones and its impact on percutaneous nephrolithotomy outcomes.

BACKGROUND: To evaluate the incidence of metabolic syndrome (MetS) in patients with unilateral and bilateral staghorn calculi (SC) and evaluate the impact on the outcome of percutaneous nephrolithotomy (PCNL). METHODS: The clinical data of patients who underwent PCNL for the treatment of SC between 2019 and 2022 were retrospectively reviewed. SC was divided into unilateral and bilateral. The incidence of MetS was compared between the patients with unilateral SC and the patients with bilateral SC, and the impact on the outcome of PCNL was assessed. RESULTS: A total of 1778 patients underwent PCNL between 2019 and 2022. After screening computed tomography, 379 patients were confirmed to have SC, finally, leaving 310 patients with follow-up and complete data to be included in the study. Eighty-four had bilateral SC and 226 had unilateral SC. The patients with bilateral SC had a significantly higher body mass index and higher rates of complete staghorn stones and metabolic syndrome. Higher body mass index, hypertension, diabetes mellitus, hyperlipidaemia, and MetS were present in 62.58%, 44.84%, 21.94%, 60.65% and 27.42% of all patients, respectively. The number of MetS components remained significantly associated with bilateral SC. Specifically, when the number of MetS components increases from 0 to 3-4, the likelihood of developing bilateral staghorn calculi increases by 21.967 times. Eighty-five patients with MetS( +) had a higher rate of overall complications (number (N)(%), 29 (34.12) vs.33 (14.46), P < 0.001) and a comparable stone-free rate to 225 MetS(-) patients. Multivariable analysis confirmed that hyperlipidaemia (P = 0.044, odds ratio [OR] = 1.991, 95% confidence interval [CI] 1.020-3.888) and MetS (P = 0.005, OR = 2.427, 95% CI 1.316-4.477) were independent risk factors for overall complications. CONCLUSIONS: MetS is correlated with the formation of bilateral SC and is the main predictor for complications of PCNL especially for low-grade complications (I-II).

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.

Percutaneous nephrolithotomy or flexible ureteral lithotripsy, which one is better for patients with upper ureteral calculi of 1.5-2.0 cm in diameter.

PURPOSE: First research to evaluate the clinical efficacy and safety of flexible ureteral lithotripsy (FURSL) and percutaneous nephrolithotomy (PCNL) in the treatment of the upper ureteral stone is between 1.5 cm and 2.0 cm in diameter since there is no consensus with such ureteral stone yet. METHODS: From December 2018 to October 2022, 104 patients with calculi in the upper ureter received percutaneous nephrolithotomy (PCNL)or flexible ureteroscopic lithotripsy (FURSL) in our institution. The clinical data of the patients in the two groups were retrospectively searched. Stone removal rate, operation time, blood loss, postoperative pain score, postoperative inflammatory factor, postoperative complication rates and ureteral obstruction three months after the operation were compared between the two groups. RESULTS: A total of 104 patients were included in the study. The stone clearance rate and the secondary surgery rate were 88.89% and 7.41% in the FURSL group, the figures were 97.96% and 2.0% in the PCNL group (p = 0.067, 0.497). Regarding ureteral obstruction three months after the operation, there were 2 patients in FURSL group and 0 patients in PCNL group(p = 0.497).Compared to patients in FURSL group, patients in the PCNL group had shorter operation time(PCNL 71.81 ± 18.94 min vs. FURSL 86.80 ± 22.49 min, p = 0.0004), fewer complications(PCNL 20.37% vs. FURSL 6.12%), and lower postoperative inflammatory factor(p = 0.0004), yet they got more hemoglobin drop (PCNL 13.14 ± 9.81 g/L vs. FURSL 4.77 ± 3.55 g/L, p < 0.0001), higher postoperative pain scores(p = 0.0017) in the first three postoperative days and longer hospital stay (PCNL 4.96 ± 1.21 days vs. FURSL 3.60 ± 0.83 days). CONCLUSION: Both FURSL and PCNL were effective methods for treating upper ureteral stones of 1.5-2.0 cm in diameter given the extremely high stone clearance rate and a very low secondary surgery rate, as long as rare ureteral obstruction in medium-long term observation. Additionally, FURSL can effectively reduce surgical bleeding, postoperative pain, and hospital stay, while PCNL can decrease operation time, the risk of infection, and complications. Therefore, doctors could select suitable surgical treatment for those patients depending on their different clinical situations based on these findings.

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

BACKGROUND: There are numerous methods available for predicting sepsis following Percutaneous Nephrolithotomy. This study aims to compare the predictive value of Quick Sequential Organ Failure Assessment (qSOFA), Systemic Inflammatory Response Syndrome (SISR), National Early Warning Score (NEWS), interleukin-6 (IL-6), and procalcitonin (PCT) for septicemia. METHODS: Patients who underwent percutaneous nephrolithotomy were included in the study and divided into a control group and a septic shock group. The effectiveness of qSOFA, SIRS, NEWS, Interleukin-6, and Procalcitonin was assessed, with Receiver Operating Characteristic curves and Area Under the Curve used to compare the predictive accuracy of these four indicators. RESULTS: Among the 401 patients, 16 cases (3.99%) developed septic shock. Females, elderly individuals, and patients with positive urine culture and positive nitrite in urine were found to be more susceptible to septic shock. PCT, IL-6, SIRS, NEWS, qSOFA, and surgical time were identified as independent risk factors for septic shock. The cutoff values are as follows: qSOFA score > 0.50, SIRS score > 2.50, NEWS score > 2.50, and IL-6 > 264.00 pg/ml. Among the 29 patients identified by IL-6 as having sepsis, 16 were confirmed to have developed sepsis. The qSOFA identified 63 septicemia cases, with 16 confirmed to have developed septicemia; NEWS identified 122 septicemia cases, of which 14 cases actually developed septicemia; SIRS identified 128 septicemia patients, with 16 confirmed to have developed septicemia. In terms of predictive ability, IL-6 (AUC 0.993, 95% CI 0.985 ~ 1) demonstrated a higher predictive accuracy compared to qSOFA (AUC 0.952, 95% CI 0.928 ~ 0.977), NEWS (AUC 0.824, 95% CI 0.720 ~ 0.929) and SIRS (AUC 0.928, 95% CI 0.888 ~ 0.969). CONCLUSIONS: IL-6 has higher accuracy in predicting septic shock after PCNL compared to qSOFA, SIRS, and NEWS.

Is double-J stent mandatory in complete supine percutaneous nephrolithotomy for adult patients with staghorn renal stones?

BACKGROUND: It is controversial whether double-J (DJ) stent insertion is necessary in tubeless percutaneous nephrolithotomy (PCNL) for patients with staghorn stones. We compared the outcomes of using ureteral catheters and double-J stents in tubeless complete supine PCNL (csPCNL) of staghorn stones. METHODS: In this analytical cross-sectional study, from May 2008 to August 2022, 123 patients who underwent tubeless csPCNL were assessed. Patients were divided into two groups by either tubeless csPCNL with DJ stent (Group I; n = 23) or totally tubeless just with perioperative ureteral stent (Group II; n = 100). Demographic characteristics, stone-related factors, perioperative and postoperative parameters were compared in groups. RESULTS: Baseline characteristics were comparable in groups. The operative time in group I was significantly longer than group II (68.26 vs. 55.25 min, P = 0.05). However, the duration of hospitalization in Group I was shorter than the other group (1.81 vs. 2.37 days, P = 0.03). Stone free rate was notably higher in Group I (90.5% vs. 79.8.0%) with no statistically significant difference. No significant differences were found in major complications. Patients in Group II had a significantly shorter time to return to normal life (6.48 vs. 7.91 day; P = 0.043). Multivariable linear regression showed the preoperative creatinine level and stone size can affect the operative time (P = 0.02). In addition, stone number and underlying disease can affect the length of hospital stay (P = 0.007 & 0.030, respectively). CONCLUSION: Although not inserting a double J stent after csPCNL has acceptable results, because of higher residual rate in staghorn stone which cause more incidence of renal colic, longer time of hospital stay and return to normal life, inserting DJ stent is recommended.

Development of a novel percutaneous digital flexible nephroscope: its use and application.

BACKGROUND: Renal calculi are one of the most frequent diseases in urology, and percutaneous nephrolithotomy (PCNL) being the gold standard for treating renal calculi larger than 2 cm. However, traditional rigid nephroscope cannot bend, presents significant limitations during PCNL. This study aims to develop a novel digital flexible nephroscope for PCNL and verify its safety and efficacy using 3D printed models and ex vivo porcine kidney models, providing new equipment for PCNL. METHODS: Based on the determined technical parameters, the novel digital flexible nephroscope was manufactured. First, 3D-printed model and ex vivo porcine kidney models were utilized to simulate the PCNL procedures. Then, the traditional rigid nephroscope and the novel digital flexible nephroscope were utilized to simulate the PCNL procedures on 10 ex vivo porcine kidneys for comparison. We observed and recorded the renal calyces visualized and accessed by both the traditional rigid nephroscope and the novel digital flexible nephroscope. RESULTS: In both the 3D printing and ex vivo porcine kidney models, the novel percutaneous digital flexible nephroscope smoothly entered the renal collecting system through the percutaneous renal tract. It freely changed angles to reach most target calyces, demonstrating significant advantages over the traditional rigid nephroscope. CONCLUSION: The successful development of the novel percutaneous digital flexible nephroscope allows it to be used either independently or as an adjunct in complex stone cases, providing more effective and safer surgical equipment for percutaneous nephrolithotomy.

Machine learning models to predict systemic inflammatory response syndrome after percutaneous nephrolithotomy.

OBJECTIVE: The objective of this study was to develop and evaluate the performance of machine learning models for predicting the possibility of systemic inflammatory response syndrome (SIRS) following percutaneous nephrolithotomy (PCNL). METHODS: We retrospectively reviewed the clinical data of 337 patients who received PCNL between May 2020 and June 2022. In our study, 80% of the data were used as the training set, and the remaining data were used as the testing set. Separate prediction models based on the six machine learning algorithms were created using the training set. The predictive performance of each machine learning model was determined by the area under the receiver operating characteristic curve (AUC), accuracy, sensitivity and specificity using the testing set. We used coefficients to interpret the contribution of each variable to the predictive performance. RESULTS: Among the six machine learning algorithms, the support vector machine (SVM) delivered the best performance with accuracy of 0.868, AUC of 0.942 (95% CI 0.890-0.994) in the testing set. Further analysis using the SVM model showed that prealbumin contributed the most to the prediction of the outcome, followed by preoperative urine culture, systemic immune-inflammation (SII), neutrophil to lymphocyte ratio (NLR), staghorn stones, fibrinogen, operation time, preoperative urine white blood cell (WBC), preoperative urea nitrogen, hydronephrosis, stone burden, sex and preoperative lymphocyte count. CONCLUSION: Machine learning-based prediction models can accurately predict the possibility of SIRS after PCNL in advance by learning patient clinical data, and should be used to guide surgeons in clinical decision-making.