A new alternative to percutaneous nephrolithotomy: A case report.

INTRODUCTION: Percutaneous nephrolithotomy (PCNL) is a common procedure for kidney stone removal, involving a small incision in the back and insertion of a nephroscope to extract the stones. Recent advancements include super-mini PCNL, employing smaller instruments for less invasive access to the kidney. However, conventional PCNL often requires tract dilation, which can lead to potential complications. CASE PRESENTATION: This case report presents the successful application of our surgical technique using the basic principles of PCNL with the aid of a pediatric trocar cystostomy and ultrasound guidance as a new alternative for super-mini PCNL, offering safer access with reduced bleeding risk and shorter recovery. The surgery was performed on a 55-year-old female with bilateral kidney stones, with the stone in the left kidney being larger than the one in the right kidney. The procedure was completed within 60 min without significant postoperative complications. DISCUSSION: Our new alternative for PCNL offers benefits such as reduced invasiveness, shorter recovery time, decreased risk of complications, and minimal changes in postoperative hemoglobin levels. This new alternative can be performed in developing country hospitals that do not have the expensive PCNL equipment. CONCLUSION: This new alternative of PCNL with pediatric trocar cystostomy proves to be effective and safe.

[Progress in Surgical Treatment of Upper Urinary Tract Stones in Children].

The incidence of urinary calculi in children has been increasing annually,and most of the cases are upper urinary tract stones.At present,surgery is the main way to treat upper urinary tract stones in children.With the gradual development of minimally invasive techniques in surgery,percutaneous nephrolithotomy,retrograde intrarenal surgery,and extracorporeal shock wave lithotripsy have become the main methods for treating upper urinary tract stones in children.We reviewed the current progress in surgical treatment of upper urinary tract stones in children and provided prospects for future treatment options.

Three-dimensional printing the navigation template for precise percutaneous renal puncture to treat pyonephrosis on a porcine model and a patient ：a case report.

Objective: Percutaneous nephrolithotomy (PCNL) is the main method for pyonephrosis or lithotripsy in urology. However, it often comes with high risk, as the inaccurate puncture inevitably causes bleeding, intra- and post-operative complications. So, a new inter-disciplinary approach is needed to perform the puncture more accurately. Methods: 3 signs made of lead were marked onto the skin of the posterior side of the waist of a domestic pig or a patient, which was scanned by computed tomography (CT). Based on the CT images, the computer design and the 3D printing, a navigation template made of the transparent resin material is constructed. They were attached onto the surgical area on pig or patient according to the signs. During the PCNL, with this template, the puncture position, angle and depth were optimized in order to precisely enter the targeted renal pelvis or calices. Results: With the 3D navigation templates, 18G puncture needles were used to enter the renal pelvis upon performing the PCNL on a porcine model and a patient. On the porcine model, the urine outflow was observed with minimal complication. Post-operative CT scans revealed that the needle was located in the renal pelvis. For the patient case, the puncture point was designed to target the calix with stone. No obvious bleeding and complication was found in renal puncture with template. Conclusions: The navigation template was made with the combination of 3D printing, CT images and computer design. This template allows for accurate puncture of the renal pelvis or calix. Surgical improvement in kidney stones and pyonephrosis was observed in porcine model and patient case. In the future, prospective, trandomized, controlled clinical trials are needed to further confirm its advantage.

First 100 Reported Cases of Supine Percutaneous Nephrolithotomy in Malaysia: An Alternative Effective and Safe Approach to Treat Renal Stones.

Background: Supine percutaneous nephrolithotomy (s-PCNL) offers great benefits from urological and anaesthetic points of view. We present the first evaluation of the outcomes of s-PCNL in Malaysia. Our aim was to explore the safety and efficacy of s-PCNL. Methods: Institutional review board approval was obtained from the National Medical Research Register (NMRR ID-21002225-WLP). We retrospectively reviewed 115 patients with renal pelvis stones who underwent single renal access during s-PCNL between November 2020 and May 2023. Patients who underwent simultaneous ipsilateral or contralateral endourological procedures were included. The data were analysed to determine stone-free rates (SFR), major complication rates, blood transfusion rates, operative times and lengths of hospital stay (LOS). Results: The SFR was higher for the single middle calyceal renal access (MCA) group than for the lower calyceal renal access (LCA) or upper calyceal renal access (UCA) groups (OR: 1.76; 95% confidence interval [CI]: 0.63, 4.92). In total, 0, 1 and 2 patients had major complications in the UCA, MCA and LCA groups, respectively (P = 0.453). One of the 115 patients (0.9%) needed blood transfusion. Subgroup analysis revealed mean operative times of 76.3 min and 78.6 min for patients who underwent sole s-PCNL (PCNL-only group) and those who had simultaneous ipsilateral and contralateral endourological procedures (PCNL-plus group), respectively (P = 0.786). The overall mean LOS was 2.9 days. Conclusion: s-PCNL is a safe and effective alternative treatment for renal stones. We would recommend s-PCNL for patients who require an ipsilateral/contralateral endourological procedure (URS/RIRS) because it is time-efficient. All renal accesses are safe. Single MCA is recommended for complete stone clearance.

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).

Comparison of two methods for treatment of 1-2 cm kidney stones in pediatric patients: mini PCNL and RIRS.

OBJECTIVE: This study aimed to compare the results of retrograde intrarenal surgery (RIRS) and mini-percutaneous nephrolithotomy (mini-PCNL) for the treatment of 1-2 cm kidney stones in pediatric patients. METHODS: The records of patients under the age of 18 years who were diagnosed with unilateral 1-2 cm kidney stones for the first time and underwent endoscopic surgery between February 2008 and April 2022 were retrospectively examined. The patients were divided into two groups: mini-PCNL and RIRS surgery. Parameters such as age, gender, number of stones, side, size and localization were examined. The main endpoint of the study was to compare stone-free rates (SFR) one month after both surgeries. Surgery and fluoroscopy times, postoperative hospital stay, hemoglobin decrease and complication rates were compared between the groups. SFR was evaluated one month after surgery by direct urinary system radiography and USG or CT. RESULTS: A total of 58 patients were included in the study. There were 35 patients in the mini-PCNL group and 23 patients in the RIRS group. Table 1 shows the demographic and clinical characteristics of both groups. There was no significant difference between the groups in terms of age, gender, stone size, location, side and density. Calcium oxalate stones were observed at a higher rate in both groups. Mean fluoroscopy time was higher in the mini-PCNL group (p = 0.001). The mean surgery time was lower in the mini-PCNL group (p = 0.024). The mean hemoglobin decrease was greater in the percutaneous group (p = 0.039). There were no differences between the groups in terms of postoperative hospital stay, complication rates, and SFR one month after surgery. CONCLUSION: Although mini-PCNL seems to be more advantageous in terms of operation time compared to RIRS, it is disadvantageous in terms of average fluoroscopy time, radiation received and average hemoglobin decrease.

Bowel Perforation During Percutaneous Nephrolithotomy: Diagnosis, Management, and Follow-up.

Percutaneous nephrolithotomy (PCNL) is the procedure of choice for large kidney stones, but serious complications such as bowel perforation may occur. We discuss the diagnosis and management of colonic and small-bowel perforations due to PCNL and suggest principles for care and prevention. We emphasize the significance of imaging tools to direct percutaneous access, the importance of early diagnosis, and the relatively high success rate for conservative management. Patient summary: Large kidney stones are usually treated with a keyhole surgery procedure called percutaneous nephrolithotomy (PCNL). A rare but serious complication of this procedure is puncture of the bowel. We discuss how to prevent, diagnose, and treat this complication in patients undergoing PCNL.

Experience of Multiple Super-Selective Renal Angiographic Embolization (SRAE) After Minimally-Percutaneous Nephrolithotomy Haemorrhage: A Case Report.

Minimally invasive percutaneous nephrolithotomy (mini-PCNL) maintains a stone clearance rate similar to standard PCNL while reducing blood loss. Bleeding is a complex and serious complication that can arise after PCNL surgery. Pseudoaneurysm (PA) is an uncommon type of delayed bleeding problem, which affects less than 1% of patients after PCNL. The most effective treatment for severe post-PCNL hemorrhage is super-selective renal angiographic embolization (SRAE), but it can fail in some patients and require additional surgical intervention. This report details the case of a male patient, 55 years old, who experienced severe bleeding four times and had three SRAE procedures and one laparoscopic procedure after PCNL. The presence of a renal artery pseudoaneurysm was not initially identified during the first two attempts of angiography due to arterial spasm and a small, undeveloped lesion. This case report is intended to enhance awareness of tiny pseudoaneurysms, emphasizing the importance of avoiding oversight to improve the success rate of embolization.

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.

Comparative Analysis of Standard Percutaneous Nephrolithotomy (PCNL) and Mini-Percutaneous Nephrolithotomy (Mini-PCNL) for Renal Stones Larger Than 2 cm at a Rural Hospital: A Study Protocol.

Background Percutaneous nephrolithotomy (PCNL) is considered a standard treatment option for large-size renal stones but is associated with drawbacks such as bleeding and prolonged recovery. Mini-PCNL offers a less invasive alternative, but its efficacy compared to standard PCNL for renal stones larger than 2 cm remains under debate. This study aims to compare the efficacy and safety of standard PCNL versus mini-PCNL for renal stone sizes more than 2 cm. Methods This single-centre prospective interventional study will be conducted at Acharya Vinoba Bhave Rural Hospital (AVBRH). The study will include patients 18 to 70 years of age undergoing unilateral PCNL for renal calculi. Patients with renal stones larger than 2 cm will be enrolled. Data on stone-free rate (SFR), operative duration, hospital stay time, surgical site infection, haemoglobin (Hb) drop, need for blood transfusion, and post-surgery fever will be collected and compared between the two procedures. Statistical analysis of data will be performed using descriptive and analytical statistics. Results The study aims to enrol a total of 32 patients. Data analysis will be done using IBM SPSS Statistics for Windows, Version 24 (Released 2016; IBM Corp., Armonk, New York). Conclusion This study will provide valuable insights into the comparative outcome in terms of efficacy and safety of standard PCNL and mini-PCNL for kidney stones larger than 2 cm.

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.

Preliminary experience with lost mini percutaneous nephrostomy channel retrieval by methylene blue injection.

Percutaneous nephrolithotomy (PCNL) is the primary choice for managing large renal stones and the establishment of mini-/micro-channels has been increasingly gaining practice. The smaller the channel, the easier it is to be lost, which may require a new puncture site and increase the risk of bleeding complications. In this study, we retrospectively reviewed 1,056 PCNL procedures in our single institute, The University of Hong Kong - Shenzhen Hospital, between March 2014 and August 2023. Twenty-three cases of nephrostomy channel loss during mini PCNL were identified, resulting in an incidence rate of 2.2%. Methylene blue was immediately injected into the ureteral catheter to facilitate location and retrieval of the channel. Once extravasation of the dye was identified under rigid ureteroscope, a first guidewire was introduced into the channel for maintenance, followed by another guidewire inserted in parallel to facilitate dilatation. The major reasons for PCNL channel loss were mild hydronephrosis and complete obstruction of the target calyx due to renal stones. Technical success, defined as the ability to retrieve the lost channel within 5 minutes, was 78.3% (n=18/23). Three channels were completely lost and 2 patients showed channel bleeding despite successful identification, all of which required establishment of a new PCNL channel. No major intraoperative nor postoperative complication was observed.

Nomogram including renal pelvic pressure to predict the occurrence of urosepsis following percutaneous nephrolithotomy: a dual center retrospective study of 1,448 patients.

Background: Urosepsis is a serious complication after percutaneous nephrolithotomy (PCNL). This study aimed to develop and validate a nomogram model that can effectively predict urosepsis following PCNL. Methods: A total of 839 patients who underwent PCNL at General Hospital of Southern Theater Command from January 2018 to January 2023 and a total of 609 patients who underwent PCNL at Guangdong Second Provincial General Hospital from January 2020 to January 2023 were retrospectively analyzed in this study. The center with 839 patients was used to develop the model, and another center with 609 patients was used as an external validation group. Multivariate analysis was used to determine the optimal variables. The validation of the nomogram was assessed using the receiver operating characteristic (ROC) curve, calibration curve and decision curve analysis (DCA). Results: Urosepsis was observed in 47 (5.6%) and 33 (5.4%) patients in the two centers. Four variables were selected to establish the nomogram through multivariate analysis, including operative time [P<0.001, odds ratio (OR): 1.035, 95% confidence interval (CI): 1.019-1.051], accumulated time of renal pelvic pressure ≥30 mmHg (0 vs. 0-60 s, P=0.011, OR: 3.180, 95% CI: 1.300-7.780; 0-60 vs. ≥60 s, P<0.001, OR: 6.389, 95% CI: 2.603-15.685), bladder urine culture (P<0.001, OR: 6.045, 95% CI: 2.454-14.891) and hydronephrosis (none or light vs. moderate, P=0.003, OR: 3.403, 95% CI: 1.509-7.674; moderate vs. several, P=0.002, OR: 4.704, 95% CI: 1.786-12.391). The calibration results showed that the model was well calibrated and ROC curve demonstrated excellent discrimination of the nomogram. In addition, the DCA showed that the nomogram had a positive net benefit. Conclusions: A prediction nomogram was developed and validated to assist clinicians in assessing the probability of urosepsis after PCNL.

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.

Current Practices and Challenges in the Management of Complex Renal Stones in Africa: A Scoping Review.

This study reviews the challenges and management strategies for complex renal stones in Africa. Historically viewed as infection or struvite stones, recent studies highlight diverse compositions of staghorn stones. These complex stones pose significant risks, including recurrent urinary tract infections and renal impairment. In the past, conservative management of staghorn stones was associated with high morbidity; thus, surgical intervention was necessary for complete eradication. While percutaneous nephrolithotomy (PCNL) remains the standard, it carries notable risks, leading to a shift towards minimally invasive techniques. This study reviews challenges and management practices for complex renal stones and staghorn calculi in African countries, evaluating stone-free rates and associated complications. A scoping review of the literature, following the Preferred Reporting Items for Systematic Reviews and Meta-analysis guidelines, was performed. A systematic search was conducted in PubMed, African Journal Online (AJOL) and Google Scholar, yielding 1,101 articles, but only 11 articles satisfied the inclusion criteria. The study included 1,513 patients with 1,582 renal units, predominantly male (67.2%) with an average age of 40.7 years. Percutaneous nephrolithotomy (PCNL) was the primary treatment for the majority (71.3%), followed by open surgery (21.9%), laparoscopic surgery (4.1%), and retrograde intrarenal surgery (RIRS) (2.7%). The stone clearance rates for PCNL, open surgery, laparoscopic pyelolithotomy, and RIRS were 82.8%, 83.7%, 100%, and 92.8%, respectively. Stone sizes ranged between 22 and 80 mm, with 66% being staghorn stones. Complication rates were highest for open surgery (30.8%) and lowest for RIRS (4.7%). Despite PCNL being the global standard, African studies still indicate a high reliance on open surgery, likely due to healthcare infrastructure, resource availability and socioeconomic factors. Enhancing access to urological care and addressing healthcare disparities are imperative for improving staghorn stone management in Africa.

Effect of access sheath diameter used in percutaneous nephrolithotomy on renal function: a prospective randomized study.

We aimed to determine the effect of the access sheath diameter used in percutaneous nephrolithotomy (PNL) on renal function. We also investigated the predictors of impaired renal function. Data were prospectively collected from patients who underwent PNL from December 2020 to December 2021. The patients were randomized into two groups according to access sheath diameter: Group 1 (22 Fr, n = 44) and Group 2 (28 Fr, n = 44). Relative renal function (RRF) was calculated by technetium-99 m dimercaptosuccinic acid scintigraphy, and glomerular filtration rate (GFR) was calculated by diethylenetriamine pentaacetic acid scintigraphy. A difference of 5% or more in RRF was considered a significant functional change. Preoperative and postoperative Kidney Injury Molecule-1 (KIM-1) levels were measured. Preoperative demographic data and stone characteristics were similar between the groups. There were also no statistically significant differences between the groups in terms of scar development, changes in RRF, GFR, or KIM-1/creatinine (Cr) (p > 0.05). Significant deterioration in RRF was detected in a total of six (6.8%) patients, three in each group. The factors predicting loss of function were analyzed by regrouping the patients without loss of function as Group A (n = 82) and those with loss as Group B (n = 6). Only stone volume was statistically significant in multivariate analysis (p = 0.002). Access sheath diameter had no significant effect on renal function after PNL. However, the stone volume was found to independently correlate to a loss of renal function after PNL.

Vulnerability to Financial Toxicity From Stone Surgery.

PURPOSE: Financial toxicity has been described in stone formers however little is understood regarding its causes and how it may relate to stone surgery. We therefore aimed to longitudinally describe markers of financial strain in stone formers from the preoperative to postoperative time points. MATERIALS AND METHODS: A prospective cohort study was conducted from January 2022 to April 2023. Patients were enrolled in the waiting area prior to undergoing elective ureteroscopy or percutaneous nephrolithotomy. Participants completed the Commonwealth Fund's Biennial Health Insurance Survey at this time point and at 30 days postop. Items were pre-selected from the survey to capture markers of financial strain due to healthcare costs. RESULTS: One hundred nine participants were enrolled. Participants were a majority white (70%), college educated (62%), and privately ensured (72%). Despite these traditionally protective sociodemographic features, 42% of patients reported some marker of financial strain at the preoperative timepoint. Patients with Medicaid reported even higher financial stress (67%). Furthermore, 46% of patients did not know their deductible amount. Response rate was low at 30 days postop (35%) but suggested some patients were experiencing new financial strains. CONCLUSIONS: This paper shows that a significant proportion of stone patients are already displaying markers of financial strain from healthcare bills even prior to surgery as well as poor understanding of the costs they may incur. This makes them vulnerable to experiencing financial toxicity postoperatively and emphasizes the importance of understanding all contributing factors when developing future strategies to intervene in financial toxicity.

Surgical Stone Trends from 2013 to 2021 in the US Medicare Population: Before and after the COVID-19 Pandemic.

Introduction and Objective: In early 2020, as the SARS-Cov-2 (COVID-19) pandemic progressed, many institutions limited nonurgent surgical care. This coincided with a decade-long trend of increasing percutaneous nephrolithotomy (PCNL) and ureteroscopy (URS) and decreasing shock wave lithotripsy (SWL) for surgical management of urolithiasis. Herein, we evaluate temporal stone surgery rates and surgeon volumes in the Medicare population and suggest how COVID-19 contributed to them. Methods: Retrospective analysis was conducted using the "Medicare Physician & Other Practitioners" database containing data from January 2013 to December 2021. Adult patients who underwent stone surgery were included. We evaluated surgeon characteristics and changes in case volumes over time adjusted for population. Results: In 2013, urologists performed 68,910 stone surgeries: SWL 42,903 (62%); URS 25,321 (37%); PCNL 686 (1%). Over the next 8 years, there was an average annual increase in URS (+13%) and PCNL (+13%) and decrease in SWL (-2%). In 2020, there was a 14% reduction in all stone cases: SWL (-25%); URS (-6%); PCNL (-8%). By 2021, case volumes recovered to pre-2020 levels, though SWL remained low: SWL 33,974 (34%); URS 64,541 (64%); PCNL 1764 (2%). From 2013 to 2021, the number of urologists performing SWL decreased (1718 to 1361) while URS and PCNL providers doubled (1,347 to 2,914 and 28 to 76, respectively). Conclusions: From 2013 to 2021, there was an increase in URS and PCNL and a decrease in SWL in the US Medicare population. The COVID-19 pandemic was associated with a decline in stone surgeries, particularly SWL. By 2021, PCNL and URS case numbers increased significantly with a smaller increase in SWL.

Optimizing Colon Identification by Window Setting Modulation on Noncontrast Computed Tomography Prior to Percutaneous Nephrolithotomy.

Background: Preoperative identification of the bowel on imaging is essential in planning renal access during percutaneous nephrolithotomy (PCNL) and avoiding colonic injury. We aimed this study to assess which noncontrast computed tomography (NCCT) window setting provides the optimal colonic identification for PCNL preoperative planning. Methods: Ten urologic surgeons (four seniors, six residents) reviewed 22 images of NCCT scans in both abdomen and lung window settings in a randomized blinded order. Colonic area delineation in each image was performed using a dedicated, commercially available area calculator software. A comparison of the marked colonic area between the abdomen and lung window settings was performed. Results: Overall, the mean marked colonic area was greater in the lung window compared with the abdomen window (8.82 cm2 vs 7.4 cm2, respectively, p < 0.001). Switching the CT window from abdomen to lung increased the identified colonic area in 50 cases (50%). Intraclass correlation showed good agreement between the senior readers and among all readers (0.92 and 0.87, respectively). Similar measurements of the colonic area in both abdomen and lung windows were observed in 26/44 (60%) of the seniors cases and in 7/66 (10%) of the resident cases (p = 0.002). Conclusion: Lung window solely or in combination with abdomen window appears to provide the most accurate colonic identification for preoperative planning of PCNL access and potentially reduce the risk of colonic injury. This pattern is more evident among young urologists, and we propose to introduce it as a standard sequence in PCNL preplanning.

The Application of Next-Generation Sequencing in Preoperative Evaluation for Urologic Stone Surgery.

Introduction: Next-generation sequencing (NGS) is a new molecular technique for identifying microorganisms. Treating bacteriuria in patients undergoing stone removal procedures is important for preventing postoperative urinary tract infection (UTI). The objective of this study is to assess the usefulness of preoperative urine NGS testing by comparing NGS with standard urine culture in predicting postoperative UTI after ureteroscopic lithotripsy (URSL) and percutaneous nephrolithotomy (PCNL). Materials and Methods: This prospective study was conducted from February 16, 2022, to January 11, 2024. Sixty subjects who underwent URSL or PCNL were included. Preoperative voided urine samples were collected for urine culture and tested by MicroGenDX for urine polymerase chain reaction (PCR) and urine NGS. Stone specimens obtained intraoperatively were also sent for stone culture and MicrogenDx. Patients were monitored for 4 weeks post-operation for recording clinical outcomes related to infections and complications. Results: Twenty-six (43.3%) male and 34 (56.7%) female participants were included. Twenty-six (43.3%) patients underwent PCNL (15 standard PCNL and 11 mini PCNL), and 34 (56.7%) underwent URSL. Standard urine culture identified positive results in 26 cases (43.3%), PCR for 17 cases (28.3%), and NGS for 31 cases (51.7%). The overall postoperative UTI rate was 6 (10%). Standard urine culture demonstrated a sensitivity of 50%, specificity of 57.4%, and accuracy of 56.7%. Positive predictive value (PPV) was notably poor at 11.5%. Urine NGS showed a higher sensitivity of 83.3%, specificity of 53.7%, accuracy of 55%, and PPV of 16.7%. Conclusion: Urine NGS significantly improves the sensitivity of detecting microorganisms in preoperative urine compared with standard urine culture. Despite its high sensitivity and capability to identify nonculturable bacteria, using NGS alongside standard urine culture is recommended. This parallel approach harnesses the strengths of both methods. Integrating NGS into standard practice could elevate the quality of care, especially for patients at high risk of UTIs, such as those undergoing invasive stone removal procedures.