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.

Left endoscopic combined intrarenal surgery with electrocoagulation hemostasis and right flexible ureteroscopic lithotripsy for bilateral upper urinary tract stones: a case report.

Background: Percutaneous nephrolithotomy (PCNL) is the first-line treatment for large renal stones. However, multi-tract or staged procedures may be necessitated in bilateral or anatomically-complex stones to achieve stone clearance. Endoscopic combined intrarenal surgery (ECIRS) integrates the advantages of PCNL and retrograde intrarenal surgery. In this article, we detail a hybrid surgical technique adopted for the management of complex simultaneous bilateral upper urinary tract stones. In addition, we discuss the advantages and disadvantages of combining a variety of new techniques that may improve post-operative outcomes and patient satisfaction. Case Description: We report the case of a 36-year-old male with a large left renal pelvis stone, right proximal ureteric stone, and bilateral renal stones. Biochemical results showed raised inflammatory markers but he denied pre-stenting and staged surgery. After receiving 3-day antibiotic prophylaxis, he underwent an elective hybrid procedure. Under split-leg prone position, we performed a hybrid procedure that included left ECIRS with tubeless single-tract mini PCNL and left flexible ureteroscopy, and right flexible ureteroscopic lithotripsy. Hemostasis was achieved by electrocauterization with a novel device. The patient made an uneventful recovery. Follow-up computed tomography (CT) at 1-month revealed complete stone clearance. Conclusions: Unilateral ECIRS with tubeless single-tract mini PCNL with electrocoagulation hemostasis and adjacent retrograde intrarenal surgery in split-leg prone position is a safe, feasible, and efficient technique to manage large renal stones.

A comparative study of flexible ureteroscopic lithotripsy for upper urinary tract stones in patients with prior urosepsis following emergency drainage via retrograde ureteral stent or percutaneous nephrostomy.

BACKGROUND: Patients with urosepsis associated with upper urinary tract stones require further stone management after emergency drainage. OBJECTIVE: To evaluate the safety and efficacy of elective flexible ureteroscopic lithotripsy (F-URSL) for upper urinary tract stones in patients with prior urosepsis who have undergone emergency drainage using retrograde ureteral stent(RUS) or percutaneous nephrostomy (PCN). METHOD: Between January 2017 and December 2021, clinical data were collected for 102 patients who underwent elective F-URSL following emergency drainage for urosepsis caused by upper ureteral or renal stones. The patients were categorized into two groups based on the drainage method used: the RUS group and the PCN group. The collected data included patient demographics, stone parameters, infection recovery after emergency drainage, and clinical outcomes post F-URSL. Subsequently, the data underwent statistical analysis. RESULTS: A total of 102 patients were included in the statistical analysis, with 58 (56.86%) in the RUS group and 44 (43.14%) in the PCN group. Among the patients, 84 (82.35%) were female and 18 (17.65%) were male, with an average age of 59.36 years. Positive urine cultures were observed in 71 (69.61%) patients. Successful drainage was achieved in all patients in both groups, and there were no significant differences in the time required for normalization of white blood cell count (WBC) and body temperature following drainage. Additionally, all patients underwent F-URSL successfully, and no statistically significant differences were observed between the two groups in terms of operative time, stone-free rates, postoperative fever, and postoperative hospital stay. CONCLUSION: Both RUS and PCN have been established as effective approaches for managing urosepsis caused by upper urinary tract stones. Furthermore, the impact of these two drainage methods on the subsequent management of stones through elective F-URSL has shown consistent outcomes.

A multicenter study on the application of artificial intelligence radiological characteristics to predict prognosis after percutaneous nephrolithotomy.

Background: A model to predict preoperative outcomes after percutaneous nephrolithotomy (PCNL) with renal staghorn stones is developed to be an essential preoperative consultation tool. Objective: In this study, we constructed a predictive model for one-time stone clearance after PCNL for renal staghorn calculi, so as to predict the stone clearance rate of patients in one operation, and provide a reference direction for patients and clinicians. Methods: According to the 175 patients with renal staghorn stones undergoing PCNL at two centers, preoperative/postoperative variables were collected. After identifying characteristic variables using PCA analysis to avoid overfitting. A predictive model was developed for preoperative outcomes after PCNL in patients with renal staghorn stones. In addition, we repeatedly cross-validated their model's predictive efficacy and clinical application using data from two different centers. Results: The study included 175 patients from two centers treated with PCNL. We used a training set and an external validation set. Radionics characteristics, deep migration learning, clinical characteristics, and DTL+Rad-signature were successfully constructed using machine learning based on patients' pre/postoperative imaging characteristics and clinical variables using minimum absolute shrinkage and selection operator algorithms. In this study, DTL-Rad signal was found to be the outstanding predictor of stone clearance in patients with renal deer antler-like stones treated by PCNL. The DTL+Rad signature showed good discriminatory ability in both the training and external validation groups with AUC values of 0.871 (95% CI, 0.800-0.942) and 0.744 (95% CI, 0.617-0.871). The decision curve demonstrated the radiographic model's clinical utility and illustrated specificities of 0.935 and 0.806, respectively. Conclusion: We found a prediction model combining imaging characteristics, neural networks, and clinical characteristics can be used as an effective preoperative prediction method.

Flexible ureterolithotripsy for the management of multiple gas-containing renal calculi: A case report and literature review.

Gas-containing renal stones (GCS) are rare urological entities. Current literature has suggested possible associations with premenopausal women, urinary tract infection, and metabolic diseases. We report the case of a 25-year-old young woman with no underlying co-morbidities who had multiple right GCS and suspected emphysematous pyelitis. Antibiotic therapy was initiated to control her urinary tract infection with E. coli. She then underwent elective right flexible ureteroscopy to relieve her ureteropelvic junction obstruction. Complete stone retrieval was achieved and she made an uneventful recovery with no stone recurrence during 1-year follow-up.

Incidental Finding of Intrarenal Foreign Guidewire During Percutaneous Nephrolithotomy: A Case Report and Literature Review.

BACKGROUND Percutaneous nephrolithotomy (PCNL) is indicated for large renal calculi (≥2 cm) and is often the treatment of choice due to its high success rate. Guidewire fragmentation is a rare procedural accident that can occur in PCNL but may be missed. Retention of the fragment within the upper urinary tract can lead to further complications, such as recurrent nephrolithiasis or impairment of renal function. CASE REPORT We present the case of a 54-year-old man who experienced right flank pain for 5 days. His history was significant for recurrent nephrolithiasis, managed by PCNL in other hospitals. The most recent procedure was conducted 4 years ago, and his perioperative course was uneventful. Preoperative computed tomography revealed right renal calculi and a C-shaped foreign body. He was scheduled for an elective PCNL. The foreign body was intraoperatively identified as a guidewire fragment and removed. CONCLUSIONS Currently, there is no standard management for intrarenal foreign bodies. Suspicion should be raised in young patients with recurrent stones within a short period of time. A thorough history on past urological interventions should be obtained. Symptoms can also have an insidious onset that could mimic nephrolithiasis or urinary tract infections. Extraction can be done via a standard minimally invasive approach. It is also the surgeon's responsibility to check the integrity of intraoperative instruments so as to minimize risks of complication and reassure the patient.

Ureterolithiasis in Human Immunodeficiency Virus (HIV) Patients Treated with Single-Use Ureteroscope: A Case Report.

BACKGROUND The number of HIV-positive patients is increasing worldwide. Such patients with upper urinary tract stones have been treated primarily with flexible ureteroscopy. CASE REPORT Two patients with HIV and upper urinary tract stones were treated with a single-use digital flexible ureteroscope between July 2021 and January 2022. Both cases were treated by transurethral ureteroscope lithotripsy with a Guangzhou Redpine single-use digital flexible ureteroscope. This is also the first reported case of using a disposable ureteral flexible scope to manage a patient with upper urinary tract stones in combination with HIV. The holmium laser power was set to 0.2-0.6j/20-50 Hz for fragmentation and 1.0-1.5j/10-20 Hz for the dusting of the stones. Renal stones larger than 1 cm were dusted to around 1 cm first, and then a lithotripsy basket was used to remove them. The f5 Polaris Ultra ureteral stent was implanted during the procedure. The operations went smoothly. Four weeks after surgery, CT scans revealed a 4 mm stone remnant in one case, and the ureteral stent was removed in both cases. After 3 months, a kidney, ureter, and bladder X-ray revealed no stones remaining in the case that had earlier shown a 4 mm stone residual. In both cases, the stone composition was made up of calcium oxalate monohydrate and calcium oxalate dihydrate stones. CONCLUSIONS A single-use flexible ureteroscope has a proven clinical benefit in treating HIV-combined upper urinary tract stones. After the operations, there were no urinary infections, bleeding, or other complications in either patient.

A Patient with Fragmentation of a Calcified Ureteric Stent Requiring Ureteroscopy and Laser Lithotripsy.

BACKGROUND Encrustation of the ureteral stent is a common complication that occurs after a prolonged indwelling duration. Other identified risk factors in the literature include urinary sepsis, chemotherapy, chronic renal failure, metabolic or congenital abnormalities, and nephrolithiasis. This report presents the case of a 39-year-old man with nephrolithiasis and fragmentation of a calcified right ureteric stent that required ureteroscopy and laser lithotripsy. CASE REPORT A 39-year-old man was initially admitted for ureteroscopy and laser lithotripsy after the diagnosis of bilateral urolithiasis. Ureteral stents were placed. One postoperative month later, the patient returned for follow-up and stent withdrawal. Follow-up computed tomography revealed a normal left kidney, intact bilateral ureteral stents, and residual right renal stones. However, an attempt to completely withdraw the stent failed and the patient had to undergo a secondary right ureteroscopy with laser lithotripsy. The fragmented proximal section of a calcified right ureteral stent with occluded lumen was found intraoperatively and sent for product analyses. After successful reintervention, the patient had a new right ureteral stent placed, which was successfully withdrawn during his next follow-up. CONCLUSIONS Ureteral stent encrustation may occur earlier than anticipated, possibly due to underlying patient risk factors. Complications, such as fragmentation of the ureteral stent, may occur during withdrawal. Physicians should be aware of any predictors for early ureteral stent encrustation to prevent unnecessary reintervention.

Application of nomograms in the prediction of overall survival and cancer-specific survival in patients with T1 high-grade bladder cancer.

To predict survival outcomes for individual patients with clinical T1 high-grade (T1HG) bladder cancer (BC), data from the Surveillance Epidemiology and End Results (SEER) database were analyzed in the present study. The data of 6,980 cases of T1HG BC between 2004 and 2014 were obtained from the SEER database. Uni- and multivariate Cox analyses were performed to identify significant prognostic factors. Subsequently, prognostic nomograms for predicting 3- and 5-year overall survival (OS) and cancer-specific survival (CSS) rates were constructed based on the SEER database. Clinical information from the SEER database was divided into internal and external groups and used to validate the nomograms. In addition, calibration plot diagrams and concordance indices (C-indices) were used to verify the predictive performance of the nomogram. A total of 6,980 patients were randomly allocated to the training cohort (n=4,886) or the validation cohort (n=2094). Univariate and multivariate Cox analyses indicated that age, ethnicity, tumor size, marital status, radiation and surgical status were independent prognostic factors. These characteristics were used to establish nomograms. The C-indices for OS and CSS rate predictions for the training cohort were 0.707 (95% CI, 0.693-0.721) and 0.700 (95% CI, 0.679-0.721), respectively. Internal and external calibration plot diagrams exhibited an excellent consistency between actual survival rates and nomogram predictions, particularly for 3- and 5-year OS and CSS. The significant prognostic factors in patients with T1HG BC were age, ethnicity, marital status, tumor size, status of surgery and use of radiation. In the present study, a nomogram was developed that may serve as an effective and convenient evaluation tool to help surgeons perform individualized survival evaluations and mortality risk determination for patients with T1HG BC.

Comparison of Supracostal and Infracostal Access For Percutaneous Nephrolithotomy: A Systematic Review and Meta-Analysis.

PURPOSE: In this meta-analysis, we aimed to compared efficacy and safety of supracostal and infracostal access for percutaneous nephrolithotomy (PCNL). MATERIALS AND METHODS: We included eligible studies from PubMed, EMBASE, Cochrane Library, Web of Science and China National Knowledge Infrastructure. Literature searching, quality assessment and data extraction were performed by two independent reviewers. Data were analyzed by RevMan software. Binary and continuous variables were calculated as odds ratios (OR) and mean difference (MD). RESULTS: Two prospective comparative studies and seven retrospective observational studies were included in the meta-analysis, which contained 1,024 cases of supracostal access and 1,249 cases of infracostal access for PCNL. The supracostal access resulted in a significant reduced mean hemoglobin (95% CI: 0.26-3.46, MD = 1.86 g/L, P = .02) and a higher incidence of hydrothorax (95% CI: 4.77-22.95: OR = 10.47, P < .00001) compared to infracostal access. However, there no difference between supracostal and infracostal access regarding additional procedures (95% CI: 0.70-1.69, OR = 1.09, P = .71), stone-free rate (95% CI: 0.80-1.72, OR = 1.18, P = .41), length of hospital stay (95% CI: -0.03-0.37, MD = 0.17 day, P = .10), and occurrence of fever (95% CI: 0.95-2.03, OR = 1.39, P = .09) and blood transfusion (95% CI: 0.45-1.70, OR = 0.88, P = .70). No publication bias was identified in the study. CONCLUSION: Supracostal access was effective, but not as safe as infracostal access PCNL due to a higher risk of reduced hemoglobin and hydrothorax. Therefore, infracostal access should be the preferred safe and effective approach recommended for PCNL. When a supracostal puncture is performed, essential precautions to avoid hemoglobin loss and hydrothorax should be used.