The impact of siphoning effect on renal pelvis pressure during ureteroscopy using an in vitro kidney and ureter model.

PURPOSE: To experimentally measure renal pelvis pressure (PRP) in an ureteroscopic model when applying a simple hydrodynamic principle, the siphoning effect. METHODS: A 9.5Fr disposable ureteroscope was inserted into a silicone kidney-ureter model with its tip positioned at the renal pelvis. Irrigation was delivered through the ureteroscope at 100 cm above the renal pelvis. A Y-shaped adapter was fitted onto the model's renal pelvis port, accommodating a pressure sensor and a 4 Fr ureteral access catheter (UAC) through each limb. The drainage flowrate through the UAC tip was measured for 60 s each run. The distal tip of the UAC was placed at various heights below or above the center of the renal pelvis to create a siphoning effect. All trials were performed in triplicate for two lengths of 4Fr UACs: 100 cm and 70 cm (modified from 100 cm). RESULTS: PRP was linearly dependent on the height difference from the center of the renal pelvis to the UAC tip for both tested UAC lengths. In our experimental setting, PRP can be reduced by 10 cmH20 simply by lowering the distal tip of a 4 Fr 70 cm UAC positioned alongside the ureteroscope by 19.7 cm. When using a 4 Fr 100 cm UAC, PRP can drop 10 cmH20 by lowering the distal tip of the UAC 23.3 cm below the level of the renal pelvis. CONCLUSION: Implementing the siphoning effect for managing PRP during ureteroscopy could potentially enhance safety and effectiveness.

Effect of infundibulopelvic angle on outcomes of ureteroscopy: a systematic review and meta-analysis.

PURPOSE: The infundibulo-pelvic angle (IPA) is reportedly a predictor of successful ureteroscopy for lower pole renal stones, however there is uncertainty at which IPA success is likely. We therefore aimed to perform a meta-analysis and determine at which the angle of likely success and failure. METHODS: We performed a systematic review and meta-analysis as per Cochrane guidelines in accordance to the PRISMA statement. The review was registered with PROSPERO prior to commencement (ID: CRD42022296732). We included studies reporting on outcomes of ureteroscopy for lower pole stones, with IPA. We excluded patients undergoing alternative treatments for lower pole stones, anatomical abnormalities and studies with < 10 patients. We assessed bias with the Newcastle-Ottawa scale. We performed meta-analysis in R, and summarised the findings as per GRADE. RESULTS: Overall, there were 13 studies included, with 10 included for meta-analysis. These studies covered n = 1964 patients (71% stone free). Overall, the stone free patients had a significantly less acute mean IPA (52o ± 9o), compared to the non-stone free patients (39o ± 7o), on meta-analysis (REM MD = -13.0, 95% CI: -18.7 to -7.2, p < 0.001). On examination of forest plots, at IPA < 30o no patients were stone free, whilst > 50o all were stone free. Risk of bias was moderate, and certainty of evidence was 'very low'. CONCLUSION: With a very low certainty of evidence, we demonstrate that at an IPA of < 30o no patient is stone free, whilst > 50o all patients (in this review) are stone free. More evidence is therefore needed.

The missed crossing vessel during open pyeloplasty: a potential advantage of the robot-assisted approach in children.

OBJECTIVE: To investigate whether the panoramic view offered by robot-assisted laparoscopic pyeloplasty (RALP) reduces the likelihood of missing a crossing vessel compared to open pyeloplasty in cases where initial pyeloplasty fails. METHODS: A single institution redo-pyeloplasty database was reviewed for children treated between January 2012 to July 2023. Clinical history, imaging and operative details were reviewed to identify the etiology for the redo procedure. RESULTS: Cohort consisted of 45 patients undergoing a redo RALP during the study period. 29 of 45 patients had an initial open surgical approach, whereas 16 had an initial RALP. 10 patients were noted to have a missed crossing vessel on redo pyeloplasty - 9 had an initial open approach whereas 1 had an initial RALP (p<0.0001). CONCLUSIONS: RALP may reduce the risk of missing a crossing vessel due to the panoramic view of the surgical field intrinsic to an intraperitoneal RALP approach.

The conundrum of high-grade hydronephrosis with non-obstructive drainage on diuretic renography.

BACKGROUND: Patients with high grade hydronephrosis (HN) and non-obstructive drainage on mercaptoacetyltriglycine (MAG-3) diuretic renography (renal scans) can pose a dilemma for clinicians. Some patients may progress and require pyeloplasty; however, more clarity is needed on outcomes among these patients. OBJECTIVE: Our primary objective was to predict which patients with high-grade HN and non-obstructive renal scan, (defined as T ½ time <20 min) would experience resolution of HN. Our secondary objective was to determine predictors for surgical intervention. STUDY DESIGN: Patients with prenatally detected HN were prospectively enrolled from 7 centers from 2007 to 2022. Included patients had a renal scan with T ½<20 min and Society for Fetal Urology (SFU) grade 3 or 4 at last ultrasound (RBUS) prior to renal scan. Primary outcome was resolution of HN defined as SFU grade 1 and anterior posterior diameter of the renal pelvis (APD) < 10 mm on follow-up RBUS. Secondary outcome was pyeloplasty, comparing patients undergoing pyeloplasty with patients followed with serial imaging without resolution. Multivariable logistic regression was used for analysis. RESULTS: Of the total 2228 patients, 1311 had isolated HN, 338 patients had a renal scan and 129 met inclusion criteria. Median age at renal scan was 3.1 months, 77% were male and median follow-up was 35 months (IQR 20-49). We found that 22% (29/129) resolved, 42% of patients had pyeloplasty (54/129) and 36% had persistent HN that required follow-up (46/129). Univariate predictors of resolution were age≥3 months at time of renal scan (p = 0.05), T ½ time≤5 min (p = 0.09), SFU grade 3 (p = 0.0009), and APD<20 mm (p = 0.005). Upon multivariable analysis, SFU grade 3 (OR = 4.14, 95% CI: 1.30-13.4, p = 0.02) and APD<20 mm (OR = 6.62, 95% CI: 1.41-31.0, p = 0.02) were significant predictors of resolution. In the analysis of decision for pyeloplasty, SFU grade 4 (OR = 2.40, 95% CI: 1.01-5.71, p = 0.04) and T ½ time on subsequent renal scan of ≥20 min (OR = 5.14, 95% CI: 1.54-17.1, p = 0.008) were the significant predictors. CONCLUSIONS: Patients with high grade HN and reassuring renal scan can pose a significant challenge to clinical management. Our results help identify a specific candidate for observation with little risk for progression: the patient with SFU grade 3, APD under 20 mm, T ½ of 5 min or less who was 3 months or older at the time of renal scan. However, many patients may progress to surgery or do not fully resolve and require continued follow-up.

Parapelvic Renal Cyst Treatment with Flexible Ureteroscopy: Single Centre Experience.

BACKGROUND: This study aimed to assess the feasibility, safety, and efficacy of an endoscopic parapelvic renal cyst (PRC) incision using flexible ureterorenoscopy (fURS). MATERIAL AND METHODS: We retrospectively reviewed data concerning 16 patients in whom PRC incisions had been performed using fURS between January 2016 and January 2022. Two patients were excluded from the study owing to a lack of follow-up information. The cysts of all the patients were evaluated preoperatively by computed tomography. The patients' age, gender, cyst size, presenting symptoms, postoperative complications, and pre- and post-treatment visual analogue scale (VAS) scores were evaluated. Surgical success was defined as a reduction of more than half of the cyst size in the sixth postoperative month. RESULTS: A total of 14 patients were included in this study. The patients' mean age was 52.6 ± 8.8 years, and the mean cyst size was 69.1 ± 15.5 mm. Twelve (85.7%) patients presented with flank pain. Clavien-Dindo grade 1 complications were observed in two patients (14.3%), and grade 2 complications were observed in one (7.1%). The median VAS scores were significantly lower after treatment than before in patients who presented with flank pain (2 (1-2.8) vs 8 (7-8), respectively; p = 0.002). Surgical success rate was detected in 11 patients (78.6%) six months after the treatment. CONCLUSIONS: Endoscopic incision of the PRC is a feasible treatment modality with high success rates and low complication rates. However, multicentre studies with larger populations and longer follow-ups are needed to evaluate the lasting effects.

Fluid absorption during flexible ureteroscopy with intelligent control of renal pelvic pressure: a randomized controlled trial.

PURPOSE: To investigate fluid absorption and its influencing factors during flexible ureteroscopy with intelligent control of renal pelvic pressure (RPP). METHODS: A total of 80 patients with upper urinary tract calculi underwent flexible ureteroscopy with intelligent control of RPP by pressure-measuring ureteral access sheath and were randomly divided into four groups. The RPP of Groups A, B, and C were set at - 5, 0 and 5 mmHg, respectively. Conventional flexible ureteroscopy with uncontrolled pressure served as control Group D. The perfusion flow rate was set at 100 ml/min in the four groups, with 20 patients in each group. The fluid absorption was measured by 1% ethanol every 10 min. Operation time, stone-free rate, and complications were recorded. RESULT: Seventy-three patients were finally included in the RCT. The general and preoperative data of the patients were comparable between the groups. The fluid absorption of Groups A, B, and C was significantly less than that of Group D (P < 0.01). Fluid absorption and operation time were positively correlated, and the correlation coefficients R were 0.864, 0.896, 0.918, and 0.947, respectively (P < 0.01). The fluid absorption of patients with vomiting, fever and ureteral injury was greater than that of patients without complications in the four groups (P < 0.01). In different groups, fluid absorption was greater in patients with ureteral injury Post-Ureteroscopic Lesion Scale (PULS) 1-3 than in noninjured patients (P < 0.01). CONCLUSION: Flexible ureteroscopy with intelligent control of RPP effectively reduces the absorption of perfusion fluid. Operation time and ureteral injury are also key factors affecting perfusion fluid absorption. REGISTRATION NUMBER AND DATE: NCT05201599; August 11, 2021.

Robotic-assisted laparoscopic pyeloplasty for the treatment of ureteropelvic junction obstruction - How should success be determined?

BACKGROUND: Ureteropelvic junction obstruction (UPJO) is characterised by stenosis of the ureteral lumen at the level of the renal pelvis and proximal ureter. At Haukeland University Hospital, robotic-assisted laparoscopic pyeloplasty (RLP) for UPJO has been performed since 2014. The aim of this study was to evaluate the results of the treatment and consider what determines treatment success. MATERIALS AND METHODS: Retrospective review was performed of consecutive patients undergoing RLP between 2014-2022. Outcomes of interest included symptom relief, complication rates and renographic findings at follow-up. Treatment success was defined in terms of symptom improvement and/or improvement as well as relief of obstruction on renography. RESULTS: In total, 95 RLPs were performed in 54 women and 41 men, with a mean age of 40 years (IQR: 21-58). Flank pain was the most frequent presenting complaint (n = 81, 85%) followed by infection (n = 33, 35%). More than one indication for surgery was present in 1/3 of the patients. Urodynamic relevant obstruction on renography was found in 62 patients (65%) preoperatively. Mean operative time was 123 minutes (range 60-270). Two patients experienced minor intraoperative complications. At three months follow-up, 91% of patients had symptom relief, and no obstruction on renography was recorded in 64%. There was no significant association between improvement in symptoms and renography findings at follow-up, p = 1. CONCLUSIONS: RLP can deliver a high success rate in terms of symptom relief and few complications. There was no association between renography findings and symptom relief at follow-up. Success after surgery should be determined by symptom relief rather than renography findings.

Primary mucinous tumors of the renal pelvis: Clinical, histopathological, and molecular analysis of three cases.

Primary mucinous tumors of the renal pelvis are extremely rare and pose challenges in terms of diagnosis and treatment. This study reviewed the clinical and pathological characteristics of mucinous tumors of the renal pelvis, including mucinous cystadenocarcinomas and mucinous cystadenomas. Immunohistochemical analysis was conducted in three cases, along with KRAS gene detection using the Amplification Refractory Mutation System (ARMS) method. The results revealed mucinous epithelium with acellular mucinous pools in all cases, and acellular mucinous pools were observed in the renal parenchyma and perirenal fat capsules. All tumors expressed CK20 and CDX2, and one case showed KRAS gene mutation. The study suggests that mucinous cystadenomas of the renal pelvis may exhibit borderline biological behaviors. This study is the first to report a KRAS gene mutation in a mucinous cystadenoma of the renal pelvis, offering valuable insights into the diagnosis and treatment of this rare condition.

Robotic-assisted native pyeloureterostomy with indocyanine green, after kidney transplantation.

INTRODUCTION: Postoperative ureteral strictures and vesicoureteral reflux after ureteroneocystostomy for kidney transplant can be managed by endoscopic procedures like balloon dilation and endoscopic injections. Complicated/recurrent cases, however, are usually managed by reconstructive surgery. We hereby highlight our technique of robotic-assisted native pyeloureterostomy with indocyanine green (ICG). MATERIALS AND SURGICAL TECHNIQUE: A 57-year-old woman, diagnosed with grade 4 vesicoureteral reflux on her transplanted kidney, was considered a candidate for ureteral reimplantation. After an endoscopic part, where the ICG is inserted into the renal pelvis, we proceed with the robotic native pyeloureterostomy. The renal pelvis of the transplanted kidney was identified with the help of the ICG in firefly mode. After the dissection of the graft pelvis, we performed a tension-free pyeloureterostomy using the native ureter. The postoperative course was uneventful and the patient was discharged on the third postoperative day. DISCUSSION: Robotic-assisted pyelo-ureterostomy appears as a safe and efficient technique for management of complicated urological complications postrenal transplantation using the native ureter. Intrapelvic ICG injection, not possible with open surgery, helps identifying the grafted pelvis thus reducing operative time and avoiding unnecessary dissection of the vascular hilum of the graft. Because of minimal dissection and the short operative time, abdominal drainage is unnecessary and the postoperative course is usually uneventful with a fast discharge from the hospital.

Complete Pathologic Response With Pembrolizumab and Enfortumab Vedotin in Urothelial Carcinoma of the Upper Urinary Tract.

Urothelial carcinoma of the upper urinary tract (UTUC) presents a significant clinical challenge, often requiring aggressive surgical intervention for optimal management. We present a case of an 84-year-old woman with recurrent high-grade papillary UTUC of the left renal pelvis, refractory to prior endourologic interventions, who underwent neoadjuvant treatment with pembrolizumab and enfortumab vedotin (Pembro/EV) due to contraindications to cisplatin therapy. Following a favorable response to neoadjuvant therapy, the patient underwent laparoscopic left radical nephroureterectomy, achieving a pathologic complete response. We discuss the utility of Pembro/EV in the perioperative management of patients with UTUC, particularly in those ineligible for cisplatin-based therapy. In addition, we highlight the potential role of somatic mutation testing and the integration of novel therapeutic agents such as olaparib in personalized treatment strategies for UTUC. This case underscores the importance of exploring innovative treatment approaches and optimizing patient selection for kidney preservation strategies in the management of UTUC. Further research and clinical trials are warranted to elucidate the full therapeutic potential of Pembro/EV and other emerging therapies in this setting.

Propensity score matched analysis of treatment outcomes in pediatric ureteropelvic junction obstruction: a comparison between horseshoe and non-horseshoe kidneys.

BACKGROUND: Pediatric hydronephrosis poses distinct challenges, particularly in cases involving horseshoe kidneys (HSK). This retrospective study compares treatment outcomes between HSK and non-horseshoe kidneys (NHSK) in pediatric ureteropelvic junction obstruction (UPJO) patients. METHODS: A retrospective cohort study included 35 patients with HSK and 790 patients with NHSK undergoing pyeloplasty. Preoperative, intraoperative, and postoperative parameters were evaluated. Propensity score matching (PSM) balanced patient characteristics in the NHSK group. RESULTS: In comparison with NHSK, HSK exhibited a higher crossing vessel incidence (51.6% vs. 5.12%, P < 0.001) and smaller preoperative anteroposterior pelvic diameter (APD). Post 6 and 12 months, NHSK maintained a larger APD, with a higher P/C ratio at 12 months. PSM retained significantly higher crossing vessel incidence in HSK (51.6 vs. 3.61%, P < 0.001). Laparoscopic pyeloplasty (LP) in HSK showed lower postoperative length of stay (LOS). Postoperative ultrasound parameters favored NHSK. In HSK and NHSK with crossing vessels, HSK demonstrated higher complications even post-PSM (38.5% vs. 0%, P = 0.039). CONCLUSIONS: The study emphasizes the importance of recognizing crossing vessels in HSK-related hydronephrosis. Surgical success, although comparable between HSK and NHSK, requires tailored approaches. This investigation contributes valuable insights to pediatric urology, emphasizing personalized management for optimal outcomes.

Diagnosis and Management of Ureteropelvic Obstruction in Kidney Transplant Recipients and Outcomes of Foley Y-V Pyeloplasty.

OBJECTIVES: To evaluate the etiology and diagnostic tools for ureteropelvic obstruction in kidney transplant recipients, we investigated the short-term and long-term outcomes of Foley Y-V pyeloplasty. MATERIALS AND METHODS: We retrospectively reviewed 10 patients who underwent kidney transplant followed by additional interventions to treat obstructive ureteral pathologies between 2016 and 2020. We enrolled 4 patients who had received intervention to treat ureteropelvic obstruction. For these 4 patients, serum creatinine and estimated glomerular filtration rate levels were recorded at baseline, during the symptomatic period, and long-term. In this single center study, we investigated diagnostic tools and management strategies for ureteropelvic obstruction and assessed performance of Foley Y-V nondismembered pyeloplasty in kidney transplant recipients. RESULTS: Among 4 patients, graft function (assessed by serum creatinine and estimated glomerular filtration rate) worsened significantly (P = .03) in the symptomatic period of ureteropelvic obstruction in all patients; however, graft function levels improved rapidly to levels similar to baseline (P = .07) after Y-V pyeloplasty. In addition, no statistically significant difference was detected between baseline and longterm graft functions afterY-V pyeloplasty in follow-up (P = .28). CONCLUSIONS: Diagnosis and management of ureteropelvic obstruction in kidney transplant recipients are challenging due to rarity and lack of an ideal management algorithm.There is no specific diagnostic tool to discriminate this pathology from other ureteral pathologies; therefore, a regimen of conventional imaging modalities and diuretic renogram combined with endoscopic evaluation is more reliable. Moreover, nondismembered Foley Y-V pyeloplasty is effective and safe for graft function in the short-term and long-term.

A population-based study on incidence trends of kidney and renal pelvis cancers in the United States over 2000-2020.

Cancers of the kidney and renal pelvis are among the most prevalent types of urinary cancers. We aimed to outline the incidence trends of kidney and renal pelvis cancers by age, sex, race/ethnicity, and histology in the United States (US) from 2000 to 2020. The data was obtained from the Surveillance, Epidemiology, and End Results (SEER) 22 database. The identification of patients with kidney and renal pelvis cancers with morphologies of renal cell carcinoma, nephroblastoma, sarcoma, and neuroendocrine tumor was conducted utilizing the International Classification of Diseases for Oncology version 3. The average annual percent change (AAPC) were presented. All estimates were given in the form of counts and delayed age-standardized incidence rates (ASIRs) per 100,000 people. From 2000 to 2019, a total of 490,481 cases of kidney and renal pelvic cancer were recorded across all age groups in the US. The majority of them were among Non-Hispanic Whites (NHWs) (69.75%) and those aged 55-69 years (39.96%). The ASIRs per 100,000 for kidney and pelvis cancers were 22.03 for men and 11.14 for women. Non-Hispanic Black men had the highest ASIR (24.53 [24.24, 24.81]), and increase in ASIR over the 2000-2019 period (AAPC: 2.19% [1.84, 2.84]). There was a noticeable increase in incidence of kidney and renal pelvis cancers. Individuals aged 70-84 years had the highest ASIR for kidney and renal pelvis cancers. The COVID-19 era has resulted in a significant reduction in incidence rates across all demographics.

Needle-perc-assisted endoscopic surgery versus retrograde intrarenal surgery for the treatment of 1- to 2-cm lower-pole renal stones in patients with unfavorable infundibulopelvic anatomy: a matched-pair analysis.

PURPOSE: To compare the safety and efficacy of needle-perc-assisted endoscopic surgery (NAES) and retrograde intrarenal surgery (RIRS) for the treatment of 1- to 2-cm lower-pole stones (LPS) in patients with complex infundibulopelvic anatomy. METHODS: Between June 2020 and July 2022, 32 patients with 1- to 2-cm LPS and unfavorable lower-pole anatomy for flexible ureteroscopy were treated with NAES. The outcomes of these patients were compared with patients who underwent RIRS using matched-pair analysis (1:1 scenario). The matching parameters such as age, gender, body mass index, stone size, hardness, and pelvicalyceal anatomy characteristics including infundibular pelvic angle, infundibular length, and width were recorded. Data were analyzed using the Student's t-test, Mann-Whitney U test, and Fisher's exact test. RESULTS: The two groups had similar baseline characteristics and lower-pole anatomy. The stone burden was comparable between both groups. NASE achieved a significantly better initial stone-free rate (SFR) than RIRS (87.5% vs 62.5%, p = 0.04). The auxiliary rates for the NAES and RIRS groups were 12.5% and 31.3%, respectively (p = 0.13). Finally, the SFR after 1 month follow-up period was still higher for the NAES group than RIRS group (93.8% versus 81.3%), but the difference was not statistically significant (p = 0.26). Concerning the operation duration, overall complication rates, and postoperative hospital stay, there were no differences between two groups. CONCLUSION: Compared to RIRS for treating 1- to 2-cm LPS in patients with unfavorable infundibulopelvic anatomy for flexible ureteroscopy, NAES was safe and effective with higher SFR and similar complication rate.

Utility of ultrasound-based scoring system in post-pyeloplasty recovery.

BACKGROUND/OBJECTIVE: Differentiation of uretero-pelvic junction obstruction (UPJO) from non-obstructive dilatation (NOD) is a major challenge. The aim of this retrospective study is to determine whether pyeloplasty prediction score (PPS) could predict the need for surgery and resolution after surgery. METHODS: Among patients with antenatally diagnosed hydronephrosis, those who were stable during post-natal follow-up were considered NOD. The UPJO group were the ones who worsened and underwent pyeloplasty based on conventional indications. All patients with UPJO underwent laparoscopic dismembered pyeloplasty. PPS was determined based on three ultrasound parameters obtained retrospectively: Society of Fetal Urology (SFU) grade of hydronephrosis, transverse anteroposterior (APD), and the absolute percentage difference of ipsilateral and contralateral renal lengths. RESULTS: Among 137 patients included (R:L = 59:73; M:F 102:35), 96 were conservatively managed (NOD), while 41 patients (29%) needed pyeloplasty (UPJO). Mean PPS was 4.2 (1.2) in the NOD group and it was significantly higher at 10.8 (1.63) in the UPJO group (p = 0.001). All patients with PPS > 8 needed a pyeloplasty, while two patients with PPS of 7 needed pyeloplasty due to drop in renal function. PPS cutoff value of >8 had a sensitivity 95%, specificity 100% and a likelihood ratio of 20. Post-pyeloplasty PPS resolution was proportional to the duration of follow-up. CONCLUSIONS: A PPS cutoff value of 8 or above is associated with the presence of significant UPJO. PPS is also useful in the assessment of hydronephrosis recovery post-pyeloplasty. The limitation of PPS: it can only be applied in the presence of contralateral normal kidney.

Association between NDUFS1 from urinary extracellular vesicles and decreased differential renal function in children with ureteropelvic junction obstruction.

BACKGROUND: Ureteropelvic junction obstruction (UPJO) is the most common cause of pediatric congenital hydronephrosis, and continuous kidney function monitoring plays a role in guiding the treatment of UPJO. In this study, we aimed to explore the differentially expressed proteins (DEPs) in the urinary extracellular vesicles(uEVs) of children with UPJO and determine potential biomarkers of uEVs proteins that reflect kidney function changes. METHODS: Preoperative urine samples from 6 unilateral UPJO patients were collected and divided into two groups: differential renal function (DRF) ≥ 40% and DRF < 40%.We subsequently used data-independent acquisition (DIA) to identify and quantify uEVs proteins in urine, screened for DEPs between the two groups, and analyzed biofunctional enrichment information. The proteomic data were evaluated by Western blotting and enzyme-linked immunosorbent assay (ELISA) in a new UPJO testing cohort. RESULTS: After one-way ANOVA, a P adj value < 0.05 (P-value corrected by Benjamin-Hochberg) was taken, and the absolute value of the difference multiple was more than 1.5 as the screening basis for obtaining 334 DEPs. After analyzing the enrichment of the DEPs according to Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment combined with the protein-protein interaction (PPI) network results, we selected nicotinamide adenine dinucleotide-ubiquinone oxidoreductase core subunit S1 (NDUFS1) for further detection. The expression of NDUFS1 in uEVs was significantly lower in patients with DRF < 40% (1.182 ± 0.437 vs. 1.818 ± 0.489, P < 0.05), and the expression level of NDUFS1 was correlated with the DRF in the affected kidney (r = 0.78, P < 0.05). However, the NDUFS1 concentration in intravesical urine was not necessarily related to the change in DRF (r = 0.28, P = 0.24). CONCLUSIONS: Reduced expression of NDUFS1 in uEVs might indicate the decline of DRF in children with UPJO.

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.

Low anterolateral incision for single-port extraperitoneal robot-assisted pyeloplasty: description of technique and initial experience.

PURPOSE: This study aims to describe the surgical steps for the single-port low anterolateral extraperitoneal approach to pyeloplasty, report its feasibility, and share the initial outcomes of our experience. METHODS: We analyzed all consecutive patients who underwent single-port low anterolateral extraperitoneal pyeloplasty due to ureteropelvic junction obstruction (UPJO). The surgical steps included a pure single-port approach through a 3.5 cm low anterolateral incision two fingerbreadths above the superior pubic ramus. The ureter was localized and followed cranially, a dismembered pyeloplasty was performed, and a running ureteropelvic anastomosis was completed. No drains were placed. The urinary catheter was removed upon discharge, and the ureteral stent after 3-5 weeks. RESULTS: A total of eight cases (two adults and six children) were completed successfully, without complications or conversions. Median operative time, console time, and estimated blood loss were 208.5 min, 114.5 min, and 10.0 ml, respectively. All patients were discharged within 24 h, except for one that required urinary output observation due to retention. There were no major postoperative complications. The median pain score at discharge was 0/10. Only one patient was prescribed PRN opioids at discharge. The readmission rate was 0.0%. All patients were asymptomatic on their last follow-up with no definitive obstruction on imaging, and no requirement for additional procedures or stents. CONCLUSION: Single-port low anterolateral extraperitoneal pyeloplasty is a feasible alternative for surgical treatment of UPJO in adult and pediatric patients with improved recovery outcomes.

Effect of nephrostomy sheath size on renal pelvic pressure during endoscopic combined intrarenal surgery: artificial kidney model study.

BACKGROUND: This study aimed to evaluate the intrarenal pelvic pressure in endoscopic combined intrarenal surgery using an artificial kidney model. METHODS: An artificial kidney model was created using the Urovac evacuator™. Four sizes of nephrostomy sheaths (MIP-L: 25/26 Fr, MIP-M: 16.5/17.5 Fr, MIP-S: 11/12 Fr, MIP-XS: 8.5/9.5 Fr) and two sizes of ureteral access sheaths (12/14 Fr and 10/12 Fr) were installed into the model. For each combination of nephrostomy and ureteral access sheath, renal pelvic pressure was measured with and without insertion of the retrograde flexible ureteroscope. Irrigation from the nephroscope was adjusted to 40-160 mmHg using an automatic irrigation device, and the irrigation of the ureteroscope was by spontaneous dripping at 80 cmH2O. Conditions were measured six times, and the renal pelvic pressure was compared in different conditions. RESULTS: Without ureteroscope insertion through the ureteral access sheath, the renal pelvic pressure never exceeded 30 mmHg. Meanwhile, when the ureteroscope was inserted, the renal pelvic pressure increased as the nephrostomy sheath and ureteral access sheath became narrower and as the irrigation pressure increased. Intrarenal pelvic pressure exceeded 30 mmHg when the irrigation pressure was increased in 12/14 Fr ureteral access sheath when MIP-XS was used, and in 10/12 Fr ureteral access sheath when MIP-XS and MIP-S were used. CONCLUSIONS: The use of a thin nephrostomy sheath in endoscopic combined intrarenal surgery can lead to increased intrarenal pelvic pressure. Although our results are from an artificial kidney model, special care is suggested to be required when using a retrograde flexible ureteroscope simultaneously in treatment of patients.