Ureteral duplicity with a left ureterocele: a case report.

An intravesical ureterocele is a rare condition in which a terminal ureter terminates in a cystic dilation of the bladder. We present the case of a 42-year-old female who presented with irritative lower urinary tract symptoms and left lower back pain. Computed tomography (CT) urography revealed ureteral duplication with a ureterocele complicated by upper tract obstruction. Treatment involved endoscopic ureterocelotomy, which successfully relieved symptoms and resolved renal obstruction.

Evaluation of renovated double J stents using ureter models with and without stenosis.

PURPOSE: Commercial double J stents (DJS) have a uniform shape regardless of the specific nature of various ureteral diseases. We tested renovated DJS and compared them with conventional DJS using ureter models. METHODS: One straight ureter model included stenosis at the distal ureter near the ureterovesical junction and the other did not. We used conventional DJS and renovated 5- and 6-Fr soft DJS for ureter stones and 6-, 7-, and 8.5-Fr hard DJS for tumors. The DJS comprised holes in the upper, middle, or lower one-third of the shaft (length, 24 cm; 2-cm-diameter coils at both ends). More holes were created along the shaft based on the ureteral disease location. Conventional DJS had holes spaced 1 cm apart along the shaft. Renovated DJS had holes spaced 1 cm apart along the shaft with 0.5-cm intervals on the upper, middle, or lower one-third of the shaft. Urine flow was evaluated. RESULTS: As the DJS diameter increased, the flow rate decreased. The flow rates of DJS with holes in the lower shaft were relatively lower than those of conventional DJS and DJS with holes in the upper and middle shafts. In the ureter model without stenosis, 6-, 7-, and 8.5-Fr renovated stents exhibited significantly higher flow rates than conventional stents. In the ureter model with stenosis, 5-, 6-, 7-, and 8.5-Fr renovated stents did not exhibit significantly higher flow rates than conventional stents. CONCLUSION: Renovated stents and conventional stents did not exhibit significant differences in urine flow with stenosis.

Single-port plus one in pediatric robotic-assisted Lich-Gregoir ureteral reimplantation for vesicoureteral reflux, a comparative analysis with short-term outcomes.

OBJECTIVE: To observe the safety and short-term outcomes of a new way of laparoscopic trocar placement in pediatric robotic-assisted Lich-Gregoir ureteral reimplantation for vesicoureteral reflux. METHODS: The retrospective study included 32 patients under 14 years diagnosed with primary vesicoureteral reflux (VUR). All these patients underwent robotic-assisted Lich-Gregoir ureteral reimplantation in our department from December 2020 to August 2022. These patients were divided into the following groups according to the different ways of trocar placement: 13 patients in group single-port plus one (SR) and 19 patients in group multiple-port (MR). Patients' characteristics as well as their perioperative and follow-up data were collected and evaluated. RESULTS: There was no significant difference in the data regarding patients' characteristics and preoperative data. These data included the grade of vesicoureteral reflux according to the voiding cystourethrogram (VCUG), and the differential degree of renal function (DRF) at the following time points: preoperative, postoperative, and comparison of preoperative and postoperative. There was no difference between the two groups. During surgery, the time of artificial pneumoperitoneum establishment, ureteral reimplantation time, and total operative time in the SR group were longer than those in the MR group. Yet only the time of artificial pneumoperitoneum establishment shows a statistical difference (P < 0.0001). Also, the peri-operative data, including the volume of blood loss, fasting time, hospitalization, and length of time that a ureteral catheter remained in place, and the number of postoperative complications demonstrate no difference. In addition, the SFU grade and VCUG grade at the following time point also show no difference between the two groups. CONCLUSION: The study demonstrates that SR in robotic-assisted Lich-Gregoir ureteral reimplantation has reached the same surgical effects as MR. In addition, the single-port plus one trocar placement receives a higher cosmetic satisfaction score from parents and did not increase the surgical time and complexity.

Epithelial development of the urinary collecting system in the human embryo.

The urinary collecting system (UCS) consists of organized ducts that collect urine from the nephrons and transport it to the ureter and bladder. Understanding the histogenesis of the UCS is critical. Thirty human embryos between the Carnegie stages (CS) 18 and 23 were selected from the Congenital Anomaly Research Center, Kyoto, Japan. Epithelia of the UCS, ureter, and bladder of each sample were randomly selected. Histological findings of the epithelia were analyzed according to the following criteria: type of epithelium, presence or absence of glycogen, percentage of migrated nuclei, percentage of cells in mitosis, and the surrounding mesenchyme. A thickened epithelium lining a narrow luminal cavity was observed in the pre-expanded pelvic specimens at CS18-CS23. At CS23, after pelvic expansion, the UCS showed a thin epithelium with a large luminal cavity mainly located on the early branches, whereas the epithelium covering the subsequent branches had medium thickness. Histological characteristics differed depending on the UCS part and sample stage. The degree of differentiation was evaluated, revealing that in CS18-CS23 pre-expanded pelvis specimens, the undifferentiated epithelium was found in the zeroth to third/fifth generation, whereas at CS23, after pelvic expansion, a differentiated epithelium covered the UCS zeroth to seventh generation. In a comparison of the urothelial epithelium between the UCS, ureter, and bladder, we found that urinary tract differentiation may be initiated in the bladder, followed by the ureter, UCS zeroth to seventh generations, and finally, UCS eighth to end generations. An understanding of the histogenesis of embryonic stage UCS can aid in the clinical management of congenital urinary tract defects and other diseases.

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.

Bladder Compliance: How We Define It and Why It Is Important.

Bladder compliance is the relationship between detrusor pressure and bladder storage volume. We discuss the definition of compliance, how it may be accurately measured, and its clinical relevance. Specifically, we discuss the association between low compliance and upper urinary tract deterioration. We discuss medical and surgical therapies that have been demonstrated to improve compliance and reduce upper tract risk. Finally, we propose a model, which not only considers compliance but also differential pressure between the bladder and ureters, and how this may also be an accurate predictor of upper tract deterioration. We call for further investigation to test this model.

Fluid dynamics within renal cavities during endoscopic stone surgery: does the position of the flexible ureteroscope and ureteral access sheath affect the outflow rate?

PURPOSE: To evaluate the impact of ureteroscope position within renal cavities as well as different locations of the tip of the ureteral access sheath (UAS) on fluid dynamics during retrograde intrarenal surgery (RIRS). MATERIALS AND METHODS: A prospective observational clinical study was performed. Measurements with a flexible ureteroscope placed in the upper, middle and lower calyces were obtained with the tip of the UAS placed either 2 cm below the pyelo-ureteric junction (PUJ), or at the level of the iliac crest. RESULTS: 74 patients were included. The outflow rates from the middle and upper calyxes were statistically significantly higher compared to the lower calyx, both with the UAS close to the pyelo-ureteric junction and at the iliac crest. When the UAS was withdrawn and positioned at the level of the iliac crest, a significant decrease in outflow rates from the upper (40.1 ± 4.3 ml/min vs 35.8 ± 4.1 ml/min) and middle calyces (40.6 ± 4.0 ml/min vs 36.8 ± 4.6 ml/min) and an increase in the outflow from the lower calyx (28.5 ± 3.3 ml/min vs 33.7 ± 5.7 ml/min) were noted. CONCLUSIONS: Our study showed that higher fluid outflow rates are observed from upper and middle calyces compared to lower calyx. This was true when the UAS was positioned 2 cm below the PUJ and at the iliac crest. Significant worsening of fluid dynamics from upper and middle calyces was observed when the UAS was placed distally at the level of the iliac crest. While the difference was statistically significant, the absolute change was not significant. In contrast, for lower calyces, a statistically significant improvement was documented.

[Prognosis of ureteral dilatation during procedures using a ureteral access sheath in patients with urolithiasis].

AIM: To improve the results of treatment of patients with urolithiasis who underwent endoscopic interventions using a ureteral access sheath (UAS) by developing a predictive model of ureteral dilatation without pre-stenting. MATERIALS AND METHODS: A total of 180 patients with kidney stones up to 20 mm were included in the study. They were divided into two groups: in the group 1 (n=79) UAS of 12/14 Ch was used, while in group II (n=101) UAS of 10/12 Ch was inserted. In group I, 48 (60.8%) patients underwent micropercutaneous nephrolithotomy and in 31 (39.2%) retrograde intrarenal surgery was done, compared to 42 (41.6%) and 59 (58, 4%) of patients in group 2. A non-inclusion criterion was a history of ureteral stenting. At the stage of preoperative diagnosis, 60 minutes before the X-ray examination, the patient took a single dose of 80 mg of furosemide per os to improve visualization of the upper urinary tract. After digital processing of computed tomography data and 3D-reconstruction of the upper urinary tract using the DICOM image processing program "RadiAnt DICOM Viewer," a visual assessment of the ureter was carried out to exclude significant deviations and strictures. The ureteral width was measured at three points: pyeloureteral segment, the level of the iliac bifurcation and intramural part. The number of cases of successful insertion of UAS and the rate of damage to the ureteral wall according to the classification proposed by O. Traxer and A. Thomas (2012) were analyzed. The prediction of successful insertion of a UAS was carried out using ROC analysis. RESULTS: In group 1, successful insertion of UAS was observed in 37 (46.8%) patients compared to 84 (83.2%) patients in group 2. In the remaining 42 (53.2%) and 17 (16.8%) cases, respectively, placement of UAS was not possible due to significant tissue resistance and high risk of traumatic injury. The average ureteral diameter at the points of physiological narrowing in patients with successful insertion of 12/14 Ch UAS were 2.0+/-0.1 mm, compared to 1.2+/-0.4 mm in those with failed insertion (p<0.05). In the group 2, similar indicators were 1.6+/-0.1 mm and 1.2+/-0.5 mm, respectively (p<0.05). According to ROC analysis, the diagnostic efficiency of the predictive model when using 12/14 Ch and 10/12 Ch UAS was confirmed by high AUC values (0.925 [95% CI 0.871-0.98] and 0.944 [95% CI 0.89=0.97], respectively). The total number of patients with ureteral injuries was 35 (44.3%) and 40 (39.6%) in groups with 12/14 Ch and 10/12 Ch UAS, respectively. At the same time, complications of the I degree were observed in 24 (30.4%) patients of the group 1 and in 31 (30.7%) patients of the group 2, while injuries of II degree were detected in 10 (12.7%) and 9 (8.9%) cases, respectively (p>0.05). Only in 1 (1.3%) patient, when 12/14 Ch UAS was inserted, grade III damage to the ureteral wall was determined. CONCLUSION: The proposed technique for measuring the cross-section of the ureter allows to predict the successful insertion of UAS at the preoperative stage. The probability of successful passage of UAS of 10/12 and 12/14 Ch in patients with ureteral diameter in physiological narrowings of more than 1.6 mm and 2 mm, respectively, is 95%. An insertion of UAS is a safe procedure, and most complications are classified as grades I or II.

Predictive role of ureteral wall thickness and patient characteristics in endoscopic treatment outcomes for ureteral stricture disease following stone surgery.

PURPOSE: To evaluate the role of certain radiological parameters and patient characteristics in predicting the success of endoscopic treatment in ureteral stricture disease. METHODS: Fifty one adult patients with ureteral stricture disease (< 1 cm) after developing due to upper ureteral stones with ureteroscopic laser disintegration were included and in addition to stone and patient parameters, radiological parameters including ureteral wall thickness (UWT) at the impacted stone site were also measured on computed tomography (CT) images. Patients were divided into two groups: Group 1: Patients with endoscopic treatment success and Group 2: Patients with endoscopic treatment failure. The possible relationship between the UWT values and other radiological parameter was comparatively evaluated. RESULTS: Mean UWT value assessed at the treated stone site was significantly higher in cases unresponsive to endoscopic treatment with values of 2.77 ± 1.03 mm and 4.25 ± 1.32 mm in Group 1 and 2 respectively. A cut off value 3.55 mm for UWT was found to be highly predictive for endoscopic treatment failure. CONCLUSIONS: Our current results indicated that assessment of UWT value at the obstructing stone could be helpful enough to predict the likelihood of failure following endoscopic management of strictures with high sensitivity and specificity. Evaluation of this particular parameter could let the endourologists to look for more rational treatment alternatives with necessary measures taken on time.

Inappropriate placement of urinary catheters into the ureter: A case report and literature review.

OBJECTIVE: To emphasize preventive measures and outline management strategies for inadvertent ureteral cannulation. METHODS: We present a case report and conduct a literature review of 39 case reports on ureteral cannulation, examining a total of 48 patients. RESULTS: About 67% of the cases were female, and long-term catheterization was observed in 67% of the cases. Neurological conditions such as spinal cord injury (SCI), stroke, dementia, multiple sclerosis, and myasthenia gravis were the primary factors (48%) in ureteral cannulation. Symptoms included flank pain (46%), fever (31%), oliguria (27%), non-deflatable balloon issues (25%), hematuria (21%), abdominal pain (17%), urine leak (12.5%), and nausea/vomiting (8%). Complications varied, including acute pyelonephritis (35%), acute kidney injury (27%), urosepsis (21%), and ureter rupture (17%). Despite inadvertent catheter placement, 25% of patients had no complications. More than half of the patients (58%) were managed through catheter change, while 27% underwent cysto-ureteroscopy with or without balloon puncture or ureteral stenting. Additionally, 10% received interventional radiology procedures, 6.25% underwent surgical repair, and 4% underwent ultrasound-guided balloon puncture. CONCLUSIONS: Female gender, neurologic conditions, and long-term catheterization were identified as predominant risk factors. Early detection of ureteral cannulation can prevent severe complications, particularly in certain special populations such as patients with neurogenic bladder or SCI, who may have reduced sensation and expression capabilities.

[Ipsilateral ureteroureterostomy. A safe alternative in complete duplicated collecting system with associated pathology]. / Uretero-ureteroanastomosis distal ipsilateral. Una alternativa segura en doble sistema renal completo con patología asociada.

In patients with complete double renal system with the involvement of only one system, there are several surgical alternatives for its resolution. Uretero-ureteral anastomosis has been presented as a good alternative, even in cases with atrophy of the affected system. OBJECTIVE: To report our experience in patients with complete double renal system with only one system affected, with the surgical technique of uretero-ureteral anastomosis. PATIENTS AND METHOD: Retrospective study of patients with double renal system with involvement of one of the systems, treated with uretero-ureteral anastomosis technique between January 2015 and May 2022. The variables of age, specific pathology of the affected system, preoperative study, days of hospitalization, postoperative complications (leakage, obstruction, infection), and follow-up time were evaluated. RESULTS: We analyzed 26 procedures in 25 patients, mean age 36.8 months (range: 8-80); 53.8% had ectopic ureter, 23% ureterocele, 11.5% sphincteric ureterocele, and 11.5% VUR of the lower system. All were studied preoperatively with urethrocystography and 65% with scintigraphy. 50% of the operated systems showed signs of renal atrophy. The average hospital stay was 2.2 days (range: 1-7). In an average follow-up of 26.5 months (range: 3-77), one patient presented leakage, no patient presented signs suggestive of obstruction, and one patient presented febrile urinary tract infection with persistent lower-grade reflux. CONCLUSION: In our experience, the uretero-ureteral anastomosis technique proved to be an easy and safe alternative to reproduce, with a success rate of 96%, 11% of grade I complications, and 4% of grade II complications according to the Clavien-Dindo classification.

Bacteriuria in patients with stented ureters: predictors of infection in patients presenting to the hospital and when not to treat.

PURPOSE: Patients with ureteric stents have symptoms that overlap with infection symptoms. Thus, clinicians unnecessarily give antibiotics to stented patients with bacteriuria despite guidelines. In stented patients, little is known about risk factors for developing bacteriuria or urosepsis. The objectives were to identify the frequency and risk factors for developing bacteriuria and urosepsis in patients with stents. METHODS: In this retrospective cohort study, we reviewed patients with ureteric stents placed or exchanged over 1 year. We examined associations between bacteriuria or urosepsis and host risk factors. Univariable and multivariable logistic analyses were performed. RESULTS: Of 286 patients (mean age: 57.2 years), 167 (58.4%) were male. The main stent indications were stone, stricture, cancer and extrinsic compression. The median stented period was 61 days. The frequency of bacteriuria was 59/286 (21%). ASA status 3 and 4 had 5 times the odds of having bacteriuria relative to ASA status 1. Stent duration > 2 months had 5.5 times the odds relative to ≤ 2 months. Urosepsis was infrequent, 13/286 (4.5%). Five patients had bacteraemia. A stent duration over 2 months had nearly 6 times the odds of urosepsis. CONCLUSION: ASA status higher than 2 and stent time greater than 2 months raise the odds of developing bacteriuria. A stent duration longer than 2 months was the only predictor of urosepsis. Though 21% of patients had bacteriuria, 4.5% had urosepsis. Hence, bacteriuria without sepsis should not be treated with antibiotics, thus aiding antimicrobial stewardship.

Robotic-assisted vs. open ureteral reimplantation: a multicentre comparison.

PURPOSE: Open ureteral reimplantation is considered the standard surgical approach to treat distal ureteral strictures or injuries. These procedures are increasingly performed in a minimally invasive and robotic-assisted manner. Notably, no series comparing perioperative outcomes and safety of the open vs. robotic approach are available so far. METHODS: In this retrospective multi-center study, we compared data from 51 robotic ureteral reimplantations (RUR) with 79 open ureteral reimplantations (OUR). Both cohorts were comparatively assessed using different baseline characteristics and perioperative outcomes. Moreover, a multivariate logistic regression for independent predictors was performed. RESULTS: Surgery time, length of hospital stay and dwell time of bladder catheter were shorter in the robotic cohort, whereas estimated blood loss, postoperative blood transfusion rate and postoperative complications were lower than in the open cohort. In the multivariate linear regression analysis, robotic approach was an independent predictor for a shorter operation time (coefficient - 0.254, 95% confidence interval [CI] - 0.342 to - 0.166; p < 0.001), a lower estimated blood loss (coefficient - 0.390, 95% CI - 0.549 to - 0.231, p < 0.001) and a shorter length of hospital stay (coefficient - 0.455, 95% CI - 0.552 to - 0.358, p < 0.001). Moreover, robotic surgery was an independent predictor for a shorter dwell time of bladder catheter (coefficient - 0.210, 95% CI - 0.278 to - 0.142, p < 0.001). CONCLUSION: RUR represents a safe alternative to OUR, with a shorter operative time, decreased blood loss and length of hospital stay. Prospective research are needed to further define the extent of the advantages of the robotic approach over open surgery.

Ureteral wall thickness as a predictor for non-invasive treatment success for steinstrasse. Can we save time?

PURPOSE: We aimed to define factors affecting the non-invasive overall treatment success (medical expulsive therapy (MET) ± shock wave lithotripsy (SWL)) for uncomplicated ureteral steinstrasse (SS) clearance. METHODS: We retrospectively evaluated consecutive patients who underwent SWL for renal stones between 2017 and 2021. Patients with uncomplicated SS were included. All patient's demographic and radiological data, e.g., age, gender, pre-SWL stenting, SS site, type, leading stone size in widest diameter (< 10 mm and ≥ 10 mm), ureteral wall thickness (UWT) in mm against the leading stone were collected. If SS was diagnosed, medical treatment was given for 4 weeks. In case of MET failure, either SWL for the leading stones + MET or direct URS was done. Non-invasive treatment success (SFR) was considered if complete clearance of SS occurred with no complications or the need for invasive intervention. RESULTS: A total of 145 patients were included with mean age of 45.9 ± 12.4 years. SFR in case of MET only occurred in 27.9%. Complications happened in 26 patients (17.9%). Non-invasive treatment SFR was achieved in 78 patients (53.8%) totally where SS type I, leading stone size ≤ 10 mm type and decreased UWT around the leading stone increased treatment success. CONCLUSION: Ureteral wall thickness is an important factor predicting SS management success. Besides the decreased UWT, non-invasive management should be offered for type I SS with leading stone ≤ 10 mm.

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.

Total intracorporeal laparoscopic ileal ureter replacement in a single position for ureteral stricture based on membrane anatomy.

PURPOSE: The aim of this study was to present our initial experience and prove the feasibility of total intracorporeal laparoscopic ileal ureter replacement (TILIUR) in a single position for ureteral stricture based on membrane anatomy. MATERIALS AND METHODS: Between January 2021 and April 2023, six patients underwent TILIUR in a single position for ureteral strictures based on membrane anatomy. All patients with a past medical history underwent radical hysterectomy with bilateral pelvic lymph node dissection as well as extensive ureteral stricture due to radiotherapy. The procedure is performed completely laparoscopically. Dissection of the digestive system as well as ureteral stricture or renal pelvis is based on membrane anatomy. The surgery is performed in a single position. RESULTS: TILIUR in a single position for ureteral stricture based on membrane anatomy was successfully performed without open conversion in all patients. Among the 6 patients, 3 patients underwent combined ileal ureter replacement (IUR) and abdominal wall ostomy, 2 underwent unilateral IUR, and 1 underwent bilateral IUR. The mean length of the ileal substitution was 22.83 cm (range: 15-28). The average operative time was 458 ± 72.77 min (range 385-575 min), and the average intraoperative blood loss was 158 mL (range 50-400 mL). The median postoperative hospital stay was 15.1 d (range: 8-32). The median duration of postoperative follow-up was 15 months (range: 3-29 months). The success rate was 100%. CONCLUSIONS: TILIUR in a single position may be a promising option for ureteral stricture based on membrane anatomy in selected patients. Moreover, it has a positive effect on patients with renal insufficiency and urinary incontinence. Although IUR is difficult and risky, proficient surgeons can perform the procedure safely and effectively.

Towards the establishment of national diagnostic reference levels for abdomen, KUB, and lumbar spine x-ray examinations in Sri Lanka: a multi-centric study.

Diagnostic reference levels (DRLs) and achievable doses (ADs) provide guidance to optimise radiation doses for patients undergoing medical imaging procedures. This multi-centre study aimed to compare institutional DRLs (IDRLs) across hospitals, propose ADs and multi-centric DRLs (MCDRLs) for four common x-ray examinations in Sri Lanka, and assess the potential for dose reduction. A prospective cross-sectional study of 894 adult patients referred for abdomen anteroposterior (AP), kidney-ureter-bladder (KUB) AP, lumbar spine AP, and lumbar spine lateral (LAT) x-ray examinations was conducted. Patient demographic information (age, sex, weight, BMI) and exposure parameters (tube voltage, tube current-exposure time product) were collected. Patient dose indicators were measured in terms of kerma-area product (PKA) using a PKAmeter. IDRLs, ADs, and MCDRLs were calculated following the International Commission on Radiological Protection guidelines, with ADs and MCDRLs defined as the 50th and 75th percentiles of the median PKAdistributions, respectively. IDRL ranges varied considerably across hospitals: 1.42-2.42 Gy cm2for abdomen AP, 1.51-2.86 Gy cm2for KUB AP, 0.83-1.65 Gy cm2for lumbar spine AP, and 1.76-4.10 Gy cm2for lumbar spine LAT. The proposed ADs were 1.82 Gy cm2(abdomen AP), 2.03 Gy cm2(KUB AP), 1.27 Gy cm2(lumbar spine AP), and 2.21 Gy cm2(lumbar spine LAT). MCDRLs were 2.24 Gy cm2(abdomen AP), 2.40 Gy cm2(KUB AP), 1.43 Gy cm2(lumbar spine AP), and 2.38 Gy cm2(lumbar spine LAT). Substantial intra- and inter-hospital variations in PKAwere observed for all four examinations. Although ADs and MCDRLs in Sri Lanka were comparable to those in the existing literature, the identified intra- and inter-hospital variations underscore the need for dose reduction without compromising diagnostic information. Hospitals with high IDRLs are recommended to review and optimise their practices. These MCDRLs serve as preliminary national DRLs, guiding dose optimisation efforts by medical professionals and policymakers.

Effect of increasing age and ureteral stent implantation on urinary tract infections after kidney transplantation - update of recent literature.

PURPOSE OF REVIEW: This review aims to present the recent literature regarding effects of aging and ureteral stent implantation (UrS) on the risk of urinary tract infections (UTIs) in kidney transplant (KTX) recipients. RECENT FINDINGS: UTIs in kidney transplant recipients remain a clinical challenge and represent a leading cause of morbidity, hospitalization rates, and mortality. Higher age was described as a significant risk factor for UTIs in several studies including a recent Brazilian analysis, indicating a 3.6%/years of age increase in UTI risk. Subsequently, a large meta-analysis, published in 2023, confirmed the correlation between older age and elevated UTI risk. The Swiss Transplant Cohort Study in 2022, largest of its kind, similarly confirmed a link between advanced age and heightened risk of recurrent UTIs in KTX. A recent prospective study highlighted UrS placement as a modifiable risk factor, emphasizing the need for careful consideration and antibiotic prophylaxis. Additionally, the type of stents played a crucial role, with external stents associated with a 1.69 times higher UTI risk. The challenge of determining optimal UrS removal timing further complicates posttransplant care, with insufficient evidence to guide practices. SUMMARY: The aging population of KTX recipients requires a personalized approach to effectively reduce and manage UTIs as one of the most important complications following KTX. Prophylactic stent implantation is successful in lowering ureteral complications, however, is associated with an increased incidence of UTIs. To reduce the increased risk of UTIs, the length of stent insertion requires strict supervision and maintenance.