Disposable grasper-integrated flexible cystoscope for ureteral stent removal in transplanted patients; focus on feasibility, safety, and patient experience. Results and micro-cost analysis from a tertiary referral center.

INTRODUCTION & OBJECTIVES: To evaluate ureteral stent removal (SR) using a grasper-integrated disposable flexible cystoscope (giFC-Isiris ®, Coloplast ®) after kidney transplantation (KT), with a focus on feasibility, safety, patient experience, and costs. MATERIAL AND METHODS: All consecutive KT undergoing SR through giFC were prospectively enrolled from January 2020 to June 2023. Patient characteristics, KT and SR details, urine culture results, antimicrobial prescriptions, and the incidence of urinary tract infections (UTI) within 1 month were recorded. A micro-cost analysis was conducted, making a comparison with the costs of SR with a reusable FC and grasper. RESULTS: A total of 136 KT patients were enrolled, including both single and double KT, with 148 stents removed in total. The median indwelling time was 34 days [26, 47]. SR was successfully performed in all cases. The median preparation and procedure times were 4 min [3,5]. and 45 s[30, 60], respectively. The median Visual Analog Scale (VAS) score was 3 [1, 5], and 98.2% of patients expressed willingness to undergo the procedure again. Only one episode of UTI involving the graft (0.7%) was recorded. Overall, the estimated cost per SR procedure with Isiris ® and the reusable FC was 289.2€ and 151,4€, respectively. CONCLUSIONS: This prospective series evaluated the use of Isiris ® for SR in a cohort of KT patients, demonstrating feasibility and high tolerance. The UTI incidence was 0.7% within 1 month. Based on the micro-cost analysis, estimated cost per procedure favored the reusable FC.

Single-port-plus-one robot-assisted laparoscopic Lich-Gregoir direct nipple ureteral extravesical reimplantation in pediatric primary obstructive megaureter, comparing to laparoscopic cohen.

PURPOSE: To compare the effects of a single-port-plus-one robotic laparoscopic-modified Lich-Gregoir direct nipple approach and traditional laparoscopic Cohen in treating pediatric primary obstructive megaureter. MATERIALS AND METHODS: The clinical data of 24 children with primary obstructive megaureter from January 2021 to November 2021 were analyzed retrospectively. Among them, 12 children (8 boys and 4 girls, the average age were 17.17 ± 6.31 months) treated with the laparoscopic Cohen method were defined as group C. The remaining 12 children (7 boys and 5 girls, the average age was 17.33 ± 6.99 months) underwent single-port-plus-one robotic laparoscopic-modified Lich-Gregoir direct nipple ureteral extravesical reimplantation were defined as group L. The parameters of pre-operation, intraoperative and postoperative were compared. RESULTS: There were no differences in the patient characteristics and average follow-up time between the two groups (P > 0.05).The obstruction resolution rate was 100% in both groups. The total operation time in group L is slightly longer than that in group C(P < 0.001),but the intraperitoneal operation time of the two groups was comparable(P > 0.05). The postoperative parameters included blood loss, gross haematuria time, indwelling catheterization time and hospitalization time in group L is shorter than group C(P < 0.05). One year post-operation, decreasing in ureteral diameter and APRPD, and increasing in DRF were remarkably observed in both two groups(P < 0.05). Ureteral diameter, APRPD, and DRF were not significantly different both in pre-operation and post-operation between Group L and Group C(P > 0.05). CONCLUSION: Single-port-plus-one robot-assisted laparoscopic-modified Lich-Gregoir direct nipple approach and traditional laparoscopic Cohen are both dependable techniques for ureteral reimplantation in the treatment of pediatric primary obstructive megaureter. Since Lich-Gregoir can preserve the physiological direction of the ureter and direct nipple reimplantation enhances the effect of anti-refluxing, this technique is favorable for being promoted and applied in robot surgery.

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.

Rigid ureteroscopic lithotripsy with a pressure-controlling ureteral access sheath for complex steinstrasse.

OBJECTIVE: To evaluate the safety and efficacy of rigid ureteroscopic lithotripsy with a pressure-controlling ureteral access sheath (PC-UAS) for complex steinstrasse. METHODS: Thirty-one consecutive patients (male: 18; female: 13) with steinstrasse were enrolled, six of whom had concurrent kidney stones. The mean cumulative stone size was 2.7 ± 1.3 cm. The patients were treated with rigid ureteroscopic lithotripsy using a PC-UAS. The cavity pressure parameters were set as follows: control value at -15 mmHg to -2 mmHg, warning value at 20 mmHg, and limit value at 30 mmHg. The infusion flow rate was set at 150-200 ml/min. A holmium laser (550 µm) was used to powderize the stone at 2.0-2.5 J/pulse with a frequency of 20-30 pulses/s. Analyses included cavity pressure, operative time, stone-free rates, and complications. RESULTS: Among the 31 patients, 29 were successfully treated with PC-UAS, with nine requiring adjunctive flexible ureteroscopy for stone migration to the kidney. Two procedures were converted to percutaneous nephrolithotomies due to failure of sheath placement. The cavity pressure of all 29 patients was well-maintained below 20 mmHg, with clear vision. The mean operative time was 48.2 ± 17.7 min. No complications, such as ureteral perforation, mucosal avulsion, or hemorrhage, occurred. Two cases of Clavien-Dindo grade I complications occurred. No major complications (Clavien-Dindo grade II-V) occurred. The mean postoperative hospitalization time was 1.7 days. The stone-free rates 1 day and 1 month after surgery were 93.1% and 96.6%, respectively. One patient with residual stones underwent extracorporeal shockwaves. CONCLUSIONS: Rigid ureteroscopic lithotripsy with PC-UAS can effectively control the cavity pressure, shorten the operation time, and improve the efficiency of broken stones, thus reducing the complication rate.

Flexible Ureteroscopic Guided Laparoscopic Ureteroplasty For The Treatment Of Ureteral Stricture.

INTRODUCTION: Ureteral stricture is often a consequence of urolithiasis or previous endourological procedures (1-3). Precisely delineating the stricture zone intraoperatively is crucial to minimize ureter shortening and target only the affected tissue (4, 5). Flexible ureteroscopy offers a significant advantage in this regard. OBJECTIVE: This video aims to demonstrate the step-by-step technique of flexible ureteroscopic guided laparoscopic ureteroplasty for treating ureteral stricture caused by urolithiasis and prior endourological interventions. PATIENT AND METHODS: We present a case of a 36-year-old male with a history of urolithiasis and unsuccessful endourological treatments, including endoureterotomy and balloon dilation, diagnosed with re-stenosis of the proximal ureter of 1 cm through ureteroscopy and pyelography. He underwent a successful laparoscopic ureteroplasty. While the lead surgeon performed the laparoscopy, an assistant conducted the flexible ureteroscopy. Intraoperatively, using transillumination facilitated by the flexible ureteroscope, we can precisely identify the narrowed area, allowing for resection of only the damaged segment. Subsequently, we perform the end-to-end ureteroplasty, confirming its patency through the seamless passage of the ureteroscope. Upon completion, we employ a fat patch to safeguard the anastomosis. RESULTS: The patient was discharged on the third postoperative day. Double J stent was removed six weeks after surgery. Symptoms resolved. Renal function improved: eGFR 49 to 67 ml/min. Furthermore, improvement was observed in the DTPA scan, and a decrease in hydronephrosis was noted on the follow-up tomography. CONCLUSION: Flexible ureteroscopy effectively identifies the stricture zone in laparoscopic ureteroplasty, enhancing surgical precision and outcomes. This approach is safe, effective, and reproducible, offering a valuable technique in the surgical treatment of ureteral strictures.

Exploring the feasibility of indocyanine green fluorescence for intraoperative ureteral visualisation in robotic transvaginal natural orifice transluminal endoscopy surgery during endometriosis resection.

BACKGROUND: To assess the feasibility of use of indocyanine green (ICG) in identifying and minimising urinary tract injury during surgical resection of endometriosis through robotic transvaginal natural orifice transluminal endoscopy surgery (RvNOTES). METHODS: We conducted a retrospective case series in two academic tertiary care hospitals. We examined 53 patients who underwent RvNOTES hysterectomy with planned endometriosis resection. RESULTS: The study involved 53 patients undergoing RvNOTES with ICG fluorescence for endometriosis resection. Mean patient age was 37.98 ± 6.65 years. Operative time averaged 181.32 ± 53.94 min, with estimated blood loss at 45.57 ± 33.62 mL. Postoperative stay averaged 0.23 ± 0.47 days. No ICG-related complications occurred. CONCLUSION: No complications occurred with ICG fluorescence in RvNOTES. It appears to be a safe option for ureteral localisation and preservation. ICG fluorescence is widely used in diverse medical specialities for identifying ureters during complex surgeries. Larger studies are needed to firmly establish its advantages in intraoperative ureteral visualisation during RvNOTES for deep infiltrative endometriosis.

The relationship between the force applied and perceived by the surgeon during ureteral access sheath placement: ex-vivo experimental model.

PURPOSE: To define a peak force of insertion (PFOI) threshold for ureteral damage during ureteral access sheath (UAS) placement on an experimental ureteral orifice model. METHODS: A specially designed water tank using 2 laparoscopic 5 mm ports and 2 different size (10 Fr and 8 Fr) sealing cap adaptors (SCA) as ureteral orifices was used to perform the test. A 10-12 Fr UAS was fixed to a load cell and the force of insertion (FOI) was continuously recorded with a digital force gauge.13 experts in the field of endourology who participated performed 3 UAS insertions. The FOI was recorded initially with 10 Fr followed by 8 Fr SCA. On the final insertion, the orifice was obstructed, leaving a 5 cm length to insert the UAS. The experts were asked to "Stop at the point they anticipate ureteral damage, and they would not proceed in real life". RESULTS: Using 10 Fr SCA the PFOI was 2.12 ± 0.58 Newton (N) (range:1.48-3.48) while 8 Fr SCA showed a PFOI 5.76 ± 0.96 N (range:4.05-7.35). Six of the experts, said they would stop proceeding when they reached above 5.1 N. Three experts had PFOI < 5.1 N and the other 4 stated they would go with PFOIs of 5.88, 6.16, 6.69 and 7.35 N when using SCA of 8 Fr.The highest load they would stop proceeding had a PFOI of 6.09 ± 1.87 N (range: 2.53-10.74). CONCLUSION: The PFOI threshold for ureteral damage inserting UAS of the experts is variable. Although FOI is a subjective perception, experience suggests that ureteral injury may occur at an average of 6.05 N perceived by surgeons' tactile feedback. In-vivo measurement of UAS PFOI may confirm a threshold.

Comparison of the efficacy and complications of tolterodine and α-adrenergic receptor blockers in improving ureteral stent-related symptoms: A systematic review and meta-analysis.

OBJECTIVE: We conducted a systematic evaluation of the therapeutic efficacy and complications of tolterodine and α-adrenergic receptor blockers in alleviating ureteral stent-related symptoms. METHODS: Until August 2023, we conducted a comprehensive literature search on PubMed, Embase, Web of Science, and Cochrane Library to identify randomized controlled trials evaluating the efficacy and complications of tolterodine and α-adrenergic receptor blockers in treating ureteral stent-related symptoms. Two reviewers independently screened studies and extracted data. The scores from various domains of the Ureteral Stent Symptom Questionnaire (USSQ) were summarized and compared, and statistical analysis was performed using RevMan 5.4.0 software. RESULTS: A total of 8 studies met the inclusion criteria for our analysis. These studies were conducted at different centers. All studies were randomized controlled trials, involving a total of 487 patients, with 244 patients receiving α-adrenergic receptor blockers and 243 patients receiving tolterodine. The results showed that tolterodine demonstrated significantly better improvement in body pain (MD, 1.56; 95% CI [0.46, 2.66]; p = 0.005) (MD, 0.46; 95% CI [0.12, 0.80]; p = 0.008) (MD, 3.21; 95% CI [1.89, 4.52]; p = 0.00001) among patients after ureteral stent placement compared to α-adrenergic receptor blockers at different time points. Additionally, at 4 weeks, tolterodine showed superior improvement in general health (MD, 0.15; 95% CI [0.03, 0.27]; p = 0.01) and urinary symptoms (MD, 1.62; 95% CI [0.59, 2.66]; p = 0.002) compared to α-adrenergic receptor blockers, while at 6 weeks, tolterodine showed better improvement in work performance (MD, -1.60; 95% CI [-2.73, -0.48]; p = 0.005) compared to α-adrenergic receptor blockers. Additionally, the incidence of dry mouth (RR, 4.21; 95% CI [1.38, 12.87]; p = 0.01) is higher with the use of tolterodine compared to α-adrenergic receptor blockers. However, there were no significant statistical differences between the two drugs in other outcomes. CONCLUSION: This meta-analysis suggests that tolterodine is superior to α-adrenergic receptor blockers in improving physical pain symptoms after ureteral stent placement, while α-adrenergic receptor blockers are more effective than tolterodine in enhancing work performance. Additionally, the incidence of dry mouth is higher with the use of tolterodine compared to α-adrenergic receptor blockers. However, higher-quality randomized controlled trials are needed to further investigate this issue.

Distinguishing the Uterine Artery, the Ureter, and Nerves in Laparoscopic Surgical Images Using Ensembles of Binary Semantic Segmentation Networks.

Performing a minimally invasive surgery comes with a significant advantage regarding rehabilitating the patient after the operation. But it also causes difficulties, mainly for the surgeon or expert who performs the surgical intervention, since only visual information is available and they cannot use their tactile senses during keyhole surgeries. This is the case with laparoscopic hysterectomy since some organs are also difficult to distinguish based on visual information, making laparoscope-based hysterectomy challenging. In this paper, we propose a solution based on semantic segmentation, which can create pixel-accurate predictions of surgical images and differentiate the uterine arteries, ureters, and nerves. We trained three binary semantic segmentation models based on the U-Net architecture with the EfficientNet-b3 encoder; then, we developed two ensemble techniques that enhanced the segmentation performance. Our pixel-wise ensemble examines the segmentation map of the binary networks on the lowest level of pixels. The other algorithm developed is a region-based ensemble technique that takes this examination to a higher level and makes the ensemble based on every connected component detected by the binary segmentation networks. We also introduced and trained a classic multi-class semantic segmentation model as a reference and compared it to the ensemble-based approaches. We used 586 manually annotated images from 38 surgical videos for this research and published this dataset.

Establishment of an artificial urine model in vitro and rat or pig model in vivo to evaluate urinary crystal adherence.

The current study aimed to establish an experimental model in vitro and in vivo of urinary crystal deposition on the surface of ureteral stents, to evaluate the ability to prevent crystal adhesion. Non-treated ureteral stents were placed in artificial urine under various conditions in vitro. In vivo, ethylene glycol and hydroxyproline were administered orally to rats and pigs, and urinary crystals and urinary Ca were investigated by Inductively Coupled Plasma-Optical Emission Spectrometer. in vitro, during the 3- and 4-week immersion periods, more crystals adhered to the ureteral stent in artificial urine model 1 than the other artificial urine models (p < 0.01). Comparing the presence or absence of urea in the composition of the artificial urine, the artificial urine without urea showed less variability in pH change and more crystal adhesion (p < 0.05). Starting the experiment at pH 6.3 resulted in the highest amount of crystal adhesion to the ureteral stent (p < 0.05). In vivo, urinary crystals and urinary Ca increased in rat and pig experimental models. This experimental model in vitro and in vivo can be used to evaluate the ability to prevent crystal adhesion and deposition in the development of new ureteral stents to reduce ureteral stent-related side effects in patients.

Recent developments in ureteral stent: Substrate material, coating polymer and technology, therapeutic function.

The ureteral stent is an effective treatment for clinical ureteral stricture following urological surgery, and the functional coating of the stent could effectively inhibit bacterial colonization and other complications. The present review provides an analysis and description of the materials used in ureteral stents and their coatings. Emphasis is placed on the technological advancements of functional coatings, taking into consideration the characteristics of these materials and the properties of their active substances. Furthermore, recent advances in enhancing the therapeutic efficacy of functional coatings are also reviewed. It is anticipated that this article will serve as a valuable reference providing insights for future research development on new drug-loaded ureteral stents.

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.

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.

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.

[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.

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.

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.