Postoperative Ureteral Stricture Research Articles

A comparison between vapor tunnel and virtual basket for the treatment of proximal ureteral stones using holmium:YAG laser (Cyber Ho): which is the best tool to reduce retropulsion?

To compare vapor tunnel (VT) and virtual basket (VB) tools to reduce retropulsion in the treatment of proximal ureteral stones. Patients with a single proximal ureteral stone were randomly assigned to holmium laser lithotripsy with the use of VT (Group A) or VB (Group B) tool. The 150W holmium:YAG cyber Ho generator was used. We compared operative time, dusting time, need for flexible ureteroscopy due to stone push-up and occurrence of ureteral lesions. The stone-free rate (SFR) and the occurrence of postoperative ureteral strictures were assessed. 186 patients were treated, of which 92 with the VT (49.5%, Group A) and 94 with the VB (50.5%, Group B). Mean stone size was 0.92 vs. 0.91cm in Groups A vs. B (p = 0.32). Mean total operative time and dusting time were comparable between groups. 7 (7.6%) vs. 6 (6.4%) patients in Groups A vs. B required a flexible ureteroscope because of stone push-up (p = 0.12). Ureteral mucosa lesions were observed in 15 (16.3%) vs. 18 (19.1%) cases in the VT vs. VB group (p = 0.09). 1-Month SFR was comparable (97.8% vs. 95.7%, p = 0.41). We observed one case (1.1%) of postoperative ureteral stricture in the VT group vs. two cases (2.1%) in the VB group (p = 0.19). VT and VB are equally safe and effective tools in reducing retropulsion of ureteral stones. Operative time, dusting time and SFR were comparable. They also equally avoided stone push-up and prevented ureteral lesions, which may later occur in ureteral strictures.

Japanese survey of perioperative complications and ureteral stricture after ureteroscopy with laser lithotripsy for upper urinary tract stones in multicenter collaborative study.

This study aimed to investigate perioperative complications and the details of postoperative ureteral stricture after ureteroscopy with laser lithotripsy (URS-L) for upper urinary tract stones in Japan. Patient data on intra- and postoperative complications after ureteroscopy using URS-L were retrospectively collected from multiple centers in Japan between April 2017 and March 2020 with the cooperation of the Japanese Society of Endourology and Robotics. Data included the number of patients undergoing URS-L, number and type of intra- and postoperative complications, and detailed characteristics of postoperative ureteral stricture. In total, 14 125 patients underwent URS-L over 3 years at 82 institutions. Annual URS-L numbers gradually increased from 4419 in 2017, to 4760 in 2018, and 4946 in 2019. The total complication rate was 10.5%, which was divided into intra-operative complications in 1.40% and postoperative complications in 9.18%. The annual incidences of intra- and postoperative complications were not significantly different from year to year (p = 0.314 and p = 0.112). Ureteral perforation, ureteral avulsion, and the intra-operative conversion rate were 1.35%, 0.03%, and 0.02%, respectively. Fever >38°C, septic shock, blood transfusion, and postoperative mortality were 7.44%, 0.81%, 0.07%, and 0.04%, respectively. Ureteral stricture occurred in 0.8% of cases. The median length of stricture site was 10.0 mm and the success rate of stricture treatment was 54.6%. Although URS-L utilization has increased in Japan, the annual complication rate has remained steady. Although URS-L is a useful and less invasive procedure, devastating complications can still occur.

Correlation Diagnostic Contribution of SPECT/CT Imaging to 99mTc-DTPA Dynamic Scintigraphy in Patients with Different Renal Pathologies

Introduction: Dynamic renal scintigraphy with 99mTechnetium diethylenetriaminepentaacetic acid (99mTc-DTPA) is a widely performed imaging method to evaluate kidney function of patients with various renal pathologies. However the one-stop-shop combination with subsequent SPECT/CT imaging is a rarely discussed topic. Objective: The aim of the study was to evaluate the diagnostic benefits of SPECT/CT imaging to 99mTc-DTPA dynamic renal scintigraphy. Materials and Methods: A group of 32 patients (21 females and 11 males) who underwent dy- namic nephroscintigraphy with subsequent SPECT/CT was retrospectively studied. A dose of 185MBq (5mCi) 99mTc-DTPA was intravenously applied. A low-dose non-contrast CT protocol was used for attenuation correction and anatomical correlation. Results: Impaired relative renal function in various degrees of left kidney was detected in 18 patients (56%) and of right kidney in 14 patients (44%). SPECT/CT imaging identified the particular cause for the renal dysfunction in the analyzed subjects. The hybrid imaging demonstrated urolithiasis in 11 patients, postoperative ureteral strictures in 5 patients, diagnosed urological cancer in 4 patients and external compression of ureter in 2 patients as a possible obstructive cause. Congenital renal anomalies were the identified causes of impaired renal function in 10 patients – hypoplastic kidney in 4 patients, duplex kidney in 2 patients, multiple cortical cysts in 2 patients, aberrant vessel obstructing the pyeloureteral segment in 1 patient and horseshoe kidney in 1 patient. Conclusion: Dynamic renal scintigraphy combined with SPECT/CT is a very useful clinical tool, by providing not only functional but also anatomical information of the urinary tract, especially in the evaluation of obstructive uropathies and congenital renal abnormalities, that has the potential to change clinical management.

The natural course of incidental ureteral polyp during ureteroscopic surgery: KSER research

BackgroundThe natural course of polypoid lesions in the ureter during ureteroscopic stone surgery was not yet clarified.MethodsPatient data were collected prospectively from six teaching hospitals between 2019 and 2021. Patients with polypoid lesions in the ureter distal to ureteral stones were included during ureteroscopy. Computed tomography was performed on all enrolled patients three months after the procedure. Follow-up ureteroscopy was performed only if the patient consented, due to the need for general anesthesia and ethical considerations.ResultsAmong the 35 patients who were followed up, 14 had fibroepithelial polyps and 21 had inflammatory polyps. Twenty of the followed-up patients underwent ureteroscopy, and nine of them had fibroepithelial polyps. Although fibroepithelial polyps did not disappear in the follow-up ureteroscopy (p = 0.002), the rate of postoperative hydronephrosis was not higher in the fibroepithelial group than in the inflammatory group. Postoperative ureteral stricture and moderate-to-severe hydronephrosis were found to be closely related to the number of resected polyps, regardless of the type of polyp (p = 0.014 and 0.006, respectively).ConclusionFibroepithelial polyps in the ureter may persist after treatment of adjacent ureter stones. However, conservative management may be preferable to active removal of ureteral polyps because fibroepithelial polyps may not contribute to clinically significant hydronephrosis after surgery, and inflammatory polyps disappear spontaneously. Hasty resections of polyps may increase the risk of ureteral stricture.

MP23-06 THE NATURAL COURSE OF INCIDENTAL URETERAL POLYP DURING URETEROSCOPIC SURGERY: KSER RESEARCH

You have accessJournal of UrologyCME1 Apr 2023MP23-06 THE NATURAL COURSE OF INCIDENTAL URETERAL POLYP DURING URETEROSCOPIC SURGERY: KSER RESEARCH Dae Hyuk Chung, Hyeji Park, Kyung-Jin Oh, Wonho Jung, Hyung Joon Kim, Sang Hyub Lee, Joo Yong Lee, Dong Sup Lee, and Sung Yong Cho Dae Hyuk ChungDae Hyuk Chung More articles by this author , Hyeji ParkHyeji Park More articles by this author , Kyung-Jin OhKyung-Jin Oh More articles by this author , Wonho JungWonho Jung More articles by this author , Hyung Joon KimHyung Joon Kim More articles by this author , Sang Hyub LeeSang Hyub Lee More articles by this author , Joo Yong LeeJoo Yong Lee More articles by this author , Dong Sup LeeDong Sup Lee More articles by this author , and Sung Yong ChoSung Yong Cho More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003248.06AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: The aim of this study was to observe the natural course of polypoid lesions of the ureter encountered during ureteroscopic stone treatment. METHODS: Patient data were gathered prospectively from six teaching hospitals between August 2019 and July 2021. Patients with polypoid lesions in the ureter distal to ureteral stones during ureteroscopy were enrolled in the present study. Computed tomography was performed in all enrolled patients three months postoperatively. However, the determination of follow-up ureteroscopy was contingent solely on each patient’s willingness, because of the need to undergo general anesthesia again and ethical considerations. RESULTS: Among 35 followed up patients, 14 exhibited fibroepithelial polyps and 21 were confirmed as having inflammatory polyps. Twenty (57.1%) of the followed-up patients underwent ureteroscopy; of these, nine patients had fibroepithelial polyps. Although fibroepithelial polys did not disappear in the follow-up ureteroscopy (p=0.002), the rate of postoperative hydronephrosis was not higher in the fibroepithelial group than it was in the inflammatory group. The postoperative ureteral stricture and moderate-to-severe hydronephrosis were found to be closely related to the number of resected polyps regardless of the type of polyp (p=0.014 and 0.006, respectively). CONCLUSIONS: The fibroepithelial polyp of the ureter may persist after treatment of adjacent urolithiasis. However, conservative management may be preferable to the active removal of ureteral polyps, because fibroepithelial polyps may not contribute to clinically significant postoperative hydronephrosis, and inflammatory polyps disappear spontaneously. Rather impellent resections of polyps may increase the risk of ureteral stricture. Source of Funding: The authors wish to acknowledge the financial support of the St. Vincent’s hospital, the research institute of medical science (SVHR-2018-06). In part, the present study was also supported by a grant from the Korean society of endourology and robotics in the program year of 2019 © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e307 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Dae Hyuk Chung More articles by this author Hyeji Park More articles by this author Kyung-Jin Oh More articles by this author Wonho Jung More articles by this author Hyung Joon Kim More articles by this author Sang Hyub Lee More articles by this author Joo Yong Lee More articles by this author Dong Sup Lee More articles by this author Sung Yong Cho More articles by this author Expand All Advertisement PDF downloadLoading ...

Evaluation of ureteral injuries caused by ureteral access sheath insertion during ureteroscopic lithotripsy.

To evaluate ureteral injuries caused by insertion of a 13-Fr ureteral access sheath and identify factors (other than pre-stenting) that are predictive of ureteral injury. We enrolled 201 patients who underwent ureteroscopic lithotripsy (URSL). We excluded 80 patients who underwent ureteral stent insertion before URSL, 10 patients who did not use a ureteral access sheath, and 2 patients in whom a ureteral access sheath could not be inserted. In total, 109 patients were analyzed; all underwent insertion of a 13-Fr ureteral access sheath. We investigated ureteral injuries using the Traxer ureteral injury scale. There were 21 (19.3%) cases of ureteral access sheath-related ureteral injury, including 11 (10.1%) grade 2 cases and 10 (9.2%) grade 3 cases. The ureteral injury location was the proximal ureter in 20 cases (18.3%), middle ureter in one case (0.9%), and distal ureter in zero cases. Multiple logistic regression analysis showed that male sex and smaller stone diameter were significant predictive factors for ureteral injury (p=0.037, odds ratio [OR]: 5.19, 95% confidence interval [CI]: 1.11-24.3 and p=0.02, OR: 0.83, 95% CI: 0.71-0.97, respectively). Postoperative ureteral stricture did not occur in any cases. The rate of ureteral injury caused by a 13-Fr ureteral access sheath was considerable, and most ureteral injuries occurred in the proximal ureter. Male sex and smaller stone diameter were significant predictive factors for ureteral injury. The proximal ureter should be confirmed when using a 13-Fr ureteral access sheath, particularly in male patients and patients with small stones.

Robot-Assisted Surgery in Treating Postoperative Strictures of Lower Third of Ureter

Introduction. The incidence of postoperative ureteral strictures induced by iatrogenic injuries tends to increase. Reconstructive surgery involves open or laparoscopic intervention to repair strictures. However, both methods have their drawbacks. Surgical treating strictures of the lower third of the ureter can be effectively performed by means of robotic surgery.Aim. To determine outcomes of robot-assisted reconstructive surgery in treating postoperative strictures of the lower third of the ureter.Materials and methods. Five female patients with postoperative strictures of the lower third of the ureter underwent robot-assisted reconstructive surgery. Clinical and radiological outcomes in the long-term postoperative period were determined.Results and discussion. Two patients underwent simultaneous robot-assisted reconstructive surgery, namely, robot-assisted uretero-cysto-neoanastomosis on the right side and Boari operation on the left; robot-assisted Boari operation and isolation of post-traumatic uretero-vaginal fistula. In the remaining three cases, robot-assisted Boari operation and uretero-cysto-neoanastomosis with psoas-hitch were performed. No evidence of ureteral stricture in all cases was detected via multislice spiral CT (MSCT) urography in 3 months after surgery.Conclusion. At present, robot-assisted reconstructive surgery, being suitable for simultaneous surgery, is safe and effective whentreating postoperative strictures of the lower third of the ureter.

Prospective observational study on the prognosis of ureteral lesions caused by impacted stones via dual-energy spectral computed tomography

ObjectiveUreteral lesions caused by impacted ureteral stones are likely to result in postoperative ureteral stricture. On this basis, the study aimed to investigate if dual-energy spectral computed tomography can predict ureteral hardening caused by impacted stones and to explore the relationship between different types of ureteral lesions and the risk of ureteral stricture. MethodsThis prospective study collected data of 93 patients with impacted stones from hospital automation system during January 2018 to October 2019. They underwent an abdominal scan on a dual-energy spectral computed tomography. During surgery, the operator used ureteroscopy to identify ureteral lesions, which were classified into four categories: edema, polyps, pallor, and hardening. Seven months later, 90 patients were reviewed for the degree of hydronephrosis. ResultsEndoscopic observations revealed 38 (41%) cases of ureteral edema, 20 (22%) cases of polyps, 13 (14%) cases of pallor, and 22 (24%) cases of hardening. There were significant differences in hydronephrosis, the period of impaction, the calcium concentration of the ureter, and the slope of the spectral Hounsfield unit curve between the four groups. After that, we evaluated the factors associated with ureteral hardening and found that the calcium concentration of the ureter and hydronephrosis remained independent predictors of ureteral hardening. Receiver operating characteristic curve analysis showed that 5.3 mg/cm³ calcium concentration of the ureter is an optimal cut-off value to predict ureteral hardening. The result of follow-up showed that 80 patients had complete remission of hydronephrosis, with a complete remission rate of 61.9% (13/21) in the hardening group and 97.1% (67/69) in the non-hardening group (p<0.001). ConclusionCalcium concentration of the ureter is an independent predictor of ureteral hardening. Patients with ureteral hardening have more severe hydronephrosis after ureteroscopic lithotripsy. When the calcium concentration of the ureter is less than 5.3 mg/cm³, ureteral lesions should be actively treated.

Comprehensive endoscopic management of impacted ureteral stones: Literature review and expert opinions.

Treatment of urolithiasis, a benign disease, requires high efficacy and safety. Endoscopic treatment of impacted ureteral stones remains a challenging procedure for urologists, despite recent remarkable advances in surgical technology in treatment of urolithiasis. The success rate of endoscopic treatment in patients with impacted stones is reported to be lower than that in patients with nonimpacted stones. Moreover, the presence of stone impaction is associated with high rates of intraoperative and postoperative complications. The best management for patients with impacted ureteral stones should therefore be devised based on the latest knowledge and techniques. The present review focuses on the preoperative prediction of stone impaction, the safest and most effective endoscopic surgical procedures, and the most appropriate management for postoperative ureteral strictures. We overview comprehensive endoscopic management for impacted ureteral stones based on literature review and expert opinions.

The Impact of Ureteral Access Sheath Size on Perioperative Parameters and Postoperative Ureteral Stricture in Retrograde Intrarenal Surgery.

Objective: To investigate the effect of the diameter of ureteral access sheath (UAS) used during retrograde intrarenal surgery (RIRS) on operative parameters, perioperative ureteral injury, and ureteral stricture development. Materials and Methods: The study was designed as a prospective randomized controlled trial and included 320 patients who underwent RIRS. The patients were divided into two groups according to the diameter of UAS (9.5F/11.5F [Group 1] and 12F/14F [Group 2]) placed during the operation. At the end of the operation, ureteral injury was checked visually using semirigid ureterorenoscopy and classified according to the ureter injury scale. In the postoperative first year, the control CT urography images were used to observe newly developing ureteral dilatation. Results: There was no statistical difference between the two groups in terms of patient and stone characteristics, operative time, postoperative stone-free rate, and postoperative infection development parameters. In Group 1, 30 (18.8%) of the patients had low-grade and 8 (5%) of the patients had high-grade ureteral injury, while in Group 2, 44 (27.5%) had low-grade and 19 (11.9%) had high-grade ureteral injury (p = 0.013). In the postoperative period, ureteral stricture was found in 5 (1.6%) patients, of whom 4 (2.5%) were in Group 2 and 1 (0.6%) (p = 0.371). Conclusion: The results of our study showed that the use of a 12F/14F UAS in patients who are not previously stented increases the risk of high-grade ureteral injuries; however, despite this increase there is no difference in ureteral stricture formation.

Long-Term Renal Function Following Radical Cystectomy for Bladder Cancer

ObjectiveTo evaluate long-term renal function following radical cystectomy (RC) for bladder cancer and identify risk factors associated with postoperative decline in renal function. MethodsThe study included patients who underwent RC at a single centre in Denmark between 2009 and 2019. Data was collected through national electronic medical records. Renal function was evaluated by estimated glomerular filtration rate (eGFR) using pre- and postoperative creatinine measurements. Cumulative incidence and Cox Proportional Hazards models were used to describe the loss of renal function and its association with clinicopathological variables, as well as its effect on mortality. ResultsAfter exclusions, 670 patients were eligible for analyses. Median follow-up time was 6.2 years (interquartile range 4.0 –8.4). The proportion of patients with renal insufficiency (eGFR<45 mL/min) increased from 8.9% before RC to 19% 5 years after surgery. A total of 610 patients with preoperative eGFR≥45 were included in survival analyses. The absolute risk of renal function decline to CKD stage G3b or worse (eGFR<45 mL/min) was 17% (95% CI 14 –20) at 5 years postoperatively. Loss of renal function was not significantly associated with higher all-cause mortality. In multivariate analysis lower preoperative eGFR, diabetes mellitus, prior pelvic radiation therapy, continent urinary diversion types, and postoperative ureteral stricture were all independently associated with renal function decline. ConclusionThe long-term renal function decreases considerably for a large number of RC patients. Recognizing preoperative risk factors could identify patients who benefit from enhanced renal surveillance or early intervention for modifiable factors to minimize renal insufficiency following RC.

Preoperative hydronephrosis is a predictive factor of ureteral stenosis after flexible ureteroscopy: a propensity scores matching analysis

ObjectivesUreteral stenosis is a serious complication of flexible ureteroscopy. How to predict the possibility of stricture before surgery is an important topic. This research retrospectively studied the influence of preoperative hydronephrosis on ureteral stenosis after flexible ureteroscopy, to explore whether the preoperative hydronephrosis could predict postoperative ureteral stenosis.MethodsWe conducted a retrospective study on patients who received flexible ureteroscopy in our hospital for upper ureteral calculi from January 2015 to June 2018. Patients were followed-up for 36 months after surgery, and intraoperative and postoperative complications were recorded. We divided patients into the mild hydronephrosis group and moderate to severe hydronephrosis group. Preoperative clinical baseline data of the patients were adjusted by propensity matching score analysis. Differences of intraoperative ureteral injury, operative time, postoperative ureteral stricture, and SFR one month after surgery was statistically analyzed. Kaplan–Meier’s method and Log-rank test were used to compare the differences in the cumulative incidence of ureteral stenosis between the two groups. Cox regression was used to compare the hazard ratio of ureteral stenosis between the two groups.ResultsA total of 447 patients with 469 sides surgery were included, including 349 sides in the mild hydronephrosis group and 120 sides in the moderate to severe hydronephrosis group. Twenty-nine patients with 30 sides developed ureteral stenosis. Before and after propensity, the incidence of ureteral stricture matching analysis was 6.4% and 8%, respectively. There were statistical differences in ureteral stricture and injury, but the statistical differences in SFR and operation time were inconsistent. Kaplan–Meier showed a significant difference in the cumulative incidence of ureteral stenosis between the two groups.ConclusionsPatients with moderate to severe hydronephrosis before surgery were more likely to have an intraoperative ureteral injury and postoperative ureteral stricture after FRUS. Preoperative hydronephrosis is an important predictor of ureteral stricture.

Endourological treatment for lumbar ureteral stones. What are the benefits of flexible ureterorenoscopy?

Introduction and objectivesCurrently, there are no established criteria regarding treatment for lumbar ureteral stones. The objective of this work is to present our results in the endourological treatment of this pathology, analyzing the variables associated with the use of the flexible ureterorenoscope. Material and methodsRetrospective review of 103 patients who underwent retrograde URS with semi-rigid or flexible ureterorenoscope. Proximal location: L2–L3. Medial location: L4–L5. Semirigid URS was the initial treatment, with conversion to flexible URS when it was required to complete the procedure. Success was defined as absence of residual fragments (6 weeks). Demographic, surgical, immediate postoperative variables, and those related to the stone, were analyzed. Their correlation with the use of the flexible ureterorenoscope was evaluated. ResultsMean age: 57.2 years (SD 15.6); there were 73 men (70.9%). Stone size: 8 mm (range 4–30; IQR 4.5). Proximal location: 58 (56.3%). Previous JJ: 44.7%. Previous nephrostomy: 10.7%. Semirigid URS with conversion to flexible URS: 51 (49.5%). Impacted stones: 28.2%. Intraoperative complications: 2 (1.9%). Postoperative JJ: 84.5%. Immediate postoperative complications: 23 (22.3%) (Clavien-Dindo I–II: 91.3%). Postoperative ureteral stricture: 5.8%. Success: 88.4%. Residual fragments: 12 (11.7%). Spontaneous passage: 6 (50%). Greater performance of flexible URS in proximal ureteral stones (p = 0.001) of more than 11 mm (p = 0.02) in univariate analysis, and in proximal stones [OR 3.5; 1.5–8.1; p = 0.004] in multivariate analysis. ConclusionsEndourological treatment obtained a high success rate in our sample. Size greater than 11 mm and proximal ureteral location in univariate and multivariate analysis, respectively, behaved as predictors of flexible URS.

Tratamiento endourológico de la litiasis ureteral lumbar. ¿Qué aporta la ureterorrenoscopia flexible?

Introduction and objectivesCurrently, there are no established criteria regarding treatment for lumbar ureteral stones. The objective of this work is to present our results in the endourological treatment of this pathology, analyzing the variables associated with the use of the flexible ureterorenoscope. Material and methodsRetrospective review of 103 patients who underwent retrograde URS with semi-rigid or flexible ureterorenoscope. Proximal location: L2-L3. Medial location: L4-L5. Semirigid URS was the initial treatment, with conversion to flexible URS when it was required to complete the procedure. Success was defined as absence of residual fragments (6 weeks). Demographic, surgical, immediate postoperative variables, and those related to the stone, were analyzed. Their correlation with the use of the flexible ureterorenoscope was evaluated. ResultsMean age: 57.2 years (SD 15.6); there were 73 men (70.9%). Stone size: 8mm (range 4-30; IQR 4.5). Proximal location: 58 (56.3%). Previous JJ: 44.7%. Previous nephrostomy: 10.7%. Semirigid URS with conversion to flexible URS: 51 (49.5%). Impacted stones: 28.2%. Intraoperative complications: 2 (1.9%). Postoperative JJ: 84.5%. Immediate postoperative complications: 23 (22.3%) (Clavien-Dindo I-II: 91.3%). Postoperative ureteral stricture: 5.8%. Success: 88.4%. Residual fragments: 12 (11.7%). Spontaneous passage: 6 (50%). Greater performance of flexible URS in proximal ureteral stones (P=0.001) of more than 11mm (P=0.02) in univariate analysis, and in proximal stones [OR 3.5; 1.5-8.1; P=0.004] in multivariate analysis. ConclusionsEndourological treatment obtained a high success rate in our sample. Size greater than 11mm and proximal ureteral location in univariate and multivariate analysis, respectively, behaved as predictors of flexible URS.

Тулиевая и гольмиевая уретеролитотрипсия: оценка термического воздействия на мочеточник путем измерения температуры ирригационной жидкости в условиях in vitro

Introduction. Urolithiasis refers to one of the most common diseases of the genitourinary system, which the urologist meets in his daily practice. When a stone is located in the ureter, surgical intervention is often required to restore the passage of urine and prevent the development of obstructive pyelonephritis. Currently, the holmium or thule laser ureterolithotripsy is condidered the «gold standard» of surgical treatment of ureteral calculi. The thermal effect on the ureteral wall when using a laser may be one of the reasons for the postoperative ureteral strictures development. The aim of our study is to compare in vitro thermal effects of these types of laser on the ureter wall by evaluating the change in the temperature of the irrigation fluid when they are used. Materials and methods. A tube with a diameter of 5 mm, which imitated the ureter, was placed in an aqueous medium with a temperature of 36°C. A temperature sensor (HI 98509 Checktemp 1) was installed in its lumen, at a 3 mm distance from the laser fiber. The time when the irrigation fluid reaches a temperature of 43°C, as well as its temperature at a pulse duration of 3 seconds at an irrigation rate of 25 and 50 ml/sec in the dusting and fragmentation modes, were recorded. Results and discussion. It was found that when using a thulium laser, regardless of the flow rate of the irrigation fluid, an increase in its temperature to 43°C is achieved for a longer time. Also, a lower temperature of the irrigation fluid with a pulse duration of 3 second is recorded using thulium laser. The obtained data allow us to assume that the use of a thulium laser is accompanied by a lower thermal effect on the ureter wall. Conclusion. In this study, we found that when using a thulium laser (Fiberlase U2) in the fragmentation and sputtering modes, a slower increase in the temperature of the irrigation liquid is observed than when using a holmium laser (Lumenis VersaPulse 100W), regardless of the irrigation speed. At a 3 second pulse , a lower temperature of the irrigation fluid was recorded during the use of the thulium laser.

Thulium-laser retrograde intra renal ablation of upper urinary tract transitional cell carcinoma: an ESUT Study.

Background Radical nephroureterectomy (RNU) is the gold standard treatment for upper urinary tract urothelial carcinoma (UTUC); however, patients presenting with small low-grade UTUC have been treated by flexible ureteroscopic laser ablation with good outcomes. Different types of laser have been discussed in the literature including Holmium and Neodymium lasers. We aimed to assess the safety and efficacy of Thulium laser (Tm:YAG) in the ureteroscopic ablation of UTUC. Methods A retrospective observational multicentre study of patients diagnosed with papillary UTUC between January 2015 and December 2016 was carried out. All patients underwent ureteroscopic biopsy of the UTUC followed by Tm:YAG ablation. Based on the histopathological grade of the tumor, patients were counseled to undergo either RNU (high-grade tumors) or conservative managementand follow-up (low-grade tumor). Results RNU was performed in 31 patients, while the remaining 47 patients (undergone ™:YAG ablation only) were followed up for a mean of 11.7 months with only 19.2% of patients showing upper tract recurrence and no patients showed postoperative ureteral strictures. Limitations include the short follow-up and retrospective nature of the study. Conclusions On the short term, thulium Laser ablation of UTUC is safe and feasible especially in lowgrade UTUC.

The Impact of Ureteral Access Sheath Use on the Development of Abnormal Postoperative Upper Tract Imaging after Ureteroscopy.

Ureteral access sheaths are commonly used during ureteroscopy to facilitate stone removal, improve visibility and maintain low intrarenal pressures. However, the use of a ureteral access sheath can cause ureteral wall ischemia and ureteral tears, potentially increasing the risk of postoperative ureteral stricture and obstruction. We studied the impact of ureteral access sheath use on postoperative imaging studies. Secondary objectives included studying the impact of other intraoperative parameters on postoperative imaging studies. A retrospective chart review was conducted of cases that underwent ureteroscopy for nephroureterolithiasis across 2 high volume institutions between January 2012 and September 2016. Patient demographics, cumulative stone size, operative time, use of ureteral access sheath, laser lithotripsy, basket extraction, preoperative ureteral stent and postoperative ureteral stent placement were extracted from the electronic medical record. Findings of followup renal ultrasound, kidney-ureter-bladder x-ray and/or computerized tomography at approximately 8 weeks after surgery were recorded. A total of 1,332 ureteroscopies were performed with 1,060 cases (79.6%) returning for routine upper tract imaging after ureteroscopy. Postoperative hydronephrosis was noted following 127 cases (12.0%). Factors predicting presence of hydronephrosis after ureteroscopy include lower body mass index (p=0.0016), greater cumulative stone size (p=0.0003), increased operative time (p <0.0001), preoperative ureteral stent (OR 1.49, p=0.0299) and postoperative ureteral stent placement (OR 6.43, p=0.0031). Postoperative hydronephrosis was not associated with use of ureteral access sheath, age, laser lithotripsy or basket extraction. Use of ureteral access sheath did not have a significant impact on development of postoperative hydronephrosis, suggesting ureteral access sheath is safe for use during ureteroscopy. Ureteral strictures remain rare following ureteroscopy, seen in only 1.0% of our cohort. With an observed prevalence of hydronephrosis of 12.0% on followup imaging at 8 weeks, routine upper tract imaging after ureteroscopy remains a valuable prognostic tool.

Analysis of risk factors for postoperative stenosis with single ureteral calculi treated with ureteroscopic holmium laser listhotripsy

Objective To explore the risk factors of stricture after ureteroscopic holmium laser lithotripsy (URSL) in patients with single ureteral calculi, and to provide reference for the treatment of patients. Methods Retrospective analysis of 230 patients with single ureteral calculi who underwent URSL between November 2017 and November 2018 was performed. According to the postoperative follow-up results, 26 patients with ureteral stricture were treated as observation group, and ureteral non-stenosis patients were 204 patients as a control group. The risk factors for stenosis after surgery were analyzed. Results The risk factors of postoperative stenosis showed that the diameter of calculus≥2 cm, severe hydronephrosis, stone incarceration, and long course of disease were the risk factors for postoperative stenosis. The difference between the two groups was statistically significant(P<0.05). Multivariate logistic regression analysis of ureteral stricture showed that large stones, severe hydronephrosis, incarcerated stones and long-term disease were independent risk factors for ureteral stricture after URSL, and the difference was statistically significant(P<0.05). Conclusions Severe hydronephrosis, large stones, stone incarceration and long course of disease are high risk factors for postoperative ureteral stricture. Therefore, patients should be kept away from the high risk factors causing ureteral stricture in patients during treatment for better therapeutic efficiency. Key words: Ureteral Calculi; Lithotripsy, Laser; Urethral Stricture

Thulium-laser retrograde intra renal ablation of upper urinary tract transitional cell carcinoma: an ESUT Study.

Radical nephroureterectomy (RNU) is the gold standard treatment for upper urinary tract urothelial carcinoma (UTUC); however, patients presenting with small low-grade UTUC have been treated by flexible ureteroscopic laser ablation with good outcomes. Different types of laser have been discussed in the literature including Holmium and Neodymium lasers. We aimed to assess the safety and efficacy of Thulium laser (Tm:YAG) in the ureteroscopic ablation of UTUC. A retrospective observational multicentre study of patients diagnosed with papillary UTUC between January 2015 and December 2016 was carried out. All patients underwent ureteroscopic biopsy of the UTUC followed by Tm:YAG ablation. Based on the histopathological grade of the tumor, patients were counseled to undergo either RNU (high- grade tumors) or conservative management and follow-up (low-grade tumor). RNU was performed in 31 patients, while the remaining 47 patients (undergone Tm:YAG ablation only) were followed up for a mean of 11.7 months with only 19.2% of patients showing upper tract recurrence and no patients showed postoperative ureteral strictures. Limitations include the short follow-up and retrospective nature of the study. On the short term, thulium Laser ablation of UTUC is safe and feasible especially in low-grade UTUC.

Laparoscopic ureterolithotomy versus ureteroscopic laser lithotripsy for large proximal ureteral stones: a systematic review and meta-analysis.

To review current studies and conduct a meta-analysis on the topic of laparoscopic ureterolithotomy (LU) versus ureteroscopic lithotripsy (URSL) with holmium laser for large proximal ureteral stones. A systematic research of PubMed, Ovid, Scopus (up to March 2019), and citation lists was performed to identify eligible comparative studies. All studies comparing LU versus URSL with holmium laser in proximal ureteral stones were included. Statistical analyses were performed using the Cochrane Collaboration's Review Manager (RevMan) 5.3 software. Overall, seven studies were included in analysis involving 884 patients (LU 387; URSL 497). Our meta-analysis showed that LU group had bigger stone size than URSL group (WMD 0.19 cm; P=0.001). LU group was associated with longer operative time (WMD 36.29 min; P<0.001), and length of hospital stay (WMD 1.24 d; P=0.04). However, LU group showed better initial stone-free rate (OR 11.03; P<0.001), and final stone-free rate (OR 22.37; P<0.001). There were no significant differences in all complications (RR 1.06; P=0.76). While, LU group had fewer Clavien Dindo score ≥3 complications (RR 0.21; P=0.002), fewer ureteral stricture (RR 0.26; P=0.04), and lower need of auxiliary procedures (RR 0.09; P<0.001) compared with URSL group. LU could provide a higher stone-free rate and fewer severe complications compared with URSL with holmium laser for large proximal ureteral stones. More importantly, LU could also reduce the postoperative ureteral stricture rate.