Ureteral Wall Research Articles

V01-02 THREE-DIMENSIONAL AUGMENTED REALITY ROBOT-ASSISTED SEGMENTAL URETERECTOMY WITH BUCCAL MUCOSA GRAFT FOR THE REPAIR OF UPPER COMPLEX URETERAL STRICTURES

You have accessJournal of UrologyCME1 Apr 2023V01-02 THREE-DIMENSIONAL AUGMENTED REALITY ROBOT-ASSISTED SEGMENTAL URETERECTOMY WITH BUCCAL MUCOSA GRAFT FOR THE REPAIR OF UPPER COMPLEX URETERAL STRICTURES Alberto Piana, Daniele Amparore, Giovanni Busacca, Paolo Alessio, Enrico Checcucci, Federico Piramide, Sabrina De Cillis, Gabriele Volpi, Paolo Verri, Michele Sica, Mariano Burgio, Andrea Bellin, Matteo Manfredi, Cristian Fiori, and Francesco Porpiglia Alberto PianaAlberto Piana More articles by this author , Daniele AmparoreDaniele Amparore More articles by this author , Giovanni BusaccaGiovanni Busacca More articles by this author , Paolo AlessioPaolo Alessio More articles by this author , Enrico CheccucciEnrico Checcucci More articles by this author , Federico PiramideFederico Piramide More articles by this author , Sabrina De CillisSabrina De Cillis More articles by this author , Gabriele VolpiGabriele Volpi More articles by this author , Paolo VerriPaolo Verri More articles by this author , Michele SicaMichele Sica More articles by this author , Mariano BurgioMariano Burgio More articles by this author , Andrea BellinAndrea Bellin More articles by this author , Matteo ManfrediMatteo Manfredi More articles by this author , Cristian FioriCristian Fiori More articles by this author , and Francesco PorpigliaFrancesco Porpiglia More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003221.02AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Ureteral stenosis constitutes a very complex surgical scenario with a high rate of post-operative failure. For 2-3 cm upper stenosis, a robotic-assisted segmental ureteral resection with subsequent uretero-ureteral anastomosis using a buccal mucosa graft is a fesible option. For the intraoperative identification of the stenosis, a concomitant ureteroscopy is usually performed. However, the addition of the endoscopy increases the intraoperative complexity and costs of the surgery. In order to increase the precision in locating the stricture during the surgical dissection of the ureter, we tested 3D augmented reality (AR) surgical navigation during the intervention. METHODS: AR intraoperative navigation is performed using a dedicated ICON rack connected to the DaVinci® surgical console. A 3D mouse is used by an assistant to manually overlap the 3D virtual model on the operative field. The surgeon can visualize the superimposed images in real time via Tile Pro technology. Three cases of different level ureteral strictures caused by stones embedded into the ureteral wall and located above the iliac vessels cross are shown in the video. AR is used to superimpose the 3D virtual model of the ureter together with its stone over the operative field, leading to a precise location and resection of the stricture. In the reconstructive phase, the mucosal graft is put into the abdominal cavity once the posterior plate of the anastomosis is realized with a termino-terminal suture, minimizing the tension on the defect repair. RESULTS: In all the three cases, AR allowed a proper identification of the endoluminal stricture. All the surgeries were successful without significative intra and post-operative complications. Postoperative examinations confirmed the success of the procedures. CONCLUSIONS: AR intraoperative guidance showed to be a useful and precise technological tool able to correctly identify the ureteral stricture even when not visible on the ureteral wall surface, leading to maximize the preservation of ureteral peri-strictural healthy tissue. Source of Funding: none © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e79 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Alberto Piana More articles by this author Daniele Amparore More articles by this author Giovanni Busacca More articles by this author Paolo Alessio More articles by this author Enrico Checcucci More articles by this author Federico Piramide More articles by this author Sabrina De Cillis More articles by this author Gabriele Volpi More articles by this author Paolo Verri More articles by this author Michele Sica More articles by this author Mariano Burgio More articles by this author Andrea Bellin More articles by this author Matteo Manfredi More articles by this author Cristian Fiori More articles by this author Francesco Porpiglia More articles by this author Expand All Advertisement PDF downloadLoading ...

MP42-19 BILAYERED AUTOLOGOUS ADIPOSE-DERIVED MESENCHYMAL CELL-GELATIN SHEETS RECONSTRUCT URETERAL TISSUES IN RABBITS

You have accessJournal of UrologyCME1 Apr 2023MP42-19 BILAYERED AUTOLOGOUS ADIPOSE-DERIVED MESENCHYMAL CELL-GELATIN SHEETS RECONSTRUCT URETERAL TISSUES IN RABBITS Noriyuki Ogawa, Tetsuya Imamura, Tomonori Minagawa, Teruyuki Ogawa, and Osamu Ishizuka Noriyuki OgawaNoriyuki Ogawa More articles by this author , Tetsuya ImamuraTetsuya Imamura More articles by this author , Tomonori MinagawaTomonori Minagawa More articles by this author , Teruyuki OgawaTeruyuki Ogawa More articles by this author , and Osamu IshizukaOsamu Ishizuka More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003280.19AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Treatments of ureteral defects or strictures due to disease or trauma require reconstruction by urological surgery. However, those surgeries have some limitations, such as reoperation, or depending on ureteral length. Tissue engineering techniques would provide novel approaches to avoid the limitations. In this study, we fabricated bilayered autologous adipose-derived mesenchymal cell (AMC)-gelatin sheets and transplanted them into rabbits to replace surgically excised ureteral segments. METHODS: AMCs harvested from abdominal adipose tissues of female New Zealand White rabbits were cultured on collagen-coated dishes and labeled with a red fluorescent dye, PKH26, for later identification. Monolayers of AMCs that were cultured on temperature-responsive dishes were harvested by a gelatin hydrogel sheet. Two AMC-gelatin sheets were then overlaid together with the cell sides juxtaposed, forming a bilayered AMC-gelatin sheet. Following each partial ureterectomy of approximately 1 cm, the bilayered autologous AMC-gelatin sheet was transplanted, joining the proximal and distal ends of the remaining the ureter (experimental group; n=9). Control animals were conducted with a bilayered acellular-gelatin sheet (control group; n=9). RESULTS: At 4 and 8 weeks after transplantation, the proximal regions of ureters of control groups exhibited flexures and dilations compared with experimental groups. Both the control and experimental reconstructed ureteral walls had smooth muscle layers; however, those in the experimental reconstructed ureteral walls were significantly thicker and better organized than those in the control groups. In addition, the lumina of the 8-week reconstructed ureteral tissues in experimental groups did not show histological strictures as seen in the control ureters. Some AMCs differentiated into smooth muscle marker-positive cells. The experimental ureteral walls contained smooth muscle cells derived from the PKH26-labeled AMCs and others that were derived through migration and differentiation of cells from the remaining proximal and distal ends of the original ureter. CONCLUSIONS: These results indicated that the bilayered AMC-gelatin sheets could replace and/or reconstruct ureter tissues. Source of Funding: None © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e575 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Noriyuki Ogawa More articles by this author Tetsuya Imamura More articles by this author Tomonori Minagawa More articles by this author Teruyuki Ogawa More articles by this author Osamu Ishizuka More articles by this author Expand All Advertisement PDF downloadLoading ...

MP70-04 URETERAL PERISTALSIS LONGITUDINAL MOTION MINIMIZES REFLUX

You have accessJournal of UrologyCME1 Apr 2023MP70-04 URETERAL PERISTALSIS LONGITUDINAL MOTION MINIMIZES REFLUX Kourosh Kalayeh, Haotian Xie, J. Brian Fowlkes, William W. Schultz, and Bryan S. Sack Kourosh KalayehKourosh Kalayeh More articles by this author , Haotian XieHaotian Xie More articles by this author , J. Brian FowlkesJ. Brian Fowlkes More articles by this author , William W. SchultzWilliam W. Schultz More articles by this author , and Bryan S. SackBryan S. Sack More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003338.04AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Lack of sufficient ureteral peristalsis is theorized as one of the mechanisms contributing to ureteral dilation in vesicoureteral reflux (VUR) and non-obstructing megaureters. To help understand the phathophysiologic mechanism for these disorders, we first need to understand the dynamics of normal ureteral peristalsis, which results in near complete clearance of urine from the ureter (i.e., non-dilated). We hypothesize that the clinically observed ureteral wall longitudinal motion is crucial to prevent and/or limit peristaltic reflux (i.e., retrograde flow of urine during an episode of peristalsis). METHODS: To examine this hypothesis, based on the lubrication theory in fluid mechanics, we modeled ureteral peristalsis mathematically as an infinite train of sinusoidal waves and analyzed the antegrade and retrograde flows in the ureter. In doing so, we accounted for ureteral wall longitudinal motion by imposing a periodic Gaussian longitudinal velocity on the wall, Figure 1 (a) and (b), inspired by videos of ureteral operations. RESULTS: Effects of wall longitudinal motion on peristaltic reflux and performance are shown in Figure 1 (c) & (d), and Figure 2 (a) & (b), respectively. The results are shown as an example for a typical clinical case with discharge rate of 1.62 mL/min and peristaltic amplitude of 80 % of lumen diameter. As shown, by considering wall longitudinal motion, the range of urine flow rates resulting in peristaltic reflux drops substantially. The minimum required flow rate to prevent peristaltic reflux drops by 50% when including the wall longitudinal motion effect, Figure 2 (a). Similarly, the required flow rate to limit the reflux volume fraction below a critical value of 2% (chosen as an example, based on clinical expertise) drops by 70%, Figure 2 (b). CONCLUSIONS: This computational model is the first to include longitudinal wall motion, which aligns with our hypothesis that it is important for minimizing peristaltic reflux. This supports the clinical observation of normal ureters having high emptying ability and helps direct further investigations to understand ureteral disorders. Source of Funding: This research has been partially supported by grants from the Michigan Institute for Clinical and Health Research (MICHR), and the Departments of Urology and Radiology at the University of Michigan © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e1004 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Kourosh Kalayeh More articles by this author Haotian Xie More articles by this author J. Brian Fowlkes More articles by this author William W. Schultz More articles by this author Bryan S. Sack More articles by this author Expand All Advertisement PDF downloadLoading ...

A Prospective Evaluation of the Association of Ureteral Wall Thickness With Intraoperative Stone Impaction in Ureteroscopy.

Background and objective In this study, we aimed to analyze the association of ureteral wall thickness (UWT) measured on non-contrast CT (NCCT) with stone impaction as found in ureteroscopy (URS). Materials and methods We analyzed 43 patients who underwent URSand pneumatic/laser lithotripsy for ureteric stones from May to November 2022. TheUWT was measured by an experienced radiologist on NCCT. Clinical predictors of the impacted stone were calculated by univariate and multivariate regression analysis.The receiver operating characteristic (ROC) curve was calculated for the UWT cutoff to apply it for impaction with different parameters. We also evaluated the association of intra- and postoperative parameters of the two groups with UWT. Results Out of the 43 patients with stones, 26 (60.46%) patients had impacted stones. Univariate analysis was used to analyze the site (left-sided stone impacted more commonly), stone size, stone density [Hounsfield unit (HU)], hydronephrosis, UWT, and duration between initial presentation and surgery, and multivariate analysis was utilized to assess stone density, as well as UWT's association with impacted stones. The ROC curve showed a cutoff of 3.5 mm for UWT with an accuracy of 0.83. HighUWT (≥3.5 mm) was associated with a significantly lower stone-free rate, more complications, and mean operative time as compared to low UWT (<3.5 mm) (p<0.05). Conclusion Based on our findings, high UWT is associated with high rates of impacted stones and a lower stone-free rate when compared to low UWT.

Ureteral rhabdomyosarcoma in a dobermann

AbstractA ureteral rhabdomyosarcoma was diagnosed in a 2‐year, 9‐month‐old, entire, male dobermann with persistent haematuria. Diagnostic imaging revealed unilateral hydronephrosis and hydroureter. In addition, it showed thickening of the distal ureteric wall and focal thickening of the mucosa of the bladder trigone between the ureters. No mass was identified. The patient underwent exploratory laparotomy, and biopsies of the bladder mucosal thickening and right ureteral thickening were obtained. Histopathology of the ureteral thickening was suggestive of a ureteral rhabdomyosarcoma. A right ureteroneocystostomy was performed, and histopathology confirmed the suspected ureteral rhabdomyosarcoma, which was fully excised. Six months later, the patient remains asymptomatic with no evidence of recurrence or metastases on abdominal ultrasonography.

Preoperative alpha-blockers to facilitate ureteral access sheath (UAS) insertion: a systematic review and meta-analysis

Background: Recent studies have proposed the use of preoperative alpha-blockers to facilitate urethral access sheath (UAS) placement, but the definite role of this practice is still unclear. We aimed to evaluate the efficacy and safety of alpha-blocker use for UAS placement in intrarenal endoscopic procedures. Methods: The course of this study followed the preferred reporting items for systematic review and meta-analyses guidelines. Articles investigating the use of preoperative alpha-blockers for patients who underwent intrarenal endoscopic procedures were systematically reviewed from PubMed, EMBASE, and Scopus databases. Odds ratio (OR) with 95% confidence intervals (CIs) were applied for the outcome estimates. Analyses were performed with RevMan 5.4 software. The protocol of this study is enlisted in the registry of PROSPERO (CRD42022342811). Results: Six articles comprising 462 study populations were included in the review. Meta-analysis on the success rate of UAS placement showed a significant advantage of the alpha-blocker group compared to the control group (OR: 3.83; 1.83-8.00; 95% CI; p = 0.0004). Ureteral wall trauma was higher in the control group (OR: 0.38; 0.17-0.84; 95% CI; p = 0.02). Furthermore, there was no clear association between the UAS size and the success rate of UAS insertion. Conclusion: Preoperative alpha-blockers may increase the success rate of UAS insertion while decreasing the risk of ureteral wall injury in intrarenal endoscopic procedures.

Value of preoperative ureteral wall thickness in prediction of impaction of ureteric stones stratified by size in laser ureteroscopic lithotripsy

ObjectivesTo evaluate the role of preoperative UWT in the prediction of impaction of ureteral stones stratified according to stone size in ureteroscopic laser lithotripsy.Patient and methodsThis study included 154 patients submitted to URSL for ureteral stones. Radiological data comprised the presence of hydronephrosis, anteroposterior pelvic diameter (PAPD), proximal ureteric diameter (PUD), and maximum UWT at the stone site. Collected stone characteristics were stone size, side, number, site, and density.ResultsThe study included 154 patients subjected to URSL. They comprised 74 patients (48.1%) with impacted stones and 80 (51.9%) with non-impacted stones. Patients were stratified into those with stone size ≤ 10 mm and others with stone size > 10 mm. In the former group, we found that stone impaction was significantly associated with higher PAPD, PUD, and UWT. In patients with stone size > 10 mm, stone impaction was related to higher UWT, more stone number, and higher frequency of stones located in the lower ureter. ROC curve analysis revealed good power of UWT in discrimination of stone impaction in all patients [AUC (95% CI) 0.65 (0.55–0.74)] at a cut-off of 3.8 mm, in patients with stone size ≤ 10 mm [AUC (95% CI) 0.76 (0.61–0.91)] at a cut-off of 4.1 mm and in patients with stone size > 10 mm [AUC (95% CI) 0.72 (0.62–0.83)] at a cut-off of 3.0 mm.ConclusionsStratifying ureteric stones according to size would render UWT a more practical and clinically-oriented approach for the preoperative prediction of stone impaction.

The Impact of Ureteral Wall Thickness on Spontaneous Passage and Development of Long-term Ureteral Stricture in Patients with Ureteral Stone

To evaluate the association of ureteral wall thickness (UWT) with spontaneous passage (SP) of ureteral stones and formation of ureteral stricture (US) in patients who underwent ureterorenoscopy for ureteral stones. Cohort study. Department of Urology, University of Health Sciences, Bursa Yuksek Ihtisas Training and Research Hospital, Turkey, between January 2019 and June 2021. One hundred and sixty-nine patients with ureteral stones were restrospetively reviewed for maximum stone diameter, stone density, degree of hydronephrosis, parenchymal thickness, and UWT measurement from CT images. The patients were divided into two groups; patients who had (group 1) and had not (group 2) undergone SP of ureteral stones. These two groups were compared for stone characteristics and UWT. Ureterorenoscopy was performed on 52 patients who did not experience SP. Data related to the passage of guide wire and radio-opaque material, drainage method, ureteral wall injury and patients who developed US were recorded. Ureterorenoscopy group were divided into two groups of patients who did and did not develop stricture. These two groups were compared for stone characteristics and perioperative findings. Of the 169 patients, 106 (62,7%) patients spontaneously passed stones. Ureterorenoscopy was performed on 52 patients. US developed in 9 (17%) patients. Maximum stone diameter, density, and antero-posterior (AP) diameter of the renal pelvis and UWT were statistically different between both groups. The degree of hydronephrosis, ureteral wall injury, density, AP diameter of the stones, parenchyma thickness, length of hospital stay, and UWT were found to be significantly increased in the stricture group. UWT is a simple measurement that can be used to predict SP of ureteral stones. It can also predict the development of US after ureterorenoscopy in long-term. Ureteral calculi, Ureterorenoscopy, Ureteral wall thickness, Ureteral stricture.

Value of contrast-enhanced ultrasound in the differential diagnosis of ureteral tuberculosis from ureteral malignant tumour in women.

This study aimed to evaluate the contrast-enhanced ultrasound (CEUS) features of ureteral tuberculosis (UTB) and ureteral malignant tumour and to explore its application value in the differentiation of UTB from ureteral tumour. The ultrasound (US) and CEUS imaging features of 33 and 12 cases of pathologically confirmed UTB and ureteral malignant tumour, respectively, were retrospectively evaluated, and echo of the ureteral wall, abnormal echo of the lumen, degree of ureteral dilation and CEUS patterns of the two diseases were statistically analysed. The results revealed that the lumen echo of UTB was hyperechoic or anechoic, whereas that of ureteral tumour lesions was hypoechoic (χ2 = 28.22, P < 0.001). The wall echo of the obstruction site differed between the two diseases; in UTB, the ureteral wall was thickened but the outer wall remained intact, whereas in ureteral tumour, both the malignant tumour wall and outer wall were irregular (χ2 = 30.25, P < 0.001). CEUS of UTB revealed nonenhancement or heterogeneous enhancement in the lumen, whereas that of ureteral tumours revealed significant homogeneous enhancement (χ2 = 30.25, P < 0.001). Thus, CEUS can reveal lesion microcirculation and be used to evaluate blood supply characteristics in the lesion, indicating that it has high potential for differentiating the two diseases.

Non-contrast computed tomography-based factors in predicting ESWL success: A systematic review and meta-analysis.

We assessed the efficacy of some predictive factors that can be measured with non-contrast computed tomography and may affect ESWL success with a systematic review and meta-analysis. All data sources were broadly investigated up to April 2022. Data were extracted from the relevant studies and analyzed with RevMan software. In a random effects model, standard mean difference (SMD) and risk ratio (RR) values were given with 95% confidence intervals. In total, pooled analysis included 7148 patients in 43 studies. The combined effect estimate showed significant differences between the ESWL success and ESWL failure groups in terms of Hounsfield unit (HU), Hounsfield density (HD), skin to stone distance (SSD), ureteral wall thickness (UWT), stone volume, stone area, abdominal fat parameters, diameter of proximal ureter, and hydronephrosis. However, perinephric stranding and renal cortical thickness were not found to be statistically significant between the study groups. HU, HD, SSD, UWT, stone volume, stone area, abdominal fat parameters, diameter of proximal ureter and hydronephrosis are effective factors for prediction of ESWL success. It is important to decide on treatment before the procedure for stones with appropriate diameter for ESWL.

The Impact of Ureteral Wall Thickness on Spontaneous Passage and Development of Long-term Ureteral Stricture in Patients with Ureteral Stone

The Impact of Ureteral Wall Thickness on Spontaneous Passage and Development of Long-term Ureteral Stricture in Patients with Ureteral Stone

“Rule of Five” in Ureteral Dilatation and its Role in Ureteral Access Sheath Placement during Retrograde Intrarenal Surgery

Purpose: Sequential ureteral dilatation facilitates placement of ureteral access sheath during retrograde intrarenal surgery. The authors adopted some improvisations in conventional sequential ureteral dilatation methods to achieve improved ureteral accommodation and prefer to call the sequential ureteral dilatation performed with these improvisations as “Rule of five” (ROF) ureteral dilatation. The objective of the article was to describe the “ROF” ureteral dilatation technique and share the preliminary experience with the technique. Materials and Methods: “ROF” ureteral dilatation involves repetitive dilatation of ureter for five times by 10 Fr ureteral dilator, with each dilatation lasting for 5 s. The technique was used in patients who underwent retrograde intrarenal surgery for renal calculi and in whom 12 Fr ureteral dilator passage and 9.5/11.5 Fr ureteral access sheath placement was not possible by conventional sequential ureteral dilatation methods. Preliminary efficacy and safety outcomes were reported. Results: “ROF” ureteral dilatation was performed in 14 renal units. Ureteral access sheath placement was successful in 10 renal units (71.4%) and unsuccessful in 4 renal units (28.6%). Ureteral access sheath associated low-grade ureteral wall injury was noted in 2 renal units (14.3%). None had new onset hydroureteronephrosis in follow-up ultrasonography and all patients were asymptomatic in the follow-up period. Conclusion: “ROF” ureteral dilatation is an improvisation of conventional sequential ureteral dilatation. It facilitates successful and safe ureteral access sheath placement in a proportion of patients undergoing sequential ureteral dilatation.

Ureteral wall thickness and distal ureteral density in patients with residual fragments after Ho:YAG laser semi-rigid ureterolithotripsy.

Recent data suggest that greater ureteral density distal to ureteral stones or increased ureteral wall thickness (UWT) can predict impacted stones. The aim of our study was to evaluate if patients with residual fragments present with greater ureteral density and larger UWT when compared to stone-free patients. From January onward, a consecutive series of patients undergoing semi rigid Ho:YAG laser ureterolithotripsy (ULT) for ureteral stones were enrolled. A non-contrast enhanced computed tomography (CT) scan was performed before the procedure to evaluate distal ureteral density (DUD) and wall ureteral thickness (UWT) at the site of ureteral stones. Patients with residual fragments were compared to stone-free patients using a matched-pair analysis (1:1 scenario). Cases were matched sequentially using the following criteria: age, gender, body mass index (BMI), stone length, hydronephrosis, location of stones, and mean Hounsfield unit (HU) of the stone. Overall, 160 patients were enrolled, mean age was 57.9 ± 14years, mean BMI was 25.8 ± 4kg/m2, mean length of the stone was 10.6 ± 4.9mm, and mean UWT was 1.4 ± 1.6mm. A total of 150/160 (94%) patients presented hydronephrosis; mean HU stone was 868 ± 327; mean DUD was 54 ± 17.8 HU. Ureteral distal density (51.7 vs 56.6; p = 0.535) and ureteral distal thickness (1.39 vs 1.54; p = 0.078) were similar in both groups of patients. In our study, the evaluation of distal ureteral density does not predict stone-free rate. Further studies should evaluate the role for preoperative computer tomography in predicting surgery outcome.

The association between ureteral wall thickness and need for additional procedures after primary ureteroscopy in patients with ureteral stones above the iliac crest.

To examine the parameters affecting the need for additional procedures in the primary ureteroscopy treatment in patients with ureteral stones above the iliac crest level. Seventy-one patients were included in the study who were ≥ 18 years old and had undergone ureteroscopy (URS) for ureteral stones above the iliac crest level between 2018-2020 and had a non-contrast-enhanced abdominal computed tomography before the procedures were included in the study. Patients and stone characteristics were prospectively collected. The results were evaluated six weeks after URS. The absence of any residual fragment was thought to indicate stone-free status. The patients with failure were referred for the additional procedures. The median patient age was 51 years [interquartile range (IQR): 18-66]. The median transverse stone diameter was 9.5 mm (IQR: 7.1-11.4), and the median ureteral wall thickness (UWT) was 5.8 mm (IQR: 4.3-6.5). In the univariate analysis, UWT (p < 0.001), presence of multiple stones (p = 0.008), and stone length (p = 0.022) affected stone-free status. The multivariate analysis revealed UWT as the only independent factor affecting the need for additional procedures after URS (p = 0.028). In the receiver operating characteristic curve analysis, the best threshold value for UWT according to the outcomes was identified as 5.8 mm. Ureteral wall thickness was the only independent parameter determining the need for additional procedures and affecting the treatment outcomes after the URS procedure.

Comparison of minimally invasive percutaneous nephrolithotomy and ureteroscopy in the management of impacted proximal ureteral stones

Introduction and objective: Management of large impacted proximal ureteral stones is often challenging due to the presence of mucosal edema, inflammation and angulations of the ureter and other factors which impede stone access, visibility and lithotripsy and can lead to different types of complications. The objective of our study is to compare the efficacy and safety of minimally invasive percutaneous nephrolithotripsy (mini-PCNL) and ureteroscopy (URS) in the treatment of impacted proximal ureteral stones. Material and methods: The medical records of 345 patients with impacted proximal ureteral stones 10-20 mm, treated between January 2016 – November 2022 were retrospectively reviewed. 178 patients (51.6%) underwent mini-PCNL, and 167 (48.4%) – URS. Data on patients’ preoperative characteristics, stone-free rates, operating times, intra- and postoperative complications were compared. Results: Patients’ preoperative characteristics were comparable between the two groups, except for mean stone surface and stone size, which were significantly higher in the mini-PCNL group (respectively, 137.87±44.32mm2 vs 80.94±29.66mm2, p=0.000; and 15.03±2.43 vs 12.02±2.22mm, p=0.000). The stone free rate after single procedure was 94.9% for mini-PCNL and 89,3% in the URS group (p=0,116). Four patients (2.3%) in the mini-PCNL group had significant hemorrhage necessitating selective renovasography and angioembolization of AV fistula. 21 (12.5%) patients had stones showing upward migration during the URS procedure and 3 (1.8%) had partial perforation of the ureteral wall. Hemoglobin drop was significantly higher in mini-PNL group (13.58±12.79g/l vs 4.69±5.72g/l, p=0,000). Mean operative time was significantly longer in the URS group, despite the smaller size of the stones (respectively, 41.41±13.62min vs. 30.67±10.34min, p=0,000). There were statistically significant difference of the necessity of auxiliary procedures in the URS group (respectively, 78 patients (46,4%) vs 6 patients (3.6%), p=0.000). Conclusions: For an impacted, proximal ureteral stone mini-PNL had better stone-free rates, shorter operative time and low percentage of auxiliary procedure and hospitalizations. However, URS had the advantages of less invasiveness procedure and shorter postoperative hospital stay.

Autologous Bilayered Adipose-Derived Mesenchymal Cell-Gelatin Sheets Reconstruct Ureters in Rabbits.

Repair of ureteral defects or strictures due to disease or trauma is usually dependent upon surgery that often requires either reoperation or an alternative treatment. By taking advantage of tissue engineering and regenerative techniques, it may be possible to define new approaches to ureteral repair. In this study, we fabricated autologous bilayered adipose-derived mesenchymal cell (AMC)-gelatin sheets and transplanted them into rabbits to replace surgically excised ureteral segments. AMCs harvested from abdominal adipose tissues of female New Zealand white rabbits were cultured on collagen-coated dishes and labeled with PKH26, a red fluorescent dye, for later identification. Monolayers of the cultured PKH26-labeled AMCs were detached and applied to gelatin hydrogel sheets. Two gelatin sheets were then united with the AMC monolayers apposed together, forming a bilayered AMC-gelatin sheet. Following each partial ureterectomy, a bilayered autologous AMC-gelatin sheet was transplanted, joining the proximal and distal ends of the remaining ureter (n = 9). Control animals underwent the same procedure except that the transplant was achieved with a bilayered acellular-gelatin sheet (n = 9). At 4 and 8 weeks after transplantation, the proximal regions of ureters treated with the control bilayered acellular-gelatin sheets exhibited flexures and dilations, which are not characteristic of unoperated ureters. In contrast, the bilayered AMC-gelatin sheet-transplanted rabbits did not have ureteral flexures or dilations. About midway between the proximal and distal ends, both the control and experimental reconstructed ureteral walls had smooth muscle layers; however, those in the experimental reconstructed ureteral walls were significantly thicker and better organized than those in the control reconstructed ureteral walls. Some AMCs differentiated into smooth muscle marker-positive cells. The experimental ureteral walls contained smooth muscle cells derived from the PKH26-labeled AMCs and others that were derived through migration and differentiation of cells from the remaining proximal and distal ends of the original ureter. In addition, the lumina of the 8-week reconstructed ureteral tissues in experimental rabbits did not show histological strictures as seen in the control ureters. These results suggest that the bilayered AMC-gelatin sheets have the potential to replace defective tissues and/or reconstruct damaged ureters. Impact Statement To reconstruct ureter tissues following partial ureterectomy, we fabricated bilayered adipose-derived mesenchymal cell (AMC)-gelatin sheets based on cell sheet engineering principles. The bilayered AMC-gelatin sheets were transplanted into rabbits to replace a surgically excised ureteral segment. At 4 and 8 weeks after, the ureters that received bilayered AMC-gelatin sheets did not exhibit severe flexures, dilations, or strictures. The experimental ureteral walls had smooth muscle marker-positive cells that were differentiated from the AMCs, and similar cells were present in the adjacent intact ureteral tissues. Therefore, the bilayered AMC-gelatin sheets have the potential to reconstruct ureters damaged through disease or trauma.

978 Evaluation of the Quality of Our Consent Forms Used for Ureteroscopy and Nephroureteroscopy - Is It Time to Go Digital?

Abstract Aim Consent documentation for surgical procedures must be precise and clear in order to achieve excellence in clinical practice. In this audit, we aim to compare our consent forms against BAUS information leaflets on ureteroscopy and stone procedure and assess the documentation of all serious and frequently occurring complications as mentioned on BAUS leaflet. Method We retrospectively reviewed the consent forms of 60 patients who underwent elective ureteroscopy between August 2020 - April 2021 to assess the quality of documentation as well as legibility of handwriting. Results As a total of 60 consent forms were reviewed. 35 males and 25 females contributed to the study with 59 being the median age. There were over 10 risks being commonly missed. Some of the important risks such as stone recurrence 95%, catheterisation 92%, major damage to ureter wall 86%, pain 71% and residual stone 61% were missed. The documentation also outlines other risks; ureteric stricture 53%, aesthetic risk 67%, failure to access ureter 51% and stent symptoms 47%. Minor damage to the wall of ureter 41%, alongside need of another surgery were recorded as other commonly neglected risks. However, only 7% of the consent forms did not mention bleeding and just 2% of the forms failed to include stent insertion as a common effect of procedure. Only 17% consent for did not have eligible handwriting, although this is subjective. Conclusions Documentation on consent forms for ureteroscopy lacks accuracy and missed important information. We propose use of digital consent form to assess compliance and quality of consent documentation.

975 Evaluation of the Quality of Our Consent Forms Used for Ureteroscopy and Nephroureteroscopy - Is It Time to Go Digital?

Abstract Aim Consent documentation for surgical procedures must be precise and clear in order to achieve excellence in clinical practice. In this audit, we aim to compare our consent forms against BAUS information leaflets on ureteroscopy and stone procedure and assess the documentation of all serious and frequently occurring complications as mentioned on BAUS leaflet. Method We retrospectively reviewed the consent forms of 60 patients who underwent elective ureteroscopy between August 2020 - April 2021 to assess the quality of documentation as well as legibility of handwriting. Results As a total of 60 consent forms were reviewed. 35 males and 25 females contributed to the study with 59 being the median age. There were over 10 risks being commonly missed. Some of the important risks such as stone recurrence 95%, catheterisation 92%, major damage to ureter wall 86%, pain 71% and residual stone 61% were missed. The documentation also outlines other risks; ureteric stricture 53%, aesthetic risk 67%, failure to access ureter 51% and stent symptoms 47%. Minor damage to the wall of ureter 41%, alongside need of another surgery were recorded as other commonly neglected risks. However, only 7% of the consent forms did not mention bleeding and just 2% of the forms failed to include stent insertion as a common effect of procedure. Only 17% consent for did not have eligible handwriting, although this is subjective. Conclusions Documentation on consent forms for ureteroscopy lacks accuracy and missed important information. We propose use of digital consent form to assess compliance and quality of consent documentation.

The ratio of CT attenuation values of the ureter above/below ureteral stones is a useful preoperative factor for predicting impacted ureteral stones.

Impacted stones typically make it difficult to perform ureteroscopic lithotripsy (URSL), so it is useful to preoperatively predict such impaction. We focused on CT attenuation values of the ureter above and below the stone ('HU above' and 'HU below') and calculated their ratio (HAB ratio; HU above/HU below ratio). The aim was to investigate whether HAB ratio could predict impacted stones preoperatively. Between 2011 and 2019, 171 patients from our hospital that had URSL for ureteral stones with pretreatment non-contrast computed tomography (NCCT) were retrospectively identified. Ureteral wall thickness (UWT), ureteral wall volume (UWV) and HAB ratio ('HU above' divided by 'HU below') were recorded. Impacted stones were defined as fixed stones that did not move by means of ureteroscopic manipulation or water pressure. Of the 171 procedures, 46 (27%) involved patients with impacted stones. Comparing patient characteristics and stone parameters according to impaction status, factors with significant difference included grade of hydronephrosis, UWT, and HAB ratio (all P < 0.01). Multivariate analysis indicated that significant independent predictors of impacted stones were thicker UWT and lower HAB ratio (all P < 0.01). HAB ratio was a significant preoperative predictor of stone impaction in patients undergoing URSL for ureteral stones. HAB ratio may be informative for selecting the treatment and preoperative preparations.

The role of inflammatory serum markers and ureteral wall thickness on spontaneous passage of ureteral stone < 10 mm: A prospective cohort study

IntroductionUreteral stone is a worldwide disease and accounts for 20% of all urolithiasis. There is a widespread discussion on the preferred initial treatment method, whether medical or surgical, and each has its pros and cons. In this study, we aimed to assess the role of both ureteral wall thickness around the stone and inflammatory markers in guiding the decision-making process. MethodsIn this prospective study, 161 patients who presented with ureteric colic and were diagnosed with ureteral stone with NCCT were included. UWT around the stone was measured, and the NLR and PLR were calculated. The patients were given a single daily dose of tamsulosin 0.4 mg for 4 weeks with weekly follow-up to determine SSP or failure. ResultsOf the 161 patients with a mean age 40.12 ± 12.36 SD, 55.9% had a spontaneous stone passage. Receiver operating characteristics showed a cut off value of 2.45 mm UWT of non SSP patients with an 83% sensitivity and 86% specificity. Moreover, there was a significant correlation between higher NLR, PLR and increased UWT (Pearson correlation of 0.314 and 0.426 respectively). The combined higher NLR, PLR and increased UWT were associated with failure of SSP (p-value <0.001). ConclusionMany factors play a role in decision making for management of ureteral stones. Our study concludes that patients with high NLR, PLR, and UWT around the stone have lesser chance of SSP using MET. Their rise can be used as predictors to decide early intervention.