Total laparoscopic hysterectomy with posterior cul-de-sac obliteration: step-by-step procedures based on precise anatomical landmarks.

BACKGROUND: Dense adhesion due to severe endometriosis between the posterior cervical peritoneum and the anterior sigmoid or rectum obliterates the cul-de-sac and distorts normal anatomic landmarks. Surgery for endometriosis is associated with severe complications, including ureteral and rectal injuries, as well as voiding dysfunction. It is important to develop the retroperitoneal avascular space based on precise anatomical landmarks to minimize the risk of ureteral, rectal, and hypogastric nerve injuries. We herein report the anatomical highlights and standardized and reproducible surgical steps of total laparoscopic hysterectomy for posterior cul-de-sac obliteration. OPERATIVE TECHNIQUE: We approach the patient with posterior cul-de-sac obliteration using the following five steps. Step 1: Preparation (Mobilization of the sigmoid colon and bladder separation from the uterus). Step 2: Development of the lateral pararectal space and identification of the ureter. Step 3: Isolation of the ureter. Step 4: Development of the medial pararectal space and separation of the hypogastric nerve plane. Step 5: Reopening of the pouch of Douglas. CONCLUSION: Surgeons should recognize the importance of developing the retroperitoneal avascular space based on precise anatomical landmarks, and each surgical step must be reproducible.

Ureteral Diameter as Predictor of Ureteral Injury during Ureteral Access Sheath Placement.

PURPOSE: We determined the association between ureteral diameter and ureteral injury during ureteral access sheath placement. MATERIALS AND METHODS: Patients were prospectively enrolled in the study from July 2014 to September 2015. All patients underwent preoperative noncontrast computerized tomography and had a 12Fr to 14Fr ureteral access sheath placement without pre-stenting. A measurement of proximal ureteral diameter was carried out by 2 urologists and 1 radiologist. Ureteral wall injuries were evaluated by 2 endourologists using the 5-grade classification. RESULTS: A total of 68 patients were included and the overall success rate for sheath placement was 94.1% (64). Among this group 46 patients (71.9%) had evidence of any type of injury to the ureter wall and the rate of high grade injuries was 26.1% (12). The ureteral diameter of patients who had a high grade injury was significantly smaller compared to those with low grade injuries (mean±SD 3.29±0.46 mm vs 4.5±0.97 mm, p <0.001). On multivariate analysis narrower proximal ureteral diameter was associated with a higher risk of high grade ureteral injury (OR 2.8, 95% CI 1.9-3.4, p <0.001), regardless of age, gender, body mass index, and middle and distal ureteral diameter. CONCLUSIONS: The proximal ureteral diameter is associated with high grade ureteral injury. A smaller ureteral diameter increases the risk and the severity of ureteral injury. Therefore, preoperative measurement of the ureteral diameter is recommended for ureteral access sheath placement to predict the risk of ureteral injury.

Can ureteral wall thickness (UWT) be used as a potential parameter for decision-making in uncomplicated distal ureteral stones 5-10 mm in size? A prospective study.

OBJECTIVE: To evaluate the correlation between ureteral wall thickness (UWT) and stone passage (SP) and its cut-off value in distal uncomplicated ureteral stones. PATIENTS AND METHODS: In the prospective study from January 2019 to January 2020 at a tertiary care hospital, we reviewed 212 patients aged above 18 years with single, symptomatic, radiopaque, and distal ureteric stone sized 5-10 mm, who were treated with MET (Silodosin 8 mg once daily) until SP or a maximum of 4 weeks. There were 2 groups: responders and non-responders. Demographic data of the patients and all stone radiological parameters including stone size, laterality, density, UWT, the diameter of the ureter proximal to the stone (PUD), and the degree of hydronephrosis were recorded and compared between the 2 groups. RESULTS: There were 126 (59.4%) in the responder group and 86 (40.6%) in the non-responder group. On univariate analysis, gender, stone density, stone size, PUD, UWT, and the degree of hydronephrosis were significant factors for stone passage. However, using multivariate analysis, only UWT and the degree of hydronephrosis were significant. ROC analysis showed that 3.75 mm is the cut-off value for UWT, with 86% and 87.3% sensitivity and specificity, respectively. CONCLUSIONS: UWT and hydronephrosis can be used as potential predictors for SP and can help with decision-making in patients with uncomplicated 5-10 mm lower ureteric stones.

[Three-dimensional MRI reconstruction research on the anatomical relationship among uterosacral ligament and ureter or rectum in pelvic organ prolapse patients].

Objective: To study the anatomical relationship among uterosacral ligament and ureter or rectum by using MRI three-dimensional reconstruction model in pelvic organ prolapse (POP) patients. Methods: According to the research standard, 67 POP patients were enrolled, who accepted pelvic MRI before surgery in Nanfang Hospital, Southern Medical University during May 2015 to March 2020. Three-dimensional model of uterosacral ligament was reconstructed. The intersection point of the fitting curve of uterosacral ligament and ischial spine level marked point P0, every 1 cm increasing from P0 towards the sacrum marked points P1, P2, and P3. Distances were measured between rectum or ureter to uterosacral ligament respectively at the P0-P3 horizontal levels. Results: (1) The distances between the left ureter and the left uterosacral ligament were (15.45±7.46) to (19.31±11.38) mm, and the distances between the right ureter and the right uterosacral ligament were (13.77±8.16) to (14.78±9.18) mm. At the P1 horizontal level ureters were the closest to uterosacral ligaments, and the right ureter was the closest to right uterosacral ligament [(13.45±9.34) mm] at P2 horizontal level in severe POP group. The farthest distance presented at the P3 horizontal level between bilateral ureters and uterosacral ligaments. (2) At the P0 horizontal level, the rectum was the closest to the bilateral uterosacral ligaments [left: (20.62±9.99) mm, right: (16.82±9.63) mm; P=0.026], and the rectum was closer to the right uterosacral ligament. There were no significant differences in the distance between rectum and bilateral uterosacral ligaments in mild POP group (P>0.05), and the results of severe POP group also showed the rectum was closer to the right uterosacral ligament [(15.64±10.31) mm at P0 horizontal level]. Conclusions: Right ureter and rectum are closer to the right uterosacral ligament. Gynecologists should pay more attention to avoid damaging the right ureter and rectum during the operation of the right uterosacral ligament in POP patients.

The magnetic resonance imaging appearances of the interureteric crest of the urinary bladder.

PURPOSE: This study was devised to evaluate the imaging appearances of the interureteric crest (IUC) of the bladder on magnetic resonance imaging (MRI). The primary objective was to determine how commonly the IUC was observed on pelvic MRI examinations. The secondary objectives were to determine the average size of the IUC, its MRI signal characteristics and whether there is variation between men and women. By defining the imaging findings we hope to prevent misinterpretation of normal anatomy on MRI and, therefore, prevent unnecessary further investigations and procedures. METHODS: We retrospectively reviewed 114 adult patient's magnetic resonance imaging examinations of the pelvis. Two readers independently recorded information about the presence and characteristics of the IUC with a third reader used to arbitrate in cases of disagreement. RESULTS: The IUC was demonstrated on MRI in 75% of patients. It was best observed on T2w sequences as a continual ridge of low signal intensity between the ureters. The mean AP diameter of the IUC at its mid-point on the sagittal images was 2.4 mm. CONCLUSIONS: The IUC is often seen on MRI on T2w images of a non-collapsed bladder. Its characteristic appearance can be used to help the reporting radiologist confidently differentiate identify this normal structure from an area of focal bladder wall thickening that might be misinterpreted as a bladder tumor.

Near-infrared fluorescence laparoscopy of the ureter with three preclinical dyes in a pig model.

BACKGROUND: Ureteric injury is reported to occur in 1-7.6% of colorectal surgeries. To reduce the incidence of ureteral injury, it is essential to identify the ureters. The use of near-infrared fluorescence (NIRF) imaging with intravenously administered dyes might be of added value for ureteral visualization during laparoscopy. The aim of this study is to assess the performance of three preclinical dyes; IRDye® 800BK, IRDye® 800NOS and IRDye® 800CW, for near-infrared fluorescence laparoscopy of the ureter in pigs. METHODS: In three female Dutch landrace pigs, the new dyes were evaluated. In each pig, 1 dye was tested using a 6-mg intravenous dose in a concentration of 1 mg/ml. Imaging was performed in fluorescence mode and white light mode with a laparoscopic imaging system. In order to further evaluate the dyes, an ex vivo imaging experiment was performed, in which 8 decreasing concentrations per dye, diluted in PBS, were evaluated in a transparent test tube with NIRF mode at a distance of 1, 5 and 10 cm from the laparoscope. RESULTS: All three dyes were effective in allowing the identification of the ureter with NIRF imaging. The ureter became fluorescent after 35, 45 and 10 min, respectively, for IRDye® 800BK, IRDye® 800NOS and IRDye® 800CW with a maximum target-to-background ratio (TBR) of 2.14, 0.66 and 1.44, respectively. In the ex vivo imaging experiment, all three dyes produced a strong fluorescence signal at all concentrations and all distances evaluated. CONCLUSIONS: Intravenous administration of the preclinical dyes IRDye® 800CW, IRDye® 800 BK and IRDye® 800NOS facilitated successful identification of the anatomical course of the ureter in living pig models. The highest measured TBR occurred with the use of IRDye® 800BK. Ex vivo, a correlation was observed between the fluorescence intensities of the signal with the concentration of the dye and with the distance to the object.

Standardization of laparoscopic extrafascial hysterectomy: anatomic considerations to protect the ureter.

PURPOSE: To describe the procedure of laparoscopic extrafascial hysterectomy to avoid ureter injury. METHODS: Data were obtained from: (1) anatomic study of ten fresh female cadavers to measure the distance between the point where the ureter and uterine artery cross and the level of section of the ascending branch of the uterine artery during extrafascial dissection of the uterine pedicle and uterosacral ligament (Paris School of Surgery). The Wilcoxon test was used to compare measurements within each subject. P < 0.05 was considered to denote significance; (2) prospectively collected clinical data from women undergoing laparoscopic extrafascial hysterectomy from July 2006 to March 2014 at Poissy University Hospital, to describe the laparoscopic extrafascial hysterectomy technique with analysis of surgical complications using the Clavien-Dindo classification. RESULTS: Anatomic study: The mean (SD) distance between the point where the ureter and uterine artery cross and the level of the section of the ascending branch of the uterine artery were: 11.6 mm (5.2) in neutral position and 25 mm (7.5) after pulling the uterus laterally; and 25mm (8.9) after sectioning the ascending portion of the uterine pedicle and 38.6 mm (4.5) after complete uterine artery pedicle dissection through the uterosacral ligaments. After release of the ureter, the curve in front of the uterine artery disappeared. Clinical laparoscopic study: Sixty-eight patients underwent laparoscopic extrafascial hysterectomy. No ureteral complications occurred. CONCLUSION: Laparoscopic extrafascial hysterectomy is a safe and feasible procedure. Combined lateralization and elevation of the uterus, section of the ascending branch of the uterine artery, and its extrafascial dissection along the uterosacral ligament contribute to protecting the ureter during the procedure.

[Is the ureteral length associated with the patient's size?] / La longueur de l'uretère est-elle liée à la taille du patient ?

OBJECTIVE: To assess the relation between the ureteral length and the patients' size. PATIENTS AND METHOD: Prospective study made between September 2012 and May 2014, on 87 patients with 42 men and 45 women, in whom the ureteral measure was performed during the various procedures that require the use of a pigtail stent. The average age of the population was 53 years old (±15.9) with an average height of 168.3cm (±8.4). This has been achieved through ureteral catheter combining fluoroscopy and endoscopy. RESULTS: The ureteral average length was 23.5cm (±2.33). The ureteral average length was 23.8cm (±2.18) for man and 23.2cm (±2.44) for women. In this population, there were a positive correlation between the size of the patients and the length of the ureters (r=0.75; P=0.01). However, this correlation was not found in all subgroups, particularly among women (r=0.16; P=0.30) and on the right side of men (r=0.34; P=0.12). This correlation was still true for the left side in the men's group (r=0.50; P=0.02). CONCLUSION: In this study, there is a positive correlation between the patients' size and the ureteral length. But this correlation is not found in some subgroups. It is better to perform in vivo the ureteral measurement to have the precise length in order to set up a pigtail stent adapted to the patient. LEVEL OF EVIDENCE: 3.

Morphological study of the ureterovesical junction in children.

Morphological and morphometric assessment of the elements of the ureterovesical junction in children was performed in the present study in different age groups ranging from 24 weeks of gestation to 16 years old. We tried to answer the question whether, in human ontogenesis, there is a period of anatomical predisposition to primary vesicoureteral reflux. The study included 210 urinary bladders with juxtavesical parts of the ureters that had been obtained from routine autopsies. As a result of the study, we showed that provided the pregnancy is uncomplicated there is no inherited susceptibility that would account for reducing or disturbing the development of ureterovesical junction elements. Based on the analysis of our results concerning the anatomy and morphological changes taking place in the elements of the ureterovesical junction in different age groups, one could put forward a hypothesis that anatomical predisposition to primary vesicoureteral reflux occurs in age group II, i.e. between 28 and 37 weeks of gestation. The parameters that define interrelations between elements of the ureterovesical junction and that are considered essential for normal functioning of antireflux mechanism were still observed in age group VI in our study. This suggests that these relations are not unambiguous in children with normally structured and functionally competent vesicoureteral junction.

The anatomy of the sacral promontory: How to avoid complications of the sacrocolpopexy procedure.

Because of problems with vaginal meshes and the high rate of recurrences of native tissue repair, more and more surgeons treat pelvic organ prolapse with laparoscopic sacrocolpopexy. This surgery requires skilled surgeons. The first step of sacrocolpopexy is the dissection of tissues in front of the sacral promontory to reach the anterior longitudinal ligament. Some complications can occur during this dissection and the attachment of the mesh. This step is dangerous for surgeons because of the proximity of vessels, nerves, and ureters. The lack of knowledge of anatomy can lead to severe complications such as vascular, ureteral, or nerve injuries. These complications can be life-threatening. To show anatomic concerns when surgeons dissect and affix the mesh on the anterior longitudinal ligament, we have developed a video of the promontory anatomy. By reviewing anatomic articles about vessels, nerves, and ureters in this localization, we propose an educational tool to increase the anatomic knowledge to avoid severe complications. In this video, we show an alternative location for dissection and graft fixation when the surgeon believes that mesh cannot be fixed safely on the anterior surface of S1, as currently recommended.

Ureter Complications: A Rare Complication but which Requires the Highest Degree of Management Expertise.

INTRODUCTION: 0% of all urinary tract injuries are iatrogenic lesions. Although they only occur in < 5%, they can lead to severe ipsilateral renal dysfunctions. These lesions can be treated with extensive knowledge on the genesis of the lesion, the anatomy, the individual patient's history and high operative expertise in diverse surgical methods. MATERIAL AND METHODS: In this article, we show which reconstruction options are possible, depending on the lesion's severity according to the AAST and EAU Guidelines from 2009 on the classification of ureter injuries, as well as the localisation. A special focus is on the anatomy. It is important to adhere to surgical ground principles, such as making sure all pathological tissue is removed, the ureter ends are spatulated and a tension-free and watertight anastomosis is maintained. RESULTS: Iatrogenic ureter lesions are rare complications, but being able to deal with these frequently requires a urologist's expertise. Whenever surgeons operate close to the ureters, there is always a risk of an iatrogenic ureter lesion, which in turn requires that all available reconstructive measures are used dynamically. CONCLUSION: Ureter complications are rare but require surgeons' excellent management expertise.

The sheath of Waldeyer is not a specific anatomical trait of the ureterovesical junction.

The function of the ureterovesical junction depends upon a peculiar structure, the adventitial fibromuscular sheath of Waldeyer, which coats the distal end of the ureter. The origin of the smooth muscle of Waldeyer's sheath (WS) is disputed. Evidence points more likely to an ureteral one. In this regard we hypothesized the WS is not specific to the distal ureter but is rather a common trait. We therefore aimed at exploring whether or not the proximal ureter is provided with a similar adventitial fibromuscular coat. We performed an immunohistochemical study on human samples of proximal ureter resulted after nephrectomies in ten patients. We applied myoid immunohistochemical markers: α-smooth muscle actin (α-SMA), desmin, and heavy chain of smooth muscle myosin (SMM) which labeled additional adventitial smooth muscle bundles, a discontinuous inner circular one applied on the muscular coat, and outer longitudinal cords specifically located on one side of the ureter, as is the case for WS. Moreover, the lamina propria myoid deep layer showed isolated smooth muscle fibers and spindle-shaped stromal cells with telocyte morphology. Our results support the idea that WS may not be a specific structure of the distal ureter, instead being just a common anatomical characteristic of the ureter.

Distal Ureteral Diameter Ratio is Predictive of Breakthrough Febrile Urinary Tract Infection.

PURPOSE: Distal ureteral diameter ratio is an objective measure that is prognostic of spontaneous resolution of vesicoureteral reflux. Along with likelihood of resolution, improved identification of children at risk for recurrent febrile urinary tract infections may impact management decisions. We evaluated the usefulness of ureteral diameter ratio as a predictive factor for breakthrough febrile urinary tract infections. MATERIALS AND METHODS: Children with primary vesicoureteral reflux and detailed voiding cystourethrogram were identified. Ureteral diameter ratio was computed by measuring largest ureteral diameter within the pelvis and dividing by the distance between L1 and L3 vertebral bodies. Demographics, vesicoureteral reflux grade, laterality, presence/absence of bladder-bowel dysfunction, and ureteral diameter ratio were tested in univariate and multivariable analyses. Primary outcome was breakthrough febrile urinary tract infections. RESULTS: We analyzed 112 girls and 28 boys with a mean ± SD age of 2.5 ± 2.3 years at diagnosis. Vesicoureteral reflux was grade 1 to 2 in 64 patients (45.7%), grade 3 in 50 (35.7%), grade 4 in 16 (11.4%) and grade 5 in 10 (7.2%). Mean ± SD followup was 3.2 ± 2.7 years. A total of 40 children (28.6%) experienced breakthrough febrile urinary tract infections. Ureteral diameter ratio was significantly greater in children with (0.36) vs without (0.25) breakthrough febrile infections (p = 0.004). Controlling for vesicoureteral reflux grade, every 0.1 U increase in ureteral diameter ratio resulted in 1.7 times increased odds of breakthrough infection (95% CI 1.24 to 2.26, p <0.0001). CONCLUSIONS: Children with increased distal ureteral diameter ratio are at greater risk for breakthrough febrile urinary tract infections independent of reflux grade. Ureteral diameter ratio provides valuable prognostic information about risk of recurrent pyelonephritis and may assist with clinical decision-making.

Origin and nature of pelvic ureter innervation.

AIMS: Innervation of the pelvic ureter traditionally comes from the pelvic plexus. This innervation is independent: adrenergic and cholinergic. The purpose of this study was to describe more precisely the origin and nature of its innervation (adrenergic, cholinergic, nitrergic, and somatic). METHODS: Six specimens of normal human fetal pelvis (four male and two female) from 20 to 30 weeks gestation were studied. The sections of these fetuses, carried out every 5 µm without interval, were treated with Hematoxylin Eosin (HE), with Masson's trichrome (TriM), immunolabeling of smooth muscle cells with smooth anti-actin, of nerves with anti-S100 protein, anti-tyrosine hydroxylase, anti-VAChT, anti-nNOS, and with anti- peripheral myelin protein 22 (PMP 22). The slides were scanned and two-dimensional images reconstructed in 3D, and analyzed. RESULTS: The terminal pelvic ureter travels above and inside the inferior hypogastric plexus (IHP). The nerve fibers that innervate the ureterovesical junction come mainly from the superior hypogastric plexus (SHP) which gives off the hypogastric nerves and pelvic branches of the sacral plexus that form the IHP. Most nerve fibers meet below the ureter, behind the bladder to form an ascending bundle, which innervates the pelvic ureter. Immunohistochemical analysis shows that the nerves of the pelvic ureter consist of adrenergic, cholinergic, and nitrergic fibers. CONCLUSION: The innervation of the distal ureter depends mainly on the SHP. This innervation is adrenergic, cholinergic, and nitrergic. It innervates the pelvic ureter in an ascending manner. This anatomical information can change rectal resection and ureteral reimplantation techniques and drug treatments for pelvic ureter stones. Neurourol. Urodynam. 36:271-279, 2017. © 2015 Wiley Periodicals, Inc.

Vaginal hysterectomy, vaginal salpingoophorectomy and uterosacral ligament colpopexy: a view from above (in English and Spanish).

AIM OF THE VIDEO: The aim of this video is to make vaginal hysterectomy (TVH), vaginal salpingoophorectomy and uterosacral ligament (USL) colpopexy approachable by showing the key procedural steps from both the vaginal and abdominal perspectives. METHODS: This production shows TVH with salpingoophorectomy and USL colpopexy that was performed on a cadaver and filmed simultaneously from the vaginal and abdominal views. The video begins with an anatomy overview from the open abdomen and proceeds with the TVH. The anterior and posterior peritoneal entries, a technique to safely and easily access the adnexa, as well as the placement of USL suspension sutures are highlighted. The proximity of the ureter and its distance from the three locations most vulnerable to injury during this procedure (the uterine artery pedicle, the infundibulopelvic ligament and the USL) are illustrated. The location of the USL suspension sutures in relation to the ischial spine, the rectum and the sacrum are demonstrated. For all of these crucial steps, a series of picture-in-picture views simultaneously showing the abdominal and vaginal perspectives are presented so that the viewer may better understand the spatial anatomy. CONCLUSION: This video provides the viewer with a unique anatomic perspective and helps more confidently perform TVH, vaginal salpingooophorectomy and USL colpopexy.

Vesicoureteral refux detection in children: a comparison of the midline-to-orifice distance measurement by ultrasound and voiding urosonography.

BACKGROUND: Due to the questionable clinical role of vesicoureteral reflux (VUR) and the search for noninvasive, radiation-free procedures sufficiently reliable to detect VUR, we compared the correlation between the midline-to-orifice distance (MOD) measured by ultrasonography (US) and echo-enhanced voiding urosonography (VUS) for detecting VUR in children. The aim of the study was to determine whether measuring MOD by US could be a reliable predictor of VUR in children. METHODS: A total of 116 children, aged 0.25-84 months, with 232 potentially refluxing units were investigated simultaneously by measuring the MOD and performing VUS. Indications for cystography were urinary tract infection and follow-up of a previously detected VUR. VUS was performed after the MOD measurement. The results were analyzed with VUS as the reference method. RESULTS: The MOD was significantly larger in VUR grade III (10.7 mm; p = 0.003) and VUR grade II (9.9 mm; p = 0.001) refluxing units than in non-refluxing units (7.8 mm), even when controlling for the estimated volume/expected maximal capacity (Vest/Vmax) ratio. A MOD cutoff value of 7.4 mm was chosen as a predictor of either the presence or absence of VUR; the sensitivity and specificity of this cutoff measurement for VUR detection were found to be 89 and 24%, respectively. CONCLUSIONS: Despite the statistically significant difference between the MOD of refluxing versus non-refluxing units identified in our study, the MOD measurement needs further evaluation to determine its potential value as a diagnostic tool for the detection of VUR.

Developing a preoperative predictive model for ureteral length for ureteral stent insertion.

BACKGROUND: Ureteral stenting has been a fundamental part of various urological procedures. Selecting a ureteral stent of optimal length is important for decreasing the incidence of stent migration and complications. The aim of the present study was to develop and internally validate a model for predicting the ureteral length for ureteral stent insertion. METHODS: This study included a total of 127 patients whose ureters had previously been assessed by both intravenous urography (IVU) and CT scan. The actual ureteral length was determined by direct measurement using a 5-Fr ureteral catheter. Multiple linear regression analysis with backward selection was used to model the relationship between the factors analyzed and actual ureteral length. Bootstrapping was used to internally validate the predictive model. RESULTS: Patients all of whom had stone disease included 76 men (59.8%) and 51 women (40.2%), with the median and mean (± SD) ages of 60 and 58.7 (±14.2) years. In these patients, 53 (41.7%) right and 74 (58.3%) left ureters were analyzed. The median and mean (± SD) actual ureteral lengths were 24.0 and 23.3 (±2.0) cm, respectively. Using the bootstrap methods for internal validation, the correlation coefficient (R2) was 0.57 ± 0.07. CONCLUSION: We have developed a predictive model, for the first time, which predicts ureteral length using the following five preoperative characteristics: age, side, sex, IVU measurement, and CT calculation. This predictive model can be used to reliably predict ureteral length based on clinical and radiological factors and may thus be a useful tool to help determining the optimal length of ureteral stent.

A Novel Endoscope System for Position Detection and Depth Estimation of the Ureter.

Iatrogenic injury of ureter occurs occasionally in the clinical laparoscopic surgery. The ureter injury may cause the serious complications and kidney damage. To avoid such an injury, it is necessary to detect the ureter position in real-time. Currently, the endoscope cannot perform this type of function in detecting the ureter position in real-time. In order to have the real-time display of ureter position during the surgical operation, we propose a novel endoscope system which consists of a modified endoscope light and a new lumiontron tube with the LED light. The endoscope light is modified to detect the position of ureter by using our proposed dim target detection algorithm (DTDA). To make this new system functioning, two algorithmic approaches are proposed for the display of ureter position. The horizontal position of ureter is detected by the center line extraction method and the depth of ureter is estimated by the depth estimation method. Experimental results demonstrate that the proposed endoscope system can extract the position and depth information of ureter and exhibit superior performance in terms of accuracy and stabilization.

Ureteral length in live donor kidney transplantation; Does size matter?

The aim of this study was to evaluate the role of ureteral length on urological complications. Data were retrospective collected from the INEX-trial database, a RCT to compare the intravesical to the extravesical ureteroneocystostomy. Ureteral length was measured in 198 recipients and used to divide recipients into three categories based on interquartile ranges: short (≤8.5 cm), medium (8.6-10.9 cm) and long ureters (≥11 cm). Urological complications were defined as the number of percutaneous nephrostomy placements (PCN). Fifty recipients fell into the short, 98 into the medium and 50 recipients into the long ureter category. Median follow-up was 26 (range 2-45) months. There was no significant difference in number of PCN placements between the categories. There were 9 (18%) PCN placements in the short ureter category, 21 (20%) in medium ureter category and 10 (21%) in the long ureter category, P = 0.886. Risk factor analysis for gender, arterial multiplicity and type of ureteroneocystostomy showed no differences in PCN placements between the three ureteral length categories. We conclude that ureteral length alone does not seem to influence the number of urological complications.