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Objectives To create an in vitro anatomic bench model that can mimic in vivo intrapelvic pressure (IPP) during ureteroscopy (URS) and compare it against existing in vivo and ex vivo data. Methods A silicone kidney model (Simagine Health) that permits intrarenal endoscopic navigation was engineered to have a fluid-tight seal for the ureteral opening and a Tuohy-Borst valve in the renal pelvis incorporating a 0.2 mm pressure sensor (Opsens). To calibrate the model, a Cobra ureteroscope (Wolf) was inserted to the pelvis with 200cmH2O irrigation, and the valve adjusted until an IPP of 54cmH2O was obtained (prior human data). All experiments were conducted with a laser fiber in the working channel, with and without ureteral access sheaths (UAS) (11/13F, 13/15F) at irrigation setting of 61, 102, 153, and 193cmH2O using an automated system (Rocamed). Study outcome was mean steady-state IPP for each UAS/irrigation condition. Results Fluid leakage through the Tuohy-Borst valve, which could be adjusted, was critical to simulate ureteric outflow during URS. IPP values for each condition corresponded with data from in vivo and ex vivo models. In the no UAS condition, IPP increased with increasing irrigation pressures, and surpassed 40cmH2O when ≥153cmH2O. When using a UAS, IPP was below 40cmH2O for all irrigation pressures. Conclusions An in vitro kidney model can simulate in vivo and ex vivo IPP profiles, and be tailored to different conditions by controlling fluid outflow. This bench model can be useful for testing of new technologies and their impact on IPP.

We aimed to investigate whether the angle created by the most lateral portion of the lower ureter is responsible for the difficulty in ureteral access sheath insertion. All male patients scheduled to undergo flexible ureteroscopy were enrolled. Patients with ureteral stricture in any course of the ureter and patients with problems at the ureteral opening were excluded. We set the coordinates of the most lateral portion of the lower ureter as M (x, y, z) using computed tomography. The bladder outlet was marked as the zero point O (0, 0, 0). The vector that passed through the urethra and point O was expressed as Vuo (0, 0, − u). The vector that passed through points O and M was expressed as Vom (x, y, z). Thus, an angle (90° − α) could be calculated between Vuo and Vom using the rotation angle formula. A total of 671 male patients were enrolled, among whom the ureteral access sheath could not pass through the most lateral portion of the lower ureter in 14 patients. The mean values of the α angle were 38.56° and 48.48° in the patient and control groups, respectively, compared with the 42 age- and sex-matched control subjects (p

Duplicated collecting systems with minimal-to-no function of the upper moiety are often treated surgically with upper pole heminephrectomy and ureterectomy. Complications associated with the ureteral stump can occur and are collectively known as ureteral stump syndrome. We present a case of ureteral stump syndrome treated with percutaneous transgluteal access into the stump which aided in identification of an ectopic ureteral opening that could not be identified by surgical means alone.

In dogs, ultrasonography is performed to locate the ureteral orifices in the urinary bladder, but reference values for their normal location using this technique are missing. In this study, the ureterovesical–vesicourethral and inter-ureterovesical distances were determined in 20 freshly euthanized medium size dogs by detecting artificially produced ureteral jets in color-flow Doppler ultrasonography at two different bladder volumes, and comparing them to manual measurements in the dissected bladder. All distances determined by ultrasonography were in agreement with values found by dissection (P ≥ 0.100). With increasing bladder volume only the left ureterovesical–vesicourethral distance changed (P = 0.041). The right ureteral opening was more cranial than the left in 16 dogs. The inter-ureterovesical distances differed by gender (P = 0.016), but spay/neuter status had no influence (P ≥ 0.847). In conclusion, ultrasonography is a reliable modality for screening ureteral orifices in medium size dogs and agrees with anatomical findings.

Objectives: To define an exact pressure-flow correlation in the upper urinary tract using an improved measurement method, to quantitatively characterize the degree of postrenal obstruction and to find a simple way of calculating it in everyday urological practice. Methods: The data of 112 cases were included in the analysis. The dynamic method of a multistep, constant pressure perfusion study was used to precisely measure a wide range of pressure-flow dependences. Values of established parameters measuring the degree of obstruction were compared: the intrapelvic pressure, the ureteral opening pressure and the newly introduced ‘obstruction coefficient’. Results: Pressure-flow relations can be best presented by a parabolic curve described by the simple formula Y = AX2 + B. Depending on the degree of obstruction, the shape of this curve can be characterized by a single number, that we defined as the ‘obstruction coefficient’. Computer-based evaluation software for the easy calculation of this coefficient is presented here and freely available on demand. The Whitaker-test, the ureteral opening pressure, and the ‘obstruction coefficient’ showed significant correlation proving that the latter was clinically applicable in measuring the degree of obstruction. Conclusion: Calculation of the ‘obstruction coefficient’ enables us to exactly define the degree of upper urinary tract obstruction and to safely monitor for a long period conditions inhibiting ureteric passage.

The antegrade nephrostogram is an important tool in the evaluation of the upper urinary tract. However, the information currently provided by a nephrostogram is largely limited to anatomical details. To establish a meaningful pressure-flow parameter that may be incorporated into a routine nephrostogram, we evaluated the ureteral opening pressure (defined as the pressure at which contrast material is first seen beyond the suspected site of obstruction) and correlated these findings with the results of pressure-flow studies performed with an external infusion and/or furosemide induced diuresis.A total of 52 renal units were studied under a prospective pressure-flow study protocol. All patients had grade 3 or 4 hydronephrosis (Society of Fetal Urology classification) and patient age range was 0.2 to 12 years (median 1.1). The suspected sites of obstruction were the ureteropelvic and ureterovesical junctions in 42 and 10 renal units, respectively. With the patient under general anesthesia 22 gauge percutaneous nephrostomy needles were inserted. Pressure-flow studies with an external infusion and/or furosemide induced diuresis were then performed. As the renal pelvic pressure progressively increased during the course of the pressure-flow studies, the renal pelvic pressure at which contrast material was first seen to appear distal to the suspected site of obstruction was recorded as the ureteral opening pressure. Ureteral opening pressures were compared to the results of the pressure-flow studies.With a positive test defined as renal pelvic pressure greater than 14 cm. water, positive ureteral opening pressures were associated with positive pressure-flow study results in 100% of the cases, regardless of which form of pressure-flow study was used or where the suspected site of obstruction was located. In contrast, negative ureteral opening pressures had specificities and negative predictive values of only 19 to 57%, depending on the form of the pressure-flow study and the suspected site of obstruction.An elevated ureteral opening pressure was 100% predictive of obstruction and may obviate the need for more elaborate pressure-flow analyses. However, if the ureteral pelvic pressure remained low, the possibility of a potentially significant obstruction could not be definitively eliminated and further evaluation was required.

Materials and Methods: A total of 29 patients (a total of 37 ureters), with primary grades I to V VUR were treated with a single subureteral injection from 2001 to 2004; these patients were followed for an average of 21.5 months. Each patient underwent preoperative voiding cystourethrogra- phy, renal ultrasound, a dimercapto-succinic acid (DMSA) scan and urine culture. With the patient under general anesthesia, the PDS implant was injected transurethrally at the 6 oclock position of the ureteral opening in the affected renal unit by a modified subureteral transurethral injection (STING) procedure. Renal ultrasound was done at 1 week and voiding cystourethrography was done at 3 months to rule out obstruction at the injection site and/or persistent reflux, respectively. Cure was defined as an absence of VUR on voiding cystourethrography at 3 months after injection. Statistical analyses were performed using the chi-square test. Results: The grade of reflux was I, II, III, IV and V in 6, 4, 12, 9 and 6 ureteral units respectively. After a single injection, the VUR was cured in 30 ureteral units (81.1%). There were 7 (18.9%) patients who received a second injection after a failed single injection. In these patients, the injected PDS volume was not changed on ultrasound. On the other hand, cystoscopy showed mound displacement in 4 patients, no volcano ap- pearance but rather a broad elevation in 2 patient, and distal ureteral fistula and mound extrusion in 1 patient. Conclusions: These results suggest that endoscopic subureteral polydi- methylsiloxane injection is an effective treatment of VUR. The efficacy of subureteral injection can be improved by using the correct injection

Purpose : To assess the usefulness of MRI in the detection of a single ectopic ureteral opening and thelocation and dysplastic change of ipsilateral kidney. Materials and Methods : Nine patients (mean age; 4.8 years,M:F=3:6) in whom a single ectopic ureter was suspected clinically and sonographically underwent conventionalradiologic studies ( IVP, VCUG, 99mTc-DM-SA scan, as well as US) and MRI. We evaluated images of the point of theectopic ureteral opening and the lo-cation and dysplastic or hydronephrotic change of the ipsilateral kidney, andcompared those findings with the endoscopic, surgical, and pathological findings. Results : Eight patients had aunilateral single ectopic ureter and one had bilateral lesions. Seven normally po-sitioned kidneys in six patientsshowed dysplastic (n=3) or hydronephrotic (n=4) change. In two patients an ectopic dysplastic kidney was locatedin the pelvis and one had ipsilateral renal agenesis. Conventional radio-logic studies failed to reveal twoectopic dysplastic kidneys, one renal agenesis, and eight ectopic ureteral openings. In all patients, MRI clearlydemonstrated the location of the kidney and ectopic ureteral opening, and dysplastic or hydronephrotic change ofthe kidney, and in one patient, uterine duplication. Except in two patients whose ectopic ureteral opening was notfound on endoscopy, MRI findings were concordant with en-doscopic and surgical findings. Conclusion : MRI wasuseful for the detection of a single ectopic ureteral opening and for demonstrating the location and dysplasticchange of ipsilateral kidney.

To prevent dermal invasion which causes gradual stomal stenosis in cutaneous ureterostomy, transplantation of autologous vaginal vestibular mucosa around the ureteral opening was examined in 9 female dogs. Results of a full-thickness graft to a full-thickness skin bed were hopeful. Though surface keratinization occurred, the thick graft survived well on the abdomen without obvious shrinkage, and the ureteral patency was maintained through the follow-up period with an average of 18 months. This method seemed to be applicable to clinical patients and to dog experiments as a model for separate renal function study.

Nach einem Uberblick uber bisherige Veroffentlichungen von Kreuzbeinagenesien und zugleich bestehenden urologischen Komplikationen, wird ein Fall von missgebildeter unterer Wirbelsaure vergesellschaftet mit einer ektopen Harnleitermundung vorgestellt. Unseres Wissens kann eine Beschreibung des Zusammentreffens dieser beiden Komplikationen zum ersten Mai gebracht werden. In einer ausfuhrlichen Diskussion wird die Ursache der Harninkontinenz in diesem speziellen Fall zu erklaren versucht. Durch eine operative Verlagerung des Ostiums wurde der Patient urologisch geheilt. Das gute Operationsergebnis bestatigt die Annahme, dass bei unserem Patienten in erster Linie die ektope Uretermundung zusammen mit der durch die Kreuzbeinagenesie bedingten neurogenen Sphinkterschwache als Ursache der Inkontinenz angesehen werden muss.

A unique case of left ureteral opening into a seminal vesicle, ipsilateral renal hyperplasia and crossed ectopia of the seminal vesicles is reported. This 24-year-old white man underwent a nephroureterectomy for relief of symptoms of lower urinary tract infection. The embryological development of this abnormality is discussed briefly.