Cause Of Ureteral Obstruction Research Articles

The STING in the tale of Teflon®: Delayed ureteric obstruction after subureteric transurethral injection with polytetrafluoroethylene paste for vesicoureteral reflux

Introduction“Subureteric Teflon INGection” (STING) of polytetrafluoroethylene (PTFE/polytef) paste to treat vesicoureteral reflux (VUR) in children was popularised in 1984. It was later abandoned as an implantation material because of the possibility of migration from the injection site. Giant-cell foreign-body granuloma to Polytef in the bladder is a rare cause of ureteric obstruction. Only a handful of cases have been reported in the literature. MethodsWe performed a prospective analysis of a series of 6 adult patients who had childhood STING and presented with foreign-body granuloma to Polytef in the bladder. We report their clinical presentation, findings and treatment. Results1 male and 5 females with a history of STING procedure in childhood for VUR presented in later life with foreign-body granuloma to Polytef. The median age at first STING procedure and at presentation to the Urology Department was 3 and 34 years respectively. The most common clinical presentations were flank pain and urinary tract infection (UTI) and all patients had radiological findings of calcified lesions at the vesicoureteric junction(s). 4 patients had histological findings of giant-cell foreign-body granuloma. 4 patients required definitive ureteric reimplantation. ConclusionPolytef granuloma causing distal ureteric obstruction may give rise to significant morbidity and renal damage. Due to the likelihood of progression of the granuloma, excision and ureteric reimplantation is considered the standard approach in the management of patients with viable kidneys. Level of evidenceLevel 5.

A novel in vivo model of ureteral fibrosis induced by calcium oxalate beads in C57BL/6J mice.

The global incidence of ureteroliths in humans is increasing, particularly posing a problem in developed countries. The most common stone type is calcium oxalate, which is associated with a high recurrence rate. In veterinary medicine, stones are the most common cause of ureteral obstruction in cats, accounting for 72-87% of cases. In cats, stones cause irreversible ureteral damage, necessitating stone treatment as well as ureteral therapy. However, the mechanisms underlying the ureteral damage caused by stones remain unclear. Therefore, this study aimed to create a mouse model suitable for studying the ureteral fibrosis caused by oxalate stones by artificially embedding calcium oxalate in the ureter. Pathological tissue analysis was used to compare normal ureters without ligation and ureters with sham or oxalate bead implantation. The ureters of the sham and oxalate bead groups showed granulation tissue formation, transitional epithelium exfoliation, and densely packed connective tissue in the proprietary and muscle layer regions. Particularly in the oxalate bead group, infiltration of degenerated neutrophils, presence of foreign body giant cells, and hyperplasia of the transitional epithelium were observed. The proportion of fibrosis was higher in the oxalate group than in the sham group. Overall, this mouse model created using oxalate bead implantation has the potential to efficiently induce ureteral obstruction. This mouse model is expected to be used for elucidating the molecular mechanisms of ureteral fibrosis and evaluating therapeutic drugs in future.

Metachronous ureteral metastasis of a gastric adenocarcinoma: a case report and review of literature

BackgroundUreteral metastasis from gastric cancers are rare and can be a cause of ureteral obstruction. There have been few published case reports in the literature. In this paper, we report an additional case and a review of the literature of all the previous reported cases.Case presentationA 67 years old North African women who was treated four years before for a gastric adenocarcinoma, presented with abdominal pain. Imaging and endoscopy showed a mural stenosis of the left ureter, without any other abnormality. Histopathology confirmed the gastric origin of the metastasis. A palliative chemotherapy was foreseen, but due to the deterioration of the general condition of the patient, she received palliative care. We have also reviewed the literature and reported the previously published cases of ureteral metastasis from gastric cancer.ConclusionsIt is worth recalling that in a context of neoplasia and with the presence of signs of ureteral obstruction, it is important to keep in mind the possibility of a ureteral metastasis.

Effects of hormone therapy on the clinical outcomes of endoscopic intervention in patients with endometriosis-related ureteral obstruction.

We investigated whether endoscopic interventions, including laser endoureterotomy and balloon dilatation following hormone therapy, are a good choice to treat ureteral obstruction due to ureteral endometriosis instead of laparoscopic or open surgery. Patients with ureteral obstruction due to endometriosis who underwent endoscopic intervention between 2004 and 2021 were reviewed. Patients with other causes of ureteral obstruction or previous ureteral surgery were excluded from the study. The primary endpoint was the 3-month success rate of endoscopic intervention with or without hormone therapy. Secondary endpoints were the success rate of endoscopic intervention between the hormone-treated and hormone-untreated groups at 6 months and the success rate according to the hormone therapy response of endometriosis at 3 and 6 months. Eighteen patients with 19 ureter units were evaluated in this study, including 12 patients receiving hormone therapy and six patients not receiving hormone therapy. Among patients receiving hormone therapy, one patient had bilateral ureteral obstruction. The success rate of endoscopic intervention was higher in patients who received hormone therapy than in those who did not receive hormone therapy three months after endoscopic intervention (76.9% vs. 0.0%, p=0.003). The same result was also found 6 months after endoscopic intervention (75.0% vs. 0.0%, p=0.005). In addition, the success rates were higher in the hormone-responsive group than in the non-responsive group (100.0% vs. 57.1%), although the difference was not statistically significant (p=0.122). Ureteral obstruction caused by endometriosis can be effectively treated by endoscopic intervention with hormone therapy in select patients.

Multicenter retrospective evaluation of transmural migration of subcutaneous ureteral bypass devices within the digestive tract in cats.

BackgroundPlacement of a subcutaneous ureteral bypass (SUB) device is an effective method to relieve all causes of ureteral obstruction in cats. Complications involving migration within the gastrointestinal tract have been seldomly described.ObjectivesTo characterize transmural migration of SUB devices within the digestive tract in cats.AnimalsEleven migrated SUB catheters identified in 8 cats between 2017 and 2021.MethodsRetrospective review of medical records of cats with a SUB device in which migration into the gastrointestinal tract was identified.ResultsThe median time from SUB device placement to implant migration was 928 days (201‐2298 days). Seven cats had obstruction of the SUB device and a positive urine culture at diagnosis. The migration was identified by ultrasound in 6/11, pre‐operative contrast radiography in 2/2, and only at time of surgery in 3 SUB devices. All cats underwent surgical correction. Four nephrostomy and 7 cystotomy catheters migrated. Migration occurred into the duodenum (3/11), jejunum (7/11), and colon (1/11). SUB devices were removed in 7 cats and replaced in 2 cats, with 1 cat diagnosed with 2 migration events. Gastrointestinal resection and anastomosis were performed in 7/8 cats and an enterotomy in 2 cats. Six cats survived to discharge. The median follow‐up time after migration diagnosis was 365 days (range, 0‐1114 days) and 2 cats are still alive.Conclusions and Clinical ImportanceAlthough a rare complication, migration of SUB device should be considered in cats with SUB device obstruction and a positive urine culture.

V08-09 SERIES OF MISSED FIBROEPITHELIAL POLYPS IN THE PEDIATRIC POPULATION

You have accessJournal of UrologyCME1 May 2022V08-09 SERIES OF MISSED FIBROEPITHELIAL POLYPS IN THE PEDIATRIC POPULATION Aznive Aghababian, John Weaver, Sahar Eftekharzadeh, Sonam Saxena, Iqra Nadeem, Pooja Unadkat, Katherine Fischer, Karl Godlewski, Sameer Mittal, Christopher Long, Dana Weiss, Arun Srinivasan, and Aseem Shukla Aznive AghababianAznive Aghababian More articles by this author , John WeaverJohn Weaver More articles by this author , Sahar EftekharzadehSahar Eftekharzadeh More articles by this author , Sonam SaxenaSonam Saxena More articles by this author , Iqra NadeemIqra Nadeem More articles by this author , Pooja UnadkatPooja Unadkat More articles by this author , Katherine FischerKatherine Fischer More articles by this author , Karl GodlewskiKarl Godlewski More articles by this author , Sameer MittalSameer Mittal More articles by this author , Christopher LongChristopher Long More articles by this author , Dana WeissDana Weiss More articles by this author , Arun SrinivasanArun Srinivasan More articles by this author , and Aseem ShuklaAseem Shukla More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002606.09AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Fibroepithelial polyps in the urinary tract are a rare cause of obstructive uropathy. We hypothesized that the presence of polyps should be considered as a potential cause of ureteral obstruction during ureteral spatulation at the time of reconstruction in older children. METHODS: We queried our institution’s prospectively managed pyeloplasty and ureteroureterostomy databases to identify patients with findings of fibroepithelial polyps between 2008-2021. Baseline demographics, clinical presentation, imaging details, and post-operative details including resolution of symptoms/hydronephrosis or need for further intervention were aggregated. RESULTS: We identified 7 patients (all male) with fibroepithelial polyps who presented at a median age of 10.4 years (IQR: 9.1, 12.9) [Table 1]. All patients underwent cross-sectional imaging with no polyps visualized. There was a possible crossing vessel visualized in 2 patients who underwent magnetic resonance urography (MRU). 6/7 patients underwent pyeloplasty for presumptive ureteropelvic junction obstruction (UPJO), while one patient underwent an upper to lower pole ureteroureterostomy (UU) following a ureteroscopy that revealed polyps in the distal upper pole ureter of a duplicated system. The median age at surgery was 10.5 years (IQR: 9.5, 13.1). During surgery, retrograde pyelogram (RPG) was performed in 3/7 patients and polyps were visualized in 2 cases. During the median follow-up duration of 27.4 months (IQR: 6.3, 43.6), 2 patients required further intervention: 1 patient required 2 endoscopic interventions for persistent polyps, and 1 patient required 6 endoscopic interventions for persistent polyps/recurrent stones, ultimately requiring a redo pyeloplasty 5.9 years after the index procedure. CONCLUSIONS: In our series, polyps were missed on preoperative imaging (including cross-sectional imaging) in all cases. It is critical for urologists to be aware of polyps as a potential source of obstruction as they can increase the complexity of a reconstruction and, if missed, may result in a failed repair. Performing a RPG prior to upper tract reconstruction can potentially reveal the diagnosis and more clearly delineate the extent of the polyps. Failure to adequately spatulate the ureter and remove all the polyps can result in recurrence which is why we advocate for longer post-operative follow up in these patients. Source of Funding: NA © 2022 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 207Issue Supplement 5May 2022Page: e716 Advertisement Copyright & Permissions© 2022 by American Urological Association Education and Research, Inc.MetricsAuthor Information Aznive Aghababian More articles by this author John Weaver More articles by this author Sahar Eftekharzadeh More articles by this author Sonam Saxena More articles by this author Iqra Nadeem More articles by this author Pooja Unadkat More articles by this author Katherine Fischer More articles by this author Karl Godlewski More articles by this author Sameer Mittal More articles by this author Christopher Long More articles by this author Dana Weiss More articles by this author Arun Srinivasan More articles by this author Aseem Shukla More articles by this author Expand All Advertisement PDF DownloadLoading ...

Nutraceuticals for Dissolving Nephrolites in Cats

Background: Nephrolithiasis is a condition frequently observed in felines, with or without concomitant chronic kidney disease, constituting the major cause of ureteral obstruction and causing progressive damage to the renal parenchyma. About 90% of nephrolites are composed of calcium oxalate, which cannot dissolve, and its incidence has increased substantially in recent years, along with its recurrence. There are functional foods known as nutraceuticals provides health benefits such as renoprotection. Due to these benefits and the high prevalence of nephrolithiasis in feline species, the present study aimed to evaluate the efficacy of the association of some nutraceuticals in the dissolution of nephrolites.Materials, Methods & Results: The included cats had an ultrasound diagnosis of nephrolithiasis that, on clinical examination, showed: (i) the absence of previous or concomitant treatment for urinary infections and/or vesical and renal lithiasis; (ii) absence of genitourinary clinical manifestations; (iii) absence of obstructive processes; and (iv) absence of concomitant ureterolithiasis. We separated 51 cats with nephrolithiasis into 2 groups: control (n = 12) and study (n = 39). The control group received a placebo and the study group, nutraceuticals (magnesium chelate, resveratrol, vitamin K2, docosahexaenoic acid, and eicosapentaenoic acid). Laboratory tests (blood and urine) and abdominal imaging (ultrasound) were performed at day 0 and 30 days after enrollment. Monitoring the therapeutic efficacy in both groups was performed on day 30 for the CG and on days 30, 60, and 90 for the EG. The CG cats, after this step, were referred to surgery or to the EG, with prior authorization from their tutors. The diameter of nephrolites was significantly different before and after treatment, indicating a reduction in nephroliths over time. During the use of the nutraceutical formulation by the EG and use of placebo by the CG, there were no clinical and/or laboratory manifestations of side effects.Discussion: The dissolution of nephrolites was correlated with the synergism promoted by the combination of nutraceuticals and not with the individual beneficial action of each nutraceutical since nutraceuticals have individually been used in isolation for a long time in veterinary medicine without having yielded the same benefit. Those undissolved were attributed to a different type of mineral composition than the one associated with the nutraceutical compound in this study, such as struvite or ammonium urate, of mixed composition or comprising solidified dried blood, which has shown an increasing increase in use in recent years. The dissolution of nephrolites was correlated with the synergism promoted by the combination of nutraceuticals and not with the individual beneficial action of each nutraceutical since nutraceuticals have individually been used in isolation for a long time in veterinary medicine without having yielded the same benefit. The undissolved nephrolites were attributed to the nephrolites that obtained partial dissolution at the end of 90 days, in that they possibly needed a longer time to obtain complete dissolution or that they present another mineral composition in their nucleus; that is, it is a compound-type urolith. The nutraceutical compound proved to be effective in the dissolution of nephrolites in the cats included in this study, and the time of use (up to 90 days) showed no negative influence on the clinical or laboratory tests during the entire treatment period.Keywords: cats, food supplement, functional foods, natural products, nephrolithiasis, nutraceuticals.

Thulium laser ablation for ureteritis cystica

Patients with ureteral obstruction often present a diagnostic dilemma on imaging techniques. Ureteritis cystica (UC) is one benign condition which can occasionally be a cause of ureteric obstruction and almost always eludes diagnosis unless ureteroscopic examination is performed. Although no definitive operative technique has been defined for its cure in the literature, ureteroscopic laser ablation is an effective minimally invasive option. We hereby present a short case report of thulium laser ablation in an elderly female with UC in the left upper ureter.

Our experience in laparoscopic ureterolysis and omental wrapping as a definitive surgical management of ureteric obstruction related to retroperitoneal fibrosis

Introduction and Objectives: Retroperitoneal fibrosis (RPF) is a rare fibro-inflammatory disease and a cause of ureteric obstruction that leads to obstructive uropathy. Although the mainstay of RPF treatment is medical, ureterolysis becomes a necessity if medical treatment fails or if patients are unable to tolerate side effects of conservative/medical management, including those of ureteric stents. We aimed to investigate our experience of laparoscopic ureterolysis (LU) and omental wrapping as a definitive surgical treatment for RPF. Patients and methods: We conducted a retrospective analysis of 17 patients who underwent LU between September 2009 and October 2018 in a single institution. Mode of presentation, investigation and interventions were reviewed. Outcome measures were stent or nephrostomy-free rates, post-ureterolysis change in estimated glomerular filtration rate (eGFR), operative time, estimated blood loss, length of hospital stay, complications and need for additional procedures. MAG3 renography was performed to assess ureteral patency. Results: Among 17 patients, a total of 23 LU procedures were performed in 20 operative sessions. Median (IQR) length of hospital stay was 4 (2–6) days. Median length of follow-up was 23.5 months (range 4–92 months), where 14 patients completed at least 15 months of follow-up. All patients were either stent ( n=9) or nephrostomy ( n=8) dependent before ureterolysis. Some 82.4% patients ( n=14) remain stent/nephrostomy free after LU. Renal function remains stable after ureterolysis with a median (IQR) change in eGFR at latest follow-up of: +7.5 (−8 to +23), ( P=0.74). Conclusions: LU is safe and effective at halting decline in renal dysfunction secondary to RPF. It has reliably avoided internal or external ureteric drainage in most patients. Consideration should be given to early referral to a specialised centre for ureterolysis in the context of multi-disciplinary management of benign RPF, to preservation of renal function and to render patients stent or nephrostomy free. Level of Evidence: 4 (case series).

Double-J Stenting Versus Percutaneous Nephrostomy; Postoperative Complications in Management of Ureteral Obstruction

Background: Ureteral obstruction is a common surgical problem and managed by stent insertion or percutaneous nephrostomy. However, there is still confusion that which procedure is better in terms of the complications. Objective: To compare the efficacy of double J stenting and percutaneous nephrostomy for ureteral obstruction in terms of post-operative complications. Study Design: Randomized Clinical Trial. Settings: Urology Department, Shaikh Zayed Hospital, Rahim Yar Khan-Pakistan. Duration: One years from January through December 2016. Methodology: Male/female patients (aged: 19-63 years) presenting in the OPD of the hospital with ureteral obstruction were registered during study period. Either of the groups i.e. A (double J stenting, n = 55) or B (percutaneous nephrostomy, n = 55) was allotted to the subjects, randomly. The procedures and subsequent complications were addressed as per hospital protocols. Results: Most of the patients i.e., 75 (68.2% of 110) were male whereas age statistics were, as: M = 49.47, SD = 8.2 (range 19-62) years. Ureteral stone(s) was found as the most prevalent cause of ureteral obstruction in group A (49.1%, n = 27) and B (40.0%, n = 22). Hematuria was seen as a common complication: 33.3 (n = 5) and 42.9% (n = 3) in group A and B, respectively. The rate of complications was significantly lower in group B than A [12.7% (n = 7) vs. 27.3% (n = 15), respectively] (p = .04). Conclusion: Percutaneous nephrostomy is a better procedure (in terms of post-operative complications) than double J stenting in management of ureteral obstruction. Keywords: Ureteral obstruction, Percutaneous nephrostomy, Stents, Postoperative complication.

Multiple cystic lesions in the abdominopelvic cavity one and a half years after resection of presacral neurogenic tumor: tumor recurrence or other?

Cystic lesions of abdominopelvic cavity include a variety of pathologies and diagnosis can sometimes be challenging. Urinoma can be caused by iatrogenic injury, spontaneous rupture of ureters or by various causes of ureteral obstruction. It needs to be differentiated from abdominopelvic cystic diseases including tumors that can undergo cystic degeneration. Here we report a case of a 41 years old female underwent a presacral neurogenic tumor resection at a local hospital 5 years ago. The tumor recurred three and a half years after the first surgery and removed at another hospital. She experienced abdominal distension and difficulty in urination from the last 2 months and was diagnosed as having a recurrence of tumor once again at both hospitals on separate CT scans. They believed that the tumor was too large and encroaching on adjacent organs to be surgically resected, she was finally diagnosed as infected urinoma during surgery in our hospital. Even though spontaneous rupture of ureters and urinoma formation is a rare disease but it should be considered as a main differential diagnosis of recurrence of neurogenic tumors especially in post abdominopelvic surgeries patient.

Double trouble: diagnostic dilemma in a rare association of proximal ureteric valve with orthotopic ureterocele\u2014case report

BackgroundAssociation of the ureterocele and proximal ureteral valve is a rare congenital anomaly which can lead to quick detoriation of renal function due to double obstruction. Though ureteral valves have been associated with other ureteral anomalies, this specific association is extremely rare.Case presentationA 7-month-old boy was referred to us for antenatally detected hydronephrosis. Provisional diagnosis of orthotopic ureterocele with pelviureteric junction (PUJ) obstruction was made based on preoperative imaging. Endoscopic incision of ureterocele was done and retrograde pyelography showed tight obstruction at PUJ which necessitated a pyeloplasty. Examination of resected specimen confirmed a ureteral valve. Postoperatively, the patient had good improvement in kidney function.ConclusionTo conclude, congenital ureteral valves are a rare cause of ureteric obstruction and its association with ureterocele is rarer still. Identification of an ureterocele should not deter us from searching for an associated pathology like a ureteric valve when imaging shows more severe hydronephrosis suggestive of more proximal obstruction.

Laparoscopic ureteral reconstruction in infant with congenital mid ureteric valve

Congenital mid ureteric valve (MUV) stenosis is a very rare cause of ureteric obstruction and hydronephrosis (HN) in children. We describe how we manage laparoscopically one case of a patient with congenital MUV. We describe a 6-month-old boy born with antenatal left HN, with an anteroposterior diameter (APD) of 1,5cm. Follow-up renal ultrasound at 3 months of age showed an increase in left kidney HN, approximately 2.5cm below the PUJ associated with distal stenosis. Renal scintigraphy with DTPA showed an obstructive pattern. Urography scan showed an abrupt reduction in the caliber of the mid left ureter Based on a preoperative diagnosis of MUV stenosis, we performed a laparoscopic left ureteroplasty. Abrupt tapering of the left ureter at 3cm from the PUJ was identified. Proximal ureter repair was performed before the resection of the narrowing segment. The two edges of the ureter were spatulated and continuous anastomosis was performed without tension. An antegrade JJ stent was inserted after the posterior part of the anastomosis was done. Patient made an uneventful recovery and was discharged on the first postoperative day. Laparoscopic ureteroplasty is a complex but feasible option to treat patients with congenital MUV stenosis.

Endourologic Treatment in Two Cases of Ureteral Valves.

Introduction: Congenital ureteral valves are a rare cause of ureteral obstruction that may lead to renal function deterioration. We present two clinical cases treated endoscopically by monopolar electrocautery and laser fiber ablation. Presentation of Case: The first case is a 13-year-old male with several episodes of abdominal pain and was found to have severe left hydronephrosis. Ultrasonography showed a dilated ureter and pelvicaliceal system with an obstructive renogram curve. We performed a retrograde pyelogram, finding a dilated ureter 5 cm up from the vesicoureteral junction with ureteral valves in that place. Ablation of the valves was conducted using monopolar electrocautery. The second case is a 2-year-old male with left ureterohydronephrosis shown in abdominal ultrasonography. In the radiologic findings, a high-risk pyelocaliceal dilatation with renal parenchyma thinning and a diameter of 3.3 cm for the left ureter is described, with an obstructive renogram. We performed a cystoscopy, observing the presence of valves in the ureter at 3 cm that conditioned an obstruction. The complete section of the valves was performed through a 270μm holmium laser fiber. Our patients made an uneventful postoperative recovery and continue to remain completely asymptomatic. A significant decrease in renal dilation was observed and renal function recovered in both cases. Conclusion: Ureteral valves are an uncommon cause of ureteral obstruction. Advances in endourologic techniques allow us to give a minimally invasive approach to these diseases, obtaining good long-term results in our small series of patients.

Retrocaval Ureter: a Rare Cause of Abdominal Colic

Retrocaval ureter is an uncommon cause of ureteric obstruction, and presentation as abdominal colic is even rarer. It usually manifest in the 3 rd decade of life and presents with flank pain and hematuria or incidentally detected. Most common is type 1 deformity in which classical reversed J or fish hook deformity is seen on imaging. Contrast study is essential for diagnosis. Renal dynamic scan is helpful to confirm obstructed drainage and function. Surgical intervention mandates excision of atretic segment and end-to-end ureteroureterostomy. We present a 28-year-old male presenting with acute abdominal colic diagnosed with right retrocaval ureter.

Retrocaval ureter: a rare cause of urinary tract obstruction

Retrocaval ureter is an uncommon cause of ureteric obstruction due to a rare congenital anomaly of inferior vena cava. We report a case of 23 year old male who presented with right flank pain and was diagnosed with ultrasound and intravenous urography. He underwent open retroperitoneal ureteroureterostomy.

A rare indication of robot-assisted uretero-ureterostomy: ovarian vein syndrome

Ovarian vein syndrome is a rare cause of ureteral obstruction. Most of these cases occur during pregnancy likely from the gravid uterus causing ovarian vein dilatation and valvular incompetence. Hormonal changes associated with pregnancy also affect the muscular wall of ureter, causing decrease in tone and may facilitate compression as well. There is a predilection for right side and in thin females. The traditional treatment has been the ligation of ovarian vein and ureterolysis. We report a case of ovarian vein syndrome in a young female which was managed by robot-assisted laparoscopic ovarian vein ligation, resection of stenosed ureteric segment and end-to-end ureterostomy.

Treatment outcomes of ureteral stenting for malignant extrinsic ureteral obstruction: a comparison between polymeric and metallic stents.

PurposeTo compare treatment outcomes, more specifically patency rate, of polymeric and metallic stents for malignant ureteral obstruction.Patients and methodsBetween August 2007 and September 2017, we retrospectively analyzed the data of 92 patients (126 ureters) having a diagnosis of malignant extrinsic ureteral obstruction treated with indwelling ureteral stents (polymeric and full-length metallic stents). Of these patients, 35 (54 ureters) were treated with polymeric stents and 57 (72 ureters) with a Resonance® metallic stent. The observation period was censored to 1 year. Survival rate in cases of malignant ureteral obstruction was calculated, and the relationship between the causes of ureteral obstruction, the stent type, and the patency rate was evaluated.ResultsThe median observation period was 145 days, with a median survival time of 258 days. The stent patency rate was 70.9% at 1 year, regardless of stent type. Stent occlusion was observed in 20 patients (33 ureters). According to stent type, occlusion of the polymeric and metallic stents was identified in 12 (22%) and 8 (11%) cases, respectively. The clinical features associated with stent failure were assessed. In univariate analysis, the patency rate was significantly better for the metallic stent than for the polymeric stent (1-year patency rate; 78.4%, 61.1%, respectively, HR, 2.15; 95% CI, 1.07–4.33; p=0.031). However, the patency rate among patients with abdominal dissemination, lymph node metastasis, and direct compression by tumor was not significantly different.ConclusionIndwelling ureteral stents, particularly metallic stents, are effective for the treatment of malignant ureteral obstruction.

Outcomes of patients with ureteral obstruction who achieved stent-free state following balloon dilatation

Objective: The aim of this study was to assess the therapeutic role of ureteral stent removal following balloon dilatation (BD) in patients with a stent implanted for unilateral ureteral obstruction and with normal contralateral renal function.Materials and methods: This retrospective cohort study consisted of 37 consecutive patients with unilateral ureteral obstruction whose stents were removed after BD. All patients satisfied the following criteria: normal contralateral renal function, no evidence of malignancy, and the patient was eager to obtain a stent-free state (SFS) without invasive treatment. The relative function of the affected kidney and total renal function before and after stent removal were analyzed using renal scans and estimated glomerular filtration rate (eGFR). A successful outcome was defined as SFS without pain or febrile urinary tract infection plus maintenance of eGFR.Results: The mean age of all patients was 58.2 years. The mean follow-up periods before and after stent removals were 15.7 and 23.6 months, respectively. The most common underlying cause of ureteral obstruction was pelvic or abdominal surgery (51.4%). Of the 37 patients, 32 (86.5%) achieved successful SFS at last follow-up. Overall in the 37 patients, the eGFR (from 77.1 to 69.8 ml/min/1.73 m2; p = 0.017) and relative renal function of the affected kidney (from 35.5 to 30.2%; p = 0.002) were significantly compromised. However, the reduction in total eGFR was not significant (p = 0.075) in the successful SFS group.Conclusion: The removal of a stent with BD is a viable option for achieving a successful SFS in patients with unilateral ureteral obstruction.

Management of ureteral obstruction with daVinci laparoscopic surgery

Management of ureteral obstruction with daVinci laparoscopic surgery