Metallic Ureteral Stents Research Articles

Metallic Ureteral Stents in Malignant Ureteral Obstruction: Clinical Factors Predicting Stent Failure

To provide clinical outcomes of the Resonance metallic ureteral stent in patients with malignant ureteral obstruction, as well as clinical factors predicting stent failure. Cancer patients who have received Resonance stents from July 2009 to March 2012 for ureteral obstruction were included for chart review. Stent failure was detected by clinical symptoms, image studies, and renal function tests. Survival analysis for stent duration was used to estimate patency rate and factors predicting stent failure. A total of 117 stents were inserted successfully into 94 ureteral units in 79 patients. There were no major complications. These stents underwent survival analysis and proportional hazard regression. The median duration for the stents was 5.77 months. In multivariate analysis, age (P=0.043), preoperative serum creatinine level (P=0.0174), and cancer type (P=0.0494) were significant factors associated with stent failure. Cancer treatment before and after stent insertion had no effect on stent duration. Resonance stents are effective and safe in relieving malignant ureteral obstructions. Old age and high serum creatinine level are predictors for stent failure. Stents in patients with lower gastrointestinal cancers have longer functional duration.

Metallic stents in the management of ureteric strictures

Management of ureteric strictures is a challenging task. Subtle presentation, silent progression and complex aetiology may delay diagnosis. A wide range of available treatment options combined with the lack of adequate randomised trials has led to the introduction of personal bias in the management of this difficult group of patients. Metallic ureteric stents offer an alternative to the conventional treatment modalities. A review of the currently available metallic stents and their role in the long-term management of ureteric strictures is presented. Materials used in the manufacture of indwelling urological devices are evolving all the time. Improved endo-urological techniques combined with new devices made from better compounds will continue to improve patient experience.

E78 Experience with a novel technique for removal of metallic ureteric stents

E78 Experience with a novel technique for removal of metallic ureteric stents

E77 Our experience with metallic ureteric stents for treating ureteral strictures and fistulae

E77 Our experience with metallic ureteric stents for treating ureteral strictures and fistulae

Tandem Ureteral Stents for the Decompression of Malignant and Benign Obstructive Uropathy

To evaluate the utility of two ipsilateral ureteral stents placed for benign and malignant ureteral obstruction. We performed a retrospective analysis of all cases of tandem ureteral stent (TUS) insertion at our institution from July 2007 through January 2013. Student t, Fisher exact, and log-rank test were used. TUS insertion or exchange was performed in 187 cases. There were 66 patients (75 renal units) who underwent successful TUS insertion. Malignant ureteral obstruction (MUO) was the cause for obstruction in 39 renal units (34 patients) vs benign ureteral obstruction (BUO) in 36 renal units (32 patients). Four patients with BUO and 15 patients with MUO underwent stent exchanges at a mean 145 and 128 days, respectively. Serum creatinine levels were stable poststent placement (P=0.4). Degree of hydronephrosis improved (paired t test P<0.03) after stent placement for both benign and malignant cohorts. TUS placement was noted to fail (flank pain with worsening hydronephrosis or increasing creatinine level) in five renal units with MUO (12.8%) and none with BUO. Stent failure (either conventional or TUS) suggested worsening survival in those with MUO. Median survival for those with MUO and a history of stent failure (10 of 14 died, 71%) was 66 days compared with 432 days for those without a history of stent failure (8 of 20 died, 40%) (log-rank test P=0.007). Our experience with the TUS, the largest to date, demonstrated that they are highly successful in both benign and malignant causes of obstruction, comparing favorably with metallic ureteral stents. Stent failure may be predictive for shorter survival.

Metallic ureteral stents in malignant ureteral obstruction: short-term results and radiological features predicting stent failure in patients with non-urological malignancies

To provide short-term result of the metallic ureteral stent in patients with malignant ureteral obstruction and identify radiological findings predicting stent failure. The records of all patients with non-urological malignant diseases who have received metallic ureteral stents from July 2009 to March 2012 for ureteral obstruction were reviewed. Stent failure was detected by clinical symptoms and imaging studies. Survival analysis was used to estimate patency rates and factors predicting stent failure. A total of 74 patients with 130 attempts of stent insertion were included. A total of 113 (86.9 %) stents were inserted successfully and 103 (91.2 %) achieved primary patency. After excluding cases without sufficient imaging data, 94 stents were included in the survival analysis. The median functional duration of the 94 stents was 6.2 months (range 3-476 days). Obstruction in abdominal ureter (p = 0.0279) and lymphatic metastasis around ureter (p = 0.0398) were risk factors for stent failure. The median functional durations of the stents for abdominal and pelvic obstructions were 4.5 months (range 3-263 days) and 6.5 months (range 4-476 days), respectively. The median durations of the stents with and without lymphatic metastasis were 5.3 months (range 4-398 days) and 7.8 months (range 31-476 days), respectively. Metallic ureteral stents are effective and safe in relieving ureteral obstructions resulting from non-urological malignancies, and abdominal ureteral obstruction and lymphatic metastasis around ureter were associated with shorter functional duration.

Multicenter Experience of the Newly Designed Covered Metallic Ureteral Stent for Malignant Ureteral Occlusion: Comparison With Double J Stent Insertion

This study was designed to evaluate the effectiveness of the newly designed covered metallic stent (CMS) for malignant ureteral obstruction by comparing with double J stent (DJS). CMSs were placed for malignant ureteral obstruction caused by various types of cancers for 42 ureters in 32 patients from 7 institutes. Retrospective data were collected for DJSs, which included 72 malignant ureteral occlusions in 56 patients from a single institute. Twenty-seven DJSs were placed percutaneously, and 45 DJSs were cystoscopically inserted. Technical failure of the CMS group was compared with that of the radiologically inserted DJS group. Primary patency of the CMS group was compared with assisted primary patency of the DJS group. Technical failure of the CMS group is lower than that of the radiologically inserted DJS group: 0% (0/42) vs. 25.9% (7/27; p = 0.002), respectively. Primary patency of the CMS group is better than assisted primary patency of the DJS group (p = 0.012). Primary patency of the CMSs is 100, 94.5, 74.7, 70.3, 65.3, 65.3, and 65.3% at 1, 3, 6, 9, 12, 18, and 24 months, respectively. Assisted primary patency of the DJS is 78.6, 75.1, 59.1, 48.7, 38.7, and 37.8% at 1, 3, 6, 9, 12, and 18 months, respectively. No serious complications were noted in the CMS group. Migration of the metallic stent occurred in one patient (2.3%). Covered metallic stent placement for malignant ureteral obstruction is superior to the double J stent placement in terms of technical success and patency.

Degradation and antibacterial properties of magnesium alloys in artificial urine for potential resorbable ureteral stent applications

This article presents an investigation on the effectiveness of magnesium and its alloys as a novel class of antibacterial and biodegradable materials for ureteral stent applications. Magnesium is a lightweight and biodegradable metallic material with beneficial properties for use in medical devices. Ureteral stent is one such example of a medical device that is widely used to treat ureteral canal blockages clinically. The bacterial colony formation coupled with the encrustation on the stent surface from extended use often leads to clinical complications and contributes to the failure of indwelling medical devices. We demonstrated that magnesium alloys decreased Escherichia coli viability and reduced the colony forming units over a 3-day incubation period in an artificial urine (AU) solution when compared with currently used commercial polyurethane stent. Moreover, the magnesium degradation resulted in alkaline pH and increased magnesium ion concentration in the AU solution. The antibacterial and degradation properties support the potential use of magnesium-based materials for next-generation ureteral stents. Further studies are needed for clinical translation of biodegradable metallic ureteral stents.

Cook Resonance™ Metallic Ureteric Stent Insertion Technique and North Wales Clinical Experience

Abstract Introduction: The Cook Resonance™ metallic ureteric stent has recently been introduced as an alternative method for upper urinary-tract obstruction.1–3 In this short video, initially, we d...

Use of Full-Length Metallic Stents in Malignant Ureteral Obstruction

Malignant ureteral obstruction (MUO) has traditionally been a difficult problem to manage. Indwelling ureteral stents have a failure rate up to 50%, necessitating the placement of percutaneous nephrostomy (PCN) drainage, which has associated complications and impacts on quality of life. Recently, metallic ureteral stents have emerged as a treatment for extrinsic ureteral obstruction. We present our initial experience using Resonance (Cook Urologic, Spencer, IN) full-length metallic stents for MUO. 20 patients (27 renal units) with advanced cancers and MUO were treated with metallic stents. Patients were followed prospectively to evaluate for recurrent obstruction. Perioperative morbidity and overall mortality were recorded. The mean patient age was 49.9 years (SD 18.9). The primary malignancies causing MUO were gastrointestinal (8), gynecologic (6), genitourinary (2), or other (4). All but two renal units had been previously treated with traditional stents. Eight out of 20 (40%) patients required further intervention for their MUO. Mean time to failure for the metallic stents was 7.4 months (222 days). Two patients required conversion to percutaneous drainage. Five patients required change to traditional stents (3) or removal of metallic stents. At the last follow-up, sixteen patients had died. Fourteen of the sixteen patients died with functioning metallic stents in place, although one patient who initially had bilateral metallic stent placements had a left stent removed due to migration. Of the remaining four living patients, two have functioning metallic stents at a mean follow-up of 42 months. MUO remains a difficult clinical problem in a group of patients with a high mortality. While metallic stents ultimately have a failure rate similar to that of traditional stents, the mean time to failure is longer. Therefore, metallic stents may benefit patients with MUO, because the longer dwell time may eliminate the need for more frequent stent changes or further interventions.

Five-Year Experience with Metallic Stents for Chronic Ureteral Obstruction

We present 5 years of outcome data on metallic ureteral stents in a cohort of patients treated for chronic ureteral obstruction. We retrospectively identified and analyzed the records of all patients in whom a Resonance® Metallic Ureteral Stent was placed between early 2007 and late 2011 at our institution. We performed a descriptive analysis of key outcomes, including the failure and death rates, and stenting duration, defined as the time from initial stent placement to last stent failure or patient death. We also performed a secondary comparative analysis of patients with a benign vs malignant etiology of obstruction. A total of 139 metallic stents were placed in 47 patients, including 27 (57%) with malignant and 20 (43%) with a benign etiology. Of the patients 15 (32%) had bilateral obstruction. Maximum followup was 59 months (mean 20, median 13, IQR 4-31). Stent failure occurred in 13 patients (28%), including 4 in the benign and 9 in the malignant group (p = 0.35). The median duration of stenting for benign and malignant obstruction was 22 (IQR 9-39) vs 7 months (IQR 3-25) (p = 0.106). Stenting duration was equivalent when controlling for the higher death rate in the malignant group. Resonance metallic stents are an adequate management strategy for benign and malignant ureteral obstruction. A subset of patients in each group continued to do well at more than a 3-year overall duration of stenting. Failure rates were similar for benign and malignant etiologies.

Evaluation in an Animal Model of a Hybrid Covered Metallic Ureteral Stent: A New Design

To evaluate a new design for a hybrid, dynamic, metallic ureteral stent that might avoid the formation of urothelial hyperplasia after ureteral metallic stenting in an experimental study. A total of 30 healthy female pigs were included in the present study, and an experimental obstructive uropathy in the right lumbar ureter was created in each pig. Obstruction was confirmed using percutaneous ultrasonography and retrograde ureteral pyelography and endoluminal ultrasonography 6 weeks after obstructive uropathy model creation. Then, the pigs were randomly distributed into 2 groups. Group 1 underwent standard metallic ureteral self-expanding internally covered stent deployment. Group 2 received a new hybrid metallic ureteral self-expanding internally covered stent. The follow-up period was 6 months. The hybrid metallic ureteral self-expanding internally covered stent group had a lower rate of urothelial hyperplasia (21% vs 70%), reduced stent migration (6.6% vs 33.3%), and a greater success rate after 6 months of follow-up (86.6% vs 47%) compared with the standard metallic ureteral self-expanding internally covered stent deployment group, with statically significant differences between the 2 groups. Our experimental results have indicated that the use of the hybrid metallic ureteral self-expanding internally covered stent in ureteral strictures is feasible, safe, and effective and reduces the formation of urothelial hyperplasia without secondary interventions to maintain ureteral patency.

Cost Analysis of Metallic Ureteral Stents with 12 Months of Follow-Up

The metallic ureteral stent was first developed for patients with ureteral obstruction related to malignant disease, but it can be used in all patients needing chronic indwelling ureteral stents, including those with benign disease. The traditional method of polymer stent management often necessitates multiple exchanges per year depending on patient and logistical factors. This has significant direct financial cost and likely a negative effect on patients' overall health. The objective was to analyze and compare the costs associated with chronic indwelling metal and silicone-based ureteral stents. A prospective database of patients undergoing metal stent placement from February 2008 to June 2010 was reviewed. Mean charges for a single traditional nonmetal and metal stent insertion were calculated. Charges were based on direct hospital charges related to stent cost and surgery. Cost data were based on the fiscal year 2010 cost for polymer or metal stent insertions. Twenty-one patients underwent metal stent placement at our institution. Of these, three traditional stent placements were omitted from analysis because of bundled charges for ureteroscopy at the same setting. Mean charges per single traditional and metal stent placement were $6072.75 and $9469.50, respectively. The estimated annual charges for traditional stents (3-6 exchanges) would be $18,218.25 to $36,436.50. Compared with metal stents, this is a potential financial savings of 48% to 74%. The mean direct cost to patients was 21.6% and 25.4% of the charges for metal and polymer stents, respectively. No patient needed early discontinuation of his or her metal stent because of lower urinary tract symptoms or gross hematuria. Metal stents are well tolerated by patients with ureteral obstruction of various etiologies and provide a significant financial benefit compared with polymer ureteral stents. For patients who are not fit for surgical intervention regarding their ureteral occlusive disease, the metal Resonance stent is a financially advantageous and well-tolerated option.

2131 URETERIC STRICTURES FOLLOWING RENAL TRANSPLANTATION: A MINIMAL INVASIVE TREATMENT APPROACH WITH A THERMO-EXPANDABLE NITINOL URETERIC STENT

INTRODUCTION AND OBJECTIVES: The incidence of postrenal transplant ureteric stenosis ranges from 2%‐12%. Currently the gold standard treatment is open revision, but minimally invasive endourological procedures may provide an attractive alternative. We present our data on the successful use of a thermo-expandable, metallic alloy ureteric stent, (Memokath® 051) as a long-term treatment for posttransplant ureteric strictures. METHODS: We retrospectively analysed the medical records of patients undergoing Memokath 051® insertion for ureteric strictures following renal transplantation. The records were reviewed for age, site of stricture, duration of stenting and complications. RESULTS: Seven male patients, mean age 48 (23-74) with strictured or otherwise obstructed ureters following kidney transplantation have been treated with ureteric Memokath (MMK) 051® insertion. At a mean follow up of 3 years, 4 stents were patent and patient’s kidney function has been normal. Average indwelling time of these stents was 31 month. In two patients the stricture extended the whole ureter so that full length MMKs (60mm and 150mm) were inserted; one patient had a 4 cm proximal ureteric stricture which was bridged by a 10 cm MMK, one presented with a blocked, previously inserted Wallstent bridging the stricture through which the Memokath (10cm) was placed. Spontaneous resolution of the stricture without the need for further stenting was seen in two patients: an anastomotic stricture between transplant ureter and a Boari flap resolved spontaneously and the MMK was expelled after 5 month indwelling time. The other patient underwent removal of his MMK due to blockage after 13 month indwelling time - intraoperatively, the stricture showed to be resolved so no further treatment was necessary. In one patient MMK treatment had failed: After extra-anatomical implanted kidney he developed a massively torted, obstructive ureter, which was bridged by a full length Memokath. Due to migration, this was removed after 1 month and replaced with a JJ stent. The overall success rate of Memokath placement was 85% (4 stents patent in situ and 2 spontaneous resolutions of stricture, 1 failure). No other morbidities were recorded and all other patients tolerated the stents well. CONCLUSIONS: Permanent ureteric stenting with the Memokath® 051 is a safe and effective minimally invasive treatment alternative for ureteral strictures after kidney transplantation. It provides an attractive alternative to open surgery and is well tolerated by patients.

1173 OUTCOMES OF METALLIC RESONANCE® STENTS IN MALIGNANT URETERAL OBSTRUCTION

You have accessJournal of UrologyUrinary Diversion: Bladder Reconstruction, Augmentation, Substitution, Diversion1 Apr 20121173 OUTCOMES OF METALLIC RESONANCE® STENTS IN MALIGNANT URETERAL OBSTRUCTION Zachariah Goldsmith, Agnes Wang, Michael Lipkin, Lionel Banez, Muhammad Iqbal, Gastón Astroza, Michael Ferrandino, Brant Inman, and Glenn Preminger Zachariah GoldsmithZachariah Goldsmith Durham, NC More articles by this author , Agnes WangAgnes Wang Durham, NC More articles by this author , Michael LipkinMichael Lipkin Durham, NC More articles by this author , Lionel BanezLionel Banez Durham, NC More articles by this author , Muhammad IqbalMuhammad Iqbal Durham, NC More articles by this author , Gastón AstrozaGastón Astroza Durham, NC More articles by this author , Michael FerrandinoMichael Ferrandino Durham, NC More articles by this author , Brant InmanBrant Inman Durham, NC More articles by this author , and Glenn PremingerGlenn Preminger Durham, NC More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2012.02.1397AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Malignant ureteral obstruction (MUO) often necessitates chronic indwelling ureteral stents. The indwell time of a metallic ureteral stent has been suggested for up to 12 months, yet its clinical outcomes in MUO have not been completely defined. We sought to evaluate the outcomes of metallic ureteral stents placed for MUO, and to identify clinical predictors of failure or success. METHODS All patients undergoing placement of the metallic Resonance® stent (Cook Medical) for MUO at Duke University were identified retrospectively. Patient demographics, oncologic variables, and clinical outcomes were examined. Stent failure was defined as unplanned stent exchange or nephrostomy tube placement for signs or symptoms of recurrent ureteral obstruction (recurrent hydronephrosis or increasing creatinine) or stent migration. Predictors of time to stent failure were assessed using Cox regression. RESULTS A total of 37 stents were placed in 25 patients with MUO beginning in September 2010. Mean age was 65 years. Mean follow-up was 13.1 weeks. Twelve stents (32%, 12/37) were identified to fail. Progressive hydronephrosis (58%, 7/12) and increasing creatinine (50%, 6/12) were the most common signs of stent failure (not mutually-exclusive), followed by flank pain (25%, 3/12). Three failed stents (25%, 3/12) had migrated distally. No stents required removal for recurrent infection. The majority of stent failures (83%, 10/12) were identified during routine oncologic surveillance. Stent failure was managed by replacement with a new metallic stent (50%, 6/12), placing an alternative ureteral stent (17%, 2/12), nephrostomy tube (17%, 2/12), or observation (17%, 2/12). Cystoscopic evidence of malignant bladder invasion at the time of stent placement was associated with a significantly increased risk of failure (HR: 6.50, 95% CI: 1.45 – 29.20, P=0.015). Notably, symptomatic subcapsular hematomas were observed in three patients following metallic stent placement. Each of these cases was managed conservatively, but required an average of 4 imaging tests per patient with an estimated cost of $21,688. CONCLUSIONS This is the largest series of MUO patients managed with the metallic Resonance® stent. Patients with a bladder tumor at the time of stent placement are at significantly higher risk for stent failure. Patients should be counseled on the risk of hematoma formation with this stent. With a 32% failure rate in this short-term series, long term follow-up is needed to determine the utility of this device for MUO. © 2012 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 187Issue 4SApril 2012Page: e475 Advertisement Copyright & Permissions© 2012 by American Urological Association Education and Research, Inc.MetricsAuthor Information Zachariah Goldsmith Durham, NC More articles by this author Agnes Wang Durham, NC More articles by this author Michael Lipkin Durham, NC More articles by this author Lionel Banez Durham, NC More articles by this author Muhammad Iqbal Durham, NC More articles by this author Gastón Astroza Durham, NC More articles by this author Michael Ferrandino Durham, NC More articles by this author Brant Inman Durham, NC More articles by this author Glenn Preminger Durham, NC More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

New Metallic Ureteral Stents: Improved Tensile Strength and Resistance to Extrinsic Compression

Extrinsic ureteral compression challenges a ureteral stent's ability to facilitate urinary drainage and to protect the kidney. Our purpose was to evaluate the performance of new metallic coil-based ureteral stents in terms of tensile strength and radial compression force. Three stent designs tested from Prosurg Inc included Passage 7.0F, Snake 6.0F, and Snake 7.0F with the straight section covered with a biocompatible polymer tubing. A MTS Microbionix Testing System using Testworks II software, vibration isolation table, and a 5-N load cell were used to measure tensile and compressive strength. Stents were placed in hydraulic grips and stretched at a rate of 5 mm/s for 1 second under uniaxial tension. Extrinsic compression was exerted in 0.1-mm increments to maximum compression. The Young Modulus, E, was calculated from each trial using engineering stress. Data were analyzed using Mann-Whitney and t tests. The Passage, Snake 6F, and Snake 7F stents had tensile strengths of 27±3, 5±0.1, and 73±26 kPa, respectively. Mann-Whitney tests show statistically significant difference between stents (P<0.05). Elastic modulus needed to cause extrinsic compression was highest for Snake 6F (145,842±14332 Pa) compared with that of Passage (124,999±3182 Pa) and Snake 7F (126,132±19316 Pa), (P<0.05). The Snake 6F stent had the lowest tensile strength and was least resistant to extrinsic compression. The Snake 7F had the highest tensile strength and was most resistant to extrinsic compression. All three stents are more resistant to extrinsic compression than the Applied Silhouette or Cook Resonance, yet have lower tensile strengths.

E70 The influence of extracorporeal shock wave lithotripsy on tissue viability around metallic ureteral stents

E70 The influence of extracorporeal shock wave lithotripsy on tissue viability around metallic ureteral stents

E74 Mechanical testing and surface damage analysis of metallic ureteral stents after Shockwave lithotripsy

E74 Mechanical testing and surface damage analysis of metallic ureteral stents after Shockwave lithotripsy

A visit to the Endourology and Stone Service at St. Bartholomew’s Hospital (Barts), London, UK

I was pleased to have been accepted to visit the Endourology and Stone Service at Barts by the director of the service, Mr. Noor Buchholz. This 1-month visit from June to July 2011 turned out to be one of my most valued professional experiences. St. Bartholomew’s Hospital is part of the Barts and The London NHS Trust, a tertiary university hospital trust caring for an often underprivileged population of >600,000 people in the east of London. The Endourology and Stone Service has gained a national and international reputation, and was recently accredited by the European Board of Urology (EBU) as a sub-speciality centre of excellence. Its director, Mr. Buchholz, is on the board of the urolithiasis section of the European Association of Urology-EULIS, an organisation which strives to foster research and education within the field of urolithiasis in Europe and beyond. Under his guidance, I found myself in an environment of high medical professionalism, close collegiate co-operation and open intellectual exchange. On the first day, Mr. Buchholz cordially welcomed and introduced me to the whole team of specialist nurses, junior doctors, residents and consultants. The team is truly multi-national and multi-cultural, so that I was immediately made to feel ‘at home’. I was attached to a German doctor, Dr. Christian Bach, who is currently following a 2-year EBU-accredited fellowship programme in the service. He guided and assisted me throughout my time at Barts, in a highly competent and friendly manner. I had the chance to observe all activities and procedures undertaken by the service, such as morning ward rounds led by consultants and senior residents, outpatient clinics, lithotripsy, clinical conferences, interventional radiology lists, day-case procedures and main theatre lists, with state-of-the-art and sometimes highly complex endourological procedures. I took careful notes of all interesting details, which I intend to implement later into my work. Typically, on an operating day, patients arrive at the hospital at 07:00 h, are seen by the surgeons and the anaesthetists, and the first operation starts at 08.30 h. This is an efficient time-saving way of scheduling operations, enabling the team to perform many cases every day. Of particular interest to me was the way my British colleagues performed the operations. I was impressed by the wide range of surgical procedures and the variety of instruments and disposables at the surgeon’s disposal. Although here too, the main asset of the surgeons is their manual skills, experience, and the tactical solutions they are able to apply in each individual case. I had the chance to observe several special endourological procedures, like prone and supine percutaneous nephrolithotomy, retrograde intrarenal surgery with the latest digital flexible ureteroscopes, insertion of metal ureteric stents, end-to-end urethroplasty (‘rail-roading’) and various other surgery and techniques from which I learned much that will help my in my practise. Of special interest for me was permanent ureteric stenting with metallic ureteric stents, in which this centre has a leading role worldwide, and for which Mr. Buchholz is probably the most experienced expert. Of note was that each operating list, performed under the guidance of the consultants Mr. Buchholz, Mr. Junaid Masood and Mr. Islam Junaid, was taken as an opportunity for learning and teaching. Residents and Fellows typically assisted each other, under the close observation of the consultants, who would assist only when and where needed. This culture of education was apparent throughout my time at Barts. Fortuitously, I also had the chance to participate during my time at Barts in one of the post-graduate surgical simulation workshops, as they are conducted regularly and frequently. My visit to Barts gave me not only the chance to observe and learn from very many open and endoscopic procedures, but I was also warmly welcomed into the social life of the department, which furthers team-bonding and friendships between team members, who all are enthusiastic professionals and talented instructors. I have returned home with new surgical skills and insights, and the enthusiasm to perform some of the procedures and tricks I have seen during my visit; and of course made new friends.

Metal Ureteral Stent for Benign and Malignant Ureteral Obstruction

Metal ureteral stents are a relatively new version of a device with a long history of relieving ureteral obstruction. Metal stents are effective for relieving ureteral obstruction but success regarding patient tolerability has been variable. We present our single institution experience with long-term metal ureteral stent placement. The charts of patients undergoing metal ureteral stent placement for chronic ureteral obstruction were reviewed. Data collected included patient age, gender, diagnosis/cause of obstruction, laterality, duration of indwelling metal stent, number of routine metal stent changes, complications and early discontinuations or stent changes. A total of 23 patients underwent placement of metal ureteral stents between February 2008 and September 2010. Bilateral stents were placed in 5 patients and 9 underwent a yearly metal stent exchange for a total of 42 ureteral units treated with metal ureteral stents. All metal stents were placed to relieve ureteral obstruction due to ureteral stricture, ureteropelvic junction obstruction, retroperitoneal fibrosis or extrinsic malignant obstruction. There were 3 metal stent failures in 2 patients with malignant ureteral obstruction. There were no complications, or early discontinuations or changes due to adverse symptoms, patient dissatisfaction, worsening renal function or progressive hydronephrosis. Metal ureteral stents are effective for benign and malignant ureteral obstruction in the absence of urolithiasis. Good tolerability and annual stent exchange make metal stents an appealing alternative for patients with chronic ureteral obstruction treated with indwelling ureteral stents.