Extra-Anatomic Stents in Ureteric Obstruction: Our Experience

Long-term Indwelling Tandem Polymeric Ureteral Stents for Benign Ureteral Obstruction

Objective: To assess the outcome of tandem polymeric internal stents (TIS) for benign ureteral obstruction (BUO). Material and Methods: We conducted a retrospective study that included all consecutive patients treated for BUO by means of TIS in a single tertiary center. Stents were replaced routinely every 12 months or earlier, when indicated. The primary outcome was permanent stent failure, and the secondary outcomes included temporary failure, adverse events, and renal function status. Kaplan-Meier and regression analyses were used to estimate outcomes, and logistic regression was used to assess the association between clinical variables and outcomes. Results: Between July 2007 and July 2021, 26 patients (34 renal units) underwent a total of 141 stent replacements, with median follow-up of 2.6 years (interquartile range [IQR] 0.75-5). Retroperitoneal fibrosis was the leading cause of TIS placement (46%). Permanent failures occurred in 10 (29%) renal units, and the median time to permanent failure was 728 days (IQR 242-1532). There was no association between preoperative clinical variables and permanent failure. Temporary failure occurred in four renal units (12%), which were treated by nephrostomy and eventually returned to TIS. Urinary infection and kidney injury rates were one event for every four and eight replacements, respectively. There was no significant alteration in serum creatinine levels throughout the study (p = 0.18). Conclusion: TIS provides long-term relief for patients with BUO and offers a safe and effective solution for urinary diversion, while avoiding the need for external tubes.

Post-Transplant Ureteric Stricture Managed By Extra-Anatomical Stenting With Modification on the Originally Described Stent Location: A Case Report

Ureteric strictures are a relatively uncommon complication following renal transplant, which may be managed endoscopically or surgically by repairing the stricture. Extra-anatomical bypass is a useful procedure in complex cases that bypasses the ureter by creating a subcutaneous route, although it is uncommonly used given its rare indication. We report a case of renal transplant ureteric stricture, in which we utilized a modified extra-anatomical stenting technique with a Detour® stent to avoid the fibrotic planes surrounding the lateral aspect of the kidney graft.

Extra-anatomical stents in benign ureteric obstruction; experience and outcomes

Objectives To present our experience with the Patterson-Forester extra-anatomic stent (EAS, Cook Medical) in patients with benign ureteric obstruction. Utilising an EAS in complex ureteric obstruction can have a significant positive impact on quality of life as a result of removing external drainage devices. Materials and methods Between November 2012 and January 2021 10 patients underwent 33 EAS procedures. All patients had benign ureteric obstruction. Mean age at primary procedure was 58 years (range 43-63). Median follow-up was 27.5 months (range 11-100). Results Eight patients were successfully managed with EAS, with 6 patients continuing to have routine EAS exchanges. Two patients had the distal end exteriorised due to refractory bladder symptoms. There were three short-term failures; the distal end migrated out of the bladder requiring reinsertion one week later; one patient developed urosepsis requiring intravenous antibiotics and the stent removing within 30 days; one proximal stent migrated resulting in cutaneous erosion. The patient is now awaiting further EAS insertion. Conclusion The Patterson-Forester EAS is another tool in the endourologists' armamentarium when managing complex ureteric obstruction. In appropriately selected patients, it can improve their quality of life and is a durable long-term strategy in benign obstruction.

Management and treatment options when facing malignant ureteral obstruction

Malignant ureteral obstruction is an unfortunate finding that can be caused by a wide-ranging number of malignancies with a prognosis of limited survival. Given its presentation and progression, it can be refractory to treatment by traditional single polymeric ureteral stents. With a higher failure rate than causes of benign ureteral obstruction, a number of other options are available for initial management, as well as in cases of first-line therapy failure, including tandem stents, metallic stents, percutaneous nephrostomies and extra-anatomic stents. We reviewed the literature and carried out a PubMed search including the following keywords and phrases: "malignant ureteral obstruction," "tandem ureteral stents," "metallic ureteral stents," "resonance stent," "metal mesh ureteral stents" and "extra-anatomic stents." The vast majority of studies were small and retrospective, with a large number of studies related to metallic stents. Given the heterogenous patient population and diversity of practice, it is difficult to truly assess the efficacy of each method. As there are no guidelines or major head-to-head prospective trials involving these techniques, it makes practicing up to the specific provider. However, this article attempts to provide a framework with which the urologist who is presented with malignant ureteral obstruction can plan in order to provide the individualized care on a case-by-case basis. What is clear is that prospective, randomized clinical trials are necessary to help bring evidence-based medicine and guidelines for patients with malignant ureteral obstruction.