Category: New Technology: Miscellaneous

MP22-4 - The Effectiveness of Ureteric Metal Stents in Transplant Obstructions: A Systematic Review

Sat, Sep 22
2:00 PM - 4:00 PM

Introduction & Objective :

The incidence of ureteric stenosis after kidney transplantation is 0.5-4.7%. The standard treatment is surgical correction but minimally invasive endourolgical procedures such as ureteroplasty, ureterotomy or long term ureteric stenting with metallic ureters may provide an attractive alternative. Metallic stents have greater tensile strength and stability compared to double J stents which makes them less likely to obstruct and results in fewer stent changes. A variety of mesh (Uventa, Wallstent, Memotherm) and non-mesh (Memokath) metal stents have been used for  ureteric stenosis in renal transplant patients with varying success. In this systematic review we evaluate the literature for indications, effectiveness, safety and long term patency of metal ureteric stents in renal transplant patients.

Methods :

A systematic review was performed in accordance with PRISMA guidelines. Scientific literature databases (PubMed, EMBASE, Medline, Web of Science, ScienceDirect and Cochrane Library) were systematically searched in March 2018. Article selection was performed by two independent evaluators (B.G and T.N). Articles written in European languages were included. If duplicate study populations or analysis of repeated data were identified, the publication reporting a larger sample size or prolonged follow up was preferentially assessed.  Extracted data was collated and analyzed in Excel (Microsoft Corp.).

Results :

A total of 278 publications from six databases were screened. After accounting for duplicates and applying eligibility criteria, 15 studies were selected (Table 1). This search criteria yielded 86 renal transplanted individuals with ureteric stenosis requiring metallic stents. 58% of strictures were documented in the distal ureter. The most common metallic mesh stents were Memotherm (20), SinusFlex (16) and Uventa (11) and the most common non-mesh stent was Memokath (27). The majority of stents were depolyed antegrade (53).  The patency of mesh stents (52/56; 92%) compared to the Memokath (21/27; 77%) were statically significant (p<0.01). Migration of stents was only noted in the Memokath stent (5/27; 18%). Urinary tract infections occured in 9% of individuals and one resulted in transplanectomy. 

Conclusions :

The studies in this systematic review were retrospective, single-arm and involved a low number of clinical cases. This made outlining indications and limited conclusions. Metallic stents in transplant patients showed a high rate of patency and low rates of migration and infection. Memokath stents migrate more than mesh stents, however they may have poorer patency than mesh metallic stents.   

Brent Gilbert

Urology Registrar
QEII Hospital
Brisbane, Queensland, Australia

Taryn Naidoo

General Surgery Registrar
QEII Hospital
Brisbane, Queensland, Australia