Extra-Anatomical Urinary Stent for Complex Ureteral Strictures: A Systematic Review and Narrative Synthesis

Complex ureteral strictures, irrespective of their aetiology, constitute a therapeutic challenge in everyday clinical practice. They are usually managed with antegrade or retrograde ureteral stent or double-J stent insertion, or the placement of a nephrostomy tube. The Detour® extra-anatomical stent (EAS) is a subcutaneous pyelovesical bypass proposed as an alternative solution for urinary diversion. The aim of this systematic review and narrative synthesis was to evaluate the safety and effectiveness of Detour EAS.

A literature search of MEDLINE, Scopus and Web of Science databases was performed using the following terms: Ureter* AND ("Subcutaneous pyelovesical bypass" OR "Extra-anatomical stent*" OR "Detour" OR "Artificial ureter" OR "Nephrovesical bypass"). Published observational and interventional studies evaluating the efficacy of Detour subcutaneous pyelovesical bypass placement in the management of complex ureteral stenosis were included. The primary outcome was functional stent success, whereas secondary outcomes included complications.

Of 182 records identified, 25 studies including 344 unique patients were analysed. Functional success rate in most of the studies exceeded 85% at follow-up, ranging from 0% in a cohort of patients with ileal conduits to 100% in case reports and poor-quality case series. The most common complications included urinary tract infections, encrustation, infection of the overlying skin and dislodgement of the stent's vesical end. The EAS had to be removed in a total of 50 patients, while five deaths occurred, three due to prosthesis-related septic events, one due to palliative care cessation and one due to abdominal abscess-related sepsis. Despite these risks, Detour placement seemed to improve both renal function and quality of life in most cases.

In selected patients Detour EAS might be considered as an alternative but its safety and efficacy need further investigation. Careful patient selection and surgical procedure optimisation are essential to improve its safety-related results.