Management of malignant ureteral obstruction

OBJECTIVE: To describe the different therapeutic alternatives in malignant ureteral obstruction (MUO), and to analyze short and long-term results. METHODS: We conducted a bibliographic search about MUO in Spanish and English languages in PubMed and Google Scholar. We examined the most relevant reviews, original manuscripts and their respective citations. Last search was on April 2016. RESULTS: Polymeric double J stent is the cheapest and most accessible internal urinary diversion, but has also the shortest duration. Early and late failure rates were 0-35% and 14-49% respectively. Mean time to late failure was 3-12 months. Percutaneous nephrostomy is the safest alternative in terms of failure rates, though it has frequent complications such as tube dislodgement, and may have a negative effect on quality of life. The only metallic double stent with enough bibliographic background is the Resonance (R) stent. Early failure was 0-15% and late failure 4-41%, with a mean time to late failure of 2.6-13 months. Regarding metallic stents, Memokath 051 (R) has obtained the best results, with 0-5% early failure rates, 19-49% late failures and mean time to late failure of 7-11 months. In patients with polymeric double J stent failure, patients benefited from tandem double Jstents, metallic double, J catheters or metallic stents, avoiding the need of a percutaneous nephrostomy. The evidence level was low in all cases. CONCLUSIONS: Results in MUO are very heterogeneous and have a low evidence level. Factors that influence results include stent characteristics, status and prognosis of the obstructive condition and probably patient and physician's preferences. Polymeric double J stents seem to have higher early and late failure rates than metallic double J catheters and metallic stents. Even though, the difference is not clearly evident. Prospective, multicenter, multidisciplinary trials are necessary to elucidate convenience and adequate selection of each type of stent.