Double J ureteral stents (DJ), whatever their material, are rapidly covered by a biofilm, subject to encrustation onset. To prevent this, it is admitted that DJ should be replaced periodically. However, encrustation may vary with indication, with a highest risk in “stone” patients. Our target was to evaluate the actual DJ medium/long-term indwelling times and relevant encrustation rates perceived by urologists in daily practice.

Data were collected through an observational retrospective study. Six European centres were selected for high activity and trained urologists to collect all data of all consecutive removed DJs of a same material implanted for more than 2 months within the 2-year referred period 01/01/2010 to 31/12/2012. Three current materials with various softness or with/without coating were tested: Vortek^® (n=61), Vortek hydro^® (n=94), Biosoft duo^® (n=346). Encrustation rates were evaluated according to indwelling times and stent indication. It must be noticed that encrustations likely to be spontaneously reported by surgeons onto patient's file are assumed to be “significant encrustations”, i.e. rather severe.

Four hundred and seventy-three stents met inclusion criteria with no missing data. Indwelling times of these medium-/long-term stents vary between 60 and 462 days. Among these, we noticed an unexpected number of long term: globally one third stay in place more than 6 months, and 9% more than 1 year. Longest times are observed for non-stone indications (44% more than 6 months and 17% more than 1 year in malignant indications). For non-stone indication, “significant encrustation” rates stay very low before 4 months (1.3%) and quite low before 6 months (5%) increasing with time to reach around 10% in long term. However, as expected, the rate is higher for stone indication with a threshold at 4 months (8% before 4 months, nearly ¼ after) (refer to study results Table 1).

The results in this large sample confirm short-term use of DJ, namely for stone patients, with a clear rise in encrustation rate after 4 months in this indication. However, it must be noticed that long term beyond 6 months or even 12 is still requested in a significant number of non-stone patients, and relatively well supported in usual practice.