**8. Conclusion**

The long term data show that EAS offers an excellent temporary or permanent internalization of urinary drainage with a minimally invasive method where open surgery has been tried and failed or was not considered feasible, and avoids the need for long-term nephrostomy drainage.

An ideal EAS should be associated with minimal or no peri-operative morbidity; whilst at the same time does not require regular changes. Such a stent does not currently exist but it is likely that the rapid advancement in tissue engineering and biomaterials will make it possible to design one soon.
