In this week's BMJ, Nabi and colleagues1 present a meta-analysis of randomised controlled trials of the insertion of indwelling stents after uncomplicated ureteroscopy. During the past quarter of a century the development and use of endoscopic equipment in urology has increased. Semirigid and flexible instruments have been developed with working channels to allow passage of biopsy forceps, baskets, and laser fibres. Stones in the ureter, and even within the pelvis and peripheral calyces of the kidney, can now be fragmented and extracted. Upper tract transitional cell carcinomas can be diagnosed and, where indicated, treated endoscopically.

There remains controversy, however, about whether indwelling stents should be routinely inserted after these procedures. Balloon dilatation of the ureteric orifice, stone fragmentation and basket retrieval of fragments, biopsy, and destruction of mucosal lesions can all cause trauma …