Lithotripsy for ureteric stones: throw away the ureteroscope


ESWL revolutionized the management of renal stones; the imaging capacity of first- and second-generation machines limited the effective localization to the collecting system. Research using first-generation machines had stressed the importance of the fluid–stone interface at the shockwave focus, and urologists accepted that the use of lithotripsy as a sole treatment for stones in the ureter was strictly limited. Third-generation ESW lithotripters provide continuous in-line control during treatment and facilitate the precise localization of ureteric stones. Because the shockwave focus is larger than most ureteric stones, these calculi are ideal candidates to be treated.

The choice now exists to treat ureteric calculi with primary ESWL or primary ureteroscopy. The efficacy and complications of these two methods were recently compared for stones in the distal ureter [1]. In a prospective trial, 64 patients with a solitary (< 1.5 cm) radio-opaque distal ureteric stone were randomized to either ureteroscopy or in-situ ESWL, using the second-generation Dornier HM3 lithotripter. Stone-free rates were equivalent for the two techniques but morbidity was lower and discharge quicker with ESWL.

Modern interventional treatment should rely on evidence; it may be that current clinical evidence is at variance with some sections of the accepted guidelines upon which endoscopic stone management is advised by the AUA [2] and EUA [3]. Both groups advocate the conservative management of stones of < 5 mm. There is also agreement that the primary treatment for upper ureteric stones of < 1 cm should be in-situ ESWL. The EUA guidelines suggest that mid-ureteric stones are also best treated initially with in-situ ESWL, but both the EUA and AUA hold that the primary approach to distal ureteric stones could be either with ESWL or ureteroscopy. Obviously, the availability of local resources and the economics of healthcare delivery have implications for treatment options.

It is therefore timely to address the best contemporary treatment for mid- and distal ureteric stone. In a recent retrospective review of our practice of primary in-situ ESWL for 209 consecutive patients with ureteric stones, treated on a Storz Modulith SLX-MX within 15 days from the referral date, 95% of patients were stone-free after a mean of 1.6 sessions per stone (unpublished observations). These included 27 mid- and 59 lower ureteric stones, with a mean stone size of 5.5 × 7.5 mm, including three patients with stones of ≥ 1.5 cm. Only seven patients (two upper, two mid- and three lower ureter) required ureteroscopic stone extraction for ESWL failure, and all secondary ureteroscopy was successful. Another UK series reflects this experience, although they report slightly lower stone-free rates using a different (Dornier MFL 5000) third-generation lithotripter [4].

There appears to be consensus agreement that for stones of < 1.5 cm in the upper ureter, primary ESWL is the treatment of choice. Trials now confirm the benefits of ESWL over ureteroscopy in the distal ureter, and for stones in the mid-ureter there are advocates for both ESWL and ureteroscopy. However, in our hands we have had only two treatment failures from 27 treatments for mid-ureteric stones. A multi-institutional randomized trial addressing ESWL vs ureteroscopy for mid-ureteric stones would be opportune and a welcome addition to the urology literature. The economics of ESWL compared with ureteroscopy has often attracted differing comments from European and American groups, and a broad cost-benefit analysis should be actively addressed in all future clinical trials.

We suggest that ESWL is as effective as, if not better than, ureteroscopy in treating ureteric calculi and should be considered, to avoid ureteric injury and other morbidity, as the primary treatment for stones in all positions in the ureter. Finally, in patients with large or chronically impacted upper or mid-ureteric stones the role of early laparoscopic ureterolithotomy should be considered and patients referred to a unit with expertise in this area [5].

Of course, urologists should keep a stock of high-quality ureteroscopes and ancillary equipment to treat stones complicated by pregnancy, abnormal anatomy, aortic aneurysm and strictures. However, the frequency of ‘routine ureteroscopy’ as the procedure becomes reserved for difficult conditions and may decline dramatically. Is the profession prepared to accept the implied consequence of our and other's observations reported here, that stone treatment centres are inevitable?