Nielsen TK, et al. – The study aims to evaluate the risk of needing treatment with an internal ureteral double–J stent (JJ) after extracorporeal shockwave lithotripsy (ESWL) treatment. It was considered that commercialised ESWL treatment can achieve an overall success rate of more than 90% applying a mobile lithotripsy system. As expected, an inverse relation between stone size and success rate was observed. Moreover, patients who do not need treatment with a JJ prior to ESWL will only rarely need treatment with a JJ after ESWL, irrespective of stone size and intra renal stone location.

Methods

• Researchers treated 461 patients with a total of 589 renal stones applying a mobile lithotripsy system at a single Danish institution during an eight–year period.
• Applying a Storz Modulith SLK system, a commercial company performed all treatments.
• They prospectively registered each stone according to size, intra renal location and the presence of a JJ at the time of treatment.
• They retrospectively assessed the number of required ESWL treatments and auxiliary procedures.

Results

• According to the data, 69% was considered as a success rate after the initial ESWL procedure, which increased to an overall success rate of 93% after repeated treatment.
• There was a negative association between stone size and the overall success rate (r = –0.2, p < 0.01).
• It was noted the upper calyx was associated with a significantly better success rate, but otherwise intra renal stone location was not predictive for treatment success.
• Furthermore, a sum of 17 patients (2.9%) required treatment with a JJ after the ESWL procedure.
• They did not find significant difference between the stone size or intra renal location and the risk of needing treatment with JJ after ESWL.