Percutaneous nephrolithotomy for renal stones following failed extracorporeal shockwave lithotripsy: different performances and morbidities.

The purpose of this study is to summarize the results of percutaneous nephrolithotomy (PCNL) for renal stones following failed extracorporeal shockwave lithotripsy (SWL), and to investigate the effect of previous SWL on the performances and morbidities of subsequent PCNL. Sixty-two patients with a history of failed SWL who underwent PCNL on the same kidney (group 1) were compared to 273 patients who had received PCNL as first treatment choice (group 2). Patient demographics, stone characteristics, operative findings, and complications were documented and compared. Groups 1 and 2 had similar patient demographics and stone characteristics. Mean time to establish access was comparable in both groups (10.5 ± 4.2 vs. 9.6 ± 4.5 min, p = 0.894). Time required to remove stones and total operative time were longer in group 1 (71.5 ± 10.3 vs. 62.3 ± 8.6 min, p = 0.011 and 95.8 ± 12.0 vs. 80.6 ± 13.2 min., p = 0.018, respectively). Group 1 had lower clearance rate compared to group 2 (83.9 vs. 93.4 %, p = 0.021), while postoperative complications were similar in both groups. Scattered stone fragments buried within the tissues made the procedure more difficult for stone fragmenting and extracting, which lead to longer operative time and inferior stone free rate. However, the PCNL procedure was safe and effective in patients with failed SWL. The risk of complications was similar and clearance rate was encouraging.