Outcomes and complications of percutaneous nephrolithotomy as primary versus secondary procedure for kidney stones: a prospective cohort study.

Introduction: Currently, percutaneous nephrolithotomy (PCNL) is the gold standard of treatment for large renal stones. The high prevalence of urolithiasis is associated with a high recurrence rate increasing the risk of re-intervention. This study aimed to compare the effectiveness and complications of PCNL among patients with previous therapeutic interventions for renal stones.

Methods: Between August 2018 and September 2023, 245 patients were prospectively enrolled in this study and who underwent PCNL for renal stones at our institution. We compared patients who had no previous renal surgery (group 1: n=171) with those who had a history of open renal surgery (group 2: n=45) or previous PCNL on the ipsilateral kidney (group 3: n=31). All patients underwent surgery in the Galdakao-modified Valdivia position. Data on stone characteristics and perioperative and postoperative parameters were collected. Technical features, success rates and morbidity were analyzed and compared between the groups.

Results: The fluoroscopy time was significantly longer in the group of patients with previous open surgery than in groups 1 and 3 (161.47±52.44, 223.05±33.29, 172.27±30.51 sec, P<0.001). Similarly, the operative time was longer in group 2 (138.20±38.86 min, P<0.001). The immediate stone-free rates in groups 1, 2, and 3 were 74.8%, 72.1%, and 77.4%, respectively (P=0.945). At 1-month, these rates increased to 98.8%, 96.2% and 96.8%, respectively (P=0.857). No difference was detected between the groups in terms of complication rate. The average Hb variation was 1.08±0.82, 1.34±1.01 and 0.94±0.69 g/dl for groups 1, 2 and 3, respectively(P=0.082). Hospital stay was longer in group 2 than in groups 1 and 3 (2.17±1.03, 2.53±1.22, 1.88±1.00 days, P=0.07), respectively.

Conclusion: PCNL in patients with a history of renal surgery was associated with longer fluoroscopy and operative time. However, the success and morbidity rates as a secondary procedure were similar to those of PCNL in patients with no previous intervention.