Comparison of minimally invasive percutaneous nephrolithotomy and ureteroscopy in the management of impacted proximal ureteral stones

Introduction and objective: Management of large impacted proximal ureteral stones is often challenging due to the presence of mucosal edema, inflammation and angulations of the ureter and other factors which impede stone access, visibility and lithotripsy and can lead to different types of complications. The objective of our study is to compare the efficacy and safety of minimally invasive percutaneous nephrolithotripsy (mini-PCNL) and ureteroscopy (URS) in the treatment of impacted proximal ureteral stones. Material and methods: The medical records of 345 patients with impacted proximal ureteral stones 10-20 mm, treated between January 2016 – November 2022 were retrospectively reviewed. 178 patients (51.6%) underwent mini-PCNL, and 167 (48.4%) – URS. Data on patients’ preoperative characteristics, stone-free rates, operating times, intra- and postoperative complications were compared. Results: Patients’ preoperative characteristics were comparable between the two groups, except for mean stone surface and stone size, which were significantly higher in the mini-PCNL group (respectively, 137.87±44.32mm2 vs 80.94±29.66mm2, p=0.000; and 15.03±2.43 vs 12.02±2.22mm, p=0.000). The stone free rate after single procedure was 94.9% for mini-PCNL and 89,3% in the URS group (p=0,116). Four patients (2.3%) in the mini-PCNL group had significant hemorrhage necessitating selective renovasography and angioembolization of AV fistula. 21 (12.5%) patients had stones showing upward migration during the URS procedure and 3 (1.8%) had partial perforation of the ureteral wall. Hemoglobin drop was significantly higher in mini-PNL group (13.58±12.79g/l vs 4.69±5.72g/l, p=0,000). Mean operative time was significantly longer in the URS group, despite the smaller size of the stones (respectively, 41.41±13.62min vs. 30.67±10.34min, p=0,000). There were statistically significant difference of the necessity of auxiliary procedures in the URS group (respectively, 78 patients (46,4%) vs 6 patients (3.6%), p=0.000). Conclusions: For an impacted, proximal ureteral stone mini-PNL had better stone-free rates, shorter operative time and low percentage of auxiliary procedure and hospitalizations. However, URS had the advantages of less invasiveness procedure and shorter postoperative hospital stay.