Vacuum-assisted Mini-percutaneous Nephrolithotomy for 2–3-cm Renal Stones: A Comparative Study with Retrograde Intra-renal Surgery

Abstract

Purpose

To compare vacuum-assisted percutaneous nephrolithotomy (VAmini-PCNL) with retrograde intra-renal surgery (RIRS) for the treatment of renal stones measuring 2–3 cm in diameter.

Material and methods

This retrospective study included children receiving treatment for pyelocalyceal stones of 2–3 cm in diameter from November 2018 to September 2022. Consecutive patients undergoing VAmini-PCNL after 2020 were compared with a historically matched group undergoing RIRS. VAmini-PCNL was performed using a 12-Ch nephroscope through a 16-Ch vacuum ClearPetra access sheet. RIRS was performed using a flexible ureteroscope through a ureteral sheath. The endpoints included the need for pre-stenting, duration of surgery, complications, stone-free rate (SFR), and need for secondary procedures.

Results

The patients were grouped into two with 15 patients for each group. VAmini-PCNL group was not different from the RIRS one for age at surgery [median (range) 6.6 (1–12)years vs. 7.7 (1.5–14)years], and stone diameter [median (range) 2.4 (2.0–2.9)cm vs. 2.3 (2.1–2.8)cm] and density [median (range) 577.5 (421–1068) vs. 541.5 (462–927) Hunsfield Units]. Pre-stenting was necessary in five RIRS patients (33 %). The median duration of surgery was 85.3 (76–112)min for VAmini-PCNL vs. 150.6 (132–167)min for RIRS, p = 0.00001. No major complications were observed. The SFR was 100 % after VAmini-PCNL and 60 % after RIRS, p = 0.02. All residual fragments were removed with a second RIRS.

Conclusion

VAmini-PCNL was feasible and safe in children aged >1 year. It allowed for a significantly higher SFR despite a significantly shorter operative time than RIRS, which also requires pre-stenting in one-third of patients and a second RIRS in 40 % of cases.

Level of Evidence

III.