Outcome of Mini-percutaneous Nephrolithotomy for Renal Stones in Infants and Preschool Children: A Prospective Study

Abstract

Objective: To assess the safety and efficacy of Miniperc for renal stones in preschool-age patients. To the best of our knowledge, this may be the first prospective study on this subject. Reports on Miniperc are still few and mostly retrospective using a sheath size of ≥ 18Fr, which is still relatively large for young children.

Patients and methods: From January 2012 to May 2013, Miniperc was performed for 26 children (≤ 6 years old) with renal calculi <5 cm through 14Fr sheath using a 9.5Fr semirigid ureteroscope with Holmium:yttrium-aluminum-garnet laser lithotripsy. Effects of different factors on operative time, complications, and stone-free rate (SFR) were compared using chi-square, Fischer exact, or Mann-Whitney tests as appropriate using SPSS v15.0.

Results: Primary SFR, SFR after retreatment, and SFR after auxiliary extracorporeal shock wave lithotripsy (ESWL) were 77%, 85%, and 92%, respectively. Retreatment rate was 8%. Auxiliary ESWL was done in 11%. Complications were bleeding (8%), hematuria and blood transfusion (4%), renal pelvis perforation (4%), leakage (8%), and fever (15%). Operative time was significantly prolonged in multiple (>2) stones (P = .006), calyceal stones (P = .002), or stone size ≥ 30 mm (P = .022). SFR was significantly lower in children with >2 stones (P = .028) and increased stone size ≥ 30 mm (P = .014).

Conclusion: Miniperc is a safe and effective minimally invasive procedure for pediatric renal stones using 14Fr access sheath. SFR was significantly lower in children with >2 stones or increased stone size ≥ 30 mm. This was overcome by retreatment and auxiliary ESWL.