Retrograde intrarenal surgery and mini PCNL for 10-20 mm renal stones carry similar risk of bleeding: Study
Researchers have determined that retrograde intrarenal surgery (RIRS) and minimally invasive miniaturized percutaneous nephrolithotomy (mini-PCNL) expose patients to similar risks of clinically significant bleeding when renal stones have a diameter of 10–20 mm. A recent study was conducted by Davide P. and colleagues published in the journal BJU International.
Renal stones of 10-20 mm require effective interventions that reduce complications, particularly bleeding. Traditionally, percutaneous procedures have been thought to carry a risk for higher complications, such as bleeding, compared to endoscopic approaches, such as RIRS. A lot of caregivers, though, have believed otherwise, and this study looked to determine validity of the hypothesis that the assumption is incorrect, by scoring outcomes regarding bleeding following a standardized scoring method of evaluating stone size and hardness.
Total 176 patients who had renal stones with a size between 10 and 20 mm were enrolled in the study. The Stone Management According to Size-Hardness (SMASH) score=(Hounsfield units × stone maximum size in cm)/100 was used to guide the treatment to either group A or group B.
Group A: RIRS, (n = 90) Patients with SMASH score <15.
Group B: mini-PCNL, (n = 86) Patients with SMASH score ≥15.
Both groups received treatment with the Cyber Ho laser. Statistical comparisons were made for preoperative characteristics, stone-free rates, complication rates, and outcomes regarding bleeding.
The key findings of the study were:
Comparable Preoperative Features:
Mean stone size: 17.1 mm (RIRS) vs 16.8 mm (mini-PCNL) (P = 0.13).
Efficacy:
Stone-free rate: 87.8% (RIRS) vs 95.3% (mini-PCNL) (P = 0.07).
Complication Rates:
Overall complication rate: 14.4% (RIRS) vs 18.6% (mini-PCNL) (P = 0.09).
Bleeding Risk:
Gross hematuria: 5.5% (RIRS) vs 8.1% (mini-PCNL) (P = 0.07).
Mean hemoglobin drop:
Day 1: 12 g/L (RIRS) vs 17 g/L (mini-PCNL) (P = 0.06).
Day 3: 2 g/L (RIRS) vs 3 g/L (mini-PCNL) (P = 0.21).
No blood transfusions or renal embolizations were required.
The management of renal stones between 10 and 20 mm with RIRS and mini-PCNL seems to be equivalent in terms of efficacy and shows a very low incidence of clinically significant bleeding. Such results support the use of SMASH scores for individualized selection of the best treatment for the patient.
Reference:
Perri, D., Besana, U., Maltagliati, M., Pacchetti, A., Calcagnile, T., Pastore, A. L., Romero-Otero, J., Micali, S., Govorov, A., Somani, B., Liatsikos, E., Knoll, T., Rocco, B., & Bozzini, G. (2024b). Risk of bleeding after retrograde intrarenal surgery vs miniaturised percutaneous nephrolithotomy for 10-20 mm renal stones: a not so different safety profile. BJU International. https://doi.org/10.1111/bju.16585
