Session: MP05: Stone Disease: Basic Research & Pathophysiology
MP05-13: Comparison of Efficacy and Safety of Narrow Focus versus Wide Focus Shock Wave Lithotripsy in Management of 1-2cm Renal Calculi Using Tri-Focal Lithotripsy Machine: First Double-Blind Randomized Study
Introduction: The objectives of this study were to compare efficacy and safety of shock wave lithotripsy (SWL) using a narrow focus of 2mm (F1) versus a wide focus of 8 mm (F3) for renal stones 1-2cm using a new tri-focal SWL machine. Methods: This double-blind randomized study recruited adult patients presented with solitary radio-opaque renal pelvic stone 1-2 cm. Patients were electronically randomized into two groups; F1-group received narrow focus (2 mm) SWL while F3-group received wide focus (8mm) SWL using Piezo Lith3000 plus (Richard Wolf, Germany). Ramping protocol was employed under simple analgesia, with maximum shocks of 3000 and maximum sessions of 3, two weeks apart. Baseline patient’s and stone characteristics were collected. The SFS (%) and complications were identified. Primary outcome was overall SFS (%) calculated one month following the 3rd session. Secondary outcomes were presence of complications in terms of pain and hematuria. Two urinary renal injury markers [neutrophil gelatinase-associated lipocalin (NGAL) and Kidney Injury Molecule-1 (KIM-1)] were measured with ELISA before, 2 hours after and 72 hours after the 1st SWL session. Results: A total of 135 patients were recruited; 67 in F1 group and 68 in F3 group. Preoperative parameters were comparable in terms of age (p=0.16), female gender (p=0.52), BMI (p=0.71), stone size (1.2±0.3 vs. 1.1±0.3mm; p=0.18), and HU (858±2 vs. 844 ± 2; 0.70), NGAL (101.7±32.5 vs. 104.1±38.33 ng/dL; p=0.71), KIM-1 (4.3±0.9 vs. 4.5±1.1 ng/dL; p=0.17). The overall SFS and auxiliary interventions were comparable (92.5% vs. 91.2%; p=0.77) and (23.4% vs. 23.2%; p=0.23), respectively. In terms of complications, patients in F1 group had significantly higher experience of hematuria (Clavien 1) (95.5% vs. 83.8%; p=0.02), and pain (Clavien 1) (65.7% vs. 19.1%; p<0.001). Following the first SWL session, the rise in 2-h NGAL was comparable (109.6±32.7 vs. 112.7±40.6; p= 0.62). However, the rise in the 2-hr KIM-1 was significantly higher in F1 (4.9± 1.1 vs. 4.4±1.4; p=0.022). Nevertheless, both markers were significantly improved to almost half of the baseline after 3 days (56.7±14 vs. 59.7±16.2; p=0.26) and (2.1±0.55 vs. 2.1± 0.5; p=0.96), respectively. Conclusions: Narrow and wide focus were associated with comparable lithotripsy outcomes and re-treatment rates. However, narrow focus was associated with significantly higher pain and hematuria. Both F1 and F3 SWL of Piezo Lith3000 plus were potentially safe in terms of the renal injury. SOURCE OF Funding: None
