Benchtop Evaluation of Miniature Percutaneous Nephrolithotomy Lithotrites

Area of Science:

• Urology
• Minimally Invasive Surgery
• Biomedical Engineering

Background:

• Percutaneous nephrolithotomy (PCNL) is standard for kidney stones >2cm.
• A trend towards smaller instruments in mini-PCNL (mPCNL) aims to reduce invasiveness.
• Evaluating the efficacy of different mPCNL lithotrites is crucial for optimizing stone clearance.

Purpose of the Study:

• To compare the stone clearance rates of various mechanical and laser lithotrites used in mini-PCNL (mPCNL) via benchtop assessment.
• To determine the most efficient lithotrite for breaking down kidney stone phantoms under simulated mPCNL conditions.

Main Methods:

• Benchtop model simulating a 16.5F mPCNL sheath with a 1cm³ hard kidney stone phantom.
• Tested lithotrites included 1.5mm and 1.9mm Trilogy, 1.83mm ShockPulse, and a 200μm Holmium:YAG (Ho:YAG) laser.
• Stone clearance rate (mg/s) and time to complete clearance were measured for each modality.

Main Results:

• The 1.9mm Trilogy demonstrated the highest stone clearance rate (11.69 ± 3.68 mg/s), significantly outperforming ShockPulse (6.29 ± 1.37 mg/s), Trilogy 1.5mm (6.84 ± 1.21 mg/s), and Ho:YAG laser (4.73 ± 0.61 mg/s).
• The 200μm laser fiber was less effective than all mechanical lithotrites tested.
• The 1.9mm Trilogy potentially reduces treatment time by 3.9 to 8.1 minutes for a 1.5cm stone compared to other tested devices.

Conclusions:

• In this benchtop model, the 1.9mm Trilogy lithotrite exhibited superior stone clearance efficiency compared to the ShockPulse, 1.5mm Trilogy, and Ho:YAG laser.
• Further clinical studies are warranted to validate these findings and establish the optimal lithotrite for clinical mPCNL procedures.