Air vs contrast pyelogram for initial puncture access in percutaneous nephrolithotomy: a randomized controlled trial

Area of Science:

• Urology
• Minimally Invasive Surgery
• Nephrolithiasis Management

Background:

• Percutaneous nephrolithotomy (PCNL) is a key procedure for large kidney stones.
• Contrast or air is used to visualize the pelvi-calyceal system (PCS) for initial puncture.
• Contrast use has limitations, including poor differentiation of anterior and posterior calyces.

Purpose of the Study:

• To compare the efficacy and safety of air pyelogram versus contrast pyelogram for PCS delineation during PCNL.
• To evaluate outcomes such as radiation exposure, access time, and stone clearance.

Main Methods:

• An interim analysis of 122 patients undergoing PCNL was conducted.
• Patients were stratified into two groups: Group 1 (contrast) and Group 2 (air) for PCS delineation.
• Data on radiation dose, exposure duration, access time, puncture success, and stone clearance were collected and compared.

Main Results:

• Group 2 (air) showed significantly lower mean radiation dosage (8.43 vs. 14.26 mGy) and exposure duration (0.66 vs. 1.02 min).
• Access time was shorter in Group 2 (3.72 vs. 5.84 min).
• Single-attempt puncture success was higher in Group 2 (84.5% vs. 56.25%), with a higher complete stone clearance rate (94.8% vs. 75%).

Conclusions:

• Air pyelogram is a feasible, safe, cost-effective, and efficient alternative to contrast pyelogram for PCNL access.
• In challenging cases, a combination of air and contrast may be superior to using either agent exclusively.