Initial Clinical Experience of Using Visual Dilatation Technique in Percutaneous Nephrolithotomy

Introduction: Tract dilatation in percutaneous nephrolithotomy can still be difficult to ascertain the optimal depth to prevent over-dilation, causing system perforation and vascular injury or under-dilation, making the establishment of access tract in a single attempt strenuous. This study aimed to use of visual dilator system to obtain real-time visual confirmation during percutaneous tract dilatation. Materials and Methods: The visual dilator system was used. The nephroscope was connected to a standard endoscopic camera system. The dilator system backloaded with an access sheath was passed over a guidewire to dilate the percutaneous tract and position the access sheath under visual guidance. Between December 2015 and December 2016, the visual dilator system was used during percutaneous tract dilatation in 13 percutaneous nephrolithotomy (PCNL) cases with mild or above hydronephrosis. Results: All tracts were successfully dilated in a single attempt. The intervening tissue layers, approach into the target calix, and the access sheath placement could be visually monitored through the dilator wall to confirm accurate dilatation. Mean dilatation time was 3.4-0.9 minutes, hemoglobin drop was 1.4-0.8 g/dL, primary stone-free rate and that after auxiliary treatment were 11/13 (84.6%) and 13/13 (100%), respectively. We experienced over-dilatation in one of the initial cases. No complications were experienced in the rest of the cases. Conclusions: PCNL access tract dilation using the visual dilatation technique is clinically feasible and provides real-time visual monitoring and confirmation of accuracy in dilatation. It may improve the overall safety and efficacy of the PCNL procedure.