'X-ray'-free balloon dilation for totally ultrasound-guided percutaneous nephrolithotomy.

The objective of the study was to evaluate the feasibility and safety of balloon dilation for 'X-ray'-free ultrasound-guided percutaneous nephrolithotomy (PCNL). From January 2012 to December 2012, patients underwent 'X-ray'-free ultrasound-guided PCNL with Amplatz dilator (Group A). From January 2013 to April 2014, patients underwent 'X-ray'-free ultrasound-guided PCNL with balloon dilator (Group B). For balloon dilation, a 10 F fascial dilator was used to dilate the tract. Subsequently, the 6 F nephrostomy balloon (8 mm in diameter) was indwelled along the guidewire with a marked length equal to the dilation depth. Under the monitoring of ultrasound, the location of balloon was secured and disappearance of balloon waist was confirmed when the balloon was inflated at a pressure of 20 atm. A total of 163 patients were involved in this study. Of 81 procedures in Group A, 45 procedures were performed by a senior urologist while 36 procedures by a resident. Of 82 patients in Group B, 47 procedures were performed by the same senior urologist while 35 procedures by another resident. For the senior urologist, there was no statistically significant difference between two groups in calyx of entry, stone-free rate, decline of hemoglobin and hematocrit, operation time and hospitalization. But for the residents, there was less decline of hemoglobin and hematocrit, tract development time and hospitalization in Group B compared to Group A (0.6 vs. 1.7 g/dl, p = 0.001; 2.3% vs. 5.5%, p = 0.003; 10.1 vs. 11.0 min, p = 0.027; 7.8 vs. 13.9 days, p < 0.001). Balloon dilation method introduced in this study is compensable for tract development when 'X-ray'-free ultrasound-guided PCNL is performed. Modified techniques make totally ultrasound guidance for PCNL feasible, easy and safe. In addition, such a procedure is preferable for initial operators because of less hemorrhage complication.