A Safe and Effective Two-Step Tract Dilation Technique in Totally Ultrasound-Guided Percutaneous Nephrolithotomy

Purpose: To evaluate the safety and efficacy of a radiation-free 2-step tract dilation technique in totally ultrasound-guided percutaneous nephrolithotomy (PCNL). Materials and Methods: From Oct 2018 to Mar 2020, we prospectively and consecutively enrolled 18 patients with 19 kidney units with urolithiasis. The nephrostomy tracts were established by the following four steps: 1) ultrasound-guided renal puncture, 2) first-stage serial dilation to 16 Fr with Amplatz dilators, 3) introduce the ureteroscope through the 16Fr Amplatz sheath for tract adjustment and confirmation, 4) second-stage dilation with a 24-Fr balloon dilator. Results: The median age of the patients was 61.5 [54, 66] years, and 11 (61%) were male. The median size of the stones was 3.3 [2.7, 6.2] cm2 with an equal distribution of the laterality(right/left). Successful tract establishment on the first attempt without fluoroscopy was achieved in 18 (95%) operations. The median tract establishment time was 10.2 [9.5, 12.4] mins, and the median operation time was 63.4 [29.2, 81.9] mins. The median decrease in hemoglobin level was 1.0 g/dL [0.5,1.6] and none of the patients required intraoperative or postoperative transfusion. Three of the patients (16%) developed fever postoperatively. Pleural injury occurred in two (11%) patients having supracostal punctures and one required drainage with a pigtail. Stone-free status was achieved in 15 (79%) operations at 3 months postoperatively. Conclusion: Our experience suggested the radiation-free 2-step tract dilation technique is a safe and effective method for tract development in ultrasound-guided PCNL.