Ultrasound-only percutaneous nephrolithotomy is safe and effective compared to fluoroscopy-directed percutaneous nephrolithotomy
Gregory Hosier1, Nizar Hakam1, Xavier Cortez1, Fadl Hamouche1, Leslie Charondo1, Heiko Yang1, Carter Chan1, Kevin Chang1, David Bayne1, Marshall Stoller1, Thomas Chi1.
1Urology, University of California, San Francisco, San Francisco, CA, United States
Introduction: Use of ultrasound guidance for percutaneous nephrolithotomy (PCNL) access has gained popularity. However, reports on ultrasound-only PCNL, in which ultrasound is used for all steps of the procedure, are limited, as fluoroscopy is often used for dilation and to check for residual stones. The study goal was to compare outcomes for ultrasound-only PCNL compared to fluoroscopy-directed PCNL.
Methods: Prospectively collected data from the Registry for Stones of the Kidney and Ureter (ReSKU) database was reviewed for all patients who underwent PCNL at one academic center from 2015–2021. Primary outcomes were complications (Clavien-Dindo classification) and stone-free rates (no residual fragments ≥3 mm) compared between those who underwent ultrasound-only PCNL and fluoroscopy-directed PCNL in which any amount of fluoroscopy was used.
Results: A total of 141 patients were identified who underwent ultrasound-only PCNL and 147 who underwent fluoroscopy-directed PCNL. The mean maximum summative stone diameter was 30 mm and 44% were Guy score 3 or 4. Stone and patient characteristics were similar between both groups. There was no difference in complication rates (15% vs. 16%, p=0.87) or stone-free status (71% vs. 65%, p=0.72) between those who underwent ultrasound-only PCNL and fluoroscopy-directed PCNL, respectively. Ultrasound-only PCNL was associated with shorter operative time (median 99 minutes vs. 126 minutes, p<0.001), lower percent drop in hematocrit (2.7% vs. 4.9%, p=0.02), higher success rate of access achieved by resident (38% vs. 16%, p<0.001), and more frequent use of supine positioning (69% vs. 25%, p<0.001) compared to fluoroscopy-directed PCNL. After adjusting for body mass index, American Society of Anesthesiology score, stone size, and stone complexity by Guy score, ultrasound-only PCNL was not associated with any increased odds of complications (odds ratio [OR] 0.7, 95% confidence interval [CI] 0.3–1.6, p=0.42) or residual stone fragment ≥3 mm (OR 0.9, 95% CI 0.5–1.8, p=0.97) compared to fluoroscopy-directed PCNL.
Conclusions: Ultrasound-only PCNL is safe and achieves similar stone-free rates compared to fluoroscopy-directed PCNL, with added benefits of shorter operative time, less blood loss, and avoidance of radiation.
