Comparative Analysis of Safety and Efficacy Between Anterior and Posterior Calyceal Entry in Supine Percutaneous Nephrolithotomy

Introduction: One advantage of supine percutaneous nephrolithotomy (sPCNL) is the ability to access anterior as well as posterior calyces, but the safety and efficacy of anterior calyceal entry has never been investigated to our knowledge. We prospectively evaluated patients scheduled for sPCNL comparing anterior and posterior calyceal access. Materials and Methods: After Institutional Review Board approval, we prospectively enrolled 100 consecutive patients undergoing sPCNL from February to September 2023. Primary outcomes included intraoperative complications, blood transfusions, 30-day complication rates, and emergency department (ED) visits or readmissions. Secondary outcomes included stone-free rates (SFR). Results: Seventy-six patients had anterior calyceal entry and 24 had posterior. No significant differences were found in terms of baseline demographics (age, body mass index), stone characteristics (location, density, complexity), or intraoperative features (operative time, location of access). Safety outcomes, including intraoperative complications (1% vs 4%), blood transfusions (3% vs 8%), 30-day complication rates (17% vs 21%), and ED visits (1% vs 0) or readmissions (11% vs 21%) were comparable between groups. Overall SFRs were equivalent (86% vs 90%). Conclusion: We found that anterior and posterior accesses in sPCNL offer similar safety and efficacy, with no significant differences in complications or SFRs. Surgeons can select either approach based on patient anatomy and surgical needs without concern for increased complications. Further research is necessary to confirm these findings and guide best practices for calyx selection in sPCNL.