Does access location influence outcome of percutaneous nephrolithotomy in staghorn stones?

Abstract

Objective: To assess the effect of lower and middle calyceal accesses on the outcomes of percutaneous nephrolithotomy (PCNL) in staghorn stones. Study Design: Observational study. Place and Duration of Study: Department of Urology, University of Health Sciences, Izmir Bozyaka Training and Research Hospital, Turkey, from April 2012 to January 2019. Methodology: Patients who underwent PCNL for staghorn stones were retrospectively analysed. The patients were grouped as Group-1 (middle calyceal access) and Group-2 (lower calyceal access). Demographic and stone characteristics (size, density), perioperative and postoperative data, and stone-free rates were compared between these two groups. Postoperative detection of > 4 mm stones was defined as residual stones. Results: There were 249 patients in the study; 108 in middle calyceal access group and 141 in lower calyceal access group. The mean stone burden was 765 (524-1322) and 777 (490-1445) mm2 in group-1 and group-2, respectively (p=0.876). The number of stone-free patients was 50 (46.3%) in middle calyceal access group and 93 (66.0%) in lower calyceal access group. The rate of stone-free status was significantly higher in lower calyceal access group (p=0.002). The overall complication rate was similar between the groups (p=0.132). The binary analysis showed that stone burden, and calyx of entry were predictive factors for success. Conclusion: Although the choice of the calyx to be entered does not affect the complication rate in staghorn stones, the stone-free rate is significantly higher in lower calyceal access.