Does Access Location Influence Outcome of Percutaneous Nephrolithotomy in Staghorn Stones?

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. Key Words: Percutaneous nephrolithotomy, Staghorn stones, Clavien scoring system, Calyx, Access.