Comparative analysis on the efficacy and safety profile of upper calyceal versus lower calyceal access in the percutaneous nephrolithotomy (PCNL): A retrospective cross-sectional study

ABSTRACT

INTRODUCTION: The goal of PCNL is to achieve a high stone-free rate while minimizing complications. Its success results from an interplay of patient, stone and renal anatomical characteristics, the access site and the level of surgical expertise. Data comparing upper versus lower calyceal PCNL as regard to efficacy and safety are limited.OBJECTIVE: To compare the clinical efficacy and safety outcomes of upper versus lower calyceal access in patients who underwent PCNL at St. Luke's Medical Center.METHODS: A retrospective chart review was done on patients who underwent PCNL at SLMC from January 2010-January 2015. The patients were classified based on the renal access site Group 1 (upper calyceal) and Group 2 (lower calyceal). The stones were classified according to Guy Stone score and complications were summarized using the modified Clavien classification.RESULTS: A total pf 91 patients underwent PCNL during the study period. Of these, only 84 patients were analyzed. Seven were excluded due to lack or incomplete postoperative imaging on follow up. Forty-one were included in Group 1, while 43 were included in Group 2. According to the Guy Stone score, the stones in Group 1 were 21(IV), 6(III), 7(II) and 6(I) while in Group 2, 18(IV), 5(III), 8(II), 12(I) (p-value=0.52) with a mean stone volume of 38.2± 44.24cm3 and 28.0± 31.04cm3 in Groups 1 and 2 respectively (p-value= 0.23). Success rate was 80.5% and 83.7% for Groups 1 and 2 (p-value=0.70), respectively and mean stone clearance rates of 98.5% and 95.8% (p-value=0.13),respectively. The mean operative time was 181.0±82.26 and 169.5±52.12mins for Groups 1 and 2 (p-value=0.451),respectively. A total of 36 complications (13 from Group 1 and 23 from Group 2) were evaluated. Fever (Grade 1) occurred in 10 (24%) and 17(39%) for Groups 1 and 2, respectively. Blood transfusion (Grade 2) was observed in 4(9%) patients and 3(7%) in Groups 1 and 2, respectively. Two patients (5%) in Group 2 required postoperative double-J sent insertion due to ureteral stone migration (Grade 3). There was no significant difference noted among the groups as regards complication rates (p-value=0.097) and length of hospital stay (p-value=0.687). There was no mortality in either group.CONCLUSION: Based on our experience, both upper and lower calyceal access PCNL achieve equivalent efficacy and comparable safety profile in the treatment of complex renal stones.