Management of symptomatic caliceal diverticular calculi: Minimally invasive percutaneous nephrolithotomy versus flexible ureterorenoscopy

Objective To retrospectively evaluate appropriate treatment for patients with symptomatic caliceal diverticular calculi, by comparing the therapeutic outcomes for those undergoing minimally invasive percutaneous nephrolithotomy (MPCNL) and flexible ureterorenoscopy (F-URS). Methods From March 2009 to May 2014, 36 consecutive patients with caliceal diverticular calculi were divided into 2 groups: 21 patients underwent MPCNL, and 15 were treated by F-URS. All procedures were performed by one surgical group, which ensured relatively constant parameters. Patient characteristics, operative time, hospital stay after surgery, stone-free rate, symptomatic improvement rate, complications, diverticular obliteration, and stone composition were analyzed retrospectively in the 2 groups. Results Patient preoperative variables were comparable between the two groups, with no significant difference (P > 0.05). Mean operative time was 136.9 ± 22.8 min in the MPCNL group and 117.3 ± 24.3 min in the F-URS group (P = 0.019). Hospital stay was significantly longer in the MPCNL group than in the F-URS group (9.4 ± 3.1 vs. 6.9 ± 2.1 days, P = 0.010). The stone-free rates after MPCNL and F-URS were 90.5% (19/21) and 60.0% (9/15), respectively (P = 0.046). Additionally, 71.4% (15/21) of patients in the MPCNL group and 46.7% (7/15) of patients in the F-URS group had symptomatic improvement at the 6-month follow-up (P = 0.175); the rates of complications in the 2 groups were 19.0% (4/21) and 13.3% (2/15), respectively (P = 0.650). Complete diverticular obliteration was achieved in 16 (76.2%) cases in the MPCNL group and 5 (33.3%) cases in the F-URS group (P = 0.017). The distributions of calcium oxalate and hydroxyapatite in the stones were 66.7% (14/21) and 33.3% (7/21), respectively, in the MPCNL group; however, the distributions in the F-URS group were 46.7% (7/15) and 53.3% (8/15), respectively (P = 0.310). Conclusion MPCNL is an effective method for the treatment of caliceal diverticular calculi. However, F-URS is an alternative technique in selected patients with a patent infundibulum, despite lower stone-free rates than with MPCNL. Fulguration of the diverticular lining with a high-power holmium laser and permitting the cavity to collapse are useful to increase the chance of diverticular obliteration.