Introduction. Percutaneuos nephrolithotripsy (PNL) is mostly performed through the lower calyceal access, but in a distinct group of patients upper calyceal access is indicated. Our study was aimed at comparing results of PNL performed with different access.

Materials and methods. This study includes outcomes of PNL in 568 patients with primary renal stones, who were treated at the urology clinic of North-Western State Medical University named after I.I. Mechnikov based on urology department of City Hospital №2 and center of urology and robot-assisted surgery of Mariinsky hospital. Patients with recurrent stones and history of previous renal and upper urinary tract surgery were excluded from this study. There were 360 (63,4%) male patients and 208 (36,6%) female patients. Mean age of patients was 48,6 ± 15,2 (28–76) years. Patients were distributed among two groups: I (primary) group – 240 (42,5%) PNL performed through the upper calyx; II (control) group – 328 (57,5%) PNL performed through the lower calyx. Mean stone size in group I was 2,6 (2,4 – 3,8) cm, and in group II it was 2,6 (2,4 – 3,8) cm. We performed a comparative analysis of operative time and efficacy, intraoperative and postoperative complications, hospitalization time.

Results. There were no conversions to open surgery. In group I PNL was effective in 206 (85,8%) of 240 patients, and in group II – in 335 (91,0%) of 368 patients. However, number of patients with staghorn calculi in group I prevailed when compared to group II (25,6% / 14,8%). Mean operative time (56,0 ± 18,5 / 48,4 ± 14,5 min), hospitalization time (4,5 ± 1,8 / 4,2 ± 1,4 days) and analgesia duration (2,4 ± 1,0 / 2,2 ± 0,9 days), incidence of postoperative fever (7,9% / 8,1%) did not differ significantly. There were no repeat PNL due to residual stones. In group I additional interventions were required in 34 (14,2%) patients (25 – ESWL, 9 – ureteroscopy), in group II – in 33 (9,0%) patients (23 – ESWL, 10 – ureteroscopy). There were no cases of abdominal trauma. Blood transfusion was required in 17 (7,1%) patients in group I and in 12 (3,3%) patients in group II. In primary group there were 3 (1,3%) cases of pleural injury which led to hydrothorax (2 cases) and hemothorax (1 case). These patients underwent puncture and drainage. No such complications were observed in control group.

Conclusion. Percutaneous approach through the upper calyx provides a direct access to the main part of renal collecting system and allows to remove a greater part of a staghorn calculus and to remove upper ureteral stones. A frequent complication of intercostal approach to the collecting system is the pleural injury, which is managed depending on severity of symptoms and may require drainage of pleural cavity.

Authors declare lack of the possible conflicts of interests.