Is there a difference in percutaneous nephrolithotomy outcomes among various types of pelvicaliceal system?

During PNL procedures, stone clearance can be achieved by single access or multiple accesses for same stone size and configuration. At this point, we believed that pelvicaliceal system type may play a significant role on stone clearance. In our study, we aimed to investigate the effect of pelvicaliceal system type on PNL outcomes.

A total of 498 patients who had preoperative intravenous urography were enrolled in our study. PCSs of the patients were classified as A1, A2, B1, and B2 according to Sampaio system after evaluation of IVU images. The exclusion criteria were unclassified pelvicaliceal system due to the presence of exaggerated renal hydronephrosis, IVUs with poor quality, radiolucent renal stones, and absence of CT or IVU in postoperative period.

There was no clinically significant difference for patient gender, history of open surgery, and history of previous SWL. Success rates of PNL were 79.5, 82.0, 74.3, and 80.3 % in Sampaio type A1, A2, B1, and B2 PCS, respectively (p 0.61). Multiple accesses were required for 35 (18.8 %), 14 (17.9 %), 55 (30.1 %), and 6 (11.8 %) patients according to Sampaio classification type A1, A2, B1, and B2, respectively (p 0.008). There was no clinically significant difference for stone size, stone configuration (simple or complex), and complications.

Sampaio type B1 PCSs require increased number of access for achieving stone clearance. Therefore, surgeons should be aware and also inform patients that treatment of patients with Sampaio type B1 PCS may need high number of access during PNL procedure.