Percutaneous nephrostomy for complex renal stones: Percutaneous renal access behind the stone versus renal calyx dilation

OBJECTIVE: To evaluate the technical success rate and complications associated with percutaneous nephrostomy (PCN) via percutaneous renal access behind the stone and renal calyx dilation in patients with complex renal stones. MATERIALS AND METHODS: From January 2010 to February 2021, we identified 69 patients with 70 complex renal stones who underwent PCN. Complex renal stones were classified as simple (renal pelvis only) (27.1%, 19/70), borderline staghorn (8.6%, 6/70), partial staghorn (51.4%, 36/70), or complete staghorn (12.9%, 9/70). All PCNs were performed under ultrasound and fluoroscopic guidance using one of two renal-entry techniques: puncture behind the stone (56%, 39/70) or renal calyx dilation (44%, 31/70). Then, we retrospectively evaluated the technical success rates and complications associated with each renal entry access technique. RESULTS: The overall technical success rate was 100%, and the complication rate was 20.0% (14/70). For those who underwent renal access behind the stone, the complication rate was 15.4% (6/39), and six patients (six PCNs) had transient gross hematuria. For those who underwent dilated renal calyx entry, the complication rate was 25.8% (8/31), and one patient had significant bleeding complications requiring transfusion. Furthermore, seven patients (seven PCNs) had transient gross hematuria. Overall, the complication rates did not differ between the technique groups (p = 0.279) CONCLUSION: PCN for complex renal stones has a high technical success rate and an acceptable complication rate regardless of the specific technique. Renal entry behind the stone is as safe and feasible as approaching via a dilated renal calyx.