PCNL in the prone position VS PCNL in the modified supine Double-S position: is there a better position? A prospective randomized trial.

The study was performed to evaluate the efficacy of our modified supine position (called "Double-S") in percutaneous nephrolithotripsy (PCNL) and to make a contribution to the question: "Is there a better position in PCNL?". The superiority of one position is still under debate in the scientific community. In our study, we described and compared our position with the standard prone one to evaluate the possible benefits. This is a prospective randomized clinical trial conducted for 17 months. It consisted of two sub-studies: trial A (patients with stones approachable with a single anterograde access) and trial B (patients with stones approachable with a single anterograde access combined with a retrograde access). A 1:1 randomization was performed in both trials to compare the supine Double-S position with the prone one. We found that the Double-S position presents the same safety and efficacy outcomes as the standard prone one. Moreover, we proved that this particular position can reduce the patient positioning time and effort sustained by professional nurses if compared to the prone one. The same outcomes were found in trial A and in trial B. Trial B confirms the efficacy of our position also when a combined access is needed. We proved that the Double-S position is safe and effective both in anterograde treatments and in combined anterograde-retrograde procedures with benefits in the positioning time and effort level.