Introduction

Real-time virtual sonography (RVS) is a diagnostic imaging support system that synchronizes real-time ultrasonography and computed tomography images to provide volume and position data, side-by-side, in real-time. The aim of our study was to evaluate the clinical utility of RVS to guide percutaneous renal puncture for endoscopic combined intrarenal surgery (ECIRS) for large renal calculi.

Methods

We retrospectively evaluated surgical outcomes in 15 patients with renal calculi (36.3 ± 4.2 mm) who underwent RVS-guided ECIRS at our center between April 2014 and July 2015. Preoperative computed tomography images, obtained with patients in the prone position, were used as input into the RVS system. Renal puncture was performed using the RVS system, with patients in the prone split-leg position, under direct endoscopic vision. Renal puncture was repeated until a papilla was successfully pierced. After inserting the miniature percutaneous tract, two urologists worked simultaneously to fragment the renal calculi. We evaluated the number of puncture attempts required to gain papilla access through the calyx, the surgical time, the stone-free rate, and the occurrence of complications.

Results

All renal punctures were successfully performed, with an average of 1.6 ± 0.3 attempts required to gain papilla access through the calyx. In 86.7% of cases, renal punctures were performed through the lower pole of the calyx. The mean surgical time was 118.3 ± 15.3 min, with no requirement for nephrostomy tube insertion in 60.0% of cases (9 cases). The mean decrease in hemoglobin level was 0.9 ± 0.3 g/dL. Complete stone clearance after a single treatment session was achieved in 80.0% of cases(12 patients). Three patients experienced complications, including two cases of transient fever. None of the patients required a blood transfusion, and there was no incidence of complications with a Clavien grade ≥ 2.

Conclusions

We successfully applied RVS guidance to targeted renal puncture, providing evidence of the clinical utility of RVS for improving the precision of the calyceal puncture while decreasing the incidence of bleeding-related complications during ECIRS. RVS-guided renal access may have great potential to improve treatment for renal calculi and as a learning tool for novice operators.

Funding

none