Construction of a three-dimensional model of renal stones: comprehensive planning for percutaneous nephrolithotomy and assistance in surgery

To construct a three-dimensional (3D) model of renal stones to facilitate comprehensive planning for percutaneous nephrolithotomy (PCNL) and to assist in surgery. Fifteen patients with complex renal stones, including one patient with a horseshoe kidney, eight patients with partial/complete staghorn, and six patients with multiple renal stones, participated in our study. Computed tomography images of the unenhanced, arterial, venous, and excretory phases were obtained before surgery. Image segmentation and 3D reconstruction of the renal stones were performed using Mimics 12.1 software. A virtual safe and reliable percutaneous renal access route were established for each patient by comprehensive planning based on the 3D model of renal stones. PCNL was subsequently performed with the assistance of the 3D model. Patient demographics, surgical details, and postoperative treatment parameters were recorded. The 3D models of renal stones accurately represented the interrelationships between the intrarenal arteries and veins, collecting system, stones, and adjacent anatomical structures. PCNL was completed successfully in all 15 patients. The mean operating time was 75.6 +/- A 13.4 min. The change in hemoglobin concentration was 1.2 +/- A 0.3 g/l. The one-stage stone-free rate was 93.3 %, and the final stone-free rate was 100 %. No major postoperative complications were noted, except for postoperative pain in one case. Construction of a 3D model of renal stones with the aim of minimizing the risks of percutaneous procedures and achieving higher one-stage stone-free rates is feasible for comprehensive PCNL planning and assistance in patients with complex renal stones.