Ultrasound guidance for endoscopic and percutaneous procedures has gained popularity. Kidney mockups could be used for training, however, available mockups are normally incompatible with ultrasound imaging. We designed and developed a reproducible method to manufacture an ultrasound-compatible collecting system mockup. We used computed tomography (CT) of a patient to segment and create a 3D digital model of a urinary collecting system and the overlying skin surface. Positive and negative molding methods were used.
a) Reconstructed left kidney collecting system with overlying skin surface from CT scan using 3D slicer. b) CAD model of shaft to the collecting system that preserves the original orientation relative to the skin surgface, c) CAD model of the containment box with thw skin surface as its base
A containment mold (negative) was made to follow the shape of the skin surface using a 3D printer. A collecting system mold (positive) was also printed with a 3D printer, but made of a dissolvable material. The containment mold was filled with a gelatin formula of 300 bloom gelatin, glycerin, sorbitol, and water (at a ratio of 300:300:200:2500 g) at 55°C. After the gelatin solidified, high purity D-Limonene solution, is continuously irrigated using a peristaltic liquid pump into the hollow collecting system mold, until completely dissolved.
a) 3D printed collecting system with shaft, b) 3D printed containment box with the collecting system in place
The final mockup was then ready to be extracted out of the containment mold. The result is a personalized, anatomicaly accurate, gelatin based, ultrasound compatible collecting system model that can be used for training purposes at academic centers.
a) Collecting system cavity inside the mockup, b) Its ultrasound image