Abstract

Background: Cholecystectomy is associated with bile duct and vascular injury. The aim of this study was to create a realistic and diathermable 3D printed model for cholecystectomy with the “Moynihan hump” vascular variant of the right hepatic artery. A hybrid 3D printed/silicone injection method was developed as silicone offers excellent biomechanical properties for surgical simulation. However, due to its hydrophobic nature and low electrical conductance, it has limited wetting-based applications, for example in hydrographics, diathermy or adherence to hydrophilic substances.

Methods: All 3D objects were sculpted in Blender modelling software, with reference to anatomical atlases and published literature. Polyvinyl alcohol (PVA) printed moulds were pressure injected with silicone (shore 10A) before dissolving the PVA support. Silicone models were immersed in a 3 mg.mL−1 dopamine solution (37°C, pH 8.5, 20 h). In order to simulate the diathermy of the connective tissue and peritoneum the electrical conductivity of PVA was increased by adding normal saline. The model validity was assessed by three surgeons.

Results: A high-fidelity, diathermable model with key anatomical landmarks and a cystic artery variant was created. The polydopamine coating significantly changed the water contact angle from 102 ± 2° to 86 ± 2° (P = 3.6 × 10⁻⁵) and improved hydrographic sheet adherence to the silicone models. The conductivity of the PVA–saline solution was 15 mS.cm⁻¹ and permitted successful employment of electrical diathermy during dissection.

Conclusions: Silicone moulded anatomical models can be made more realistic and diathermable through this low-cost method. This model offers realistic surgical training in cholecystectomy and exposure to challenging anatomical variants.

Supplementary material

Supplementary video 1. Available at https://youtu.be/IBYEbxNK_HI