Synthetic tissue structures for electrosurgical training and simulation

A simulated rectum model for training transanal minimally invasive surgery is provided. The model includes three substantially concentric layers, a first layer, a second layer and a third layer, made of electrically conductive hydrogel material sized and configured to simulate a mucosal layer, a muscle layer and a mesorectum layer, respectively. Each layer is made of a dual interpenetrating cross-linked network having a ratio of covalently cross-linked acrylamide to ionically cross-linked alginate. The ratio for each layer is selected for the desired adhesion properties between two adjacent layers. The model is capable of expanding in size when insufflated and simulating a billowing condition. When the model is dissected with electrosurgical instruments, the hydrogel material realistically emits vapor simulating smoke and causes char to build up on instruments. Artificial polyps and transverse folds are molded on the inner surface of the model.