Simulated tissue models and methods

A simulated tissue model, comprising:

• a substantially cylindrical tube having an inner surface and an outer surface extending between a proximal end and a distal end and defining a central lumen having a longitudinal axis, wherein the cylindrical tube comprises:
• a first layer made of silicone having a first tubular sidewall with an inner surface and an outer surface and at least one recess having a depth formed in the outer surface of the first tubular sidewall;
• a second layer made of silicone having a substantially planar inner surface opposite a substantially planar outer surface defining a thickness therebetween;
• the second layer being sized and configured to fit inside the recess;
• a third layer made of silicone having a second tubular sidewall with an inner surface and an outer surface;
• the second tubular sidewall being substantially uniform;
• the third layer and the first layer are adhered together such that the inner surface of the second tubular sidewall faces and contacts the outer surface of the first tubular sidewall and such that the second layer inside the recess is captured between the first layer and third layer.