Abstract: A medical device for implantation and a TET system which includes the device as a component are provided. The device is designed so that it does not substantially restrict blood flow in the tissue surrounding the implanted device, thereby minimizing the risk of ischemia and necrosis. This enables the device to be implanted near tissue layers that are otherwise susceptible to blood flow restrictions when a device of the same volume and height is implanted. Blood flow adequate to prevent ischemia and necrosis is maintained by minimizing extravascular tissue pressure caused by the implantation of the device.