Engineered Organs Don't Have to Look Like Existing Organs
Tissue engineering offers the opportunity to augment the function of an organ without necessarily recreating the evolved natural structure of that organ. There may be numerous paths forward in which it is much easier to create a pseudo-organ or tissue sections that perform only some of the necessary functions of the real organ rather than engineer a full replica. This is more evidently the case for tissues intended to generate regulatory proteins or other biochemicals: it often isn't necessary that these tissues exist in the exact location evolution has placed them. So for example functions of the thyroid or pancreas could be augmented with tissues implanted into lymph nodes - and that is an easier prospect than recreating the whole organ in question.
Here researchers demonstrate that it is also feasible to consider distributing some of the mechanical duties of the heart. They aim to produce novel small organs that wrap blood vessels to aid blood flow:
[Researchers have] invented a new organ to help return blood flow from veins lacking functional valves. A rhythmically contracting cuff made of cardiac muscle cells surrounds the vein acting as a 'mini heart' to aid blood flow through venous segments. The cuff can be made of a patient's own adult stem cells, eliminating the chance of implant rejection. "We are suggesting, for the first time, to use stem cells to create, rather than just repair damaged organs. We can make a new heart outside of one's own heart, and by placing it in the lower extremities, significantly improve venous blood flow."The novel approach of creating 'mini hearts' may help to solve a chronic widespread disease. Chronic venous insufficiency is one of the most pervasive diseases, particularly in developed countries. Its incidence can reach 20 to 30 percent in people over 50 years of age. It is also responsible for about 2 percent of health care costs in the United States. Additionally, sluggish venous blood flow is an issue for those with diseases such as diabetes, and for those with paralysis or recovering from surgery.
[The researchers have] demonstrated the feasibility of this novel approach in vitro and are currently working toward testing these devices in vivo.
Link: http://smhs.gwu.edu/news/gw-researcher-invents-%E2%80%98mini-heart%E2%80%99-help-return-venous-blood