Since the first artificial kidney was invented in 1943, medical researchers have searched for ways to replace defective organs with synthetic ones. Here is an overview of seven decades of progress.
USA 2009: LEGS A robotic leg developed by the Chicago Rehabilitation Institute translates nerve impulses into movement, using 13 sensors and 96 electrodes placed at knee level in the leg stump.
USA 2005: VAGINA The Wake Forest Institute for Regenerative Medicine created a bioartificial vagina from stem cells. It has been implanted in four patients who were born without them.
FRANCE 2016: PANCREAS People with Type 1 Diabetes, a disease caused by the malfunctioning of insulinsecreting pancreatic cells, can wear external insulin pumps. The French company Defymed is developing an implantable bioartificial organ secreting insulin that should be ready for clinical trials next year.
USA 2017: KIDNEYS External renal dialysis, first introduced by Willem Kolff in the Netherlands in 1943, filters waste products from blood by passing it through a semipermeable membrane. An implantable, autonomous artificial kidney capable of doing exactly this has been developed by researchers at the University of California, San Francisco and will undergo initial testing in the near future.
USA 2025: LUNGS The artificial lungs used in medical settings are external oxygenation devices. The first clinical trials for the fully implantable BioLung, made by the U.S. company MC3, will be carried out within five to 10 years. Lungs have 40 different kinds of cells, making them the most difficult organs to reproduce in a lab.
SWEDEN 2011: TRACHEA A synthetic trachea made of biocompatible plastic covered with stem cells was implanted in a patient at Karolinska University Hospital. Research is moving towards tracheal transplants that are autologous, or entirely composed of the recipient’s own tissues.
FRANCE 2012: LARYNX A University of Strasbourg Hospital patient wore the first artificial larynx, made of porous titanium, for a year. The device will ultimately allow patients to speak, eat and breathe normally.
USA 2011: EYES The Argus retinal implant, manufactured by Second Sight in the U.S., allows the blind and visually impaired to regain partial vision. Glasses outfitted with a camera send visual signals to electrodes placed in and around the retina via a mini-computer worn on a belt.
JAPAN 2013: LIVER External hepatic dialysis can filter and eliminate some toxins; despite some limitations, it is used while waiting for a transplant or natural liver regeneration. Yokohama City University scientists recently tested a liver grown on mice from human stem cells.
FRANCE 2013: HEART The autonomous French-made Carmat mechanical heart is the latest prototype implanted in a patient. Today, external battery-powered ventricular assist devices that partially replace cardiac function are generally used.
SCOTLAND 2007: HANDS The i-Limbs bionic hand allows its wearer to grasp objects, write and type on a keyboard. Nextgeneration devices equipped with sensors will permit a sense of touch by giving return force feedback to the patient.
USA & AUSTRIA ~1970: EARS Cochlear implants have been commercially available since the 1970s; they enable the hard of hearing and children born deaf to hear and communicate. A microphone records sound and sends it in the form of an electrical signal to nerve fibres in the auditory nerve via an implant.
Waiting for an organ
The preferred solution in the event of organ failure is still transplantation. Unfortunately, the supply of organs covers only about half the demand. In Europe, 80,000 patients await a donor; 4,100 of them died waiting in 2013. Doctors hope to use artificial organs as a temporary solution while waiting for a compatible donor.
Treatment options
TRANSPLANTATION Transplantation remains the optimal solution, when compatible donors are available. Immunosuppressant treatments are required to reduce the risk of rejection.
EXTERNAL DEVICES Most artificial devices are now portable (e.g. insulin pumps) or fixed (dialysis) external machines. By miniaturising them, researchers hope to make them more transportable, or even implantable.
MECHANICAL ORGANS A mechanical device, like an artificial heart, would make it possible to avoid using an external device or undergo immunosuppressant treatment.
TISSUE ENGINEERING Regenerative medicine aims to create tissues – and even entire organs – from healthy stem cells. This approach is considered very promising.
PROSTHESES These synthetic devices can now replace most of the body’s joints. They should become even more resistant, and sensory feedback should improve – for example in the case of hand prostheses.
By Céline Bilardo and Daniel Saraga
Illustration: Mathieu De Steur
Sources: Journalist Workshop on Organ Donation and Transplantation: Recent Facts & Figures, 26 November 2014, European Commission; Global Observatory on Donation and Transplantation; Newsletter Transplant Vol. 19, No 1 (2014), Edqm/Council of Europe; Beat Walpoth, Geneva University Hospitals (Switzerland); Cécile Legallais, Université de Technologie de Compiègne (France) & European Society for Artificial Organs; Stefan Weber, Olivier Guenat & Dominik Obrist, University Of Bern (Switzerland)