A programmable medical robot has been developed that could be implanted into an animal and help increase the size of the tube-like organs by pulling on them appropriately. The robot can stimulate tissue growth. This new robotic system was unveiled in an article published in the Science Robotics.
Researchers at the Boston Children's Hospital have developed such a robot that works painlessly and does not cause discomfort but increases the traction force to increase the length of the tubular organs of the body without interfering with other organs around it. The robot works by increasing the cell proliferation and multiplication at the esophagus of the large animal. The esophagus or the food pipe is the tubular structure that connects the mouth to the stomach. This new implantable robot was attached to the esophagus of the large animal that had not grown previously to its full size. The new robotic system could help in the growth of this tube by about 75 percent without surgery or any pain and discomfort to the animal.
According to the researchers, this principle could be used in a rare condition called long-gap esophageal atresia (LEA) wherein part of the esophagus is missing. It could also increase the length of the small intestine in short bowel syndrome. LEA affects 1 in 4,000 babies born in the United States. Short bowel syndrome however is more common. At present lengthening of the esophagus in esophageal atresia is done by a surgical process by which the end of the underdeveloped esophagus is tied up with stitches and pulled back onto an anchor at the back of the patient. This is done by gradual traction on the organ that can be painful and carries a risk of the esophagus from tearing due to the pull. The patient needs to be paralyzed into a medically induced coma while the pull was in place to allow the esophagus to grow without the risk of damage. This medically induced coma would mean that the patient would be placed in the intensive care unit on mechanical ventilation for up to four weeks. This coma, immobilization and period of ventilation comes with high risks of infections, fractures of bones and formation of blood clots.
Making of these robots can now solve this problem without having to put the person in coma. He or she would be able to move around and perform their daily functions while the robot worked on the traction to increase the size of the food pipe say researchers.
The team made a tiny robotic system that has a motor and is attached to the esophagus. It has a “smooth, biocompatible, waterproof” covering or skin with two attachment rings on either side. These rings are placed around the esophagus and sutured into place. The robot can then be controlled from outside using a programmable control unit that provides slow and steady traction or pull forces at the two rings to lengthen the tissue in desired direction and size. For this study, the team tested the device on 5 pigs and their food pipes. Three other pigs were treated the conventional way and served as controls. The researchers increased the distance between the two rings by 2.5-millimeter a day for 8 to 9 days. During this time, the animals fed normally and moved around without showing any signs of pain or discomfort. They noted at after 10 days, there was an increase of 77 percent in the food pipes on an average. The esophagus that was so elongated maintained its structure and function and was normal in every way. Pierre Dupont, PhD, the study's senior investigator and Chief of Pediatric Cardiac Bioengineering at Boston Children's said that the examination afterwards showed that the esophagus lengthened not just by stretching but by cell growth.
Russell Jennings, MD, surgical director of the Esophageal and Airway Treatment Center at Boston Children's Hospital, and a co-investigator on the study explained that this was a “proof-of-concept” study that showed that these tiny robots could actually work and induce the growth of an organ “inside a living being for repair or replacement” and did not necessitate paralysis and sedation or coma. He added that this concept would be useful for other organs as well in future and more exploration and studies are necessary. They are now trying to test these robotic systems in large animals with short bowel syndrome.
The study received support from the Translational Research Program and Manton Center for Orphan Disease Research at Boston Children's Hospital along with help from Swiss National Science Foundation.