Illustration - Robotic system implanted in short bowel syndrome (A) and long-gap oesophageal atresia (B).

Implanted programmable robots help regenerate tissue from the inside of the body

Until recently, placing robots within the human body to aid in biological function restoration or enhancement seemed to be a figment of the imagination. However, a group of researchers have successfully tested devices that induce tissue regeneration.

A Boston Children’s Hospital team created a robotic implant that offers a less invasive treatment for diseases affecting tubular-like organs (e.g. oesophagus, intestines, and blood vessels). The implant achieves in vivo tissue regeneration through mechanostimulation; ultimately resulting in the lengthening of tubular organs.

The robotic system consists of a small, cylindrical pouch encased in a biocompatible waterproof skin containing sensors and a tiny motor. It is attached to a pair of steel rings that wrap around the organ in a pincer-like fashion. The rings are then slowly pulled apart by applying computer-controlled traction forces that encourage new tissues to grow.

A video about the robotic system can be found here.

These devices were tested in healthy pigs and resulted, in average, in 77% longer oesophagi; therefore, proving that mechanic stimulation successfully induced cell proliferation. The process involved continuous traction that increased the distance between the rings by 2.5mm per day, during a period of a week and a half.

More importantly, this was achieved without entailing diameter reduction and was performed while the animal remained awake, mobile, and maintained regular eating habits. In essence, it lengthens tubular organs without disrupting function or provoking apparent discomfort during the procedure.

Particularly, the team’s focuses on short bowel syndrome (see Illustration – (A)) where lengthening the organ would increase surface area for absorption of necessary fluids and, therefore, reduce (or even eliminate) the dependence on intravenous feeding.

The main focus is, however, long-gap oesophageal atresia (OA), where sufficiently grown segments are surgically connected to form a complete oesophagus. OA is the most common congenital anomaly of the oesophagus (one in every 2,500-4,500 live births) and current treatment encompasses a corrective surgery – the Foker procedure – which still presents a challenge in paediatric surgery.

Relevantly, the Foker technique requires the suturing of anchors to the patient’s back, that gradually pull on the oesophagus. To prevent tearing, individuals must undergo the procedure in a medically-induced coma and are immobilised for an extended period (1-4 weeks), with the associated risk of presenting blood clots and bone fractures.

As Russell Jennings, MD, surgical director of the Oesophageal and Airway Treatment Centre, commented “this project demonstrates proof-of-concept that miniature robots can induce organ growth inside a living being for repair or replacement, while avoiding the sedation and paralysis currently required for the most difficult cases of oesophageal atresia”.

It is expected, then, that miniature traction devices could be implanted in humans with the advantage of having a recovery process that disrupts daily life less. The potential uses of similar robotic systems, including applications for non-tubular organs, have yet to be fully explored and developed.