How to make removing colon polyps safer

Materials World magazine
,
29 Aug 2019

A newly developed gel cushion could make colon polyp removal safer, reducing the patient’s chance of developing cancer. Idha Valeur asks how it works.

A new liquid-come-gel could help lift colon polyps to enable easier removal, lowering the risks of colon lining tearing and cancer. With numerous colonoscopies performed globally each year, having a process to remove polyps safely and easily is paramount for preventing cancer.

Researchers from Massachusetts Institute of Technology (MIT), USA, found that a liquid which turns solid when it reaches tissue can make for a better, more stable cushion than the current method of injecting saline into the polyp to elevate it to assist removal.

‘That really makes a huge difference to the gastroenterologist who is performing the procedure, to ensure that there is a stable area that they can then resect using endoscopic tools,’ MIT Department of Mechanical Engineering Assistant Professor and Brigham and Women’s Hospital Gastroenterologist, Giovanni Traverso, said in a press release.

To remove a polyp, surgeons normally use saline to lift the colon polyp and remove the tissue with a tool similar to a lasso to trap it, before cutting it off. The complication with this process is the saline solution will quickly disappear and deflate the polyp. With intricate lesions taking 10–20 minutes to remove or longer, and the saline only lasting for a few minutes, the surgeon often has to re-inject saline.

The new elevating method is a shear-thinning gel made from materials that are semi-solid under normal conditions, but by applying force ‘their viscosity decreases and they flow more easily. This means that the material can be easily injected through a narrow needle, then turn back into a solid gel once it exits into the colon tissue’, the release read.

The materials used to create the gel are Laponite – powdery clay – and alginate derived from algae, although various materials could be used to create shear-thinning gels.

‘We chose these materials because they are biocompatible and they allow us to tune the flowing behavior of the resulting gels,’ Lead Author of the study and former MIT postdoc, Yan Pang, said.

The material has been tested on pigs and has not caused any detrimental side effects to date. The researchers aim to begin patient trials in three to five years. The research has received funding from the National Institute of Health, the Alexander von Humboldt Foundation, the Division of Gastroenterology at Brigham and Women’s Hospital, and the MIT Department of Mechanical Engineering.