Development of a wire-driven film-type device for tissue elimination in rectal cancer endoscopic surgery

In rectal cancer endoscopic surgery, the tissue hangs down and obstructs the surgical field when using a scalpel to make an incision to expose the tumor. Thus, there is a need for a tissue elimination device because the surgical field can be secured by lifting the hanging tissue during this surgery.

We developed a wire-driven film-type device for tissue elimination that can be driven even in limited spaces such as the spatial constraints in the rectum. The device is composed of a polyethylene terephthalate film and stainless steel with a belt-loop structure to reduce film swelling. The belt-loop prevents film swelling and facilitates device movement without restriction of the obstacles above it. In addition, the device generates a force exceeding 1 N at a displacement of 0-10 mm. We used a mechanical model to analyze the relationship between the force at the device tip and the tensile force acting at the belt-loop position. This analysis facilitated the optimization of the belt-loop position.

A maximum force of 4.25 N was achieved at a tensile force of 40 N under the specified displacement conditions. Further, the device with the optimized belt-loop position achieved a maximum force of 10.3 N at a tensile force of 40 N, which was approximately 2.4 times higher than that of the device before optimization.

The wire-driven film-type device for tissue elimination can optimize the belt-loop position to satisfy the required specifications. Furthermore, evaluation results of the devices indicate it possesses sufficient performance for use in rectal cancer endoscopic surgery.