Development of a Laparoscopic System for In Vivo Observation of the Bonghan Structure

Abstract

Bonghan structures composed of corpuscles and ducts have been observed in numerous animal experiments. The structure has been suggested to be the physical substrate for acupuncture points and meridians used in traditional Chinese medicine. The corpuscle-duct structure on the organ surface has been extensively studied. However, it was only observed after the abdomen of a rat was fully exposed. It may be desirable to observe these structures under minimally invasive conditions. Our laparoscope is specifically designed for in situ, in vivo observation of the Bonghan structure on the surface of internal organs in rats. We made a laparoscope consisting of a borescope combined with an illumination module and an imaging data acquisition part. The Bonghan structure is transparent and is hard to see, even with the borescope. Spraying a specific dye, trypan blue and washing with saline is a necessary process to visualize the structure. For this reason, we devised a staining and washing system attached in parallel with the borescope in the laparoscopic system. The system operated successfully to reveal a Bonghan structure without surgery. This tool opens a host of possible applications such as observation of flow of stained liquid or drug in the Bonghan duct flowing from the skin to internal organs, and long-term observation of the physiological changes in Bonghan corpuscles.

Historical Review about Research on “Bonghan System” in China

“…They used Trypan blue dyeing and other techniques to show that PVs exist not only on the surface of the internal organs, but also in the nerve system, cardiovascular system, lymphatic system, fascia of the abdominal cavity, adipose tissue, generative system (testis), skin and abdominal wall, primo fluid and microcells, egg vitelline membrane, and cancer [27] in rabbits, rats, mice, dogs, and pigs. They have observed the structure of PVs by using modern instruments as electron microscope and laparoscope [28, 29] and analyzed their protein profiles of PVs tissue using proteomic technique [30], claiming that their results will shift the level of the oriental medicine from the traditional wisdom and art with a long history to the biomedical sciences. Recently, Kwon and colleagues [11, 31] observed microscopic nodes and ducts inside lymphatics, as well as on the surface of internal organs in the rat.…”