What did Hanaoka Seishu develop
?

Developed an anesthetic called "Tongsensan

At the age of 25, Seishu began researching anesthetics while examining and treating patients as a surgeon.

An anesthetic is a drug that temporarily removes the sensation of pain from the patient. In the absence of anesthetics, patients had no choice but to endure the pain desperately while undergoing surgery.
After years of research, Seishu succeeded in developing an anesthetic called "Tongsensan," and in 1804, he performed the world's first successful surgery under general anesthesia using Tongsensan.

Hanaoka Seishu
Hanaoka Seishu
1760-1835
Surgeon

The main ingredient of Tongsensan
is a plant poison?

Tongsensan was made from a combination of several plants, including the mandarage plant.
Mandarage is actually a poisonous plant that causes numbness in the human body. By using this poison, it was possible to perform surgeries without the sensation of pain.

Mandarage flower Image courtesy of Seishu no Sato Foundation

What did he do with Tongsensan?

In 1804, Seishu performed the world's first general anesthesia using tongsensan, and successfully operated on a 60-year-old woman for breast cancer.
Outside of Japan, a general anesthesia surgery using ether was successfully performed in the United States in 1846.
Seishu's success is unprecedented and remarkable, since the general anesthesia surgery was performed more than 40 years before the American operation.

Why did you choose breast cancer surgery first?

Breast cancer is a disease that mainly affects women, and is a swelling called a tumor that forms in the breast.
In the past, it was said to be a disease that, once contracted, could not be cured, and even Seishu lost his younger sister to breast cancer. Therefore, Seishu had a strong desire to have a successful operation for breast cancer.

Scene of anesthesia experiment Image courtesy of a private collection

What kind of work did you do?

Nowadays, hospitals are divided into departments, such as internal medicine for colds and otolaryngology for ear diseases, but in the past there was no such distinction. In the olden days, however, there was no such distinction, and Seishu examined, treated, and operated on all kinds of illnesses and injuries.
Seishu developed many medical and surgical tools. He also performed a variety of surgeries using an anesthetic, Tongsien ( Tongxianzang), and it is said that he performed more than 100 different surgeries.
Seishu was a genius doctor who saved many people from suffering from illness and injury.

Was Seishu a cheapskate who never taught anything except to his students? Seishu never taught anyone but his disciples how to make tongsensan or how to administer anesthesia. This was not because Seishu was stingy.
Using anesthesia requires a high level of skill and knowledge. For this reason, Seishu taught anesthesia only to his students who had learned it properly, so as not to endanger his patients.