[Seishu Hanaoka Did Not Describe His Anesthetic as Tsusensan--A Misunderstanding of the Terms Mafutsusan and Tsusensan].

It is widespread even among medical professionals as well as medical historians that the formal term of the general anesthetic that Hanaoka developed is Tsusensan and its alias name is Mafutsusan. Hanaoka himself, however, described it as Mafutsusan in his Nyugan Chikenroku, the case report of the first breast cancer excision under general anesthesia with the anesthetic, and a large number of his disciples all used the term Mafutsusan to denote the anesthetic in their manuscripts. The description of Tsusensan has not been found in the documents written in the Edo period, and this name is detected only in the epitaph of Hanaoka. Consequently, we should refer to Hanaoka's anesththetic as "Mafutsusan, another name Tsusensan" instead of "Tsusensan, another name Mafutsusan."