Development of Mafutsusan by Seishu Hanaoka and General Anesthetics in the Very Early Part of the 19th Century in Japan.

Seishu Hanaoka's medicine is famed for its breast cancer surgery. Hanaoka, who,was motivated by Dokushoan Nagatomi's Man-yu zakki, published in 1771, had the idea to excise a breast cancer tumor and not to perform a breast amputation. Because he recognized that general anesthesia was indispensable for performing a surgical operation of the breast, he developed a general anesthetic and surmounted various difficulties: selection of an anesthetic method, anesthetic ingredients, determination of the opti- mal dosage, administration methods, indications and contra-indications, evaluation of the depth of anesthesia, facilitation of the smooth emergence from anesthesia, and postoperative care. I reviewed previous articles on these subjects and, using several unpublished manuscripts, provided new information on disseminated general anesthetics in Japan during the decade after the first general anesthesia for Kan Aiya in 1804.