a medical operation, or series of operations, by which someone's body is changed to match their gender

In 1946, Gillies carried out the first female-to-male sex reassignment surgery. 1946年，吉利斯进行了第一个从女性到男性的变性手术。

The male chromosomes do not change with either hormonal treatment or sex reassignment surgery 男性染色体不会因为荷尔蒙治疗或变性手术而改变。