If you do not want to be stripped while you are under general anesthesia, then you should get undressed before they bring you to the OR.
Seriously, if the surgery is being performed laparoscopically, then it is absolutely vital that your cervix be accessible during the surgery. When your abdomen is inflated, your anterior abdominal wall will be raised above your viscera (intestines and other guts). But somewhere under those guts will be your uterus and tubes. The entire tube must be visualized before a segment is selected for cauterization (or application of clip or Fallope ring, or whatever method has been selected). In order to elevate the uterus and tubes above the viscera, a device will have been inserted into your cervix after you are asleep. This instrument is commonly called a HUMI (for Harris-Kroner Uterine Manipulator/Injector) but there are other brands as well. Whatever device is used, elevation and manipulation of the uterus is important in order to properly identify the tube.
The round ligament arises from the uterus immediately adjacent to the fallopian tube, and is roughly the same size as the tube. The HUMI is used to elevate the uterus into the space between the viscera and the abdominal wall so the surgeon can visualize the fimbriae. Following the tube all the way to the fimbria is important to verify that the surgeon is cauterizing the correct structure.
Can I keep my panties on during a tubal ligation surgery? I do not want to be stripped while I’m under meds and asleep.