day surgery; outpatient surgery
A surgical procedure where the patient is admitted and discharged on the same day, without an overnight hospital stay.
I had day surgery for cataracts.
Day surgeries are increasing at this hospital.
外来手術 also means outpatient surgery, but 日帰り手術 emphasizes same-day return home, while 外来手術 can include procedures done in a clinic without hospital admission.
Compound of 日帰り (day trip, same-day return) and 手術 (surgery).