Besides the quicker recovery, there is thought that general anesthesia can contribute to/accelerate Alzheimer's as well as
cancer spread.
For some reason, US tends to use general for mastectomy whereas Europe is open to spinals. My mom had general for a parathyroid surgery about a year before "known" recurrence.
Anyway..sure sounds like it worked out. Might give your mom greater peace knowing there may be multiple benefits.