My mom wants to have a gastric sleeve done next year. she's 275 lbs.how safe is this surgery?is this major surgery? could she die from it?

Major but safe: Laparoscopic sleeve gastrectomy (lsg) is one of the bariatric surgery options. It is major surgery, less effective but safer than the more popular roux-en-y gastric bypass. The benefits of the lsg is that the incidence of late side-effects, such as vitamin and mineral deficiencies is reduced, as is the risk of "dumping syndrome". I would discuss the options with your bariatric surgeon.