If someone is very frail, would they be able to withstand a liver transplant surgery? what are some of the signs that someone is too frail?

Risk for anesthesia: The usual reasons for the "frail" description would be advanced age, serious heart or lung disease (which increases the risk for anesthesia given during surgery), chronic disease e.g. diabetes, rheumatoid arthritis requiring steroid drugs, cancer, etc, and malnutrition. The surgeon will be the one to assess overall risk. Liver transplant is about the most serious surgery one could have.