GAVE's Syndrome

My mother is a 74 year old with a long history of insulin dependent diabetes with some heart and liver disease involvement.  About 18 months ago, she developed uncontrollable GI bleeding within her stomach and has been transfused weekly since then.  She was diagnosed with portal hypertensive gastropathy and underwent a TIPS procedure which did not decrease the stomach bleeding.  She has also been treated numerous times with argon plasma coagulation without success.  The GI doctors have now diagnosed her with GAVE's Syndrome.  She is now requiring about 5 units of blood per week and has had approximately 150 units of blood since she started bleeding 18 months ago.  This past week, she required 7 units of blood.

The GI doctor says there is nothing else they can do and that a surgeon will likely not agree to do a gastrectomy due to her overall poor health related to the diabetes, heart and liver disease.  My question is... Is this true?  Why wouldn't it be better to attempt a gastrectomy and give a person a chance at surviving as opposed to continuing to slowly bleed to death.