possible post surgery complications for being overweight

I have rectal cancer and if the aggressive treatments of chemoradiation and chemotherapy does not shrink the tumor away; I will have to have surgery. Because of the location of the tumor, no matter how small it gets, if it is not gone, I will have to have a colostomy bag. The operation, I’m told is 6-8 hours long with them putting in a permanent stoma and a plastic surgeon reconstructing parts needed. The issue is that I am morbidly obese (BMI 51%) and my surgeon (I asked for honesty) said that I would survive the operation but the complications of wound healing, infection, hernias etc after the surgery are very probable and dangerous at my size. He said the last person he had that was my size died to due complications.
I have a great team working with me, please pray for me that the tumor will go away with the treatments and I will not have to be operated on.
Thank you