Yes, that's it. Total parenteral nutrition.
My son was also a diving accident. Happened in 1987 when he was 16.
After a year in the hospital, and many medical complications, we took him home and gave him TPN. Then in 1991, he lost his kidneys.
We used peritoneal dialysis, at home. Hooked him up every night for 12 hours.
Unfortunately, we lost him due to doctor error in 1993. He was 22.
You have my sympathies FRiend.
Regards