I also had problems with the healing of my surgical wound because of radiation. I had my anus removed, and nothing - no wound management technique would get it to heal. Finally, I was referred to one of the best colorectal surgeons in the country, and one of the first things he said to me was that I might be a candidate for Hyperbaric Oxygen Therapy. I had never heard of it, and none of the 7 other doctors I had consulted mentioned it. Long story short, after 6 weeks of daily HBOT treatments, my wound had begun to show signs of healing for the first time in 2 years. It did take another 5 months to finally close, but I remain convinced that it never would have if I hadn't gone for HBOT.
I was also offered a flap surgery much like yours, although mine would have used the gracilis muscle in my thigh. I decided that I would pursue every option that was less invasive first, and I'm so glad I did! Because of the HBOT, my wound healed without surgery.
SBS, please click on my name (Padfoot) on the left side of this post. That will take you to my profile, and the forum topics I have initiated. One of them is about HBOT. Please read it, and then find out more about it - there is lots on the internet about it, on reputable sites like the Mayo Clinic. I hate to sound cynical, but sometimes surgeons only think in terms of surgery as a solution. You owe it to yourself to at least know about, and consider all the options. This may or may not be an option for you, but how will you know if you don't know about it? I had pretty much given up hope that my wound would ever heal, and HBOT was a Hail Mary. But it worked.🙂
Feel free to send me a private message if you want.