tumor in pulmonary vein

My dad has stage 4 non small squamous cell lung cancer. He went for surgery but they had to pull out because of a tumor in his pulmonary vein too close to his heart to cut. He went through chemo and radiation and they said they shrunk the tumors in this lung but they are not sure about the one is his pulmonary vein. So we go next week for surgery to see if it has infact shrunk. He will be so devistated if they pull out again we all will. I have researched a lot on lung cancer but never able to find out anything with his tumor in his vein so anything that anyone knows would be great. Also he had a very long blood clot in his head goes from his neck up to the top of his head then comes down to above his ear and I really haven't been able to learn much about that either.