I hope you found some resolution! I’m unsure how surgeons decide to use post surgery drains. I didn’t have drains. The seroma formed from the node removal was worse than radiation. Draining it when the fluid became infected was traumatic. I asked my PCM for a chest CT months later after a lot of discomfort at a secondary tumor site near the chest wall. Viola! A seroma at that site also. I changed surgeons to someone whose wife is a 20yr breast cancer survivor and feel more comfortable with him on my team. The seromas may not completely resolve and they are uncomfortable almost 2yrs out, but not another infection!