I need help with this procedure. Doctor recently started doing these. So I need help with the coding.

Per notes:
1. Revision of scar
2. Drainage of left anterior chest wall seroma
3. Drainage of left axillary seroma
4. Left axillary lymphadenectomy
5. Layered closure of 23 cm left chest wall incision

post diagnosis:

1. Left breast cancer status post left mastectomy and sentinel lymph node biopsies with identified lymphatic metastasis.
2. Anterior left wall seroma
3. Left axillary seroma

I would really appreciate any advice on how to do these.