(This page is specific to breast surgery, as this is the only case of which I have experience.)
After breast surgery I am sure your wife will be told about breast forms and suppliers of underwear. We used Amoena, whose web site is here.
Depending on the details of the surgery, she may also be warned about lymphoedema (a build up of fluid that, after surgery, does not drain naturally from the arm on the affected side).
To limit this fluid build up, it may be necessary to wear an elastic sleeve. In our case a specialist physiotherapist measured for and supplied this.
Our local hospice also has a complementary therapist, whom Abigail visited from time to time for lymphatic drainage massage. This massage was very effective in reducing the swelling in her arm, as well as feeling nice for the patient.
We realised that it would be much better if she could have this massage daily, so that there was not an excessive build up of fluid. The therapist was happy to teach me to do the massage, which was not very difficult to learn. On subsequent visits she could check my technique, and I could clarify any uncertainties. There are also several web sites that give information on this, including one here.
I massaged Abigail’s arm for 15 minutes or so each evening, which was good for both of us. It was effective in controlling the oedema, and Abigail found the massage a pleasant sensation. I was pleased that I had found something positive that I could contribute to her ‘treatment’, rather than always feeling helpless when it came to ‘medical’ aspects of the situation.
If lymphoedema is relevant to your case I strongly recommend that you find a therapist who will teach you the technique.