Am sure your surgeon would have had a look at the situation inside and decided against the drainage
, if he felt that there wasn't much space left behind and not too many raw surfaces left behind.
I'm sure he must have given you a pressure garments or a tight vest. You haven't mentioned if you had the implants replaced or was it only a removal. Just keep an eye out for any abnormal swelling which might appear indicating a collection and get in touch with your surgeon if such a thing happens.
But am sure he made sure everything was alright and that's why opted not to put in a drain.
Wishing you a speedy recovery.