Downsizing from 450cc gel high profile to 330/360cc gel moderate profile: will it require additional work to fit properly?

Your surgeon can tighten the lateral pocket so that the implant does not move too much to the side, especially when you lay down.

More often than not, when breast revision surgery is performed, the lateral pocket will need sutures to tighten the fit. If this is not done, the implant will have a tendency to fall off laterally (to the side), especially when lying down. Also one other note: by downsizing you will lose some of the upper pole as well. There are ways to prevent losing too much of the upper pole, i.e. using a more cohesive gel implant.
I would recommend you see a board certified plastic surgeon to further discuss your breast revision options.

Dear mdubs12,
breast revision surgery is the most difficult plastic surgery procedure performed. Botched breast surgery alters normal tissue planes and laxity, the ability of breasts to heal properly, and leaves scar tissue that dramatically affects the level of difficulty of the corrective surgery.Many patients come in to correct poor outcomes from their initial surgeries. The most common problems are due to implant malposition, bottoming out of the implant, poor scarring, and incorrect implant size.While the type of revision required will depend on the result of the previous surgery and the desired result of the patient, some revisions involve extensive pocket repair that may or may not need specialized external bras.If you are considering breast surgery revision, you should speak with a board certified plastic surgeon and have yourself properly assessed. Only after a thorough examination you will get more information and recommendations. Also, you have to make sure that your surgeon understands your breast augmentation goals.
Daniel Barrett, MD
Certified, American Board of Plastic Surgery
Member, American Society of Plastic Surgery
Member, American Society of Aesthetic Plastic Surgery