Specifically in Santiago?
Dominican Republic Butt Augmentation Doctor Recommendation
Doctor Answers 2
Buttock Augmentation - Brazilian Buttock Lift
Unfortunately I do not know of any surgeons in your area that perform that particular procedure. Located in Miami, I see patients frequently that have a desire for a fuller, rounder, firmer buttocks and this procedure has become a significant part of my practice. It is important to find a physician that performs this procedure frequently and consistently achieves good results. You should seek a highly qualified plastic surgeon who can also demonstrate high quality before and after photos of their cases to help give you an idea of what to expect.
Use Board Certified Dominican Plastic Surgeons
Even though I don't practice in Santiago (I do my practice in Santo Domingo), I can assure that there are several plastic surgeons in Dominican Republic who offer the procedure in a safe and professional environment.
Just make sure you visit board certified plastic surgeons, as there are lots of people practicing plastic surgery without the proper training, and lacking of all the certification need it.
If travelling to Dominican Republic, make sure that the plastic surgeon you are visiting is a member of the Dominican Society of Plastic, Reconstructive and Aesthetic Surgery (Sociedad Dominicana de Cirugía Plástica, Reconstructiva y Estética), which is affiliated with FILACP (Latinamerican Chapter) of IPRAS (The International Confederation of Plastic, Reconstructive and Aesthetic Surgery). That gives you all the guarantees you are seeking to rest assure that you are treating with an actual plastic surgeon.