Should I replace my textured implants with smooth, round implants? If so, should they again be sub muscular? (photos)

 I recommend an in-office examination as well as a detailed discussion with a surgeon who you are comfortable with.   Finally, make sure your surgeon is a Double-Board Certified Plastic Surgeon certified by the American Board of Plastic Surgery (ABPS), a member of the American Society of Plastic Surgery (ASPS), a member of the American Society of Aesthetic Plastic Surgery (ASAPS), and a fellow of the American College of Surgeons (FACS).Best,Dr. DesaiBeverly Hills Institute for Aesthetic Plastic SurgeryHarvard Educated, Beverly Hills & Miami Beach TrainedDouble Board-Certified, Double Fellowship-Trained Beverly Hills Plastic Surgeon

I appreciate your concern and agree that the textured Sientra implants should be replaced with round, smooth Sientra implants. This will avoid the possibility of BIA/ALCL from developing due to the textured surface. And yes, the submuscular space is the ideal "pocket" for you.
Your photos show that you have ptosis with "bottoming out" of the prostheses. Ideally, a mastopexy small reduction can be done at the same time to give you the ideal shape and safer implants. Ask you plastic surgeon about this place. Good luck!

That is an excellent question and I can understand your concern. The FDA has updated their website with more information on BIA-ALCL since the first time the data was reported, and while this T cell lymphoma has been found way more often associated with textured implants, there were still cases reported following smooth implants. (Per the FDA website, based on info as of Sept 2017, of 414 reported cases of BIA-ALCL, 272 of these specified the surface of the implant, and 242 of these were textured. This means there were still 30 of those 272 cases that had smooth implants.) There is no current recommendation to change out textured implants for smooth ones, and if this was your only concern then you don't necessarily need to change them out, unless for you personally you would not be able to get peace of mind without doing so. In looking at your photos, it appears you have bottoming out of your implants, with displacement of your inframammary fold. In this case you would benefit from a full breast lift, with reconstruction of your inframammary fold back at it's higher position, and if you are going in for that procedure, you can use that as a time to change to smooth round implants. I would recommend leaving the implants behind the muscle. I would suggest seeing a board certified plastic surgeon in consultation, one who is experienced with breast implant revisions, since a full history and exam is the only way to get true advice or recommendations.