Breast implant associated ALCL or anaplastic large cell lymphoma, is a very rare lymphoma that can occur around any type of implant, not just breast implants.  It is true that that the incidence ALCL is higher with textured implants, but that incidence is still very low.  In addition, the incidence is even lower with the less aggressive textures like Sientra implants.  In fact, Sientra, and Silamed, the international manufacturer of the same implant, have had only a couple of cases of ALCL worldwide as compared to other implant manufacturers who have a more aggressive texture surface.  Patients with smooth walled implants are not immune to developing ALCL either although smooth walled breast implants have the lowest incidence of breast implant associated ALCL or BIALCL.
If you have Sientra breast implants in place, you should simply be vigilant for any problems with your breasts.  ALCL usually occurs 7 to 12 years after the implants were placed and the presentation is normally one side becomes very swollen.  Treatment is very successful if the diagnosis is made correctly.
Sientra recently increased their warranty to 20 years and provides financial support if you have a problem.  With most manufacturers you have to pay to get something similar in terms of a warranty and they only go for 10 years, so Sientra’s warranty amounts to a free 20-year insurance policy for any problems with your breast implants.
In short, Sientra makes the best breast implant on the market today.  Even though they are textured, they are still very safe.  Your chances of having other life-threatening problems in the future are significantly higher than your chance of developing ALCL.