The Best Under Stress: An Analysis of Breast Tissue Expander Response to External Forces.

Background: The use of breast tissue expanders (TEs) in breast reconstruction is accompanied by undesired changes to the chest wall and lateral plane. Breast TEs are designed to create a naturally formed breast pocket by capitalizing on the ductile response of skin tissue; however, in practice, the use of expanders is accompanied by undesired changes to the chest wall and lateral plane.

Objectives: The authors of this study compared 3 comparably sized and commercially available breast TEs to assess the mechanical profile and functionality of each design.

Methods: Authors compared MENTOR Artoura PLUS Smooth (Irvine, CA), Allergan 133 Smooth (Irvine, CA), and Sientra AlloX2 Smooth (Santa Barbara, CA) filled to 100% of their label volume. The mechanical profile of TEs was assessed via vertical compression. Dimensions were recorded at baseline and percent changes were calculated at each compressive load (5-35 lbf intervals of 5 lbf).

Results: Base width and projection were recorded at compressive loads of 10, 20, and 35 lbs. For percent changes of base width, MENTOR had 0.98%, 2.09%, 3.84%; Allergan 4.21%, 9.15%, 15.52%; and Sientra 4.72%, 10.19%, 19.15%. For percent changes of projection, MENTOR had -19.06%, -25.44%, -30.88%, Allergan -35.53%, -42.90%, -50.09%, and Sientra -29.64%, -37.68%, -44.69%. For percent change of height, MENTOR had 1.44%, 2.62%, 4.27%, Allergan 10.26%, 16.49%, 22.97%, and Sientra 6.99%, 11.93%, 16.90%. MENTOR's TE had the most pronounced lower pole with volume expansion.

Conclusions: The MENTOR TE demonstrated the least lateral deformation and projection loss across the range of compressive loads, as well as the highest force resistance compared with the other models.