Mentor™ CPX ™ 4 PLUS Enhance Breast Tissue Expander

The Mentor CPX 4 PLUS Enhance Breast Tissue Expander is a temporary subcutaneous or submuscular implant used for breast reconstruction following mastectomy, correction of underdeveloped breasts, scar revision, and tissue defect procedures. The device consists of a silicone elastomer shell with an integral injection dome and self-sealing technology (BUFFERZONE), designed to be filled incrementally with saline solution over up to six months of use.

The device features a smooth silicone elastomer shell with superior and anterior reinforcement for directional expansion in the lower pole, an integral magnetically-detected injection dome with a rare-earth permanent magnet, and BUFFERZONE self-sealing gel technology to prevent leakage from accidental needle puncture. It is provided sterile and deflated with fill volume options from 850 cc to 1445 cc, identical in all materials and patient-contact components to the predicate device.

ASTM F1441-03 Standard Specification for Soft-Tissue Expanders was used for mechanical testing including overexpansion and bladder leak testing. ISO 10993-1:2018 was referenced for biocompatibility contact categorization as an implant with tissue contact for greater than 30 days.

Substantial equivalence is established because the proposed device has identical materials, design features, and specifications to the predicate K241918, with no changes to components, mechanical properties, or biocompatibility. The only modification is expanding the lower fill volume limit from 930 cc to 850 cc to align with predicate K152496; since mechanical testing previously demonstrated the device meets performance criteria at the worst-case volume of 1445 cc, reducing the lower limit does not require additional testing and does not affect safety or effectiveness.