**5.1 Acellular dermal matrices and synthetic mesh**

The invention of acellular dermal matrices (ADMs) and synthetic mesh provided surgeons the tools to adapt the breast pocket and optimise it for implant use. First introduced for breast reconstruction in 2005 [42], these surgical adjuncts have been widely adopted to improve implant position regardless of plane and offer additional support (**Figure 1**).

#### **Figure 1.**

*Implant reconstruction following a skin sparing mastectomy. Robust mastectomy flaps envelope an implant with synthetic mesh support. The implant is inserted into the pre-pectoral plane and a tension free closure is achieved to primarily close the breast pocket.*

#### *Immediate Breast Reconstruction with Implants DOI: http://dx.doi.org/10.5772/intechopen.114061*

ADMs are extracellular matrix structures which can be of either human, bovine or porcine origin. Processing removes cellular antigens which can elicit an immune response while preserving the structural matrix that encourages angiogenesis and tissue regeneration [43]. This lack of immunologic response allows for integration of the matrix to native tissue without encapsulation or contracture. ADMs are available as flat sheets of material that can be fashioned as required and many different applications of ADM have been described.

For submuscular implants, ADMs can artificially elongate the pectoralis muscle to cover the inferolateral pole of the implant which would be otherwise exposed in a dualplane reconstruction negating the need to raise surrounding muscle for implant coverage [44]. Its use for pre pectoral implant placement has revolutionised this plane as a viable option for reconstruction. ADM can be formed as an internal bra surrounding the implant and securing it to the chest wall [45]. This can occur as anterior coverage only with the pectoralis major muscle in contact with the posterior surface of the implant. This technique masks upper pole implant visibility however it is technically more challenging to fashion the pocket without risking implant herniation or rotation. Complete coverage of the pre-pectoral implant requires a large volume of product to be secured together and aids in implant position. This provides an additional layer of tissue coverage and the additional support can relieve pressure on the mastectomy flaps. For both submuscular and prepectoral implants the use of ADM also helps to define and secure the inframammary fold while optimising implant position and lower pole projection [46].

Various synthetic meshes are also available on the market, providing an alternative to ADM. These meshes are incorporated through fibroblastic and foreign body reactions. They can be available as a preformed pocket thereby reducing surgical time when insetting and avoids over-handling of the product (**Figure 2**) [47]. ADMs have a significant economic burden and can be a deterrent to use while the relative cost-effectiveness of synthetic meshes makes it an appealing alternative option [48]. Meshes are also associated with less frequent infections and seroma formation in comparison with ADMs [49]. It is important to understand that though offering similar support, synthetic meshes do not provide additional soft tissue coverage, which ADMs can provide, and caution should be exercised with thin mastectomy skin flaps.

#### **Figure 2.**

*The breast implant is placed within a synthetic mesh pocket. The mesh is sutured together to completely encompass the implant and to create fixation tabs from the excess material to enable optimal placement within the breast pocket.*
