Effect of acellular dermal matrix thickness and surface area on direct-to-implant breast reconstruction.

Background: The use of an acellular dermal matrix is advantageous for direct-to-implant breast reconstruction after skin-preserving mastectomy, but is associated with postoperative complications, especially increased seroma. Therefore, this study aimed to determine whether acellular dermal matrix surface area and thickness are associated with an increased risk of seroma. Methods: This retrospective chart review was based on the medical records of patients who underwent submuscular direct-to-implant breast reconstruction from January 2011 to June 2018 by a single surgeon. The acellular dermal matrices were divided into groups according to surface area and thickness (group I, thin and small; group II, thin and large; group III, thick and small; and group IV, thick and large). The drainage volume and period were analyzed between the groups using an analysis of variance. The factors influencing drainage were analyzed using Pearson correlation coefficients. Results: Of the 219 cases of direct-to-implant breast reconstruction (217 patients), 77, 63, 42, and 37 were in groups I, II, III, and IV, respectively. A large acellular dermal matrix resulted in a larger drainage volume, longer drainage period, and more complications. The drainage volume increased as the body mass index (r=0.217; P<0.01), mastectomy volume (r=0.358; P<0.01), and implant volume (r=0.385; P<0.01) increased. There was no difference in drainage volume, drainage period, and complications depending on the thickness and manufacturer of the acellular dermal matrix. Conclusions: In direct-to-implant breast reconstruction, the use of a larger acellular dermal matrix, not a thicker acellular dermal matrix, increases the drainage volume and period, thereby resulting in a greater risk of seroma or infection.