**Abstract**

In prosthesis-based breast reconstruction, surgeons select the sub-muscle layer for implant placement, but the pectoralis major muscle is not sufficient to cover the implant. The pectoralis major muscle does not reach the inframammary sulcus line, so the muscle pockets for implant inevitably have defects. From 2016 to 2019, we performed direct-to-implant (DTI) breast reconstruction for 123 patients, during which the implant was placed partially under the muscle plane and the inferior-lateral portion was placed directly underneath the skin flap. We divided the pectoralis major muscle and serratus anterior muscle in their origin partially and arranged their shape and position. To maintain their intended placement, we used the absorbable mesh sling. From 2020, we had arranged this method and performed DTI in 35 patients using absorbable strings simply as a substitute for mesh. The DTI reconstruction using mesh or using absorbable strings could show the acceptable safety and feasibility. Both techniques were associated with a low risk of surgical complications, reoperation (with mesh 4.1%, and without mesh 0%), and removal of implant (with mesh 2.4%, and without mesh 0%).

**Keywords:** direct-to-implant, breast reconstruction, early surgical complication, absorbable mesh sling, anchoring by absorbable strings

## **1. Introduction**

In Japan, allograft skin is not covered by public health insurance and cannot be used for breast reconstruction in practice. In such a situation, we have pursued the optimal methodology of direct-to-implant (DTI) breast reconstruction with various ideas [1, 2]. Since 2019, we have started a new method and have obtained good outcomes, so I would like to report it here.
