The success of microvascular reconstruction depends on many factors. Although many factors cannot be dictated by a surgeon, the success of anastomosis can be maximized by honing skill with performing anastomoses. However, size discrepancy of vessels remains a common challenge, given the lack of an ideal technique. In this study, the authors introduce their experience in using composite deep inferior epigastric arterial and venous grafts to overcome the vessel size and pedicle length discrepancy in lateral thigh and superficial inferior epigastric artery (SIEA) flaps. Of the 1095 flaps performed, the authors identified a total of 12 flaps (one lateral thigh flap and 11 SIEA flaps) on nine patients for breast reconstruction. The authors used deep inferior epigastric vessels to act as interposition grafts between the internal mammary artery and flap pedicle. For the SIEA flaps, the authors anastomosed the SIEA system to the deep inferior epigastric arterial system, checked the viability of the flap, and then transferred the flap to the internal mammary artery and flap pedicle. For the SIEA flaps, the authors anastomosed the SIEA system to the deep inferior epigastric arterial system, checked the viability of the flap, and then transferred the flap to the internal mammary artery system in three patients. In the last five patients, the authors anastomosed the deep inferior epigastric vessels to the internal mammary artery system first, and then transferred the SIEA flap. For the lateral thigh flap, the authors anastomosed grafts to the internal mammary artery system first as well. There were no flap losses or fat necrosis. Although the authors' outcomes are limited to only breast reconstruction, they believe this method could be expanded to different types of reconstruction, especially reconstruction of the head and neck.