Incidence of postoperative sternomediastinitis depends on various risk factors and makes up 8%. Surgical debridement with local management of the wound are used to achieve wound sterility. In some cases, sternectomy or subtotal sternal resection are performed for total sternal osteomyelitis with osteoporotic bone and multiple fractures. This procedure results an extensive bone defect. The final stage is anterior chest wall reconstruction. The most popular method is wound closure with autologous muscle or omental flaps. The authors describe a patient with sternomediastinitis who underwent staged treatment. At the final stage, subtotal sternectomy with simultaneous omentoplasty were performed. Additionally, mammary-gastroepiploic bypass grafting with right internal mammary artery and right gastroepiploic artery was carried out for additional vascularization of the omental flap. We found no similar surgery for sternomediastinitis in the literature. Long-term treatment outcome was followed-up (>50 months of relapse-free period and good quality of life).