Introduction <p>The standard treatment for severe open limb fractures comprises fracture fixation and flap surgery. In complicated injuries, secondary surgeries are required for flap-covered fracture sites. Given the risk of flap necrosis, secondary surgery using a flap-dividing approach is generally avoided. Nonetheless, a more efficient secondary surgery can be undertaken in combination with strategies to prevent flap necrosis. We describe a “trans-flap approach” for secondary surgery and the subsequent treatment course and clinical outcomes of patients who were treated with this novel approach.</p> Methods <p>We retrospectively identified and enrolled patients who underwent flap surgery for severe open limb fractures and subsequently received secondary surgery using the trans-flap approach between 2020 and 2023. Patient demographics and injuries, type of flap used for acute soft tissue reconstruction, indications for secondary surgery, duration from soft tissue reconstruction to secondary surgery, soft tissue healing, and postoperative complications were investigated.</p> Results <p>Among the 15 study participants, the injuries involved the hand in 3 cases, lower leg in 9 cases, and foot in 3 cases. The flaps used for acute soft tissue reconstruction included a pedicled flap in 2 cases and a free flap in 13 cases. In all cases, the wounds healed without necrosis and complications, except for a deep infection in 1 patient.</p> Conclusion <p>Regardless of the type of flap, wound healing was achieved without necrosis in all 15 cases. Trans-flap approach can be an effective option in secondary surgery for severe open limb fractures.</p>