Microvascular Free Flap Reconstruction of Thigh Defects After Tumor Resection in the Setting of Radiation.

[BACKGROUND] Soft tissue reconstruction of the thigh defects can usually be achieved with local options. Free tissue transfer may be indicated in very large defects with exposed vital structures and/or a history of radiation therapy where the healing potential of local option is poor. In this study, we evaluated our experience on microsurgical reconstruction of oncological and irradiated thigh defects to assess the risk factors for complications.

[METHODS] Institutional review board-approved retrospective case series study using electronic medical records from 1997 to 2020 was conducted. All patients with irradiated thigh defects derived from oncological resections who underwent microsurgical reconstruction were included. Patient demographics and clinical and surgical characteristics were recorded.

[RESULTS] Twenty free flaps were transferred in 20 patients. Mean age was 60 ± 11.8 years, and median follow-up time was 24.3 months (interquartile range [IQR], 71.4-9.2 months). The most common type of cancer was liposarcoma (n = 5). Neoadjuvant radiation therapy was performed in 60%. Most commonly used free flaps were latissimus dorsi muscle/musculocutaneous flap (n = 7) and anterolateral thigh flap (n = 7) Nine flaps were transferred immediately after resection. Overall, 70% of arterial anastomoses were end-to-end, whereas 30% were end-to-side. Deep femoral artery branches were chosen as the recipient artery in the 45%. Median length of hospital stay was 11 days (IQR, 16.0-8.3 days), and median time to start weight-bearing was 20 days (IQR, 49.0-9.5 days). All were successful except for 1 patient who required additional pedicled flap coverage. The overall major-complication rate was 25% (n = 5, hematoma = 2, venous congestion requiring emergent exploration surgery = 1, wound dehiscence = 1, surgical site infection = 1). Cancer recurred in 3 patients. One required amputation due to cancer recurrence. Age (hazard ratio [HR], 1.14; P = 0.0163), tumor volume (HR, 18.8; P = 0.0006), and resection volume (HR, 2.24; P = 0.0019) were statistically significantly associated with having a major complication.

[CONCLUSIONS] Based on the data, microvascular reconstruction of irradiated post-oncological resection defects shows high flap survival rate and success. Given the large size of flap required, the complex nature and size of these wounds, and history of radiation, wound healing complications are common. Despite this, free flap reconstruction should be considered in irradiated thighs with large defects. Studies with larger cohort and longer follow-up are still required.