PURPOSE: A hemipelvectomy is a high-level pelvic amputation, in which half of the pelvis and ipsilateral lower limb are removed, often due to sarcoma in the proximal thigh/pelvis. Reconstruction after hemipelvectomy in these cases presents many challenges due to a large defect size, multiple critical structures that need coverage, potential hernia space that must be repaired/obliterated, and difficulty with fitting an adequate prosthesis. Commonly, very large caliber vessels are contained within the area of resection to obtain tumor-free margins, leading to size mismatches with recipient vessels during free tissue transfer. The free fillet of leg flap is a powerful tool in the reconstruction of hemipelvectomy defects that would otherwise require sacrifice of the distal leg, particularly when a pedicled fillet option is not available and locoregional flaps do not offer enough tissue bulk. Only a few cases of the free fillet of leg/thigh have been presented in the literature world-wide, with most performed in large cancer centers.
METHODS: This is a case study of a 68-year-old male with a 22.5x9.8x27 cm, biopsy-proven synovial sarcoma of the right proximal thigh, who required reconstruction after oncologic resection involving a hemi-pelvectomy. Metastatic workup was negative and no chemotherapy or radiation was planned. The goals of reconstruction were to repair the post-resection hernia, support the genitourinary organs, eliminate sufficient dead space, and provide enough tissue bulk/projection to allow the patient the ability to sit and to wear a bucket prosthesis. The patient suffered no complications and demonstrated a well-healed hemipelvis at one-month follow-up. At 12-months follow-up the patient is recurrence free and successfully able to wear a strap-on bucket prosthesis.
In this case presentation, we discuss several technical refinements of the free fillet of leg flap, including videos of the dissection steps, practical solutions for limiting ischemia time, a systematic approach for vessel selection and handling size mismatches, tips for collaboration with oncologic surgeons, and potential complications that were avoided.
RESULTS: Following reconstruction with the free fillet of leg flap, the patient suffered no complications and demonstrated a well-healed hemipelvis at one-month follow-up. At 12-months follow-up the patient was recurrence free and able to comfortably sit and able to wear a strap-on bucket leg prosthesis for standing and ambulation.
CONCLUSION: By providing a substantially larger volume of tissue than other free tissue transfer options, the free fillet of leg flap is a “spare parts” flap that offers no increase in donor site morbidity while providing adequate bulk for sitting or wearing a prosthesis after a hemipelvectomy for proximal thigh/pelvic tumors.