Optimizing Outcomes in Hemipelvectomy Reconstruction with the Free Fillet of Leg Flap

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.

METHOD

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.

RESULT

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.