Fibula Free Flaps

A team consisting of the following personnel is required:

• Anesthesiology team
• Primary Surgeon (plastic surgeon, orthopedic surgeon, head and neck surgery, or oral surgeon )
• Surgical assistants
• Radiographic technician
• Circulating nurse
• Surgical technician

Recipient site evaluation includes identification of appropriate vessels to perfuse the flap, determining appropriate patient positioning, choosing the method of bone fixation. All types of implants should be available (e.g., plates, screws, K-wires, external fixators, and intramedullary nails).

Preoperatively, donor site skin, muscle bulk, and vascular status are evaluated. Strong and independent pulses should be present at both the dorsalis pedis and the posterior tibial artery. Any uncertainty about their status should be further investigated with Doppler ultrasonography. In certain cases, CT (computed tomography) angiography or MR (magnetic resonance) angiography may be required to assess the vascular status. Documentation of a preoperative neurological assessment is necessary because transient postoperative nerve palsy can occur. 

For tibial reconstruction, the contralateral fibula is preferred, while the ipsilateral fibula is generally used for femoral reconstruction. Upper limb recipient sites may use either fibula, and the choice of the fibula for head and neck reconstruction will depend on the status of neck vessels, as well as whether the mandible or maxilla is being reconstructed, and whether the skin flap will replace oral mucosa or facial skin.

After informed consent, prophylactic antibiotics are administered, and general anesthesia is induced. An Esmarch bandage is used to exsanguinate the leg, and a tourniquet is applied to either 150 mmHg above systolic blood pressure or 350 mmHg. All pressure points should be padded carefully because of the long duration of the case. Ideally, two teams work simultaneously to decrease operative time, one at the recipient site and the other at the harvest site.[18] Particular attention should be paid to patient positioning to ensure both teams can work efficiently and that the microscope has enough room to be brought close to the field for microvascular anastomosis.

Recipient site surgery: Recipient site surgical dissection depends upon the diagnosis. For example, the extent of bone resection required in cases of pseudarthrosis or the amount of debridement and curettage for chronic osteomyelitis. Resection and reconstruction can be performed as a single procedure or can be done in 2 stages as in osteomyelitis (eradication of infection followed by free fibula transfer) or oncologic resection (ablation of tumor and lymph node dissection followed by fibula transfer after negative margins have been confirmed). It is critical to select and isolate appropriate recipient vessels for vascular anastomosis and to communicate the size of the defect to the fibular harvest team to ensure a graft of adequate length.[19]

Donor site surgery: The lateral surgical approach is the most commonly used, with a longitudinal incision made along the lateral lower leg. The central portion of the fibula is harvest for most indications, as the distal 5 cm is important for ankle joint stability. The proximal 5 cm of bone is also left in place in order to protect the peroneal nerve. Bony cuts are made proximally and distally. Some surgeons consistently harvest the entire fibula between the proximal and distal 5 cm, planning to shorten the bone as necessary after harvest; some harvest only what length is needed to reconstruct the defect. Care is taken to avoid injury of the peroneal artery and its accompanying 2 venae comitantes. If a longer vascular pedicle is required, the use of the distal fibula will provide up to 15 cm in length. In some cases, a graft 2 to 3 cm longer than the bony defect may be required, as overlapping the graft on the osteotomy site may be necessary for fixation.[20]

Fixation of graft: Fixation may be accomplished with a plethora of different techniques, depending on the type of reconstruction. Intramedullary nails, compression plates, and the Ilizarov fixator are all options. Hardware should not be changed once vascular anastomosis is complete, and care should be taken when placing the screws as they can compromise the blood supply to the graft.

Anesthesia-related Complications[21]

• Nausea and vomiting
• Dental injuries during intubation
• Sore throat
• Anaphylaxis to anesthetic agents
• Myocardial infarction
• Respiratory depression
• Aspiration pneumonia
• Hypothermia
  

Intraoperative Complications[22]

• Bleeding
• Length discrepancy of graft
• Iatrogenic graft fracture
• Improper fixation
• Damage to the neurovascular bundle

Postoperative Complications

• Graft fracture (most common complication)
• Surgical site infection (2nd most common complication)[17]
• Great toe contracture (flexor hallucis longus lengthening usually corrects the contracture)
• Peroneal nerve injury[23]
• Hardware failures or extrusion
• Gait disturbance due to pain[24]
• Nonunion/malunion
• Growth abnormality due to physis injury[18]
• Wound dehiscence
• Amputations[25]
• Leg length discrepancies
• Valgus malalignment of the donor limb
• Equinus deformity of the ankle [26]
• Nerve injury with sensory loss or motor deficit
• Chronic ankle pain
• Expanding hematoma
• Thrombosis of the anastomosed vessels and partial or complete flap failure

Autogenous vascularized fibular grafting plays a vital role in the reconstruction of long bone defects, infected nonunions, and following tumor resection in adults and children. Vascularized fibular grafts not only provide osteoinductive and mechanical support but also have the ability to remodel and hypertrophy to withstand loading, making fibular grafting different from other types of bony reconstruction. A successful outcome depends not only on surgeon experience but also on appropriate patient selection and preoperative expectation management.

Patients are usually initially followed by a team of intensivists, surgeons, physical therapists, and speech/swallowing therapists in head and neck cancer reconstruction. Intraoperatively, an interprofessional group consisting of orthopedic/plastic/head and neck/oral surgeons, radiology technicians, surgical technologists, an anesthesiologist, and nursing staff must perform these complicated operations. When two surgical teams can operate simultaneously, the workload is divided operative time is decreased, which lowers the risk of perioperative cardiopulmonary complications.[27]

Patients should be optimized medially before surgery, and the vascularity of the lower extremity should be evaluated with angiography or ultrasound. Careful preoperative evaluation of the patient will establish candidacy for microvascular fibular free tissue transfer and ensure the patient and surgeon share realistic expectations.

Attentive nursing care is critical in the immediate postoperative period to monitor for flap complications. Physical therapists will help to mobilize the patient early, which can prevent such perioperative complications as deep vein thrombosis and pulmonary embolism. In cases of mandibular or maxillary reconstruction, speech and swallowing therapists and nutritionists are critical to helping maintain the patient's caloric intake.

Monitoring the flap for signs of failure is critical in the first two weeks of healing, but even more so during the first 72 hours, during which the anastomosed vessels are re-epithelializing. Signs of flap failure include a dusky or pale color, a cool temperature (unless the flap is intraoral), the rigidity of the soft tissue due to edema, either very rapid or absent capillary refill of the skin paddle, either very rapid return of dark blood or no return of blood at all when pricked with a lancet, and absent Doppler signals. Often, loss of the Doppler signal is the last sign of a flap failure, because venous congestion accounts for 80% to 90% of flap failures, and the arterial signal may not disappear until very late in the process. In the case of vascular failure, rapid return to the operating room for revision of the anastomoses is critical.[28]