Fibular osteocutaneous free flap

Reconstruction of this defect should focus on restoration of the maxillary alveolus with the bony portion of the flap, and sealing the palate with the soft tissue portion of the flap. If the defect involves external cheek skin, a portion of the soft tissue flap can be depithealized and the distal portion fashioned to restore this area as well. This flap can be adapted to restore any length of the horizontal component of the defect.

It is critical that the surgeon pays strict attention to the vascular pedicle geometry as it passes through the tunnel into the neck.

For this procedure the Weber Ferguson approach to the midface is utilized.

The proposed osteotomy lines are marked on the maxilla (eg. with a Bovie cautery). Care is taken to resect at least 1 cm of normal tissue on each side of the tumor.

An incision is made in the palate to maintain a 1 cm margin around the tumor. This can be done with a surgical blade or a needle tip cautery.

Teeth on either side of the tumor may be removed for easier access, but is usually not necessary.

Utilizing either sagittal or reciprocating saws, an osteotomy is made in the anterior maxillary wall.

A second osteotomy is made along the palate around the tumor. Osteotomes can be used to complete the bony cuts and the segment is mobilized.

If the resection extends to the maxillary tuberosity, a fine curved osteotome is used with the curvature pointing downwards to complete the cut, and to separate the posterior maxilla from the pterygoid plate.

Pitfall: An upward oriented osteotome will not reliably separate the posterior maxilla and palate from the pterygoid. It is also associated with increased danger of bleeding from the pterygoid plexus and internal maxillary artery.

The remaining soft tissues are incised with electrocautery and the tumor is delivered.

The nasal mucosa can either be preserved or excised depending on the involvement of the tumor.

The specimen is submitted en bloc for permanent pathological examination.

Surgical margins are now checked with frozen sections to ensure the adequacy of the tumor resection.

The fibula osteocutaneous flap is harvested in the standard fashion with the following considerations:

• The maximal length of fibula should be harvested so as to obtain the longest vascular pedicle possible.
• Skin portion of the flap should be positioned more distally on the bone to optimize its position for reconstruction of the palate.

The length of pedicle necessary to reach the neck vessels should be measured. The periosteum of the proximal portion of the fibula should be elevated off the bone to match the necessary pedicle length.

The fibula is cut with a reciprocating saw at this point and the excess proximal bone is discarded.

Wedge shape osteotomies must be made in the fibula to create the proper curvature and 3-dimentional contour of the alveolus and lower maxilla. A template can be created by the surgeon to accurately position the osteotomies to create the appropriate alveolar contour.

The bone should extend posteriorly only long enough for ultimate positioning of dental implants. The fibula segments should have a minimum length of 3 cm to maintain bone viability. The fibular segments are joined by 1.5 mm plates. The edges of the bones can be further contoured with a burr to maximize bone contact.

The vascular pedicle should be on the palatal side, while the plates should be fixed on the buccal side of the fibular bone.

The vascular pedicle is positioned to pass through a tunnel in the pterygoid region to anastomose to the recipient vessels in the neck. The use of a silicone tube could be helpful in order to protect and avoid pedicle rotation during the passing.

The fibula construct is fixated with 1.5 mm craniofacial plates to the remaining maxilla in at least two points:

• The alveolus
• The zygoma

The soft tissue component of the flap is rotated into its preplanned position to restore the palate with care not to create undue torsion or tension within the perforators.

The fibula soft tissue is sutured to the sublabial mucosa (laterally) and cut edge of the palate (medially) with resorbable suture to create a water tight seal, before or after the microvascular anastomosis has been completed.

The detailed procedure for the revascularization is outside the scope of this surgery reference. However, in short the procedure consists of the following steps:

• A neck incision is made and the appropriate recipient vessels are selected in the neck and dissected so as to be available for anastomosis
• Creation of a tunnel from the ptyerigoid region to the neck incision lateral to the mandible of adequate size for the passing of the vascular pedicle
• A coronoidectomy may be helpful to widen the tunnel adequately
• The recipient and the donor vessels adventitia are cleaned under a microscope
• Appropriate vessel geometry is assured and the vessels are placed into a microvascular clamp and anastomosis carried out eg. using 9-0 nylon sutures
• Vascularization is restored after both arterial and venous anastomoses are completed
• For adequate vessel length to create the anastomoses (without tension), vein grafts are sometimes necessary

The use of the following perioperative medication is controversial. There is little evidence to make strong recommendations for postoperative medications.

• Analgesia as necessary
• Antibiotics (many surgeons use perioperative antibiotics). There is no clear advantage of any one antibiotic but evidence supports their use for 24h. The spectrum should be according to the existing bacterial flora, especially in the combined intra and extra cranial procedures.
• Steroids may help with postoperative edema.
• Regular perioral and oral wound care has to include disinfectant mouth rinse, lip care, etc.
• Antibiotic ointment is used on the wounds for 72 hours
• If a free flap is utilized for the reconstruction, 100 mg of aspirin/day is recommended.

Remove sutures from skin after approximately 7 days if nonresorbable sutures have been used. If the patient has had previous radiation, the sutures should be left in for 10 – 14 days.
Moisturizing lotion should be used on the skin wounds to minimize excessive scarring after sutures are removed.

Avoid sun exposure and tanning to skin incisions for several months.

Diet depends on the reconstructive method. For patients who have obturators placed, initial liquid diet followed by a soft diet as tolerated is initiated after surgery.

For patients with free flap reconstruction of the maxilla, a feeding tube is placed during sugery allowing the patient to be kept nil per os for 5-7 days. If issues develop with velopharyngeal insufficiency or dysphagia, assessment by a speech and swallowing rehabilitation specialist may be indicated. When the lateral nasal wall is reconstructed, especially when a bulky soft tissue flap is used, the nasal airway should be stented with gauze packing or a merocel sponge for five days.

Typically the patients are seen in clinical follow-up one week after discharge, and then on a weekly basis until such time the clinician determines that less frequent follow ups are needed.

Patients with intraoral incisions and/or wounds must be instructed in appropriate oral hygiene procedures. A soft toothbrush (dipped in warm water to make it softer) should be used to clean the surfaces of the teeth. Chlorhexidine oral rinses should be prescribed and used at least 3 times a day to help sanitize the mouth. For larger debris, a 1:1 mixture of hydrogen peroxide/chlorhexidine can be used. The bubbling action of the hydrogen peroxide helps remove debris.

For individuals reconstructed with a maxillary prosthesis, the surgical packing is left for seven to ten days postoperatively. The patient will need to remain on appropriate gram positive antibiotic coverage over that time.

Upon returning to clinic, the patient is seen by the maxillofacial prosthodontist and the obturator and the packing are removed, the cavity is cleaned and inspected and the patient is then started on frequent nasal saline irrigations and home humidification. The obturator is modified as needed and replaced.

Over time, the maxillary prosthesis can be altered to best fit the evolving defect.

When a free flap is utilized, it should be regularly monitored to ensure vascular integrity. Physical examination, assessing the flap color, turgidity, and capillary refill should be routine for at least the first 48 hours postoperatively. Hand-held Doppler probes can be used to assess blood flow. In case of doubt of the vitality of the flap, pin-prick assessment with a 25 gauge needle to look for bright red bleeding.. In cases of buried flaps, an implantable Doppler placed just distal to the venous anastomosis can be utilized

Radial forearm free flap
The radial forearm free flap donor site should be closed with a skin graft and a bolster placed over the area. The arm is then cast or placed in a volar splint for 7 days prior to removal to ensure graft take. If bone is taken and the radius plated, appropriate follow-up with an orthopedic or hand specialist should be arranged.

Fibula free flap
After a fibula free flap, the donor lower leg should be cast with the ankle slightly dorsiflexed for 5 days. The patient can touch-down their body weight as tolerated. After the cast is removed they can ambulate and work with physical therapy to optimize leg function. A splint should be placed to keep the foot flexed when in bed.

Scapula free flap
Flaps from the subscapular system require no particular rehabilitation care but closed suction drains should remain until a minimal output is still draining to avoid seroma formation.

Rectus abdominous and iliac crest
Rectus abdominous and iliac crest donor sites require that the patient not strain or lift heavy objects for at least 4 weeks to avoid hernia formation.

Anterolateral thigh
Patients should avoid climbing stairs for 2-4 weeks after surgery. They should also be observed for seroma formation at the wound bed.

Furthermore, patients often need physical therapy to rehabilitate the donor site.