Iliac crest-internal oblique free flap

Reconstruction of this defect should focus on restoration of the orbital rim and floor, 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, the soft tissue portion can be 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 the neck.

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

An incision is made along the midline of the palate, extending posteriorly and lateral to the maxillary tuberosity. This can be done with a surgical blade or a needle tip cautery.

A sagittal saw is used to make an osteotomy through hard palate and one to two teeth beyond the tumor margin, to the nasal floor. The nasal mucosa can either be preserved or excised depending on the involvement of the tumor. The nasal septum is typically able to be preserved.

One tooth may be removed for easier access, but is usually not necessary.

A malleable retractor is placed along the orbit to protect the globe.

The next osteotomy is made lateral to the nasal bone into the orbital floor.

A malleable retractor is maintained along the orbit to protect the globe.

The osteotomy is then extended along the floor to the medial aspect of the zygoma.

A sagittal saw is then used to osteotomize the zygomatico maxillary junction.

Posteriorly a fine curved osteotome is used with the curvature pointing downwards to complete the cut, and to separate the posterior maxilla from the pterygoid plates.

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 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.

Because the lacrimal system is interrupted, the punctae are intubated with a silicon lacrimal tube and left in the nasal cavity for at least six weeks (Dacrocystorhynostomy).

The iliac crest-internal oblique free flap with internal oblique muscle is harvested in the standard fashion with the following considerations:

• The volume and shape of iliac bone harvested should match that of the size of the bony defect to be reconstructed.
• An adequate amount of internal oblique muscle should be harvested to restore the palatal soft tissue defect.
• The hip ipsilateral to the defect should be utilized to ensure the appropriate placement of the pedicle and correct curvature of the bone.
• If an external skin defect exists, a cutaneous component of this flap can be harvested to restore the external defect.

The iliac crest bone is contoured using a cutting burr or a saw, and then placed so that the crest replaces the alveolus and the inferior portion of the graft replaces the orbital rim. The contour of the bone should match the normal anatomy as closely as possible. Particular attention should be paid to appropriate height and projection of the globe.

The vascular pedicle should be protected when using these bone cutting instruments to minimize risk of damage. The natural shape of the iliac bone rarely requires additional osteotomies to create the zygomatic shape.

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 iliac bone is fixated with 1.5 mm craniofacial plates at three locations:

• The alveolus
• The zygoma
• The nasal bone (when possible)

The internal oblique muscle is sutured to the sublabial mucosa (laterally) and cut edge of the palate (medially) with resorbable sutures to create a water tight seal, either before or after the microvascular anastomosis has been completed.

47 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.