Authors of section

Authors

Brian Burkey, Neal Futran

Executive Editors

Gregorio Sánchez Aniceto, Marcelo Figari

General Editor

Daniel Buchbinder

Open all credits

Plate and radial forearm fasciocutaneous free flap

1. Introduction

The need for reconstruction of mandibular defects is either due to trauma or tumor resection.

The vast majority of oral cavity tumors are squamous cell carcinoma, and these arise from the mucosa. These tumors are therefore adjacent to the mandible and significant growth frequently leads to invasion of the bone.

A composite resection (segmental mandibulectomy) is the treatment of choice for oral malignant tumors that invade the mandibular cortex and marrow space. It provides an oncologically sound margin for these tumors; however, it disrupts the continuity of the mandible.

primary closure

General goal of reconstruction

Reconstruction of the mandible allows for the restoration of form and function. It must address all the tissue losses in order to provide for the best function.

The general goal of reconstruction is the:

  • Restoration/maintenance of airway
  • Restoration of mandibular continuity
  • Restoration of dentition
  • Restoration of chewing (mastication) and swallowing (deglutition)
  • Restoration of facial contour
  • Consistently obtain a healed wound

Some patients neither have the resources nor desire to undergo dental restoration. Therefore reconstruction of the mandible in these patients is limited to restoration of form and continuity of the mandible using a plate and soft tissue flap to avoid a drift of the mandibular segments.

Internal fixation hardware

Mandibular fixation is best achieved with the use of a load bearing locking mandibular reconstruction plate.

A wide variety of options are currently available:

  • 2.4 Uni-lock reconstruction plates
  • Matrix mandible reconstruction plates of different profiles (2.0, 2.5, 2.8), and screw diameters
  • Anatomically preformed mandibular reconstruction plates

For illustration purposes we will here show the use of a 2.4 reconstruction plate.

The advantage of the locking plate is that it does not require 100 % adaptation to the mandibular contour. Small gaps can be tolerated since the threaded screw head locks to the plate resulting in an internal "ExFix" construct.

plate and pectoralis major myocutaneous pedicle flap

Reconstruction with vascularized soft tissue graft

When osteocutaneous flaps are not desired or indicated, intraoral soft tissue defects may be reconstructed with vascularized soft tissue flaps.

When the radial forearm fasciocutaneous free flap is used, the presence of the lateral antebrachial cutaneous nerve provides the option of innervating the flap and restoring sensation to the oral cavity.

radial forearm fasciocutaneous free flap

2. Approach

The location and size of the tumor will dictate the surgical approach necessary for the performance of the ablative procedure.

The two following approaches are frequently used for the mandible:

Reconstruction of midface Brown II defect

3. Resection

Marking of the osteotomy lines

The proposed mandibulectomy margins are marked on the mandible. Care is taken to resect at least 1 cm of normal bone on each side of the tumor.

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Defining the soft tissue margins of the composite resection

The tumor is visualized and palpated and 1.5 cm soft tissue margins are marked (eg. with electro cautery) around the tumor in the oral cavity.

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Reconstruction plate

A template is contoured to the external mandible staying just superior to the inferior border of the mandibular body. At least 3 fixation screws are planned on either side of the mandibulectomy.

The plate is then bent to match the template. The plate is placed onto the mandible and final adjustments are made to produce a near perfect passive fit.

plate and pectoralis major myocutaneous pedicle flap

A minimum of three bicortical fixation screw holes are drilled and locking screws inserted through the most proximal and distal plate holes.

Note: The screws close to the resection border should be at least 5-7 mm away from the osteotomy line.

The screws and plate are then removed, tagged and placed on the back table.

plate and pectoralis major myocutaneous pedicle flap

Pearl: In order to return the proper length screw into its respective hole, the screws can be organized in a screw caddy as shown.

plate and pectoralis major myocutaneous pedicle flap

Extraction of teeth

In a dentate patient, the teeth in the line of the osteotomies are extracted.

plate and pectoralis major myocutaneous pedicle flap

Osteotomy cuts

Bone cuts are now carried anterior and posterior to the tumor using a saw. Care is taken to resect at least 1 cm of normal bone on each side of the tumor.

plate and pectoralis major myocutaneous pedicle flap

Removal of the bone segment and tumor

The bone is retracted laterally, thus exposing the medial soft tissue resection margin.

Soft tissue cuts are made through the previously marked resection margins in the floor of mouth, the mylohyoid muscle and deep tongue muscles if necessary.

The specimen is submitted en bloc for permanent pathological examination.

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

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4. Reconstruction

Replacement of the reconstruction plate

The plate is replaced and fixed in the preplanned position taking care that the proper length screws are used.

The patient's occlusion is verified to ensure proper occlusion.

plate and pectoralis major myocutaneous pedicle flap

Harvest of graft

The radial forearm fasciocutaneous free flap is harvested in the standard fashion with the following considerations:

  • It is harvested of sufficient size to cover mucosal defect.
  • As an option, the lateral antebrachial cutaneous nerve is harvested with the flap so as to be anastomosed to the proximal stump of the lingual nerve in order to restore sensation of the oral cavity.
radial forearm fasciocutaneous free flap

Insetting of flap soft tissue

The skin paddle may be draped with the pedicle medial or lateral to the plate depending on the surgeon's preference.

It is crucial to wrap the plate with the flap during the reconstruction to prevent post operative plate exposure.

plate and radial forearm fasciocutaneous free flap

In most oral cavity and oropharyngeal defects, the oral mucosa is closed directly to the skin of the flap with interrupted absorbable suture in a vertical mattress fashion (eg. 3-0 Vicryl). A water tight closure is essential to avoid a salivary leak into the neck with subsequent infection in the surgical site and an orocutaneous fistula.

Care must be taken during closure to avoid injury to the vascular pedicle which may be traversing the defect.

lateral mandible mucosa tongue less than1 3

Revascularization of the free flap

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

  • Appropriate recipient vessels are selected in the neck and dissected so as to be available for anastomosis
  • 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 using 9-0 nylon sutures
  • Vascularization is restored after both arterial and venous anastomoses are completed
  • Nerve anastomosis is accomplished between the lateral antebrachial cutaneous nerve and the proximal lingual nerve stump (in those cases where the lingual nerve has been sacrificed during the tumor resection). This is done using 4 to 6 interrupted 9-0 nylon sutures. Recovery of sensation in the reconstructed area can be usually be achieved in 6 to 9 months
construction of mandibular ramus and condyle

5. Aftercare following mandibular reconstruction

Medication

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 oral bacterial flora, but the physician should be aware of changes that may occur after the use of radiation therapy.
  • 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, 80-100 mg of aspirin/day is recommended.

Wound care

Remove any 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.
Wound should be cleaned at least twice daily with hydrogen peroxide or mild soap and water. 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

Diet depends on the reconstructive method. In general patients with superficial wounds can begin an oral diet within 48h postoperatively. Patients who have undergone a more significant surgery eg. flap reconstruction are kept NPO for 5-10 days and nutrition is administered via nasogastric tube. Oral feedings are begun using thickened liquids only after swallowing is assessed by the surgeon or the speech pathologist, and the risk of aspiration is minimal. Diet can be advanced as tolerated by the patient.

Clinical follow-up

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.

Oral hygiene

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) or water flosser 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.

Reconstruction with free flap

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.

Closed suction drains are routinely used at the donor site. The drain is removed when output is <30cc per 8 hour period, for three consecutive periods. Patients are typically discharged from the hospital 5-10 days after surgery, depending on their postoperative course and comorbidites. Close outpatient follow-up after discharge is recommended for evaluation of surgical sites.

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.

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. The routine use of a compression stocking for one month postoperatively will reduce the amount of lower leg dependent edema and aid in improved wound healing.

Scapula free flap
In the initial postoperative recovery, the ipsilateral arm should be positioned anteriorly and medially, usually supported on the patient’s abdomen by a pillow. Once the patient is ambulating, the arm is supported by a shoulder sling which supports the elbow and prevents inferior drift of the arm. Inpatient physical therapy is initiated once the patient is mobile. A post-operative physical therapy regimen is established with the patient to be maintained after hospital discharge. The sling is used for 2-3 weeks and physical therapy maintained until postoperative function is optimized, usually 4-6 weeks.

Iliac crest
The iiliac crest donor site requires that the patient not strain or lift heavy objects for at least 4 weeks to avoid hernia formation. Patients are typically limited to a bed or chair for 48h postoperatively and then physical therapy is begun with the patient initially ambulating with the aid of a walker or cane and progressing as tolerated.

Latissimus dorsi
No specific rehabilitation is necessary following the use of this flap.