Mandible Reconstruction With Fibula Flap With Templates



Mandible Reconstruction With Fibula Flap With Templates


Eric G. Halvorson





ANATOMY



  • The anatomy relevant to fibula flap harvest is presented in Chapter 10 of this section, as well as techniques for neomandible creation using CAD/CAM osteotomy jigs.


  • This chapter focuses exclusively on how to create a neomandible using traditional templates and closing wedge osteotomies.


PATIENT HISTORY AND PHYSICAL FINDINGS



  • Risk factors for wound healing complications should be assessed, including radiation exposure, smoking, diabetes, steroid use, poor nutrition, and obesity.


  • Prior neck dissection can make reoperation and recipient vessel exposure difficult. A history of lower extremity trauma, surgery, or peripheral vascular disease may preclude use of the fibula flap.


  • The oral cavity is examined and the expected defect analyzed for quantity of bone and lining required.



    • Patients with poor dentition who will require adjuvant radiotherapy may benefit from dental extraction.


    • Occlusion is assessed and carefully noted, as one goal of surgery is to maintain native occlusion.


  • Distal lower extremity pulses and skin texture are examined.



    • Patients with potential vascular disease should undergo preoperative imaging to evaluate three-vessel runoff.


    • Patients with taut or thin skin will likely require a splitthickness skin graft for donor-site closure.


IMAGING



  • Craniofacial CT scans are performed to assess the extent of disease (tumor, traumatic defect, osteoradionecrosis, infection).



    • Three-dimensional renderings are helpful but not necessary.


  • Lower extremity angiography is commonly performed (CTA or MRA) to assess three-vessel runoff. If these studies are inadequate, conventional angiography is performed.



    • Patients must have at least a patent anterior tibial or posterior tibial artery (in addition to the blood supply of the flap derived from the peroneal artery) to be candidates for fibula flap harvest.


SURGICAL MANAGEMENT


Preoperative Planning



  • Excellent communication between the extirpative and reconstructive surgeons is necessary to coordinate perioperative planning, including staging of disease, imaging, labs, and clearance for surgery.


  • In delayed reconstruction, eg, in patients treated for traumatic defects, it is helpful to have two surgeons involved (one to recreate the defect and expose recipient vessels and the other to elevate the flap). However, this is not an absolute requirement.


  • A secure airway is required in the perioperative period, as flap swelling, abnormal deglutition, and secretions can compromise the airway. In addition, emergent reintubation may compromise microsurgical reconstruction and disrupt the repair. As a result, a tracheostomy is almost always indicated until adequate healing has occurred to allow decannulation.


  • Adequate nutrition is important in the perioperative period.



    • A flexible nasogastric or nasoduodenal tube is often placed at the end of surgery for early initiation of tube feedings.


    • If patients are malnourished prior to surgery, a percutaneous endoscopic gastrostomy tube may be considered.


Positioning



  • Patients are placed in supine position with a bump under the shoulders and the neck extended.


  • A folded towel or blanket is placed under the hip to facilitate internal rotation when the hip and knee are flexed.


  • A padded roll or IV bag is secured to the table so the foot can rest on it with the hip and knee flexed (and internally rotated). This facilitates exposure and dissection.


  • The heels and lower extremity are padded to avoid pressure sores during these long procedures.


  • The entire lower extremity is prepped and a sterile tourniquet is used so the thigh can later be used as a donor site for a split-thickness skin graft if needed.



Approach



  • If the defect is truly central, and both necks are available for recipient vessels, then either extremity can be utilized to harvest a fibula flap.



    • The left is preferable as most patients use their right leg for driving, etc., but angiographic findings may also dictate which side to use.


  • An ipsilateral flap (with respect to the location of the defect in the jaw) is typically used. This approach places the septum carrying the cutaneous vessel/s externally and inferiorly.



    • This allows the septum and skin to be brought over the hardware and into the oral cavity for standard gingiva/floor of mouth defects.


    • In addition, using the ipsilateral flap places the pedicle vessels laterally on the fibula flap thus localizing the vessels in optimal position for microsurgical anastomosis to the neck vessels.


  • A contralateral flap will place the septum and skin island internally and superiorly, which may be preferable when there is a large intraoral defect that extends beyond the gingiva/floor of mouth.


  • A two-team approach is preferable to reduce operative time.



    • The flap can be elevated during extirpation, provided there is good communication between the two operative teams and an accurate estimate of the defect is made.


    • It is prudent to take more flap than you think you might need.


    • The neomandible can be created in situ on the leg, further reducing both operative and ischemic time.

Dec 15, 2019 | Posted by in Reconstructive surgery | Comments Off on Mandible Reconstruction With Fibula Flap With Templates

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