Reconstruction of Total Glossectomy Defects

DEFINITION

Total glossectomy defects occur most commonly in patients with malignancies of the tongue or floor of mouth.
These complex defects require reconstruction with moderate to large volume flaps to restore the bulk of the tongue.
Because the muscular action of the tongue is not restored by this procedure, the bulk of the reconstructed tissue is necessary for swallowing (by pushing the food to the back of the mouth). However, restoration of swallowing is not always feasible and depends on the amount of residual normal tongue base and floor of mouth that is preserved.

ANATOMY

The oral cavity comprises the floor of mouth, oral tongue, alveolar ridge, buccal mucosa, and hard palate.
The tongue itself is composed of intrinsic striated muscles that affect its shape. Extrinsic muscles, including genioglossus, hyoglossus, palatoglossus, and styloglossus, insert into the tongue and affect its position in the oral cavity.
The blood supply to the tongue is almost entirely derived from the lingual arteries, which arise from the external carotid arteries.
The base of tongue, which represents the posterior third of the tongue, is attached to the hyoid bone and represents the anterior-most portion of the oropharynx.
The floor of mouth is the U-shaped mucosal reflection that spans the region between the mandibular alveolus and ventral tongue.
The tongue has distinct functions to support mastication, deglutition, sensation, and speech.
- For mastication, it moves food into position for chewing.
- During deglutition, the tongue propels the food bolus posteriorly into the oropharynx by progressively pressing against the hard palate in a retrograde fashion. This is followed by contraction of the palatoglossus muscles and elevation of the base of tongue. From this point onward, coordinated contraction of muscles in the pharynx and hypopharynx moves the bolus into the esophagus.
- The tongue is the most important articulator of speech and is critical to the production of all vowels and several consonants.

PATHOGENESIS

Over 95% of tongue cancers are squamous cell carcinomas.
- It is more common in males and often presents in the fifth and sixth decades of life.
The most common etiology is smoking and chewing tobacco.
Human papillomavirus has emerged as a new cause of base of tongue malignancies that arise from the lingual tonsils.

PATIENT HISTORY AND PHYSICAL FINDINGS

Most patients with tongue cancer who present to the plastic surgeon have been determined to need resection of at least 25% of the tongue.
Total glossectomy generally refers to removal of at least 75% of the tongue.
Patients should be queried about a history of carotid disease, smoking, prior surgery, or radiation therapy.

IMAGING

Patients who have a history of prior neck lymph node dissection or known carotid disease may benefit from angiography to determine optimal management.

SURGICAL MANAGEMENT

The goals for reconstruction are as follows:
- To enable complete resection of the tumor with wide margins
- To achieve wound closure
- To minimize donor morbidity
- To restore function
- In the case of the total or subtotal glossectomy, these goals are best accomplished by providing a reconstruction that minimizes dead space and provides bulk.
  - This will reduce the likelihood of aspiration and provide a platform for food boluses during swallowing.
If patients present with aspiration, the surgeon should plan for total laryngectomy at the time of total glossectomy.
In general, the above goals are best met with microvascular transfer of a vertical rectus abdominis myocutaneous (VRAM) or anterolateral thigh (ALT) perforator flap. Pedicle flaps, such as the pectoralis myocutaneous flap, may be used but do not provide as much bulk or freedom in inset.

Preoperative Planning

Potential donor sites should be examined, including the ALT and abdomen.
- A determination of the donor site should be based on surgeon preference as well as the body habitus of the patient.
- Patients who have had previous abdominal surgery or who have a large abdominal pannus may not be good candidates for a rectus-based flap.
Patients should generally have gastrostomy tubes placed preoperatively or at the time of surgery.
- If laryngectomy is not planned, patients should also have tracheostomy tube placed to secure the airway.

Positioning

TECHNIQUES

▪ Anesthesia and Assessment of the Defect

After anesthesia is initiated, the oral cavity and oropharynx are examined to assess the anticipated defect (TECH FIG 1).
Tracheostomy is usually performed first, followed by glossectomy and then neck dissection as indicated.
In cases in which a total glossectomy is known to be required, a two-team approach can be used to reduce surgery time.
For total glossectomy defects, the primary goal is to create enough bulk anteriorly to allow contact between the flap and the hard palate when the mandible is closed.
- If necessary, the flap may be folded upon itself to increase its bulk.