Epiglottic Reconstruction

Epiglottis reconstruction is mainly and most commonly performed to prevent abnormal swallowing and aspiration. ^{[1, 2]}

Malignancies of the head and neck can result in devastating functional and cosmetic deficits that have a significant psychosocial impact on affected patients. In most cases, the ramifications of undergoing treatment for head and neck cancers extend far beyond the psychological and social aspects. Aside from cosmetic deformities of the head and neck, these patients may also develop deficits in their abilities to speak, eat, swallow, and even breathe.

The incidence of head and neck cancers, and thus the need for treatment, has slowly increased, ^[3] as has the burden of posttreatment management. The morbidity associated with head and neck malignancies has necessitated the evolution of operative techniques and ushered in an era of innovative conservation surgeries and reconstructive procedures in the field of plastic surgery.

Although the 20th century saw substantial progress in the area of head and neck reconstruction, the first plastic surgery dates as far back as 3000 BC, when the first rhinoplasty in the management of facial trauma was described. ^{[1, 4]} Since then, the field of reconstructive surgery has made remarkable gains with the use of revascularized flaps, free flaps with autologous skin transplants, pedicled myocutaneous flaps, and osteocutaneous free flaps in reconstructing defects. ^{[5, 6, 7, 8]}

These historical landmarks have paved the way for current techniques in epiglottis reconstruction. The review of these techniques first begins with a discussion of the function of the epiglottis.

The epiglottis is an elastic leaf-shaped cartilage that covers the entrance to the larynx. It is important in preventing aspiration of solids and liquids. A competent and functional epiglottis is essential for normal eating and swallowing. ^{[9, 10]} Dysfunction of the epiglottis can lead to complications such as chronic aspiration, which, in turn, can cause significant pulmonary damage. ^{[11, 12]} Epiglottis dysfunction has multiple etiologies, but, in the field of reconstructive surgery, these dysfunctions typically result from anatomic deficits of the epiglottis, such as after supraglottic (horizontal) laryngectomy.

Relevant Anatomy

During embryologic development, the supraglottic structures (epiglottis, arytenoid cartilages, false vocal folds, ventricle) derive from the buccopharyngeal primordium, which arises from the third and fourth branchial arches. In contrast, the glottis and subglottis are derived from the tracheobronchial primordium of the sixth branchial arch. ^[11] Because the supraglottis is not embryologically linked to the glottis and subglottis, it derives its blood supply from the superior laryngeal arteries. The lymphatics of the supraglottis travel along the superior laryngeal vessels to the carotid sheath and drain bilaterally into the deep cervical chain nodes in levels II and III of the neck.

The epiglottis is considered to be part of the “supraglottis,” which also includes the arytenoid cartilages, false vocal folds, and ventricle. The epiglottis is divided into the suprahyoid epiglottis (lingual and laryngeal surfaces) and the infrahyoid epiglottis. At its most inferior aspect (petiole), the epiglottis is attached to the inner surface of the thyroid cartilage laminae above the anterior commissure and projects posteriorly into the pharynx. Laterally, it is attached to the quadrangular membrane, an accessory elastic structure that provides support to the supraglottic structures. Along with the thyroepiglottic ligament, the anterior surface of the epiglottic cartilage forms the posterior boundary of the pre-epiglottic space (see images below).

Sensory information is provided to the epiglottis by the internal branch of the superior laryngeal nerve, which also gives off sensory fibers to the base of tongue, the valleculae, pyriform sinus, the aryepiglottic folds, and the vestibule of the larynx down to the level of the glottis. The recurrent laryngeal nerve provides motor innervation to all the intrinsic muscles of the larynx (except the cricothyroid muscle) and sensory innervation to the glottis, subglottis, and trachea (see images below).

No standardized method has been established for reconstruction of the epiglottis; thus, this article is an overview of the various techniques that have been described in the literature.

The most important and common reason for epiglottis reconstruction is to prevent abnormal swallowing and aspiration. ^{[1, 2]}

In the case of malignancy, the decision to reconstruct the epiglottis is based on tumor staging and spread and may be influenced by postsurgical treatments such as chemotherapy and radiation therapy.

Beyond malignancy, epiglottic reconstruction may also be indicated in patients recovering from severe penetrating trauma to the larynx and epiglottis or in patients with epiglottic scarring or stenosis, as these can also significantly affect swallowing and speech function. ^[13]

The main contraindication to epiglottis reconstruction is extensive tumor invasion. In patients who are undergoing total laryngectomy or who require significant tumor resection, epiglottis reconstruction is not performed.

Peripheral vascular disease may also pose a difficulty in the patient undergoing a free flap repair, as this places the flap at risk for necrosis secondary to poor circulation.

Tissue fibrosis in a patient with a history of radiation is another limiting factor in selecting flap donor sites, as is scarring from previous surgical procedures.

Tumor extension

Extension of tumor to the epiglottis often dictates the type of reconstruction that may be performed. If only the suprahyoid aspect of the epiglottis is involved, several different reconstructive techniques may be considered (see Technique), as follows:

• Bilobed radial forearm free flap repair ^[14]

• Radial forearm free flap with hyoid bone flap ^[15]

• Tubed radial forearm free flap ^[16]

• Reconstruction with the remnant epiglottis ^[17]

If the tumor extends to the infrahyoid portion of the epiglottis, the method of reconstruction is fairly limited and may be accomplished using the hyoid bone as an osteomuscular flap. ^[16] In all of the techniques listed above, a remnant stump of the epiglottis (at the petiole) is used for reconstruction.

Alternatively, no reconstructive technique may be undertaken, and the laryngeal defect can be closed primarily (closed with suture) or secondarily (allowed to fill in with granulation tissue) or with a local rotational flap.

Nerve preservation

Epiglottic reconstruction is performed in an effort to maintain normal swallowing and voice function. In order to aid this effort, close attention must be paid to the preservation of the superior laryngeal nerve (internal branch) and recurrent laryngeal nerve during supraglottic laryngectomy (see Relevant Anatomy), as the loss of innervation can cause significant sensory and motor deficits, resulting in postoperative aspiration. ^[18]

Complication Prevention

In patients undergoing a free flap repair, vessel thrombosis is a significant concern because of the risk of flap necrosis. In these patients, it is very important to start anticoagulation therapy in the immediate postoperative period. The specific method of anticoagulation is often dependent on the physician and institution and can include ASA, low molecular weight heparin, and subcutaneous heparin. However, the choice of anticoagulation therapy does not appear to significantly affect the incidence of post-operative free flap complicationsrRef30} ^[19]

A review of 68 patients with glottic carcinoma who underwent frontal anterior laryngectomy with epiglottic reconstruction showed a 5-year disease-free survival rate of 93.5%. ^[20]

In one study involving 2 patients who underwent reconstruction with the radial forearm free flap, both patients had excellent swallowing outcomes without any evidence of leak or aspiration. ^[14]

In another study assessing the use of radial forearm free flap with septal cartilage in reconstruction of the epiglottis, 5 of 7 patients were able to tolerate oral feeds without episodes of aspiration pneumonia. ^[21] Overall, this technique appears to yield moderate to excellent swallowing results, with most patients able to tolerate oral feeding with few complications of aspiration. ^{[22, 21, 23]}

Calcaterra (1985) also achieved excellent results in 14 patients undergoing reconstruction with the epiglottis remnant. The patients all had rapid rehabilitation of deglutition without significant aspiration because of the projection of the neo-epiglottis over the laryngeal inlet, allowing for diversion of food to the pyriform fossae. ^[17]

Potential complications

Many of the complications associated with epiglottis reconstruction are complications that may be expected with any surgery, while others are associated with the technique used. ^{[24, 22]} They are as follows:

• Deep venous thrombosis/pulmonary embolism

• Bleeding

• Infection

• Pain

• Thrombosis/necrosis of the free flap

• Dysphagia/aspiration

• Difficulty speaking (weakness, breathiness)

• Difficulty breathing

• Hematoma

• Salivary fistula

• Numbness

• Cosmetic scarring