Vertical Partial Laryngectomy

Organ preservation therapy of the larynx is offered as a functional alternative to total laryngectomy. The intended goals of preservation therapy are to circumvent permanent tracheostomy, maintain laryngeal speech, and preserve swallow function. Subtypes of operations classified as organ preservation surgery of the larynx include the following: vertical partial laryngectomy (VPL), hemilaryngectomy, endoscopic cordectomy (including procedures that use lasers), and laryngofissure with cordectomy. This article focuses on the use of VPL in the treatment of early glottic cancers.

VPL is specifically designed to treat early T1 and T2 and select T3 laryngeal cancers. Despite initial local control and cure rates comparable with those of traditional radiotherapy (RT), VPL is largely reserved for patients with recurrent or persistent T1 and T2 disease for whom such therapy has failed. The intent of this article is to elucidate the clinical indications, contraindications, and technical points of interest that should be considered in connection with the use of VPL in early glottic cancer treatment.

Open transcervical vertical laryngectomy was initially proposed by Solis-Colen in 1869 to address early T1 and T2 and select T3 glottic cancer. With the advent of primary radiotherapy in the mid 20th century, open procedures were replaced as the definitive treatment for T1 and T2 disease. This was followed by the introduction of transoral laser excision (TLE), which has been popularized over the last 10 years and is considered a viable alternative to primary RT.

Classic hemilaryngectomy, in which the surgeon removes most of the thyroid cartilage on the side of a vocal cord cancer, produces variable speech and swallowing results. This problem led to the development of multiple reconstructive techniques. Among the various techniques used, the following have received particular attention: (1) false vocal cord pulldown, (2) cartilage preservation with perichondrial/sternohyoid muscle flap reconstruction,[1] and (3) epiglottic reconstruction for defects involving the anterior commissure.[2]

More sophisticated reconstructive methods have also been described, but no matter the method, the ultimate goal is maintaining normal laryngeal function. Selection of reconstructive technique partly depends on surgeon preference but is also dictated by the extent of resection required.

VPL is primarily an operation for early glottic carcinoma.

Frequency

Early carcinoma of the glottis is more common than early carcinoma of other head and neck sites because patients present with hoarseness relatively early in the course of the disease. Because radiotherapy is a well-established treatment for early glottic cancers with good oncologic and functional results, VPL is most often reserved as salvage surgery with the aim of removing the tumor with a cuff of healthy tissue.[3]

The etiology of glottic carcinoma correlates strongly with tobacco abuse, and most patients with the disease are smokers. Other etiologic factors include genetic predisposition and laryngeal papillomata. The roles of other carcinogens, such as viruses, chemicals, and inflammatory mediators, are being investigated. Some authors believe that gastroesophageal reflux disease may be a contributing factor.

Carcinoma of the larynx usually begins with dysplastic changes in the larynx, which then progress to carcinoma in situ, followed by microinvasion.

Patients with glottic carcinoma typically present with intermittent hoarseness of up to a few months' duration. A change from intermittent to constant hoarseness indicates vocal cord paralysis. In many cases, no other clinical findings are found in early glottic carcinoma other than hoarseness and indirect laryngoscopic findings of a laryngeal lesion. Early glottic cancer can manifest as leukoplakia (most common; found during examination) or as ulceration, polypoid changes, papilloma, or erythema. Consider all of these findings suggestive, particularly if found in patients who smoke.

Vertical partial laryngectomy (VPL) is indicated as both an initial therapy and as salvage therapy for early glottic cancer (T1 and T2 stages) that has been refractive to primary radiotherapy or transoral laser excision. In select cases, T3 lesions may also be addressed with this family of operations. However, it may not be appropriate in cases of recurrent glottic carcinomas, as they are often understaged and present with multiple foci of tumor throughout the larynx.

For T1 lesions that do not involve the anterior commissure, laser cordectomy can be performed. The false vocal cord reconstruction is then feasible using imbrication laryngoplasty. This operation facilitates false vocal cord reconstruction while maintaining the bulk of the neocord by transferring vascularized innervated false cord to oppose the contralateral true vocal cord. T2 lesions classified as such by impaired mobility are also appropriately addressed in this manner.

For T2 lesions that involve the supraglottis, the false vocal cord usually cannot be pulled down. If a VPL is selected, a different reconstruction technique, such as the perichondrial/sternohyoid muscle flap procedure or a muscle/free mucosal flap procedure, should be considered.

The larynx is located within the anterior aspect of the neck, anterior to the inferior portion of the pharynx and superior to the trachea. Its primary function is to protect the lower airway by closing abruptly upon mechanical stimulation, thereby halting respiration and preventing the entry of foreign matter into the airway. Other functions of the larynx include the production of sound (phonation), coughing, the Valsalva maneuver, and control of ventilation, and acting as a sensory organ.

For more information about the relevant anatomy, see Larynx Anatomy, Vocal Cord and Voice Box Anatomy, and Thyroid Anatomy.

See also Intraoperative details in the Treatment section.

Cancer that involves the anterior commissure, or is close to the Broyle ligament, makes tumor invasion of the thyroid cartilage more accessible. This risk has prompted some authors to question employing vertical partial laryngectomy (VPL) for such lesions in favor of a different organ preservation technique such as supracricoid partial laryngectomy (SCPL) with cricohyoidoepiglottopexy (CHEP) or cricohyoidopexy (CHP). Although voice results following SCPL are predictably worse than after VPL, some studies have shown the local control rates following SCPL are perhaps better for selected T2 and T3 lesions of the glottis. Each case should be individualized for the patient's particular tumor and preoperative function.

Some absolute contraindications to VPL exist. These include large T3 or any T4 lesions, arytenoid fixation, thyroid cartilage invasion, interarytenoid invasion, cricoarytenoid joint invasion, subglottic extension involving the cricoid cartilage, lesions that extend outside the larynx, and pre-epiglottic space invasion.

Because of the relative lack of lymphatics in the glottic division of the larynx, glottic cancers tend to metastasize only in advanced stages. A finding of nodal disease therefore indicates more advanced disease and is a relative contraindication to VPL.

Laboratory studies are not generally required for VPL except as indicated to evaluate any comorbid conditions. Some physicians perform a metastatic screen to look for evidence of tumor spread to lung, liver, or bone, but the yield of these tests on small tumors amenable to VPL is low.

See the list below:

• Imaging studies are not usually required except to assess patients for comorbid conditions or synchronous primary cancers. In such cases, a chest radiograph (CXR) is indicated.

• Barium swallow should be considered in symptomatic patients.

• A neck CT scan should be considered to evaluate thyroid cartilage invasion in patients with anterior commissure involvement.

• A CT scan of the head and neck with fine cuts (1 mm) through the larynx should be considered in patients with vocal cord impairment or fixation.

Other tests are needed to assess operative risk as indicated for comorbid conditions.

See the list below:

• Diagnostic tests include flexible laryngoscopy in the office to assess vocal cord and arytenoid mobility and the extent of the lesion.

• A thorough head and neck examination should be performed.

• Panendoscopy to exclude synchronous malignancy in the head and neck, tracheobronchial tree, and esophagus is controversial, but should be performed in most cases.

• Preoperative and postoperative videostroboscopy and voice recording for functional assessment and documentation are important parts of patient evaluation and care.

The histology of initial tumors usually reveals squamous cell carcinoma arising from dysplasia. Minor salivary carcinomas, most commonly adenoid cystic carcinoma, are rare. Small cell carcinoma, other neuroendocrine tumors, and sarcoma are extremely rare. Granular cell tumors, plasmacytoma, and other lesions that resemble malignancy should also be considered in the differential diagnoses.

Recurrences following radiotherapy are histologically characterized by small nests of neoplastic cells lying deep below intact mucosa. Most recurrent carcinomas present with multicentric tumor foci, whereas most primary carcinomas present with a central tumor location. Marked perineural infiltration has lead to the hypothesis that recurrent tumors grow alongnerves involving previously unaffected areas.[4]

Radiotherapy is a well-established treatment for selected laryngeal carcinomas with good oncologic and functional results. Reported failure rates have averaged 9-37% in T1 and 25-45% in T2 lesions.[5] The use of chemotherapy in combination with radiotherapy for early laryngeal cancer remains an active area of research. In the context of advanced-stage disease (T3 or T4), multiple studies demonstrate a synergistic response. In addition, Laccourreye et al have proposed the use of chemotherapy alone as a definitive treatment for select glottic squamous cell carcinoma.

Because cure rates of surgical therapy equal those of radiotherapy, patient preference should play a large role in the selection of treatment modality.

Inform patients that a temporary tracheotomy is likely required. Patients should also give consent for total laryngectomy in case the cancer is discovered to be understaged. This is especially important in salvage cases, as preoperative understaging occurs in approximately 50% of cases.[4]

Use a low collar incision. Place the tracheostomy through a separate horizontal incision below the collar incision. Attempt to keep the dissections separate. After developing subplatysmal flaps, expose the larynx by separating the strap muscles vertically in the midline and incising the external perichondrium in the midline and along the superior and inferior borders of the thyroid cartilage. This allows bilateral laterally based flaps to be created.

Cricothyroid entry during laryngofissure is depicted in the image below. Laryngofissure performed with an oscillating saw is also known as midline thyrotomy. This step is performed for all VPL procedures unless the anterior commissure is involved. In such cases, a central segment of thyroid cartilage is included in the resection by making parallel thyrotomy cuts on either side of the midline and preserving both lateral remnants or by making a cut on the contralateral side and removing the entire ipsilateral thyroid ala. Preservation of the ala is preferable for most reconstructions. See the image below.

Confirm resection with adequate margins; intraoperative frozen sections with postoperative permanent sections are mandatory to confirm margins. The images below give more particulars about the intraoperative details.

Once the laryngofissure is completed and the incision in the cricothyroid membrane made, the vocal cords are inspected from below. If the anterior commissure is disease free, the internal mucoperichondrium is divided at or near the anterior commissure, with a margin around the tumor of at least 3 mm. The entire vocal cord is then resected. For imbrication laryngoplasty, the cordectomy is performed by excising a segment of thyroid cartilage adjacent to the vocal cord. Take care to preserve an intact inferior strut of thyroid cartilage that is approximately 1 cm in height.

View reconstruction details within the images below for imbrication laryngoplasty. The simplest reconstruction after the laryngofissure and cordectomy is to suture the false vocal cord to the infraglottic mucosa as seen in the image below.

In the image below, imbricating sutures are used to place the superior strut of cartilage medial to the inferior strut, which pulls the false vocal cord down to be sutured to the infraglottic mucosa. This has the advantage of reconstructing the neocord using vascularized, innervated, mucosalized tissue, while avoiding tension, which may result in dehiscence of the mucosa or flattening of the false vocal cord. Both of which can result in a breathy voice. The technique involves 2 pairs of drill holes in the superior and inferior strut, allowing 2 imbricating sutures of 2-0 Prolene. The mucosa is approximated using 4-0 Vicryl or chromic. The laryngofissure is closed with 2-0 Prolene or 2-0 Vicryl sutures.

The anterior commissure is then re-created by suturing the internal to external perichondrium as seen in the image below. The external perichondrium and cricothyroid membrane are closed with 3-0 Vicryl suture, and the wound is closed with a Penrose drain and a dressing. A cuffed tracheotomy is used.

Penrose drains, sterile dressing, proper tracheotomy care, early oral intake, and decannulation when edema resolves are indicated. Generally, a hospital stay lasts less than one week.

Regular follow-up care is required for all patients with head and neck cancer, preferably at least every 6-12 weeks during the first postoperative year. Closer follow-up care is necessary in the early postoperative period. In the event of VPL failure, salvage total laryngectomy remains a reasonable option.

Major complications are rare but include the following:

• Wound infection (most common)

• Seroma

• Major subcutaneous emphysema

• Inadequate voice

• Aspiration

• Hematoma

• Conversion to total laryngectomy

In previously untreated patients, reported local control rates as primary therapy are greater than 90% for T1 glottic tumors and 68% for T2 glottic tumors. Increased risk factors for recurrence include anterior commissure involvement, increased T stage, and positive surgical margins.[6, 7]

In patients who undergo salvage therapy secondary to RT failure, the reported local control rates are 84% and 60% for T1 and T2 glottic tumors, respectively. The overall survival for this group of patients is reported at 77%.[5]

With regard to T3 glottic tumors, local control rates vary among different institutions, with reported failure rates as high as 50%.

Primary radiotherapy and transoral laser excision remain the prototypical therapy for early glottic tumors. Vertical partial laryngectomy (VPL) serves as both primary and salvage therapy for T1 and T2 disease with equivocal control rates for T3 tumors. Choosing the ideal surgical modality for tumors that bridge the T2/T3 classification system remains an intense area of controversy, without clear delineation in the literature. The intended goal of this article is to highlight the limits of VPL as much as its therapeutic efficacy.

Advances in transoral surgical approaches have contributed to the development and advances of endoscopic VPL. Future directions in research and technical innovation will likely focus on voice conservation, the role of chemotherapy, and stratification of patients based on tumor biology.

In particular, anterior commissure involvement, supracricoid partial laryngectomy, and the different reconstructions will continue to generate controversy and debate among head and neck surgeons. Patient desire and surgeon bias will continue to play dominant roles in the selection of treatment modality for early laryngeal carcinoma.