Supracricoid Laryngectomy

Total laryngectomy (TL) may be used either as an initial treatment or as a salvage option for many laryngeal cancers. TL has been used in particular for advanced laryngeal cancers. Although radiation (with or without chemotherapy) has been offered as an alternative to TL, in many cases risk of local failure remains significant.

In numerous European countries, the supracricoid partial laryngectomy (SCPL) was developed in the late 1950s as an alternative to TL. SCPL has the advantages of preservation of speech and swallowing function without a permanent stoma and a very high local control rate for selected glottic and supraglottic cancers.

Two types of SCPL are employed for distinctly different types of laryngeal cancers. The differences in the extent of resection achieved by these forms of SCPL require discrete reconstructions. The true and false cords, both paraglottic spaces, and the entire thyroid cartilage are resected in the SCPL that is used to treat selected glottic carcinomas. The reconstruction requires suturing the cricoid to the hyoid and the epiglottis, termed a cricohyoidoepiglottopexy (CHEP). The second form of the procedure, which is employed to ablate selected transglottic and supraglottic carcinomas, results in the resection of both true and false cords, both paraglottic spaces, the entire preepiglottic space, the epiglottis, and the entire thyroid cartilage. The reconstruction for this more extensive technique is accomplished by suturing the cricoid to the hyoid, termed a cricohyoidopexy (CHP).

Because no vocal or false cords are present in the postoperative view of the SCPL with CHEP, the normal V-shaped glottis is changed to a T shape in which the arytenoids abut each other and the epiglottis anteriorly. The postoperative anatomic configuration is different following SCPL with CHP because the epiglottis is also resected in this procedure. In this case, the neolarynx is T-shaped, with the arytenoids abutting each other in the midline and against the tongue base.

SCPL provides an effective alternative to the TL and offers better local control for selected lesions than an extended partial laryngectomy or nonsurgical therapy such as radiation with or without chemotherapy. Lesions that might typically require TL (eg, selected supraglottic carcinomas not amenable to SGL, selected T4 carcinomas, selected T3 glottic carcinomas, selected laryngeal carcinomas that have recurred following radiation therapy) may be treated effectively with SCPL-CHEP or SCPL-CHP. As with any technique, the key to successful oncologic outcome following SCPL is appropriate patient selection.

This article reviews the basics of SCPL, including the relevant surgical anatomy, indications, contraindications, and operative techniques.

An image depicting the larynx can be seen below.

Although the supracricoid partial laryngectomy (SCPL) was first described in Europe in 1959, the technique was not reported in an American journal for another 30 years. Ultimately, these techniques were published in English journals from centers around the world. By the 1990s, numerous reports confirmed that SCPL had been performed around the world for decades. However, in 1990, when the first American cases of SCPL were presented in the United States, the technique was both largely unknown and hardly noticed.

A number of factors may have contributed to the delay in the recognition of SCPL in the United States. The focus of classic conservation surgery has traditionally been on vertical partial laryngectomy (VPL) and supraglottic partial laryngectomy (SGL). The SGL was imported from South America in the 1940s, and the VPL was first described in Europe in the 19th century. While the VPL and SGL were developed for and best suited to early laryngeal carcinoma, various extended partial laryngectomy approaches were later described in the literature. The reports of these extended techniques tended to include small numbers of patients without mention of functional outcome.

The plethora of reconstructions that accompanied these extended partial laryngectomies were typically difficult to reproduce by practicing clinicians. This lack of reproducibility with the extended VPL and extended SGL resulted in the avoidance of these procedures in favor of either TL or nonsurgical organ preservation approaches such as radiation and chemotherapy. In an atmosphere of distrust for extended conservation surgery techniques, extensive conservation laryngeal surgical techniques such as SCPL were not readily embraced.

During the years after its introduction, SCPL was popularized in France and other European centers. Both oncologic and functional successes with SCPL have been reported in large numbers in the world literature. A particular advantage of SCPL when compared to extended VPL or SGL is that the surgeon does not have to deal with a vast array of difficult-to-reproduce reconstructions. In contrast, outcomes for the extended VPL and/or SGL tend to be reported in small case series, and rarely has one type of reconstruction ever been reported in more than one series of patients treated with extended VPL and/or SGL.

The laryngeal surgeon must determine whether a patient can successfully tolerate general anesthesia. The patient must also be evaluated for a number of systemic disorders, as follows:

• Cardiac disease

• Arteritis

• Diabetes mellitus

• Gastroesophageal reflux (Irritation and edema of the arytenoid mucosa postoperatively affects wound healing.)

• Rheumatoid arthritis (decreased mobility of the arytenoid cartilage)

Important findings on physical examination include the following:

• Pain due to palpation at the level of the thyroid ala indicates thyroid cartilage invasion.

• Pain or mass at the level of the thyrohyoid membrane and vallecula indicate massive preepiglottic space invasion.

• Mirror examination provides initial information regarding the tumor epicenter, surface extent, airway impairment, and laryngeal mobility. Mirror examination provides binocular vision that is unavailable in indirect laryngoscopy.

• Perform careful palpation of the neck to detect nodal involvement.

SCPL alters the sphincteric function of the larynx, leading to a decreased quality of voice and a risk for aspiration, especially in the immediate postoperative period. Adequate pulmonary reserve is necessary to tolerate the increased postoperative aspiration with the concomitant risk for atelectasis and pneumonia. Patients with severe chronic obstructive pulmonary disease (COPD), impairment of the cough reflex, and impairment of pulmonary ciliary clearance are at higher risk. A clinical assessment is typically accurate. Chronic and inefficient cough, purulent sputum, and/or an inability to climb 2 flights of stairs without shortness of breath are strong contraindications against the use of SCPL-CHEP or SCPL-CHP.

One study evaluated the incidence, risk factors, management, and outcome of postoperative aspiration in 457 patients who underwent a supracricoid partial laryngectomy (SCPL). The results found a significant relationship between aspiration and increased age, performing cricohyoidopexy, not repositioning the pyriform sinuses, and resecting an arytenoid cartilage. The data concluded that while aspiration after SCPL is a common event, it rarely is severe and can be minimized with careful patient selection and precise surgical technique. ^[1]

Furthermore, a 2009 study by Joo et al determined that age (60 years or older) and cricohyoidopexy increase the risk of pulmonary complications following supracricoid partial laryngectomy. ^[2]

Supracricoid partial laryngectomy-cricohyoidoepiglottopexy (SCPL-CHEP) and supracricoid partial laryngectomy-cricohyoidopexy (SCPL-CHP) provide useful and effective alternatives to total laryngectomy (TL). These organ preservation surgery techniques are useful for laryngeal lesions that have extended beyond the traditional indications for VPL and SGL. Unlike attempts to extend the resection margins of VPL and SGL, SCPL-CHEP and SCPL-CHP provide reliable oncologic outcomes and reproducible functional results from a fixed reconstruction technique.

A spectrum of procedures exists from smallest to largest, corresponding to a spectrum of lesions from smallest to largest. A spectrum exists for both supraglottic and glottic carcinoma. This spectrum is a useful tool for preoperative planning for organ preservation surgery. On the top of the spectrum, every other laryngeal schematic is blank. The clinician can then draw the lesion they are seeing into the appropriate point on the spectrum. The examples that are given in the spectrum are linked with the surgical procedures below. Some lesions are associated with 2 surgical procedures. This is because controversies remain in the literature concerning which is the most appropriate technique for a given lesion. Understanding these spectra helps the surgeon to see the role of the SCPLs relative to other useful organ preservation techniques.

Indications for SCPL-CHEP

See the list below:

• Bilateral vocal cord involvement with or without anterior commissure involvement (horseshoe lesion)

• Unilateral glottic carcinoma with anterior commissure involvement

• Impaired true vocal cord mobility

• T3 glottic lesion with fixation of the cord and either impaired or mobile arytenoid

• T4 glottic tumors with limited thyroid cartilage invasion

Indications for SCPL-CHP

See the list below:

• Supraglottic lesions not amenable to supraglottic laryngectomy because of ventricular invasion, extension to a vocal cord, or impaired vocal cord mobility

• T3 supraglottic and transglottic cancers with vocal cord fixation, preepiglottic space invasion, or both

• T4 lesions with limited thyroid cartilage invasion

Preoperative assessment of patients with laryngeal carcinoma requires a precise 3-dimensional understanding of the extent of disease within the complex anatomy of the larynx. The surgeon must predict the chances of being able to obtain negative margins within the larynx. Beyond the mucosal extent of the disease, understanding laryngeal anatomy provides insights into the behavior and spread of cancer within the larynx.

In 1986, a whole organ section study by Hirano et al demonstrated that 50-65% of the entire adult airway is posterior to the anterior aspect of the vocal processes of the arytenoids. ^[3] The anterior glottis (vocal cords) serves as the phonatory larynx, and the posterior glottis (interarytenoid area) is the respiratory larynx. Thus, both vocal cords can be resected with little effect on respiration and swallowing. Functional reconstruction of the larynx requires the preservation of at least one arytenoid cartilage and the cricoid ring. Creation of the neoglottis from the remaining arytenoid cartilage and the tongue base or epiglottis remnant is sufficient to achieve lung-powered phonation and permits physiological speech and swallowing without a permanent tracheostomy.

Divisions and subsites of the larynx

The supraglottis is the area above the lateral angle of the ventricle. Its subsites include the epiglottis, preepiglottic space, aryepiglottic folds, ventricles, false vocal cords, hyoid bone, and arytenoid cartilages.

The glottis is the area from the lateral angle of the ventricle to 1 cm below this point. Its subsites include the true vocal cords, anterior commissure, and posterior commissure.

The subglottis occupies the area from below the glottis to the inferior portion of the cricoid cartilage.

Key anatomic features

Anatomic landmarks of the larynx as related to cancer spread include the following features.

• Skeletal framework

  • Cricoid cartilage: The cricoid cartilage is the only complete ring in the airway. The integrity of the circumference of the cricoid cartilage is necessary to perform organ preservation surgery (OPS) of the larynx and to decannulate the trachea postoperatively.

  • Epiglottis: Normal structures such as lymphatics, submucosal glands, blood vessels, and nerves cross through the multiple fenestrations present in the epiglottis. These perforations also serve as a route for the spread of supraglottic carcinoma from the surface mucosa into the preepiglottic space.

  • Hyoid: The hyoid bone is the most superior portion of the laryngeal skeleton and serves as the point of attachment for the strap muscles and suprahyoid musculature. The hypoglossal nerve and lingual artery run close laterally, requiring careful dissection in that area. The hyoid is rarely involved in laryngeal carcinoma.

  • Thyroid: The thyroid cartilage is shared between both the larynx and the pharynx. Although fenestrations are present in the laminae of the thyroid cartilage, they are not a route for the spread of laryngeal cancer.

  • Arytenoids: These cartilages rest upon the superior aspects of the posterior laminae of the cricoid cartilage. The cricoarytenoid unit includes an arytenoid cartilage, the adjacent cricoid cartilage, the ipsilateral superior and recurrent laryngeal nerve, the interarytenoid musculature, the ipsilateral lateral musculature, and the posterior cricoarytenoid musculature. This is the basic functional unit that allows for speech and swallow following organ preservation surgery of the larynx. Ossification of the cartilaginous framework is important to consider because cancer has an increased tendency to invade ossified structures rather than cartilage.

• Connective tissue barriers: Dye and radioisotope studies were initially used to delineate the location of barriers to the spread of cancer within the larynx. Whole organ section of the larynx demonstrated the intrinsic ligaments and broad sheaths of fibrous tissues that serve as barriers to cancer spread. Further studies demonstrated that while the intralaryngeal barriers may impede early cancer invasion, advanced lesions extend through the larynx without respecting these barriers.

  • Quadrangular membrane: This membrane sweeps down from the lateral borders of the epiglottis, forming a fibrous curtain of tissue within the mucosa of the aryepiglottic folds superiorly and the false cords inferiorly. At the inferior level of the false cord, a condensation of fibrous tissue extends from the thyroid cartilage to the arytenoid. This fibrous scaffold supports the aryepiglottic folds and false cords, separating the supraglottic endolaryngeal structures from the pyriform sinuses.

  • Conus elasticus: This membrane extends from the upper border of the cricoid cartilage to the vocal tendon, vocal process, and the inferior lateral portion of the arytenoid cartilage. The anterior condensation of the conus elasticus is the cricothyroid ligament, and the superior condensations bilaterally are the vocal ligaments.

  • Thyrohyoid membrane: The membrane extends from the hyoid to the thyroid cartilage. The superior laryngeal neurovascular pedicle passes through the lateral aspect of this membrane.

  • Anterior commissure tendon (Broyles ligament): The anterior condensation of the vocal tendons with the internal aspect of the thyroid cartilage meshes with the thyroepiglottic ligament. This area of the thyroid cartilage is devoid of perichondrium.

  • Hyoepiglottic ligament: This ligament extends from the epiglottis to the hyoid and serves as the roof of the paraglottic and preepiglottic spaces. The hypoepiglottic ligament serves as a formidable barrier to invasion from the supraglottis to the tongue base.

  • Cricothyroid ligament: This ligament is the anterior condensation of the conus elasticus connecting the cricoid and inferior border of the thyroid cartilage. Unlike the thyrohyoid membrane, the cricothyroid ligament is present only in the midline. Because the conus elasticus does not form a continuous layer between the thyroid and cricoid cartilages, no significant barrier exists to cancer extension beyond the larynx at that level.

• Laryngeal spaces

  • Preepiglottic space: This space is located in the supraglottis, anterior to the epiglottic cartilage, behind the thyrohyoid membrane superiorly, and between the supraglottic portions of the bilateral paraglottic spaces laterally. The space lies between the hyoid bone and the thyroid cartilage. Contents include fat, blood vessels, glands, and lymphatics.

  • Paraglottic space

    • This bilateral space extends from the upper border of the cricoid to the top of the aryepiglottic fold. In the supraglottis, the paraglottic space is bounded by the thyroid cartilage, the thyrohyoid membrane, and the quadrangular membrane. At the glottic level, this space is bounded by the conus elasticus, the thyroid cartilage, and the pyriform sinus mucosa. Inferolaterally, this space is continuous with a space between the thyroid cartilage and the cricoid cartilage. This point provides a route for extension of carcinoma beyond the larynx. Beyond this site, the cancer can invade the cricothyroid muscle and the ipsilateral thyroid lobe. Although the indentation of the ventricle and saccule shapes the paraglottic space in an hourglass fashion, no barrier prevents the spread of tumor. Cancer within this space has superior-inferior access to the larynx and to the thyroid cartilage.

    • Invasion of the paraglottic space is possible from any mucosal surface adjacent to the space. Fixation of the true cord from a glottic carcinoma indicates that the paraglottic space at the glottic level is involved by carcinoma. Additionally, supraglottic cancer causing a bulge in the ventricle and at the glottic level with decreased vocal cord mobility is evidence of extension to the cord level via the paraglottic space. Thus, clinical evaluation of vocal cord and arytenoid mobility separately is critical in the preoperative assessment of a laryngeal cancer.

    • The precise boundaries of the paraglottic and preepiglottic spaces are controversial. These spaces are not surrounded by specific anatomic boundaries and are continuous with one another at certain points. Additionally, depending upon the physician, the paraglottic space may include the intrinsic laryngeal musculature, the ventricle, the conus elasticus, and the quadrangular membrane or just the fat-filled space lateral to the laryngeal musculature and medial to the thyroid cartilage. Radiologists define the paraglottic space as only the lateral fat and not the musculature. In order to fully appreciate the spread of laryngeal carcinoma, the organ preservation surgeon needs to understand that the paraglottic space encompasses all of the above-mentioned structures.

  • Soft tissue adnexa

    • Laryngeal mucous glands: Carcinoma can spread along the seromucinous exocrine tubuloalveolar glands through the connective tissue barriers of the larynx. The glands serve as a conduit through the fenestrations of the epiglottis and into the preepiglottic space. Additionally, these glands also open beneath the anterior commissure, providing a route of carcinoma spread submucosally that may remain undetected.

    • Laryngeal microcirculation: Blood vessels may serve as a route of extension for carcinoma within the larynx.

    • Lymphatics: The lack of lymphatics at the level of the glottis may account for the lower incidence of lymph node metastases from glottic lesions. However, the supraglottis has a rich network of lymphatics and a correspondingly increased tendency to spread to cervical lymph nodes bilaterally. The subglottis is also rich in lymphatics and drains to the delphian (cricothyroid) and paratracheal nodes.

See Larynx Anatomy, Laryngeal Nerve Anatomy, and Vocal Cord and Voice Box Anatomy for more information.

Spread of carcinoma within the larynx

Ninety to 95% of primary malignant tumors of the larynx are squamous in origin. Connective tissue sheets and ligaments serve as relative barriers to the spread of early laryngeal lesions. Glottic cancer barriers include the vocal cords, conus elasticus, and the perichondrium of the thyroid cartilage. Transglottic and supraglottic cancer barriers include the thyrohyoid membranes, the hyoepiglottic ligament, and the hyoid bone. The hyoepiglottic ligament has been observed to be a resilient barrier for spread from supraglottis to tongue base as long as tumor has not already involved the suprahyoid epiglottis. The hyoid bone is rarely involved by laryngeal lesions and can be spared in resection of supraglottic carcinoma unless tumor is found at the level of the tongue or within the vallecula. Large advanced tumors invade the larynx without respecting any of these barriers.

Although supraglottic carcinoma was previously thought to not invade to the glottic level, more recent studies demonstrate that the ventricle acts more like a funnel than a true barrier to the spread of cancer. Twenty to 54% of all cases demonstrated spread of supraglottic carcinoma to the glottis. Clear margins cannot be achieved with SGL in cases with glottic extension, but oncologic resection is possible with SCPL-CHP.

Within the subglottis, no barriers to the spread of cancer exist. Extensive subglottic lesions grow circumferentially and extend submucosally to the undersurface of the vocal cords and the trachea. They may also invade the cricoid cartilage and may extend beyond the larynx at the level of the cricothyroid membrane to invade the thyroid gland.

Weak points for the spread of laryngeal cancer are as follows:

• The area of attachment of the anterior commissure tendon to the thyroid cartilage has no perichondrium, providing carcinoma direct access to the cartilage.

• The tubuloalveolar glands of the subglottis and the anterior floor of the ventricle serve as a route of cancer spread inferiorly beneath the mucosa and anteriorly to the thyroid cartilage.

• The Broyles tendon may be ruptured in patients with infrahyoid carcinoma, leading to early invasion of the preepiglottic space.

• Numerous fenestrations within the infrahyoid epiglottis provide a route for early invasion of the preepiglottic space via blood vessels and gland ducts.

• Areas of ossification at the anterior commissure and the posterior border of the thyroid ala of the thyroid cartilage provide a route for cancer spread.

• Points of attachment of the cricothyroid ligament and the anterior origin of the thyroarytenoid musculature provide a route for cancer spread.

The main contraindication for supracricoid partial laryngectomy-cricohyoidoepiglottopexy (SCPL-CHEP) and supracricoid partial laryngectomy-cricohyoidopexy (SCPL-CHP) is preoperative evidence of severe respiratory impairment. Patients with pulmonary disease do not have sufficient pulmonary reserve to tolerate the increased aspiration that occurs in the immediate postoperative period.

Oncologic contraindications for SCPL-CHEP

See the list below:

• Tumors originating (epicenter) in the anterior commissure or ventricle, which have a propensity for early invasion of the preepiglottic space (may be resected with SCPL-CHP)

• Tumors of the glottis with ipsilateral fixation of the arytenoid cartilage (high risk of involvement of the cricoid or cricoarytenoid joint)

• Tumors of the glottis with subglottic extent reaching the upper border of the cricoid cartilage or invading the cricoid cartilage

• Tumors of the glottis invading the posterior commissure

• Tumors of the glottis invading the outer perichondrium of the thyroid cartilage or manifesting with extralaryngeal spread of tumor

Oncologic contraindications for SCPL-CHP

See the list below:

• Arytenoid cartilage fixation

• Infraglottic extension of tumor more than 10 mm anteriorly (cricothyroid membrane), more than 5 mm posterolaterally, or reaching the superior border of the cricoid cartilage

• Major preepiglottic space invasion with clinical evidence of bulging beneath the vallecula mucosa and/or extension through the thyrohyoid membranes

• Tumor abutting the hyoid bone, requiring resection of this structure

• Cricoid cartilage invasion

• Involvement of the pharynx or interarytenoid fixation

• External thyroid cartilage perichondrial invasion and extralaryngeal spread of tumor