Impact of structures resected and extent of resection on swallow function

The impact of resection of the oral tongue on swallowing function has been well reported in the literature. Patients who have a portion of the oral tongue removed exhibit worsened swallow function characterized by prolonged oral preparatory time , slowed oral transit time , increased oral residue , and increased pharyngeal residue . Oral-stage swallowing disorders tend to worsen for these patients as bolus viscosity increases . As the extent of resection of the oral tongue increases, swallowing function also worsens . Patients who have resection of the oral tongue demonstrate increased oral transit time and increased oral and pharyngeal residue as the extent of resection increases . The increased bolus residue is at greater risk of being aspirated after the swallow in patients who undergo a total glossectomy.

Patients who have resection of the tongue base may experience severe impairment of swallow function . Those who have resections of the tongue base have increased oral preparatory time, increased oral transit time, increased oral residue, along with increased pharyngeal transit time , increased pharyngeal residue, and reduced oropharyngeal swallow efficiency . Resection of greater than 25% of the tongue base is associated with inability to trigger a pharyngeal swallow, difficulty clearing the bolus from the pharynx, and severe postsurgical aspiration . Swallowing disorders tend to worsen for these patients as bolus viscosity increases .

Surgical excision of oropharyngeal structures that do not contribute to normal swallowing function have little impact on swallow in the postsurgical patient . Resection of the floor of mouth has been found to have limited impact on swallowing function , except when the resection extends to the geniohyoid or mylohyoid muscles . With resection of the floor-of-mouth muscles, patients may experience problems with hyolaryngeal elevation, resulting in residue in the pyriform sinuses that may be aspirated after the swallow.

Some tumors may infiltrate the alveolar ridge and mandible, requiring resection for disease control. A rim or marginal resection of the mandible may be all that is required when tumor invasion is limited to the alveolar ridge. A marginal resection does not disrupt the continuity of the mandibular arch and has little impact on swallowing function. More invasive tumors require segmental mandibular resection, that is, removal of a section of the mandible that separates the remaining mandible bone into two sections. Although some investigators have found that the resected mandible is not functionally different from the intact mandible , more research indicates that segmental mandibular resection without reconstruction has a profound negative impact on oropharyngeal swallow efficiency, oral residue , and mastication .

Nature of reconstruction

The swallow function of postsurgical cancer patients may also be influenced by the type of surgical reconstruction. Surgical closure or reconstruction after ablation of head and neck tumors falls into four general categories: (1) primary closure (approximation and surgical closure of the edges of the resection); (2) skin grafts (transplantation of a superficial layer of skin from another site such as the thigh into the surgical resection); (3) pedicled flaps (flaps of tissue lifted from a donor site and migrated into the surgical defect, with a pedicle or stem of tissue attached to the donor site to maintain the blood supply); and (4) microvascular free flaps (flaps of tissue lifted from a donor site and sutured into the surgical defect with the blood vessels and sometimes nerves anastomosed to the existing supply at the excision site).

Some research indicates that patients closed primarily or with skin grafts have better postsurgical swallowing function than those reconstructed with pedicled or free flaps. . The use of primary closure, however, may result in some restriction in tongue movement when a large amount of the tongue is resected or when the tongue is sutured to the floor of mouth or alveolar ridge after a composite resection. Some patients reconstructed with skin grafts demonstrate superior tongue mobility compared with those closed primarily . Skin grafts are often not viable in the oropharynx, however, especially when the patient received radiotherapy, which may disrupt the blood supply to the area.

Patients reconstructed with pedicled flaps, such as the pectoralis major myocutaneous flap, have been shown to demonstrate impaired tongue mobility scores , excessively long oral transit times, increased oral residue after the swallow , and reduced oropharyngeal swallow efficiency . Pedicled flap reconstruction is often used in the head and neck population to close a large surgical defect . These flaps are often considered to be bulky, which may interfere with movement of the remaining oral tissues . Swallow impairment in patients reconstructed with pedicled flaps may also be related to the adynamic nature of the flap: use of this type of flap introduces tissue that has no sensation or motor control into an area in which range, rate, and coordination are critical to normal swallow function .

Microvascular free flaps such as the radial forearm free flap have the advantage of being thin yet viable flaps that can be used to repair a surgical defect without adding excessive bulk to the oropharyngeal structures. This type of flap is flexible enough to permit lining of the floor of mouth without tethering the tongue. Adequate flap design permits the appropriate degree of closure without sacrificing tongue movement . Some comparative studies have indicated no difference in swallow function after reconstruction with a radial forearm free flap or a pedicled pectoralis major flap , whereas others have shown that the ability to swallow in patients reconstructed with free flaps is superior to that of patients reconstructed with pectoralis major myocutaneous pedicled flaps . Nevertheless, swallow function is still impaired after resection and free flap reconstruction. Some studies have indicated worse levels of oropharyngeal functioning in patients who have free flap reconstruction compared with primary closure . In addition, oropharyngeal swallow efficiency has been shown to be severely reduced, and pharyngeal transit time and excessive oral and pharyngeal residues increased, in patients reconstructed with free flaps , with no recovery of preoperative function by 1-year posttreatment .

Sensate flaps are microvascular free flaps that have not only their blood supply but also their innervation joined to the remaining supplies at the surgical resection site. Few objective swallow data are available for sensate flaps; some data indicate swallowing function is superior in patients who have a reinnervated flap , whereas other research does not indicate the superiority of sensate flaps over nonsensate mirovascular free flaps in improving swallow function , oropharyngeal swallow efficiency , or oral sensation .

Reconstruction of the mandible after segmental mandibular resection can be achieved using microvascular free flaps containing bone. Reports of functional outcome after mandibular reconstruction are mixed. Some studies have demonstrated a clear advantage for patients who have mandibular reconstruction in most oropharyngeal functions , whereas others have indicated that reconstruction of mandibular continuity does not contribute to improved swallow function .

Assessing the relative impact of the various surgical closure procedures on swallowing function can be difficult because of the profound impact of extent of resection on swallow function. In addition, not all closures may be used with all resections. In the one study that controlled for extent of resection of the oral tongue and tongue base, no significant differences were observed on swallow function between those reconstructed with pedicled and microvascular free flaps. Those closed primarily or with skin grafts had higher oropharyngeal swallow efficiencies and less pharyngeal residue than those reconstructed with flaps .

Supraglottic laryngectomy

For lesions involving the epiglottis, aryepiglottic folds, or false vocal folds with no involvement of the vocal folds, a supraglottic laryngectomy is the standard surgical intervention. A supraglottic laryngectomy, also referred to as a horizontal partial laryngectomy, includes resection of the epiglottis, aryepiglottic folds, false vocal folds, and the superior aspect of the thyroid cartilage, sparing the true vocal folds and arytenoids . Preservation of the hyoid bone, when possible, may help swallowing function postoperatively . Classically, supraglottic surgery also included removal of the hyoid bone . Some of these patients may present with swallow difficulties decades later, especially if they had received postoperative radiotherapy , so it is possible that clinicians currently practicing may come in contact with patients who underwent supraglottic laryngectomy and do not have a hyoid bone. Because structures involved in the protective mechanism of the airway are resected, patients who have received a supraglottic laryngectomy are at risk for aspiration during the swallow . Rates of aspiration during the swallow as high as 74% have been reported . The base of tongue and arytenoid cartilages play an important role in compensating for the supragottic structures resected in the surgery . Patients who are able to achieve good contact between the tongue base and the arytenoid after supraglottic laryngectomy are able to prevent material from entering the airway during the swallow . When the supraglottic laryngectomy procedure needs to be extended into the tongue base or to the arytenoid, this potential compensatory mechanism is compromised, and aspiration during the swallow is the likely consequence . Patients who have extended supraglottic laryngectomy, especially into the base of tongue, demonstrate increased pulmonary complications due to aspiration and take significantly longer to achieve preoperative diet and normal swallowing than those who have limited resections .

Tumors limited to a true vocal fold may be treated with a hemilaryngectomy, also referred to as vertical partial laryngectomy. This resection includes one false vocal fold, one ventricle, and one true vocal fold, excluding the arytenoids but usually taking the vocal process and a portion of the thyroid cartilage on the same side as the lesion . Because the hyoid bone, epiglottis, and arytenoids are left in place, a patient receiving a standard hemilaryngectomy should not have difficulty with airway closure when properly reconstructed with bulk tissue on the operated side . Various techniques exist for creating a pseudocord from pedicled and free flaps ; the goal of reconstruction is to provide enough bulk to allow the remaining vocal cord to make contact with the reconstructed site and permit protection of the airway . Patients who undergo a hemilaryngectomy usually have fewer incidents of aspiration and achieve oral intake and return to a normal diet sooner than those who have had any type of supraglottic laryngectomy . When the resection is extended posteriorly to include the arytenoid cartilage, however, an important component of airway closure is affected, and the risk of aspiration during the swallow increases . Aspiration rates of up to 91% during the swallow have been reported .

Total laryngectomy

Total laryngectomy may be used as the primary treatment in cases of advanced laryngeal carcinoma. Generally, aspiration is not a risk for those who have received a total laryngectomy unless there is leakage around or though a tracheoesophageal fistula that is created for voice restoration or that results from healing complications . In addition, patients who have received a total laryngectomy may experience other difficulties with their swallow. Manometric studies of patients who have total laryngectomy have indicated that the postlaryngectomy swallow is characterized by significantly lower resting pressures in the pharyngoesophageal segment, lower peak pressures after swallow, greater numbers of swallows with discoordination between contraction of the pharyngeal constrictors and relaxation of the pharyngoesophageal segment , a loss of the normal negative pressure preceding the bolus, reduced pharyngeal clearing force , and loss of asymmetric contractile forces compared with subjects who have normal anatomy. Bolus clearance through the oral cavity and pharyngocervical esophagus is often impaired in this group of patients , especially when resection is extended to the tongue base.

At the present time, total laryngectomy is used most often as a salvage procedure—after recurrence or in the case of intractable aspiration . The incidence of pharyngocutaneous fistula formation is higher after salvage laryngectomy than primary laryngectomy, especially in irradiated patients . Completion laryngectomy for patients treated with chemoradiation who experience intractable aspiration may not result in improved swallow function. Patients who have total laryngectomy must typically generate pressures greater than normal during the swallow to achieve bolus transit . Adequate tongue-base motion is important in this pressure generation. Patients who have received chemoradiation to the head and neck often experience reduced tongue-base retraction, as is discussed in the following section. Completion laryngectomy may eliminate aspiration in these patients, but they may not be able to advance their diet beyond pureed consistencies if they are unable to produce sufficient bolus driving pressure .

Impact of structures resected and extent of resection on swallow function

The impact of resection of the oral tongue on swallowing function has been well reported in the literature. Patients who have a portion of the oral tongue removed exhibit worsened swallow function characterized by prolonged oral preparatory time , slowed oral transit time , increased oral residue , and increased pharyngeal residue . Oral-stage swallowing disorders tend to worsen for these patients as bolus viscosity increases . As the extent of resection of the oral tongue increases, swallowing function also worsens . Patients who have resection of the oral tongue demonstrate increased oral transit time and increased oral and pharyngeal residue as the extent of resection increases . The increased bolus residue is at greater risk of being aspirated after the swallow in patients who undergo a total glossectomy.

Patients who have resection of the tongue base may experience severe impairment of swallow function . Those who have resections of the tongue base have increased oral preparatory time, increased oral transit time, increased oral residue, along with increased pharyngeal transit time , increased pharyngeal residue, and reduced oropharyngeal swallow efficiency . Resection of greater than 25% of the tongue base is associated with inability to trigger a pharyngeal swallow, difficulty clearing the bolus from the pharynx, and severe postsurgical aspiration . Swallowing disorders tend to worsen for these patients as bolus viscosity increases .

Surgical excision of oropharyngeal structures that do not contribute to normal swallowing function have little impact on swallow in the postsurgical patient . Resection of the floor of mouth has been found to have limited impact on swallowing function , except when the resection extends to the geniohyoid or mylohyoid muscles . With resection of the floor-of-mouth muscles, patients may experience problems with hyolaryngeal elevation, resulting in residue in the pyriform sinuses that may be aspirated after the swallow.

Some tumors may infiltrate the alveolar ridge and mandible, requiring resection for disease control. A rim or marginal resection of the mandible may be all that is required when tumor invasion is limited to the alveolar ridge. A marginal resection does not disrupt the continuity of the mandibular arch and has little impact on swallowing function. More invasive tumors require segmental mandibular resection, that is, removal of a section of the mandible that separates the remaining mandible bone into two sections. Although some investigators have found that the resected mandible is not functionally different from the intact mandible , more research indicates that segmental mandibular resection without reconstruction has a profound negative impact on oropharyngeal swallow efficiency, oral residue , and mastication .

Nature of reconstruction

The swallow function of postsurgical cancer patients may also be influenced by the type of surgical reconstruction. Surgical closure or reconstruction after ablation of head and neck tumors falls into four general categories: (1) primary closure (approximation and surgical closure of the edges of the resection); (2) skin grafts (transplantation of a superficial layer of skin from another site such as the thigh into the surgical resection); (3) pedicled flaps (flaps of tissue lifted from a donor site and migrated into the surgical defect, with a pedicle or stem of tissue attached to the donor site to maintain the blood supply); and (4) microvascular free flaps (flaps of tissue lifted from a donor site and sutured into the surgical defect with the blood vessels and sometimes nerves anastomosed to the existing supply at the excision site).

Some research indicates that patients closed primarily or with skin grafts have better postsurgical swallowing function than those reconstructed with pedicled or free flaps. . The use of primary closure, however, may result in some restriction in tongue movement when a large amount of the tongue is resected or when the tongue is sutured to the floor of mouth or alveolar ridge after a composite resection. Some patients reconstructed with skin grafts demonstrate superior tongue mobility compared with those closed primarily . Skin grafts are often not viable in the oropharynx, however, especially when the patient received radiotherapy, which may disrupt the blood supply to the area.

Patients reconstructed with pedicled flaps, such as the pectoralis major myocutaneous flap, have been shown to demonstrate impaired tongue mobility scores , excessively long oral transit times, increased oral residue after the swallow , and reduced oropharyngeal swallow efficiency . Pedicled flap reconstruction is often used in the head and neck population to close a large surgical defect . These flaps are often considered to be bulky, which may interfere with movement of the remaining oral tissues . Swallow impairment in patients reconstructed with pedicled flaps may also be related to the adynamic nature of the flap: use of this type of flap introduces tissue that has no sensation or motor control into an area in which range, rate, and coordination are critical to normal swallow function .

Microvascular free flaps such as the radial forearm free flap have the advantage of being thin yet viable flaps that can be used to repair a surgical defect without adding excessive bulk to the oropharyngeal structures. This type of flap is flexible enough to permit lining of the floor of mouth without tethering the tongue. Adequate flap design permits the appropriate degree of closure without sacrificing tongue movement . Some comparative studies have indicated no difference in swallow function after reconstruction with a radial forearm free flap or a pedicled pectoralis major flap , whereas others have shown that the ability to swallow in patients reconstructed with free flaps is superior to that of patients reconstructed with pectoralis major myocutaneous pedicled flaps . Nevertheless, swallow function is still impaired after resection and free flap reconstruction. Some studies have indicated worse levels of oropharyngeal functioning in patients who have free flap reconstruction compared with primary closure . In addition, oropharyngeal swallow efficiency has been shown to be severely reduced, and pharyngeal transit time and excessive oral and pharyngeal residues increased, in patients reconstructed with free flaps , with no recovery of preoperative function by 1-year posttreatment .

Sensate flaps are microvascular free flaps that have not only their blood supply but also their innervation joined to the remaining supplies at the surgical resection site. Few objective swallow data are available for sensate flaps; some data indicate swallowing function is superior in patients who have a reinnervated flap , whereas other research does not indicate the superiority of sensate flaps over nonsensate mirovascular free flaps in improving swallow function , oropharyngeal swallow efficiency , or oral sensation .

Reconstruction of the mandible after segmental mandibular resection can be achieved using microvascular free flaps containing bone. Reports of functional outcome after mandibular reconstruction are mixed. Some studies have demonstrated a clear advantage for patients who have mandibular reconstruction in most oropharyngeal functions , whereas others have indicated that reconstruction of mandibular continuity does not contribute to improved swallow function .

Assessing the relative impact of the various surgical closure procedures on swallowing function can be difficult because of the profound impact of extent of resection on swallow function. In addition, not all closures may be used with all resections. In the one study that controlled for extent of resection of the oral tongue and tongue base, no significant differences were observed on swallow function between those reconstructed with pedicled and microvascular free flaps. Those closed primarily or with skin grafts had higher oropharyngeal swallow efficiencies and less pharyngeal residue than those reconstructed with flaps .

Supraglottic laryngectomy

For lesions involving the epiglottis, aryepiglottic folds, or false vocal folds with no involvement of the vocal folds, a supraglottic laryngectomy is the standard surgical intervention. A supraglottic laryngectomy, also referred to as a horizontal partial laryngectomy, includes resection of the epiglottis, aryepiglottic folds, false vocal folds, and the superior aspect of the thyroid cartilage, sparing the true vocal folds and arytenoids . Preservation of the hyoid bone, when possible, may help swallowing function postoperatively . Classically, supraglottic surgery also included removal of the hyoid bone . Some of these patients may present with swallow difficulties decades later, especially if they had received postoperative radiotherapy , so it is possible that clinicians currently practicing may come in contact with patients who underwent supraglottic laryngectomy and do not have a hyoid bone. Because structures involved in the protective mechanism of the airway are resected, patients who have received a supraglottic laryngectomy are at risk for aspiration during the swallow . Rates of aspiration during the swallow as high as 74% have been reported . The base of tongue and arytenoid cartilages play an important role in compensating for the supragottic structures resected in the surgery . Patients who are able to achieve good contact between the tongue base and the arytenoid after supraglottic laryngectomy are able to prevent material from entering the airway during the swallow . When the supraglottic laryngectomy procedure needs to be extended into the tongue base or to the arytenoid, this potential compensatory mechanism is compromised, and aspiration during the swallow is the likely consequence . Patients who have extended supraglottic laryngectomy, especially into the base of tongue, demonstrate increased pulmonary complications due to aspiration and take significantly longer to achieve preoperative diet and normal swallowing than those who have limited resections .

Tumors limited to a true vocal fold may be treated with a hemilaryngectomy, also referred to as vertical partial laryngectomy. This resection includes one false vocal fold, one ventricle, and one true vocal fold, excluding the arytenoids but usually taking the vocal process and a portion of the thyroid cartilage on the same side as the lesion . Because the hyoid bone, epiglottis, and arytenoids are left in place, a patient receiving a standard hemilaryngectomy should not have difficulty with airway closure when properly reconstructed with bulk tissue on the operated side . Various techniques exist for creating a pseudocord from pedicled and free flaps ; the goal of reconstruction is to provide enough bulk to allow the remaining vocal cord to make contact with the reconstructed site and permit protection of the airway . Patients who undergo a hemilaryngectomy usually have fewer incidents of aspiration and achieve oral intake and return to a normal diet sooner than those who have had any type of supraglottic laryngectomy . When the resection is extended posteriorly to include the arytenoid cartilage, however, an important component of airway closure is affected, and the risk of aspiration during the swallow increases . Aspiration rates of up to 91% during the swallow have been reported .

Total laryngectomy

Total laryngectomy may be used as the primary treatment in cases of advanced laryngeal carcinoma. Generally, aspiration is not a risk for those who have received a total laryngectomy unless there is leakage around or though a tracheoesophageal fistula that is created for voice restoration or that results from healing complications . In addition, patients who have received a total laryngectomy may experience other difficulties with their swallow. Manometric studies of patients who have total laryngectomy have indicated that the postlaryngectomy swallow is characterized by significantly lower resting pressures in the pharyngoesophageal segment, lower peak pressures after swallow, greater numbers of swallows with discoordination between contraction of the pharyngeal constrictors and relaxation of the pharyngoesophageal segment , a loss of the normal negative pressure preceding the bolus, reduced pharyngeal clearing force , and loss of asymmetric contractile forces compared with subjects who have normal anatomy. Bolus clearance through the oral cavity and pharyngocervical esophagus is often impaired in this group of patients , especially when resection is extended to the tongue base.

At the present time, total laryngectomy is used most often as a salvage procedure—after recurrence or in the case of intractable aspiration . The incidence of pharyngocutaneous fistula formation is higher after salvage laryngectomy than primary laryngectomy, especially in irradiated patients . Completion laryngectomy for patients treated with chemoradiation who experience intractable aspiration may not result in improved swallow function. Patients who have total laryngectomy must typically generate pressures greater than normal during the swallow to achieve bolus transit . Adequate tongue-base motion is important in this pressure generation. Patients who have received chemoradiation to the head and neck often experience reduced tongue-base retraction, as is discussed in the following section. Completion laryngectomy may eliminate aspiration in these patients, but they may not be able to advance their diet beyond pureed consistencies if they are unable to produce sufficient bolus driving pressure .

Reduced salivary flow and xerostomia

Radiation for cancers of the head and neck often includes the salivary glands in the treatment volume; damage to the salivary glands results in significantly reduced salivary flow . The parotid gland is especially sensitive to the effects of radiotherapy; radiation doses in excess of 55 Gy to 64 Gy appear to result in permanent damage with no anticipated long-term recovery of salivary function . Studies of saliva flow after treatments designed to reduce the dose to the parotid gland indicate that with doses below 24 Gy to 26 Gy, saliva flow is preserved and will increase toward pretreatment levels over the first year. Glands receiving a mean dose higher than the threshold produce little saliva, with no recovery over time .

The relationships among reduced salivary flow, xerostomia (or the perception of dry mouth), and swallow function are not clear. Although patients who have significantly reduced saliva production after radiotherapy also have increased reports of perceived difficulty swallowing, dry mouth, needing water while eating, food sticking in the mouth or throat, and changes in taste , patients who have objective improvement in salivary flow over time may still complain of xerostomia . Reduced saliva weight does not correlate with slowed or inefficient swallow. Instead, reduced saliva weight seems to change the patient’s perception of swallowing ability and, on that basis, affects diet choices .

Mucositis

Mucositis is a frequent and severe consequence of radiotherapy to the head and neck . Oral mucositis is defined as an injury to the oral mucosa characterized by erythema (redness) and ulcerative lesions . Mucositis is limited to the tissues in the field of radiation, with nonkeratinized tissues such as buccal and labial mucosa, ventral and lateral surfaces of the tongue, floor of mouth, and soft palate affected more often than other tissues . Mucositis also may affect other sites along the digestive tract as a result of high-dose chemotherapy .

Nearly all patients receiving conventional (once daily) radiotherapy (97%) or chemoradiotherapy (90%) experience mucositis. It is reported that 100% of patients who receive altered fractionation (twice-daily treatments) have mucositis, with more than half experiencing the highest grades (worst level) of this toxicity . The severity of oral mucositis is directly proportional to the dose of radiation administered to the head and neck . The first mucosal reaction can be observed as a white discoloration after a cumulative radiation dose of 10 Gy to 20 Gy. Deepening erythema is usually visible after 20 Gy of cumulative radiation, and ulcerations, often covered with a pseudomembranous layer, develop after about 30 Gy, usually occurring after 3 weeks of conventional radiotherapy. After completion of radiotherapy, mucositis generally declines after 2 to 6 weeks .

Pain is a common side effect of mucositis; the ulcerative stage is especially painful . Ulceration of the oral mucosa and the resulting pain can impair a patient’s ability to swallow and eat . In the few studies that report dietary-related outcomes, there is a high and significant correlation between severity of mucositis and the incidence of gastrostomy tube feeding and weight loss .

Any irritants to the oral mucosa such as spicy foods or alcohol should be avoided while mucositis is present. There is great need for education of the patient and family on proper oral care during mucositis . The dysphagia rehabilitation specialist (commonly a speech-language pathologist) can play an important role in reinforcing oral care procedures with the patient suffering from mucositis.

Stricture

Stricture, a segment of narrowing or complete closure in the pharynx or esophagus, occurs at reported rates of 8% to 24% after chemoradiation and has a profound impact on swallowing function by limiting or blocking the passage of food or liquid . The average time after treatment completion to diagnosis is 6 to 7 months. Strictures rarely develop until the radiation dose to the hypopharynx or esophagus exceeds 60 Gy to 70 Gy , so the proximal esophagus is another organ to consider sparing with IMRT techniques.

The hypothesized pathophysiology of stricture formation begins with ulceration after severe mucositis, along with a relatively immobile larynx secondary to radiation-induced fibrosis and the lack of passage of food or liquid through lumen possibly due to use of gastrostomy tubes. These conditions lead to healing of the opposing anterior and posterior mucosal surfaces, resulting in adhesions that lead to narrowing and possible obstruction . The hypopharynx is especially susceptible to stricture formation because of the close proximity of the mucosal membranes in the posterior cricoid area and posterior pharyngeal wall .

It has been suggested that use of gastrostomy tubes may contribute to the development of strictures . Patients who have gastrostomy tubes may be at increased risk of stricture formation because of the relative inactivity of the upper esophageal/hypopharyngeal musculature. Those who have gastrostomy tubes are likely to cease all efforts at passage of food or liquid, especially when suffering from mucositis. Therefore, formation of stricture may not be related to radiation dose but to whether the patient swallowed during the course of treatment, resulting in less significant muscular fibrosis in the treated area compared with those patients who did not swallow routinely throughout the course of treatment . Lack of swallowing may result in atrophy of hypopharyngeal muscles. Patients undergoing chemoradiation should be strongly encouraged to swallow orally even if they have gastrostomy tubes or other supplemental feeding tubes in place. The use of the swallow mechanism should limit adhesion formation and disuse atrophy of pharyngeal muscles .

Chin-down

The chin-down posture (also referred to as chin tuck or neck flexion) is useful for patients who have a delayed pharyngeal swallow, reduced tongue-base retraction, or reduced laryngeal elevation. The patient is instructed to touch the chin to the neck while swallowing. This action pushes the anterior pharyngeal wall posteriorly and the tongue base and epiglottis closer to the posterior pharyngeal wall, thereby narrowing the airway entrance. This posterior shift with the chin-down posture improves airway protection, so it is useful for patients who have reduced laryngeal elevation or laryngeal vestibule closure. The vallecular space is also widened, giving a potentially larger place for the bolus to set before the pharyngeal swallow is initiated .

The chin-down posture, alone or combined with other postures or maneuvers such as head rotation, head-back to chin-down movement, or voluntary airway protection (to be discussed later) has been reported as successful in eliminating aspiration in 72% of patients who have various medical diagnoses ; success with postsurgical head and neck cancer patients ranges from 50% in patients who have tongue-base resection to 81% in esophagectomy patients and 90% in patients who have oral or laryngeal resections . The chin-down posture has been shown to significantly reduce depth of bolus penetration into the larynx and trachea . Patients prefer the simple chin-down posture technique to other interventions such as thickening liquids , and most find it easy to perform correctly .

Head back

The head-back posture uses gravity to clear the bolus from the oral cavity in patients who have difficulty with oral transit of the bolus . When there is a question about adequate airway protection, the patient may be instructed in various voluntary airway protection maneuvers (discussed later). In appropriately selected patients, the head-back posture has been shown to be 100% effective in transporting the bolus out of the oral cavity and into the pharynx .

Head rotation

Head rotation toward the weak or damaged side of the pharynx or larynx closes the damaged side so that the bolus flows down the side that is more nearly normal. This posture is useful for patients who have unilateral pharyngeal wall impairment or unilateral vocal fold weakness. Head rotation to the weaker side causes the bolus to lateralize away from the direction of rotation and increases upper esophageal sphincter (UES) opening diameter while causing a significant reduction in UES pressure . During head rotation, compensatory movement of the arytenoid on the healthy side has been observed on videofluoroscopy . Serial CT of the pharynx in a patient who had lateral medullary syndrome using head rotation indicated that hemipharyngeal closing occurs at the level of the hyoid bone and in the hypopharyngeal cavity above the pyriform sinus .

Head rotation performed alone or in combination with other postures or maneuvers is effective in reducing aspiration in postsurgical head and neck cancer patients 71% of the time . Because head rotation may cause compensatory movement of the arytenoid on the healthy side , this posture may be effective in patients who have undergone hemilarygectomy and who have difficulty achieving closure of the remaining vocal fold against the reconstructed pseudocord. In addition, because UES opening diameter is increased and resting pressure is decreased during head rotation, patients who have cricopharyngeal dysmotility problems may also benefit from the posture.

Lateral head-tilt

The lateral head-tilt posture may be used for a patient who has unilateral oral and pharyngeal impairment on the same side. The patient tilts the head to the stronger side so that gravity drains the bolus along the stronger side and avoids the weaker side . There are no reports in the literature on the efficacy of this posture in the head and neck population, but the clinician may find it useful to try this procedure in patients who have unilateral impairment.

Supraglottic and supersupraglottic swallow maneuvers

The goal of the supraglottic and supersupraglottic swallow maneuvers, also referred to as voluntary airway closure techniques, is to close the vocal folds before and during the swallow to prevent aspiration . For the supraglottic swallow, the patient is instructed to take a deep breath and hold it, swallow while continuing to hold the breath, and cough immediately after the swallow to expel any residue from the airway entrance. The supersupraglottic swallow is designed to close the entrance to the airway voluntarily by tilting the arytenoid cartilage anteriorly to contact the base of the epiglottis before and during the swallow and by closing the false vocal folds tightly. The patient is instructed to inhale and hold his or her breath very tightly, bearing down. The patient should keep holding his or her breath and bearing down while swallowing, and then cough when finished. Videofluoroscopic and videoendoscopic evaluations have demonstrated that airway closure duration is prolonged during the supraglottic and supersupraglottic swallow maneuvers in normal subjects and in treated head and neck cancer patients . Normal subjects also experience earlier cricopharyngeal opening, prolonged pharyngeal swallow, some degree of laryngeal valving before swallow, and change in extent of vertical laryngeal position before swallow. These changes in swallow physiology are more pronounced with the supersupraglottic swallow .

The supraglottic swallow was originally conceptualized for use with patients who underwent supraglottic laryngectomy, to improve the ability to protect the airway and prevent aspiration during the swallow . Endoscopic studies have demonstrated that true cord closure may not always be achieved during the supraglottic swallow, so the airway may not be protected in all patients using this procedure. The supersupraglottic swallow, however, provides an additional level of airway protection by tilting the arytenoid cartilages anteriorly to contact the base of the epiglottis (or tongue base if the epiglottis has been resected) . The supersupraglottic swallow also influences aspects of the swallow other than airway protection. In irradiated head and neck cancer patients, the supersupraglottic swallow not only closes the airway entrance earlier than without the maneuver but also results in improved tongue-base motion , greater hyoid and laryngeal elevation at the time of cricopharyngeal opening, and increased maximal hyoid and laryngeal elevation . These results suggest that the supersupraglottic swallow not only improves airway closure at the entrance but also improves tongue-base movement and the speed and extent of hyolaryngeal movement, especially early in the swallow.

Based on the observed effects of the supersupraglottic swallow on oropharyngeal biomechanics, this technique is useful for patients who have reduced laryngeal airway closure and for those who have reduced tongue-base retraction and reduced laryngeal elevation. It has been shown to be effective in eliminating aspiration in patients who have undergone supraglottic laryngectomy and in those treated with a full course of radiotherapy to the head and neck .

Effortful swallow maneuver

The effortful swallow is designed to increase tongue-base retraction and pharyngeal pressure during the swallow to improve bolus clearance from the valleculae . The patient is instructed to squeeze hard with all their muscles as they swallow.

The effortful swallow is believed to increase pharyngeal pressures, thus pushing the bolus through the pharynx and cricopharyngeous, leaving less residue in the pharynx after the swallow. Studies designed to measure oral, pharyngeal, and esophageal pressures during the effortful swallow maneuver provide conflicting information concerning the pressures generated with the procedure.

Effortful swallows performed by healthy normal adults are characterized by significantly higher oral pressures; diminished oral residue; longer laryngeal vestibule closure, hyoid excursion, and extent of hyoid elevation ; and longer pharyngeal pressure duration and UES relaxation duration . The effortful swallow also has an effect on the esophageal phase of swallow, with significantly increased peristaltic amplitudes within the distal smooth muscle region of the esophagus, possibly as a result of overflow effort from the maneuver .

There are limited data on the effortful swallow in patient populations. In patients who have pharyngeal dysfunction, the effortful swallow does not alter peak amplitude or duration of the intrabolus pressure ; however, the use of the effortful swallow in these patients significantly reduces depth of contrast penetration into the larynx and trachea. Although there is no impact on pharyngeal residue, the hyoid is held in a more superior position before onset of the swallow . In treated head and neck cancer patients, the effortful swallow is associated with higher pharyngeal pressure amplitudes and longer pressure durations than are observed with swallows using no maneuver; compared with other maneuvers, the effortful swallow produces the highest pharyngeal pressure and results in slightly less pharyngeal residue .

Although the effortful swallow was conceived to increase pharyngeal pressure during the swallow to improve bolus clearance from the vallecula, data indicate that the maneuver also has an impact on other aspects of the oral and pharyngeal stages of the swallow. Therefore, the effortful swallow may be appropriate to use in treated head and neck cancer patients who demonstrate reduced tongue strength, reduced pharyngeal contraction, reduced laryngeal elevation, reduced laryngeal vestibule closure, and cricopharyngeal dysmotility.

Mendelsohn maneuver

The Mendelsohn maneuver is a voluntary prolongation of laryngeal excursion at the midpoint of the swallow intended to increase the extent and duration of laryngeal elevation and thereby increase the duration of cricopharyngeal opening . Patients are instructed to swallow normally, and when they feel their voice box go up, to grab it with the throat muscles and not let it go down. Patients are instructed to hold it for three counts and then let it go. This maneuver can be practiced without food, and then food may be introduced with the maneuver after the patient has learned to perform it correctly.

Videomanometric data confirm that use of the Mendelsohn maneuver in healthy adults results in increased peak pharyngeal contraction and duration and increased duration of anterior and superior excursion of the larynx and hyoid (and consequently prolonged cricopharyngeal opening) by maintaining traction on the anterior sphincter wall . Significantly longer bolus transit times also occur, as would be expected when the subject is instructed to prolong laryngeal elevation.

In treated head and neck cancer patients, swallows performed with the Mendelsohn maneuver have been shown to exhibit higher tongue-base pressure amplitudes, longer pressure durations, and less pharyngeal residue compared with swallows with no maneuver . Use of the Mendelsohn maneuver can improve coordination and timing of pharyngeal swallow events, including timing of posterior movement of the tongue base to the pharyngeal wall in relation to airway closure and cricopharyngeal opening, with elimination of aspiration .

Prolonged cricopharyngeal opening times associated with the Mendelsohn maneuver may allow passage of a larger amount of the bolus into the esophagus. The improvement in laryngeal elevation may also reduce residue in the pyriform sinus after the swallow. Increased duration and magnitude of pharyngeal pressure might result in improved propulsion of bolus into the esophagus. The Mendelsohn maneuver is therefore a useful technique for patients who have reduced laryngeal movement, delayed or reduced cricopharyngeal opening, or discoordinated swallow.

Tongue-hold maneuver

The tongue-hold maneuver is a technique for enhancing posterior pharyngeal wall movement. Contact between the tongue base and posterior pharyngeal wall is important for applying pressure on the bolus to aid in transport through the pharynx . Head and neck cancer patients who have had resection of the tongue base or radiation to the oropharynx may experience difficulty achieving contact between the tongue base and pharyngeal wall. The tongue-hold maneuver was designed to augment posterior pharyngeal wall movement.

The patient is instructed to protrude the tongue and hold it between the central incisors while swallowing. Young adult subjects demonstrate a significant increase in posterior pharyngeal wall bulging while performing this maneuver . Treated head and neck cancer patients produce higher pressure at the level of the tongue base and pharyngeal wall while performing this maneuver .

It is unfortunate that the tongue-hold maneuver also results in increased pharyngeal residue (especially in the vallecula), reduced laryngeal vestibule closure, and delayed triggering of the pharyngeal swallow . Although as originally conceptualized the tongue-hold maneuver is to be used with a bolus, it is advisable to use the tongue-hold maneuver as an exercise without food for treated head and neck cancer patients because of the significant risk of aspirating vallecular residue during a swallow delay. A trial of the tongue-hold maneuver under fluoroscopy is recommended to see whether the posterior pharyngeal wall responds as anticipated.