What is bolus control in a patient with a history of transoral excision of a vallecular growth?

Bolus Control in Swallowing

Bolus control refers to the tongue's ability to form, manipulate, and propel a food or liquid mass through the oral cavity and into the pharynx during swallowing, which is critical for safe and efficient deglutition. 1

Physiological Components of Bolus Control

Formation Phase

• The tongue plays a major role in bolus formation, control, and propulsion during the swallowing process 1
• During mastication of solid foods, the tongue compresses food against the palate and actively transports portions from the oral cavity to the oropharynx through protraction (forward and upward movement) 2
• Food bolus formation occurs as a continuum from the oral cavity through the pharynx, not as a discrete oral-only event 3

Physical Properties That Define a Swallowable Bolus

• Aggregation (cohesiveness) must be achieved for a bolus to reach the swallowing threshold, even with minimal chewing 3
• Bolus adhesiveness, springiness, and cohesiveness regularly increase throughout mastication until swallowing initiation 4
• These rheological changes serve as sensory inputs that trigger the swallow reflex 4

Propulsion and Transport

• The tongue generates lingual pressures to move the bolus posteriorly 1
• Tongue base retraction is essential for complete bolus clearance from the oral cavity into the pharynx 1
• Coordinated tongue movement creates a squeeze-back mechanism against the hard palate 2

Clinical Relevance in Post-Surgical Patients

After Vallecular Surgery

In patients with history of transoral excision of vallecular growth, bolus control becomes particularly critical because:

• Vallecular residue is a common consequence of impaired tongue base retraction and reduced bolus propulsion force 1
• The valleculae serve as a temporary collection point where the bolus may pool before swallowing is triggered 1
• Surgical alteration of vallecular anatomy can disrupt normal bolus flow patterns and increase aspiration risk 1

Assessment of Impaired Bolus Control

• Videofluoroscopy can detect oral stasis of residual material and piecemeal swallowing (multiple swallows to clear a single bolus) 1
• Reduced tongue strength has been identified as a risk factor for aspiration 1
• Tongue strength declines with aging, compounding post-surgical deficits 1

Therapeutic Interventions for Impaired Bolus Control

Tongue Strengthening Exercises

• Tongue strength training has been evaluated in well-designed cohort studies showing improvements in vallecular residues and swallowing safety 1
• These exercises specifically target the muscles responsible for bolus formation and propulsion 1

Effortful Swallow Technique

• The effortful swallow is specifically indicated for patients with clinically significant residue in the valleculae 1
• This maneuver increases tongue base retraction pressure and duration, improving bolus clearance 1
• Physiologic studies demonstrate increased lingual pressures and hyolaryngeal excursion with this technique 1

Bolus Modification Strategies

• Increasing bolus viscosity improves swallowing safety by slowing bolus transit and allowing more time for airway protection 5
• However, thickened liquids increase oral and pharyngeal residue, which may lead to post-swallow aspiration 5
• Gum-based thickeners are more effective than starch-based agents at reducing aspiration (mean Penetration-Aspiration Scale score 1.42 vs 1.76, P<0.001) 6

Critical Pitfalls to Avoid

• Do not assume adequate bolus control based on patient report alone—instrumental assessment with videofluoroscopy or FEES is essential to visualize vallecular residue and aspiration risk 1, 7
• Do not overlook post-swallow residue—material remaining in the valleculae after swallowing can be aspirated during subsequent breaths 5
• Avoid premature advancement of diet texture without confirming adequate tongue strength and bolus propulsion through objective swallowing studies 7