Expansion Sphincter Pharyngoplasty

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Introduction

Snoring results from the vibration of the soft tissues in the oral cavity: the soft palate, uvula, tonsils, base of tongue, epiglottis, and lateral pharyngeal walls. These may lead to collapse of the upper airway. It is known that when inspiratory transpharyngeal pressure exceeds the pharyngeal dilating muscle action, apneas and hypopneas occur. Collapse of the upper airway is usually multilevel, at the level of the velopharynx, the base of the tongue, and the lateral pharyngeal walls. Many patients with obstructive sleep apnea (OSA) have bulky, thick lateral pharyngeal walls that vibrate and contribute to the collapse of the upper airway in these patients. The level of collapse may be assessed using the Muller maneuver and/or the end expiratory pressure noted with the fiber-optic flexible nasopharyngoscopy. The Muller maneuver is usually graded on a 5-point scale from 0 to 4. Terris et al. described the Muller maneuver finding based on three levels: soft palatal collapse, lateral pharyngeal wall collapse, and base of tongue collapse. The drug-induced sleep endoscopy has been gaining popularity; this is done by sedating the patient and dynamically observing the anatomic collapse of the upper airway.

The lateral pharyngeal muscle wall collapse has been demonstrated to be important in the pathogenesis of OSA in imaging studies. Most authors concur that it is difficult to create surgically adequate lateral pharyngeal wall tension or to debulk it to prevent its collapse.

The lateral pharyngoplasty, first described by Cahali, was aimed at addressing the lateral pharyngeal wall collapse in patients with OSA. The Cahali technique is based on splinting the superior pharyngeal constrictor muscle (see Chapter 40 ). The procedure, however, had patients with prolonged dysphagia postoperatively.

Orticochea first described the construction of a dynamic muscle sphincter by isolating the palatopharyngeus muscle without the superior constrictor and transposing them bilaterally superiorly in the midline for treatment of velopharyngeal incompetence in patients with cleft palates. Christel et al. modified Orticochea's procedure by isolating the palatopharyngeus muscle bilaterally, apposing them more superiorly, and closing the lateral pharyngeal defects with Z-plasty sutures. Utilizing these procedures, the authors present an innovative technique in creating this tension in the lateral pharyngeal wall, preventing its collapse and reducing the number of apneic episodes. The expansion sphincter pharyngoplasty basically consists of a tonsillectomy, expansion pharyngoplasty, and rotation of the palatopharyngeus muscle; a partial uvulectomy (optional); and closure of the anterior and posterior tonsillar pillars (optional).

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