1
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).
2
Patient Selection
The authors first published data on a prospective, randomized clinical trial in 45 adults, age above 18 years old, who had mainly retropalatal obstruction and lateral pharyngeal wall collapse. Their inclusion criteria included patients with small tonsils (tonsil size 1 and 2), body mass index (BMI) <30, and Friedman clinical stage II and III who had failed or cannot tolerate nasal continuous positive airway pressure therapy. The clinical examination included height; weight; neck circumference; BMI; and assessment of the nasal cavity, posterior nasal space, oropharyngeal area, soft palatal redundancy, uvula size and thickness, tonsillar size, and Friedman tongue position. Flexible nasoendoscopy was performed for all patients, and collapse during a Mueller maneuver and/or end expiratory phase maneuver was graded for the soft palate, lateral pharyngeal walls, and base of the tongue on a 5-point scale. These patients were randomized into either the traditional uvulopalatopharyngoplasty (UPPP) procedure or the expansion sphincter pharyngoplasty (ESP). The mean follow time was 6.5 months. All patients had a postoperative polysomnogram at 6 months.
3
Surgical Technique
The procedure is done under general anesthesia, with the patient in the supine position. The authors perform the procedure with orotracheal intubation and a Boyle-Davis mouth gag within the oral cavity keeping the mouth open and isolating the endotracheal tube forward. A bilateral tonsillectomy is performed ( Fig. 39.1 ). The palatopharyngeus muscle is identified; its inferior end is transected horizontally ( Fig. 39.2 ) and rotated superolaterally with a figure 8 suture, through the muscle bulk itself, with a Vicryl 4/0 round body needle. The muscle is isolated and left with its posterior surface partially attached to the posterior horizontal superior pharyngeal constrictor muscles ( Fig. 39.3 ). A superolateral incision is made on the anterior pillar arch bilaterally, identifying the arching fibers of the palatoglossus muscles ( Fig. 39.4 ). The palatopharyngeus muscle is then attached to the arching fibers of the soft palate anteriorly ( Fig. 39.5 ). A partial uvulectomy is then performed (this is an optional step). The anterior and posterior tonsillar pillars are then apposed with Vicryl 4/0 round body sutures ( Fig. 39.6 ). The same steps are repeated on the opposite side. This new technique of ESP was based on and modified from the Orticochea procedure and the lateral pharyngoplasty. The aim of this technique is to isolate the palatopharyngeus muscle (the main part of the lateral pharyngeal wall bulk) and rotate this muscle superoanterolaterally to create the lateral wall tension and remove the bulk of the lateral pharyngeal walls. The key is to not completely isolate the muscle into a tube and rotate it, but instead to keep part of its fibrous attachment to the superior pharyngeal constrictor muscle so as to create the necessary tension and pull superoanterolaterally. A complete or partial uvulectomy is performed together with this procedure.
