Tonsillectomy and Pharyngoplasty

Key points

  • The airway of obstructive sleep apnea (OSA) patients has been shown to be smaller in the lateral dimension and retropalatal region.

  • Palatopharyngoplasty can be performed alone or in conjunction with other OSA surgeries.

  • In appropriately selected patients, palate procedures are highly effective at enlarging the retropalatal space and stabilizing the lateral pharyngeal walls.

  • Tissue-preserving techniques are preferred for avoiding complications and maximizing efficacy.

Introduction

The geometry and caliber of the upper airway of patients with obstructive sleep apnea (OSA) have been shown to differ from that of healthy controls. The airway of patients with OSA has been shown to be smaller, primarily in the lateral dimension and the retropalatal region. Often referred to as the workhorse of sleep apnea surgery, palatopharyngoplasty (PPP) is performed alone or in conjunction with other OSA surgeries. The procedure, which encompasses several technical variations, including uvulopalatopharyngoplasty (UPPP), sphincter pharyngoplasty, and expansion pharyngoplasty (discussed later), enlarges the retropalatal airway via the excision of tonsil tissue (if present), trimming and reorientation of the anterior and posterior tonsillar pillars, and excision of a portion of the uvula and soft palate.

The likely origin of modern palatopharyngoplasty techniques dates back to the 1950s when Schwartz used resection of paramedian soft palate triangles on either side of the uvula in the treatment of snoring. However, the procedure most reminiscent of the palatopharyngoplasty performed today was later described by Ikematsu in Japan in 1964 after seeing a female patient who was divorced due to her loud snoring. Several iterations of the procedure have since been introduced, with Simmons and colleagues advocating for excision of the uvula versus the traditional uvular repositioning technique seen with Fujita’s approach.

Traditionally, UPPP has been and continues to be the most commonly performed of pharyngeal procedures. Historically, the Fujita classification has been used to assess the upper airway. Fujita’s classification describes 3 patterns of upper airway collapse, essentially divided into upper (type I), lower (type II), and combined (type III) pharyngeal collapse.

Surgical technique: preoperative planning

After initial evaluation, including thorough history and physical examination, including fibreoptic nasendoscopy, all patients undergoing PPP for OSA should have documented evidence of OSA or snoring. During the head and neck examination, particular care should be paid to tonsil size, palate redundancy, uvular length, and tongue base position as well as general body habitus and calculation of body mass index. Close attention to these clinical features is critical in ensuring appropriately selected patients and thus optimal results, with patient selection being shown to be the primary factor in determining the wide variety in surgical success seen in the literature. Performance of Muller’s maneuver can also aid in determining the level or levels of airway obstruction in each specific clinical scenario.

Surgical approaches

Transitioning from a uvular excision technique, in 1996 Powell and colleagues introduced the uvulopalatal flap (UPF) technique, which involves repositioning the uvula and posterior soft palate anteriorly. With this technique, the palatal muscles are preserved, which reduces the risk of velopharyngeal insufficiency, a feared consequence of overresection of the soft palate. In contrast to traditional UPPP, where incisions are made along the inferior surface of the palate and the lateral pharyngeal well, UPF incisions are made on the oral surface of the soft palate, which has been demonstrated to reduce circumferential scar, thus reducing postoperative pain as well as the risk of bleeding.

In contrast to PPP and UPF, transpalatal advancement pharyngoplasty, described in the early 1990s, stabilizes the upper airway by altering bone and soft tissue attachments of the posterior maxilla rather than radical modification of the palatal soft tissue and musculature. This technique makes use of a shorter palatal flap and greater palate mobilization than traditional PPP, with an osteotomy used to advance the palate that has soft tissue attached to the osteotomized bone fragment.

Interestingly, lateral pharyngeal wall narrowing has been shown to be the sole oropharyngeal finding on examination that predisposes to Obstructive Sleep Apnea Hypopnea Syndrome in men. As a result of this finding, lateral pharyngoplasty was proposed in which the tonsils are removed in standard fashion. Following tonsillectomy, the palatoglossus and palatopharyngeus muscles are identified, and using an operative microscope, the superior pharyngeal constrictor muscle is elevated and sectioned in a cranial-caudal direction. This results in 2 muscle flaps: first, a medially based flap, and second, a laterally based flap, which is sutured anteriorly to the ipsilateral palatoglossus muscle with a series of 3 stitches. Finally, a transverse incision on the oral surface of the soft palate is made extending laterally from the base of the uvula extending superiorly to create a laterally based palatine flap. In order to close the tonsillar fossa, the palatopharyngeus muscle is sectioned in a transverse fashion creating a superior flap that is sutured with a Z-plasty along with the palatine flap to cover the superior portion of the tonsillar fossa. The inferior palatopharyngeus muscle flap is used to suture closed the inferior aspect of the tonsillar fossa. Although the procedure has shown promising results, patients frequently complain of postoperative dysphagia.

Another variation on PPP, expansion sphincter pharyngoplasty, was originally borne from the treatment of velopharyngeal incompetence in cleft palate patients by creation of a dynamic muscle sphincter. The procedure begins with tonsillectomy, followed by rotation of the palatopharyngeus muscle. The inferior portion of the palatopharyngeus is transversely sectioned, rotated superolaterally, and fixed with a figure-of-8 suture. An incision is then made on the anterior pillar arches to identify the palatoglossus muscle fibers, such that the rotated palatopharyngeus muscle can be fixed to the palatoglossus fibers. Next, a partial uvulectomy is performed and the anterior and posterior pillars are sutured together, opposing these 2 surfaces.

Surgical technique

The patient is first positioned supine on the operating table and undergoes induction and oral intubation with an oral RAE endotracheal tube. The procedure can be performed in a seated or standing position. After induction and intubation, a mouth gag, in the form of a Boyle-Davis or a Tonsil A-Frame, is used to prop the mouth open with care taken to ensure the tongue and endotracheal tube are fixed in a midline position without obscuring either of the tonsillar beds ( Fig. 1 ).

Fig. 1
Tonsillectomy is performed in the standard fashion. Monopolar cautery is our preferred technique.

Tonsillectomy is performed in the standard fashion ( Figs. 2–3 ). The authors prefer the use of monopolar cautery to identify an extracapsular plane and facilitate removal of the tonsils from superior to inferior. Diligent care is taken to ensure meticulous hemostasis after removal of the tonsils with a combination of oxymetazoline-soaked pledgets, bipolar cautery, and/or suction cautery.

Fig. 2
After removal of the tonsils, the uvula is grasped with a toothed-forceps and trimmed.

Fig. 3
The uvula is trimmed to prevent elongated and redundant mucosa.

Jan 19, 2020 | Posted by in Oral and Maxillofacial Surgery | Comments Off on Tonsillectomy and Pharyngoplasty
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