Divisions >> Otolaryngology-Head & Neck Surgery >> Otolaryngology Surgery Update e-newsletter >> September 2015 Issue >> Clinical Care - Evolving Trends in Surgery of the Soft Palate for Obstructive Sleep Apnea
Evolving Trends in Surgery of the Soft Palate for Obstructive Sleep Apnea
Obstructive sleep apnea (OSA) is an increasingly common disease affecting 2-4% of middle aged adults in the United States. Left untreated, it contributes to impaired cognition, hypertension, cardiovascular disease, and stroke.1 While positive airway pressure (PAP) therapy remains the gold standard, patient adherence can be highly variable (32-90%).2 Historically, the effectiveness of surgical procedures to address palatal obstruction in OSA patients has proven unpredictable. However, recent advances in reconstructive soft palatal surgery for OSA have bolstered surgical outcomes data reinforcing the vital role of surgery in PAP-intolerant patients.
The traditional uvulopalatopharyngoplasty (UPPP) procedure typically involved resection of the palatine tonsils, uvula, and portions of the soft palate and lateral pharyngeal wall with circumferential suture re-approximation of the free mucosal edges. A well-known 1996 meta-analysis reported that traditional UPPP was successful in only 40% of cases. More discouraging was the finding that up to 10% of patients were made worse as a result of unfavorable late circumferential scarring patterns following mucosal resection.3 Not surprisingly, this led many to question the role of palatal surgery as a valid treatment for OSA. As a result, there has been a paradigm shift within the field of sleep surgery in recent years with an emphasis on mucosal-sparing reconstruction of the soft palate rather than ablation.
Surgical management of retropalatal airspace obstruction now focuses on the concept of lateral pharyngeal port opening. Various techniques have been described to achieve this result, including the modified uvulopalatopharyngoplasty (modUPPP), relocation pharyngoplasty, and expansion sphincter pharyngoplasty (ESP).4 , 5 While there are differences in surgical technique, the goal of these reconstructive procedures is the same: the palatopharyngeus muscle is transected horizontally and reattached superolaterally to the arching muscle fibers of the soft palate to redirect its vector of pull superolaterally. Tissue resection is kept to a minimum and includes only the palatine tonsils, supratonsillar fat pad, and partial uvula. Proper patient selection remains of paramount importance in palatal surgery for OSA. Ideal candidates are those with Friedman Stage 1 or 2 anatomy (Table I), significant lateral pharyngeal wall collapse confirmed on fiberoptic endoscopy, and a body mass index below 40kg/m2. As demonstrated in a prospective case series, objective success rates for OSA patients treated with modUPPP are strongly correlated with Friedman stage: stage I: 80%, stage II: 37.9%, stage III: 8.1%.6
A recent prospective randomized controlled trial of 65 consecutive patients with moderate to severe OSA and Friedman stage I or II airway undergoing modUPPP demonstrated a mean reduction in apnea-hypopnea index (AHI) of 60% compared with 11% in controls.7 Another prospective randomized controlled trial examining the effectiveness of ESP to traditional UPPP in patients with small tonsils (size 1 and 2) reported a 82.6% ESP success rate in reducing the AHI at least 50% and below 20 events per hour compared to 68.1% in the traditional UPPP group.5
Importantly, the majority of moderate to severe OSA patients will have multilevel obstruction at the level of the velopharynx, base of tongue (BOT), and/or lateral pharyngeal walls. Therefore palatal surgery is rarely done in isolation and is often combined with additional procedures addressing the BOT such as coblation channeling, lingual tonsillectomy, transoral robotic resection, and radiofrequency reduction. A recent prospective study by MacKay et al. incorporating modified UPPP and coblation tongue base channeling on Friedman Stage I/II patients demonstrated a 68% reduction in mean AHI (28.9 to 9.3 events/h of sleep) which compares favorably to results from a traditional UPPP meta-analysis reporting a 33% reduction (40.3 to 29.8 events/h of sleep). 4 , 8
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7 Browaldh N, Nerfeldt P, Lysdahl M, et al. SKUP3 randomised controlled trial: polysomnographic results after uvulopalatopharyngoplasty in selected patients with obstructive sleep apnea. Thorax. 2013 Sep;68(9):846-53
8 Caples MS, Rowley JA, Prinsell et al. Surgical modifications of the upper airway for obstructive sleep apnea in adults: a systemic review and meta-analysis. Sleep 2010;33:1396-1407.