1 INTRODUCTION

Obstructive sleep apnea (OSA) is the commonest sleep disorder. It is characterized by repetitive apneas and hypopneas during sleep. These events are due to partial or complete collapse of the upper airway, resulting in decreased oxygenation and sympathetic overdrive. Frequent arousals occur, causing sleep fragmentation leading to excessive daytime sleepiness, morning headaches, poor concentration, memory loss, frustration, depression and even marital discord. The mechanism of upper airway collapse in OSA is usually multifactorial. Many authors concur that most patients with moderate and severe OSA are very likely to have multilevel obstruction involving the level of the palate and the base of tongue. Endoscopic examination with Mueller’s maneuver can grade airway collapse at three levels, namely the velopharynx, lateral pharyngeal wall and the base of tongue.¹ There are surgical procedures that can address the various levels of collapse in these patients. Recently, lateral pharyngeal wall collapse has also been dealt with by creating tension in the lateral walls by lateral pharyngoplasty² or expansion sphincter pharyngoplasty.³ Palatal collapse can be treated by traditional uvulopalatopharyngoplasty, Z-plasty or transpalatal advancement; tongue base can be reduced by a glossectomy or a suspension sling suture.

The site of obstruction is unimportant when the modality of therapy is a tracheostomy or nasal continuous positive airway pressure, which indiscriminately overcomes all collapsible airway segments, much like a ‘pneumatic splint’. When upper airway surgery is contemplated, it is critical to tailor the approach according to the site of obstruction noted preoperatively on Mueller’s maneuver. The type of surgery employed would depend on the type of palatal and tongue base collapse.

Although a staged approach to the upper airway reconstruction is acceptable, and even endorsed by the American Sleep Disorders Association,⁴ when the likelihood of multilevel obstruction is high, the chances of surgical success may be nearly doubled by addressing multiple anatomic sites at a single surgical sitting,^5,6 thereby avoiding additional general anesthetic. The initial staged approach was described by Fujita, when he introduced uvulopalatopharyngoplasty for OSA⁷; he recognized that the upper airway may collapse at multiple levels. Hence, he described the laser midline glossectomy for patients who failed UPPP and who were diagnosed to have retrolingual obstruction.⁸ It was Riley et al.⁶ who first advocated simultaneous multilevel pharyngeal surgery for patients with multilevel obstruction noted clinically on Mueller’s maneuver. They showed promising success with minimal complications. Many authors have reported minimal complications with one-stage multilevel pharyngeal surgery for patients with OSA.^9–11

2 PATIENT SELECTION

The key to surgical success is patient selection. Patients with OSA must be treated in a holistic manner, as manyof these patients are overweight or obese, and have associated co-morbidities like hypertension, ischemic heart disease or cerebrovascular disease. The overweight patient should be put on a strict weight loss and dietary regime, while being on nasal continuous positive airway pressure, until ideal body weight is attained. Bariatric surgeryshould also be considered part of the surgical armamentarium in the management of these obese patients. Nasal continuous positive airway pressure (CPAP) has always taken the lead in the treatment of OSA. It is undoubted that nasal CPAP is effective in most OSA patients, ifused properly. However, it is also universally known that patient compliance is a major problem in the use ofnasal CPAP.

Surgical techniques for the treatment of OSA have long been criticized and frowned upon, especially uvulopalato-pharyngoplasty (UPPP). Uvulopalatopharyngoplasty remains the most common surgical procedure performed for sleep disordered breathing (SDB). Traditionally, UPPP was used mainly for patients with collapse/obstruction of the soft palate during Mueller’s maneuver (MM). Mueller’s maneuver was first described by Borowiecki and Sassin for the preoperative assessment of OSA.¹² According to Fujita’s three types of collapse of the upper airway during sleep,¹³ Mueller’s maneuver was able to identify Fujita type I (soft palatal) collapse, and hence, isolate patients suitable for UPPP. This, unfortunately, was not always the case,as there are multiple factors involved in the dynamics of OSA, and many patients have multilevel obstructions.Due to the varied clinical indications for this procedure, many authors have found unfavorable postoperative results. Sher et al. reviewed a meta-analysis of reported UPPPprocedures and found an overall success rate of only 40%.¹⁴ In an attempt to improve surgical success rates, Friedmanet al. devised a clinical staging system for SDB in orderto better select patients for the UPPP.¹⁵ They describedthree stages based on Friedman tongue position, tonsil size and BMI.

Friedman reported an overall success rate of 80.6% for stage I, 37.9% for stage II and 8.1% for stage III. It is well accepted that patients with Friedman tongue position 3 and 4 are indicative of a large tongue, suggesting that if surgery is contemplated, some form of tongue base surgery would be appropriate as well. Most authors concur that patients who are noted to have multilevel collapse with Mueller’s maneuver on endoscopy (of both the palate and tongue base) should have both levels addressed at the samesurgical sitting. Friedman et al. showed that selected patients with stage II and stage III disease treated with UPPP and tongue base reduction using a radiofrequency technique (TBRF) had remarkably improved results.¹⁶ Follow-up at 6 months showed successful treatment of patients with stage II disease with success rate improving from 37.9% to 74.0%, and stage III disease improving from 8.1% to 43.3%.¹⁶

Severity of OSA has also been noted to correlate with clinical examination, namely Mueller’s maneuver.¹⁷ It was demonstrated in 102 patients that OSA severity strongly correlated with Mallampati grade (r=0.389, P<0.0001), Friedman clinical staging (r=0.331, P=0.0007) and Mueller’s grades of collapsibility, at all three levels. Of significance, only 6.9% of patients with mild OSA had a >50% collapse of the base of tongue region, as compared to 65.9% of patients with severe OSA.¹⁷ This illustrates that patients with severe OSA are 10 times more likely to have tongue base collapse than patients with mild OSA. Hence, patients with severe OSA and with tongue base collapse noted on Mueller’s maneuver, falling into Friedman stage II or III, should have multilevel surgery in order to achieve the best possible results. In the uncommon event that a single, severely obstructed site in the upper airway is identified, a staged approach may be considered even if the OSA is severe.

Nasal surgery is offered when the patient has significant nasal obstruction that has failed medical therapy (topical nasal steroids), especially when the patient would want correction of the nasal obstruction independent of its effecton their sleep. However, it is reported that nasal surgery alone has only a 15.8% success rate as a treatment of OSA.¹⁸ The debate would be the safety of multilevelsurgery, addressing all three levels: the nose, palate and tongue base at the same surgical sitting. Most authors concur that there is no evidence of increased complication rate or morbidity with these procedures performed together.^11,19–21

3 OUTLINE OF PROCEDURES

3.1 HYOID MYOTOMY (SUSPENSION)

Riley et al.²² first reported a skeletal approach to hypopharyngeal obstruction by using an adaptation of the laryngeal suspension procedure originally developed to minimize aspiration in patients who had had a supraglottic laryngectomy. In their original description, the infrahyoid musculature was removed from the hyoid bone, which was then suspended from the anterior mandibular arch using fascia lata. The technique was later simplified²³ by approximating the hyoid bone antero-inferiorly to the thyroid cartilage (Figs 44.1 to 44.5). Essentially, the hyoid is releasedfrom its inferior attachments and advanced anteriorly and inferiorly over the thyroid cartilage. This applies tensionto the hyoepiglottic ligament, enlarging the hypopharynx (see figures).

Fig. 44.1 A&B, (Hyoid 2). Horizontal skin crease incision made over the hyoid bone.

Fig. 44.2 (Hyoid 3). Strap muscles are retracted laterally, and inferior attachments of the hyoid bone released.

Fig. 44.3 (Hyoid 1 A). The hyoid bone is approximated down to the thyroid cartilage.

Fig. 44.4 (Hyoid 4). Four non-absorbable sutures are used to appose the hyoid bone down to the thyroid cartilage.

Fig. 44.5 (Hyoid 5). The thyrohyoid apposition in place.

3.1.1 TECHNICAL HIGHLIGHTS

• The hyoid bone is exposed as in a thyroglossal cyst excision (Sistrunk procedure).

• The infrahyoid musculature is released from the body of the hyoid (Figs 44.1 and 44.2).

• The strap muscles are divided in the midline, and the thyroid cartilage exposed.

• Four non-absorbable #1-0 Ethibond (Johnson and Johnson) sutures are placed around the hyoid, through the thyroid cartilage to advance the hyoid bone (Fig. 44.3)

• Passive drainage (Penrose soft drain), and closure in layers.

3.2 MANDIBULAR OSTEOTOMY WITH TONGUE ADVANCEMENT

A limited rectangular mandibular osteotomy has replaced the originally described sliding inferior sagittal osteotomy²² as the preferred approach to advancing the genioglossus muscle anteriorly, thereby enlarging the retrolingual space. Powell et al.²⁴ first described this technique that made the surgery safer and more practical for the general otolaryngologist to perform. This procedure can be done in combination with the hyoid myotomy.

3.2.1 TECHNICAL HIGHLIGHTS

• A gingivolabial sulcus incision favoring the lip side to minimize the risk of dehiscence (Fig. 44.6).

• Exposure of the entire height of the mandible, with measurements made to center the osteotomies over the genial tubercle.

• Osteotomies made through the inner and outer cortex of the mandible using 2-hole saw, with particular attention to the corners (Fig. 44.7).

• Advancement of the fragment with a clamp to advance the window anteriorly (Fig. 44.8).

• Rotation of the advanced window fragment.

• Removal of the outer table of the mandible and the marrow space.

• Securing of the fragment to the lower edge of the mandible with a screw (Figs 44.9 and 44.10).

Fig. 44.6 (GGA 1). Inferior gingivolabial incision made for exposure of the anterior table of the mandible.

Fig. 44.7 (GGA 2). Rectangular window made through-and-through on the mandible, ensuring the mandibular menti, genioglossus muscle attachment is included.

Fig. 44.8 (GGA 3). Rectangular window is pulled anteriorly and twisted 90° in order to secure it.

Fig. 44.9 (GGA 4). Rectangular window anterior table is removed and the rectangular bone is secured with a screw.

Fig. 44.10 (GGA 5). Net effect of the hyoid suspension and genioglossus advancement procedure. The retrolingual space is increased.

3.3 TONGUE SUSPENSION

The principle is based on passing a non-absorbable Prolene suture through the tongue in an inverted triangle, with the apex at the inner table of the mandible, and the base of the triangle at the base of tongue region. The suture acts as a sling or hammock that creates a dimple at the base of tongue and prevents the tongue from falling posteriorly. The dimple in the base of tongue acts to allow a passage of air through, thus keeping the airway patent. This procedure is usually done in combination with a palate procedure and/or the hyoid myotomy.

• An incision is made on the floor of the mouth, at the frenulum of the tongue, above the two Wharton’s ducts.

• With an artery forceps, a plane is created to the inner table of the mandible.

• The periosteum is raised from the inner table of the periosteum.

• The right-angled drill is introduced and activated to secure the screw into the inner table of the mandible (Figs 44.11 and 44.12).

• A suture loop is passed to the patient’s right side to the base of the tongue from the frenulum incision (Fig. 44.13).

• The same is done with one end of the Prolene suture attached to the screw, to the left base of tongue (Fig. 44.14).

• A free large curve needle is used to pass the Prolene suture from one side of the tongue base at the exit point of the Prolene suture to the exit point of the suture loop (Fig. 44.15).

• The Prolene suture is then passed through the suture loop and pulled to the front.

• The Prolene suture is secured and tightened, while feeling the dimple in the base of tongue region (Figs 44.16 to 44.18).

• The incision in the frenulum is then closed with Vicryl 4/0 suture.

Fig. 44.11 (Repose 1). Inner view of the mandible, showing ideal position of screw placement (marked X) for the Repose screw.

Fig. 44.12 (Repose 2). Backward drilling device introducing the screw into the inner table of the mandible.

Fig. 44.13 (Repose 3). Suture passer used to pass the suture loop from the floor of the mouth to the base of tongue region at the circumvallate papillae.

Fig. 44.14 (Repose 4). Prolene suture passed through the tongue on the opposite side.

Fig. 44.15 (Repose 5). Using a curved needle threaded with the Prolene suture, it is passed submucosally from the suture exit hole to the suture loop exit hole and placed through the loop.

Fig. 44.16 (Repose 6). The suture loop is then pulled through thetongue dragging the Prolene suture with it to the floor of themouth.

Fig. 44.17 (Repose 7). The Prolene suture is tied and the knot buried. Tension should be adequate to create a dimple.

Fig. 44.18 (Repose 9). Final result of the tongue Repose suture showing the suture holding the tongue base forwards and preventing collapse posteriorly.

4 POSTOPERATIVE MANAGEMENT ANDCOMPLICATIONS

Intraoperative intravenous dexametasone is administered to all patients undergoing the tongue base procedure. Perioperative use of nasal CPAP is strongly encouraged. Patients who undergo multilevel surgery for OSA are monitored in the high-dependency unit overnight. All patients should be monitored closely in the postanesthesia care unit (PACU) for at least 4 hours postoperatively. Many authors believe that the postoperative complications are low, but if they were to occur, they would occur within the first 3 hours.^5,9,10

Complications of these tongue procedures inadvertently include edema of the tongue, floor of the mouth and palate. A nasal airway is frequently used to stent the upper airway for the first day postoperatively. Trauma to the Wharton’s ducts may occur in the tongue suspension procedure. It has also been documented that discoloration of the lower incisors occurs in the genioglossus advancement procedure if the teeth roots are involved.

5 SUCCESS RATES OF THE PROCEDURES

As most patients with OSA have multilevel obstruction, most of these tongue procedures are done in combination with a palate procedure. Success rates vary from one study to another; most authors define success as a reduction of Apnea/Hypopnea Index (AHI) by 50% of the preoperative value and below 20.

6 CONCLUSION

Moderate to severe OSA usually involves multiple levels of obstruction in the collapsible upper airway. Multilevel pharyngeal surgery, therefore, is usually required to surgically overcome the several sites of obstruction. Modifications of the skeletal technique have made the procedures safe and effective. Many research papers are reporting long-term and promising results for the surgical correction of the upper airway.