YOSEF P. KRESPI, MD, ASHUTOSH KACKER, MD
Obstructive sleep apnea (OSA) syndrome is a life-threatening condition with a reported prevalence of up to 4% among adult men in the United States. Upper airway obstruction most often results from collapse of excess soft tissue in the soft palate, tonsillar pillars, tongue, tongue base, and hypopharyngeal walls. Surgical therapies for hypopharyngeal obstruction and collapse range from midline glossectomy to mandibular advancement and hyoid suspension. These complex, invasive procedures entail considerable morbidity and exhibit moderate results. We introduce the technique of hyoid suspension / myotomy (HSM) as an adjunctive procedure to relieve or ameliorate OSA resulting from an obstructive tongue base.
HSM has been performed with the Repose? Bone Screw System (Influent, Inc., San Francisco, CA) in a multicenter setting on 55 patients. The majority of the patients were male with moderate to severe OSA confirmed by polysomngraphic study. Over 90% of the hyoid suspensions were preformed in conjunction with or following other upper airway procedures such as uvulopalatopharyngoplasty (UPPP), nasal septoplasty, tonsillectomy, and / or laser lingual tonsillectomy. Eighty-five percent of the patients were admitted for observation overnight.
The average length of hospital stay was 1.4 days. The time needed to perform the hyoid suspension averaged 25-30 min. All patients tolerated the procedure well, with no significant intra- or postoperative complications. Airway obstruction was not encountered in any patient. Follow-up 3-15 mo postoperatively showed improvement of OSA symptoms in over 90% of patients. Follow-up polysomnographic studies performed 3 mo to 1 yr postoperatively revealed significant improvement in the apnea-hypopnea index (AHI), ranging from 30 to 90% correction. HSM can serve as a simple, effective adjunct surgical procedure for OSA due to tongue base collapse. The procedure is relatively quick, easy to perform, minimally invasive, and safe. Our early results show subjective and objective improvement in the severity of OSA.
Obstructive sleep apnea (OSA) syndrome is definied by repeated apnea and hypopnea episodes during sleep, with associated oxhemoglobin desaturations. The apnea-hypopnea index (AHI), also known as the respiratory distress index (RDI), is defined as the number of apneas plus hypopneas per hour of sleep. Sleep-disordered breathing, defined as an AHI greater than 5, has a reported prevalence of up to 24% among adult men and 9% among adult women in the United States. 1,2 OSA, defined by an AHI of at least 10, has a reported prevalence of 4% among adult males and 2% among adult females. The Executive Report of the National Commission on Sleep Disorders Research (NCSDR) estimates that 7-18 million Americans have chronic sleep disorders. 3 Despite ever-improving diagnostic technologies, physiologic studies, and medical / surgical therapies, however, OSA continues to be an underrecognized and undertreated entity.
Upper airway obstruction results from excess and / or collapse of soft tissue in the soft palate, tonsillar pillars, tongue, tongue base, and hypopharyngeal walls. Specific anatomic risk factors predisposing to OSA include long soft palate, shallow palatal arches, large tongue base, narrow mandibular arches, and mandibular hypoplasia. 4 Other general anatomic factors often associated with OSA include obesity, large body mass index (BMI), shortened thick neck, anterior larynx location, enlarged tonsils and / or adenoids, lingual tonsils, thickened pharyngeal walls, elongated uvula, redundant soft palate, large tongue volume, deviated nasal septum, turbinate hypertrophy, and redundant or folded epiglottis. 5 Cephalometric studies employing computed tomography (CT) have correlated increased OSA severity with increased BMI, larger tongue and soft palate volumes, and decreased airway space. 6,7 Diagnostically, Fujita employed endoscopy with the Muller maneuver (reverse Valsalva) to identify sites of obstruction in the nasopharynx, oropharynx, and hypopharynx. 8 Three general profile types were identified based on the predominant areas of obstruction: Type I - retropalatal / velopharyngeal; Type II - retropalatal / velopharyngeal and hypopharyngeal; Type III - hypopharyngeal. Catheter pressure transducers employed in OSA sleep studies have shown that upper airway collapse occurred at the velopharyngeal / retropalatal and the hypopharyngeal / postlingual levels in comparable frequencies. 9,10
Clinically, the most common symptoms of OSA are snoring, choking, and snorting during sleep. Oftentimes, the patient's bed partner is the first to notice and complain. Other obstructive sleep symptoms include difficulty falling asleep, repeated night awakenings, and nocturnal sweating and enuresis. Suggestive findings include bruxism, excessive drooling, morning headaches, and erectile / libido dysfunction. 5 Sleep fragmentation, poor quality of sleep, and prolonged hypoxemia during sleep soon lead to chronic fatigue, excessive daytime somnolence (EDS), and decreased intellectual and physical performance. 11,12 Long-term complications include systemic and pulmonary hypertension, congestive heart failure, cardiac arrhythmias, and increased cardiovascular-related mortality. 13
Various modalities have been employed to relieve OSA. Medical therapies have included weight loss, exerceise programs, nasal continuous positive airway pressure (CPAP),14 bilevel positive airway pressure (BiPAP), orthognatic oral appliances, pharmacology, and nerve (hypoglossal nerve) and muscle (genioglossal muscle) stimulation devices. 15 These medical modalities, however, require extended dedication by both patients and medical specialists (physicians, dieticians, dentists, physical therapists, etc.). Poor patient compliance and variable clinical success usually limit the prolonged therapy. 5,16
OSA patients nonresponsive to medical management or CPAP can undergo a wide array of surgical procedures depending on the site and severity of obstruction. Tracheostomy provides bypass of obstruction but does not directly address the obstructive process. 17 Tonsillectomy and nasal septoplasty have been performed to address obvious areas of obstruction to ameliorate OSA symptoms. 16 Uvulopalatopharyngoplasty (UPPP), by far the most frequently employed OSA surgical procedure today, has only been able to demonstrate approximately 50% efficacy in treating OSA. 18,19 The use of laser-assisted uvulopalatoplasty (LAUP) for mild sleep apnea has gained popularity with a wide range of reported success (40-80%). 20 These procedures, however, address velopharyngeal / retropalatal and nasal obstruction but fail to address hypopharyngeal obstruction. Review of UPP studies shows only a 50% improvement, as determined by a postoperative RDI as criteria for successful outcome.
Identification of tongue base obstruction led to the development of procedures such as median glossectomy, 21 lingualplasty, 22 maxillomandibular osteotomies with hyoid suspension, 23-25 and mandibular osteotomy with genioglossal advancement. 26 These tongue base and hypopharynx procedures, however, are all fairly complicated and invasive. Potential complications include bleeding, airway obstruction, nerve damage, occlusal problems, and severe pain and dysphagia.
Recently, the Repose Bone Screw System for anterior tongue suspension (TS) was introduced in both experimental canine models and in preliminary clinical human trials. 27 Positive findings included increased anterior-posterior airway diameters and decreased airway pressures in the canine experiments, and 50% reduction or RDI in 5 / 6 patients. We introduce a series of 55 patients treated with hyoid suspension / myotomy (HSM) using the Repose Bone Screw System. The two procedures are straightforward, quick adjunctive procedures that can help relieve OSA resulting from an obstructive tongue base. Using a self-contained kit, the surgeon places a single permanent suture around the hyoid bone, suspended to the mentum. Early results have shown this procedure to be safe and effective.
MATERIALS AND METHODS
Anterior tongue base suspensions with the Sleep-In? Bone Screw System were performed in 55 patients with moderate to severe obstructive sleep apnea. The procedures were performed at the St. Like's Roosevelt Hospital Center, New York City, NY. The 45 male and 10 female patients, ranging in age from 29 to 68 years, were all initially identified by history and symptoms. Questionnaires completed by the patients and their spouses elicited symptoms such as severe snoring, nighttime choking, poor sleep, chronic fatigue, and daytime somnolence. Physical examination showed large body habitus, redundant soft palates and / or uvulas, thickened pharyngeal walls, and large tongue and tongue bases. Muller's maneuver revealed tongue base prolapse in addition to velopharyngeal and lateral pharyngeal collapse in all patients.
All patients underwent overnight polysomnographic (PSG) studies. Preoperative AHI ranged from 27 to 106, with an average of 65. Of the 55 patients, 18 had previous UPPP. Eleven patients had undergone nasal surgery previously. The HSM procedure was performed in combination with UPPP, tonsillectomy, and lingual tonsil ablation in 37 patients.
Hyoid Suspension / Myotomy
In the event of sever OSA, HSM is performed in conjunction with TS. This method inhances the anterior superior repositioning of the tongue base, enlarges the airway in a lateral dimension, and partially separates the tongue base from the lower airway by an infrahyoid myotomy.
HSM is usually performed in conjunction with and immediately following TS. The anterior neck is prepped and redraped. The anterior mandible, hyoid, and thyroid are then outlined with a skin marker, with the neck slightly extended. Lidocaine with epinephrine 1:100,000 is injected into the planned incision sites. A 1-cm incision is made under the chin in the midline; with blunt dissection, the soft tissues overlying the mandible are cleaned. The screw inserter is loaded with a new spare screw and positioned perpendicular to the mandible, and with firm pressure applied, the screws is inserted into the inferior edge of the mandible. A loop of #1 polypropylene suture has already been attached to the screw by the manufacturer (Fig 1).
A second, horizontal incision measure 5-7 cm is made over the body of the hyoid. Subcutaneous fatty adipose tissue can be dissected and removed. Electrocautery is used to separate the infrahyoid bone. A single bone hook is placed to retract and stabilize the hyoid during the dissection. The sternohyoid and thyrohyoid muscles are detached from the body of the hyoid between the lesser cornuae (fig 2). Careful dissection, avoiding injury to the pre-epiglottic far, and good hemostasis are mandatory.
The suture passer is loaded with the polypropylene suture and tunneled subcaneously into the lower (hyoid) incision (Fig 3). The suture passer is then removed. One free end of the polypropylene suture is loaded into a Mayo needle and passed through the suprahyoid muscles, with a full thickness bite of the tissue. The hyoid bone is divided in the midline (hyoid distraction). This can be performed when the hypopharyngeal airway needs to be enhanced laterally, as determined by preoperative fiberoptic endoscopy. Following the division of the hyoid bone, the polypropylene suture is passed around both sides of the divided edges in a figure-8 configuration (Fig 4).
The two ends of the polypropylene suture are then tied together to achieve a superior anterior pull of the hyoid and tongue base. The inferior wound is drained, and both wounds are closed in layers.
All patients were admitted for close observation overnight. Peri- and postoperative care included steroids, intravenous antibiotics, antireflux medications, humidified oxygen, intravenous fluids, nasal trumpet, and pulse oximetry.
FIGURE 1. A Repose system is used to insert a single screw to the bony mentum, via a small stab incision. A loop of #1 polypropylene suture is attached to the screw.
FIGURE 2. A small horizontal incision is made over the body of the hyoid bone. The infrahyoid muscles are detached from the body of the hyoid bone using electrocautery.
FIGURE 3. The loop of polypropylene suture is tuneled through the chin to the lower neck incision using a suture passer.
FIGURE 4. The hyoid is divided in the midline, the loop suture is passed around the hyoid in a figure-of-eight fashion. The loop suture will suspend the tongue base antero-superiorly enhancing the posterior air space. The hyoid distraction will limit or eliminate the hypopharyngeal wall collapse. To see figures click here
Of the 55 patients who underwent HSM, all patients tolerated the procedure well, with no intra- or postoperative complications. Patients remained hospitalized postoperatively for 1-3 days, with an average stay of 1.4 days. No episodes of airway obstruction or bleeding were encountered. The most common postoperative patients complaints included dysphagia, odynophagia, and surgical wound pain. All patients were able to tolerate liquids and a soft diet at the time of discharge. No patients requested or required removal of the suspension sutures.
After 3-12 mo of follow-up postoperatively, over 90% of the patients were subjectively improved, as determined by patient and / or spouse history. Symptomatic improvement included decrewsed snoring, improved quality of sleep, and decreased daytime somnolence. Follow-up PSG studies were performed 3 mo to 1 yr postoperatively in 52 patients. The patients who had undergone HSM showed significant improvement in the mean RDI, from 71.2 (+ / - 18.0) preoperatively to 28.4 (+ / - 16.8) postoperatively. We should note that the percentage of sleep time recorded with an oxygen saturation above 90% was 51.4% preoperatively and 80.1% postoperatively.
UPPP, presently the most frequently used procedure for OSA, has only achieved moderate success rates of approximately 50% when critically reviewed. The procedure only addresses the retropalatall area. Review of UPPP failures has revealed obstruction at the tongue base and hypopharynx to be the cause of continued OSA. 28 Cephalometric and radiographic studies have supported these findings. 29
Fujita et al introduced laser miodline glossectomy as a method of reducing the tongue base in patients who failed UPPP. 21 Woodson and Fujita later modified the procedure with laser lingualplasty, which involved a more extensive resection and suturing of the tongue base. 22 Patients undergoing lingualplasty alone showed 79% response, whereas overall response was 77%. Waite et al employed maxillomandibular advancement via LeFort I with sagittal ramus split osteotomies to widen the posterior airway space, with "surgical cure" in 65% and subjective improvement in 96% of patients. 30 All patients who underwent advancement with UPPP found surgical success. Riley et al showed similar results using bimaxillary surgery with sagittal osteotomy, hyoid suspension, and UPPP. 31
Perhaps the most important part of surgical treatment of OSA is making a correct diagnosis of the site(s) of obstruction. The difficulty with OSA and tongue base obstruction has been the poor ability to grade severity and predict surgical success. A thorough head and neck examination can identify anatomic abnormalities predisposing to obstruction, whereas fiberoptic examination with Muller's maneuver can tentatively identify areas of obstruction. Careful examination of the hypopharynx and tongue base must be done, because near-total collapse of the tongue base was the only characteristic seen on endoscopy that was associated with tongue base obstruction during sleep. 32 Sher et al noted much better results with UPPP: 73% RDI improvement when patients were preoperatively selected by the Muller maneuver. 33 They attributed the lower rates of success (approximately 50%) with UPPP seen in other studies to failure to identify sites of obstruction at other locations, such as the hypopharynx and epiglottis. Several studies, however, have indicated how inconsistent and poorly predictive both physical examination and fiberoptic examination can be. 34,35
The anterior tongue suspension procedure introduced in this article has many positive aspects in treating OSA. Initially, the suture pulls the tongue forward with some immobilization. This fixation then causes tongue base fibrosis, resulting in tongue base support and reduced hypopharyngeal collapse, particularly in the supine position. The procedure is straightforward, ease to perform, minimally invasive, and potentially reversible. As seen by the early results, there has been objective (PSG) and subjective patient improvement
The advantages of the HSM are multifold. The splitting of the hyoid allows for potential lateral widening of the hypopharyngeal airway. Division of the infrahyoid musculature allows partial separation of the larynx from the hyoid and tongue base. This incomplete laryngeal drop can keep the inferior movement of these structures separate, especially under the tremendous negative pressures that occur during the inspiration phase of respiration in an OSA patient.
There may be many potential complications of TS and HSM - including floor of mouth bleeding or infection, Warthin's duct injury, airway obstruction, prolonged odynophagia, speech problems, dental trauma, neck hematoma, wound infection, and intense pain. However, there have been very few problems in our experience. Pain and dysphagia / odynophagia, the most common complaints, have all resolved in reasonable time. Patients with prolonged dysphagia / odynophagia may benefit from instructions in a modified supraglottic swallow (tongue push and elevation with throat clearing) as mentioned by Woodson and Fujita. 22 It is important to note that there were no airway or bleeding problems in the perioperative period, nor any suture or equipment problems. A positive response to anterior TS may be a good prognostic indicator that more invasive tongue base procedures may work should OSA return.
Many areas of TS warrant investigation in the future. Preoperative and postoperative studies with polysomnograms, CT scans, cephalometry, and symptomatic questionnaires all can elicit the utility of TS. The OSA Treatment Outcome Pilot (OSATOP) project recently advocated use of a definitive diagnostic battery [Epworth Sleepiness Scale (ESS), Medical Outcomes Study Short Form 36 (MOS SF-36), OSA Patient-Oriented Severity Index (OSAPOSI), Muller maneuver findings, BMI, RDI, and minimum O2 saturation] to assess patients and surgical outcomes more thoroughly. 36 A prospective study analyzing and comparing the use of TS procedures and HSM in cases such as UPPP failures can potentially elicit differences.
HSM is an effective adjunct surgical procedure for OSA secondary to hypopharyngeal obstruction and base of tongue collapse. Hyoid suspension is relatively quick, easy to perform, minimally invasive, and incurs very few complications.