TITLE: Surgical Management of Obstructive =
Sleep
Apnea in Adults
SOURCE: Grand Rounds Presentation, UTMB, Dept. of Otolaryngology
DATE: September 24, 2009
MEDICAL STUDENT (4TH YEAR): Andrew M. Courson
FACULTY PHYSICIAN: Vicente
Resto, MD, PhD
DISCUSSANT: Vicente Resto, MD, PhD
SERIES EDITORS: Francis B. Quinn, Jr., MD
ARCHIVIST: Melinda Stoner Qui=
nn,
MS(ICS)
&q=
uot;This
material was prepared by resident physicians in partial fulfillment of
educational requirements established for the Postgraduate Training Program =
of
the UTMB Department of Otolaryngology/Head and Neck Surgery and was not
intended for clinical use in its present form. It was prepared for the purp=
ose
of stimulating group discussion in a conference setting. No warranties, eit=
her
express or implied, are made with respect to its accuracy, completeness, or
timeliness. The material does not necessarily reflect the current or past
opinions of members of the UTMB faculty and should not be used for purposes=
of
diagnosis or treatment without consulting appropriate literature sources and
informed professional opinion."
Background Information
Sleep apnea exists among a spectrum of disorders= known as sleep disordered breathing. These range from primary snoring to obesity hypoventilation syndrome. Primary snoring is characterized by a snoring with a lack of nighttime awakenings and daytime sleepiness. This is followed by upper airway resistance syndrome (UARS), wh= ich has frequent nighttime awakenings and daytime sleepiness, but an absence of apn= eic episodes. Obstructive sleep a= pnea syndrome (OSAS) has nocturnal episodes of apnea and oxygen desaturation that cause frequent nighttime awakenings and daytime sleepiness. Finally, patients with obesity hypoventilation syndrome, also know as Pickwickian syndrome, are obese, have daytime hypercapnea, and have some form of sleep disordered breathing.
Some facts about OSA are that it affects approxi=
mately
18 million Americans, with up to 70% of the cases associated with obesity.<=
span
style=3D'mso-spacerun:yes'> There is an increased incidence wi=
th
age, and patients have an increased overall mortality compared to the gener=
al
population. It is estimated t=
hat
38,000 deaths attributed to cardiovascular disease in the
History
Important points of the history when interviewin= g a patient with suspected OSA include: the presence of daytime sleepiness and restless sleep, the use of alcohol and sedatives, mouth breathing during sl= eep and throughout the day, and morning headaches (especially in females). It is helpful to ask the patient a= bout their bedtimes, awakening times, body position during sleep, caffeine intak= e, and menopausal status in females (postmenopausal is a risk factor for OSA).= It is crucial to obtain input from= the patient’s bed partner or a family member, as these patients often una= ware of their symptoms. This is in= part due to a lack of awareness during sleep, but can also be attributed to the gradual onset of symptoms.
Physical Exam
On physical exam, it is first necessary to note =
the
patient’s general body habitus, describing if they are obese and whet=
her
their weight distribution is central or peripheral. The physician should look for sign=
s of
chest wall deformity and note if the patient has a systemic disorder such as
achondroplasia or Marfan syndrome (both have a high prevalence of OSA). Additionally, the presence of
retrognathia or micrognathia should be noted, along with a quantitative
measurement of the patient’s neck size. Next, signs of nasal obstruction s=
hould
be sought out, looking for a deviated septum, polyps, turbinate hypertrophy=
, or
nasal valve collapse. On
oropharyngeal exam, the size of the palate, tongue, uvula, and tonsils shou=
ld
be described. In OSA, patients
often have an elongated palate and uvula with mucosal folding. Finally, the posterior pharyngeal =
wall
should be examined for the presence of banding. Following the oropharyngeal exam, a
thorough examination for enlarged lymph nodes, as well as an enlarged or
irregular thyroid is important.
Often tumors of the head and neck can present with new onset OSA.
In addition to the head and neck exam, a cardiovascular exam is important, as many OSA patients have comorbidities involving this organ system. A final important part of the physical exam is examination via flexible nasopharyngeal scope. This can further evaluate the nasal cavity for polyps and tumors, as well as for the presence of enlarged adenoids. Flexible scope will allow the physician to better examine the base of tongue and epiglottis. A thickened, omega shaped epiglottis can sometimes be found in patients with OSA.
Finally, the physician should have the patient p= erform the Müller maneuver. Thi= s is accomplished by asking the patient to close their mouth, hold their nose sh= ut, and inspire with maximal effort. The physician should look for signs of airway collapse at the palate, base of tongue, and lateral pharyngeal walls. The collapsibility of each structu= re can be quantified on a scale of 0 to 4, with 0 indicating minimal collapse, and= 4 indicating complete collapse.
Diagnostic Modalities
After history and physical exam, there are three= main methods of diagnosis for OSA. These include questionnaires, cephalometric analysis, and polysomnography.
A variety of questionnaires exist to aid in the diagnosis of OSA. The first type measures the degree of sleepiness throughout the day. This type includes the E= pworth and Stanford sleepiness scales. The Epworth sleepiness scale is probably the most widely used questionnaire, and asks the patient to rate their sleepiness during various everyday activities such as reading, watching TV, and driving.= The Stanford sleepiness scale is similar, but asks the patient to ra= te their sleepiness at each hour of the day.&= nbsp; Other types of questionnaires involve quality of life measures that = are specific to OSA. Downsides of= these questionnaires are that they are not highly specific to OSA, with diseases = such as narcolepsy and restless leg syndrome often having positive questionnaire= s.
The next type of diagnostic modality available is called cephalometric analysis.= This involves take lateral plain r= adiographs of the face and skull base. S= everal points are plotted in order to evaluate the position of the mandible in reference to the skull. Using= these points, several linear and angular measurements are taken. Important for the diagnosis of OSA= is the size of the posterior airway space, the length of the soft palate, and = the distance from the mandible to the hyoid bone. These measurements are especially beneficial for decisions concerning surgical management.
The gold standard for the diagnosis of OSA is th= e sleep study, or polysomnography. Although alternatives exist, the ideal sleep study takes place overn= ight at a sleep lab. A variety of measurements are taken during the study, including: pulse oximetry, electroencephalogram (EEG), electrooculogram (EOG), electrocardiogram (ECG) electromyogram (EMG), degree of respiratory effort, amount of oral and nasal airflow, and limb and body movements. Terms that are important for the diagnosis of sleep apnea are apnea, hypopnea, and apnea/hypopnea index (AHI).&= nbsp; Apnea is defined as a lack of ventilation for greater than or equal = to 10 seconds with signs of arousal. Hypopnea is defined as a decrease in respiratory movement with a dro= p in oxygen saturation or with signs of arousal. Finally, the AHI, which is also kn= own as the respiratory disturbance index (RDI) is defined as the number of apneas = plus the number of hypopneas divided by the number of hours of total sleep. While there is a large amount of d= ata generated during sleep studies, often the diagnosis of OSA is made only by = the RDI. However, other important parameters for diagnosis and determination of severity are: lowest oxygen saturation, number of desaturation episodes below 90%, and the total amount= of time below 90% oxygen saturation.
Going back to the spectrum of sleep disordered breathing, there are more technical terms based on polysomnography for each= of the disorders. Primary snorin= g has an RDI below 5. UARS has an R= DI below 5, but an arousal index above 5 (number of arousals per hour as determined by EEG). OSA must = have an RDI above 5 and oxygen desaturation episodes below 90%. For Pickwickian syndrome, the pati= ent must have a BMI greater than 30 kg/m2, daytime hypercapnea with a PaCO2 of at least 45 mmHg, and some type of sleep disordered breathing.
Surgical Indications
Surgical indications for the management of OSA i= nclude an RDI above 15, an RDI above 5 with daytime sleepiness, oxygen desaturation episodes below 90%, or the presence of cardiac arrhythmias. Underlying all of these criteria i= s that there must have been an unsuccessful trial of medical therapy, or CPAP. When patients are completely compl= iant with CPAP, it is nearly a universal cure.&= nbsp; However, 100% compliance is difficult to maintain, and patients often seek surgical alternatives with the goal of becoming free of the CPAP machi= ne or to help them better tolerate the machine. Finally, as these patients often h= ave many medical comorbidities, they must be considered medically stable for surgery.
Surgical Management
Surgical management of OSA includes a wide varie= ty of procedures that vary in their invasiveness and success rates. Most of the studies that have exam= ined the success rates are retrospective chart reviews and vary greatly in their reported numbers. Generally, success is defined as a drop in the RDI by either 50% or 20 total points.
The first types of procedures done for OSA are rhinological. Increased nasal resistance may increase negative pressure in the airway during inspiration, causing airway collapse. The = main procedures used to correct nasal obstruction are septoplasty, turbinate reduction, and functional endoscopic sinus surgery. These serve to correct problems su= ch as a deviated septum, allergic rhinitis, nasal polyposis, and chronic rhinosinusitis. These are usu= ally considered adjuncts to other procedures or treatments, with the goal often being improvement of nasal CPAP compliance. The clinical usefulness of these procedures for OSA is considered controversial, as some studies have shown that septoplasty can increase the severity of OSA.
The next type of procedure involves palatal reduction. This is typically = an uvulopharyngopalatoplasty (UPPP), which is the most common procedure perfor= med for OSA. The UPPP trims excess palatal length along with the uvula, and is often combined with a tonsillectomy. Success rates = are reported to be between 40 and 50%. However, these figures drop to 6% if macroglossia is present. This procedure, like many of the o= ther procedures for OSA, has a low complication rate, with most problems arising from airway compromise.
More aggressive and less commonly performed proc= edures involve the tongue base. The = first type is the tongue base suspension= , where a permanent suture is run through the base of tongue and attached to a screw placed on the inner aspect of the anterior mandible. This serves to prevent the tongue = from collapsing posteriorly during sleep. An advantage of the procedure is that it is quick, with operation ti= mes reported as only 20 minutes. = This procedure is considered to have a variable success rate of between 20 and 8= 2%. A newer type of tongue base proced= ure is the tongue base reduction. This is usually an office based procedure performed with the Coblator.&nbs= p; It can be done multiple times to achieve the desired result. The success rates reported in the literature are more promising at between 60 and 85%.
The next procedure is the genioglossus advancement. This is accomplished by performing an osteotomy of the anterior mand= ible with advancement of the bone segment one width of the mandible. The segment is then rotated to pre= vent retraction, and secured in place with a titanium plate or screw. The procedure serves to reduce ton= gue collapse in a similar manner to the tongue suspension. The success rate has been reported= to be anywhere from 23 to 77%. Asso= ciated complications are injury to the genioglossus muscle and mental nerve.
A more aggressive procedure for OSA is the hyoid suspension. In this procedure an external inci= sion is made on the neck, and the hyoid is dissected inferiorly and advanced over the thyroid cartilage. The hy= oid is held in place by placing a permanent suture. This procedure is typically perfor= med in conjunction with a genioglossus advancement or UPPP. As with many of the other procedur= es, it has a variable success rate of between 17 and 65%. In addition to the high failure ra= te, another disadvantage of the hyoid suspension is that it often causes dysphagia.
The next procedure is the maxillomandibular advancement. For this procedure, a Lefort I osteotomy is created in the maxilla, along with bilat= eral ramus osteotomies and an anterior inferior mandibular osteotomy. Each segment is advanced 10-14 mm = while ensuring that proper dental occlusion is maintained. This serves to enlarge the posteri= or airway and is the only procedure mentioned thus far with a reproducible hig= h success rate (75-100%). One downside = of the procedure is that it significantly alters the patient’s facial appearance. However, reports = have stated that patients are usually happy with the change.
The final procedure is the tracheotomy. This= is only indicated for the presence of severe, life-threatening OSA. It is the only procedure that has consistently shown 100% success rates for severe OSA. However, even this procedure is not completely curative for patients that already have cardiopulmonary decompensation. Many patients= with Pickwickian syndrome fall into this category and have to go on the ventilat= or during sleep. Due to obvious quality of life and social stigma issues, the tracheotomy is rarely done for treatment of OSA.
Surgical Planning
With several different procedures available to h= elp patients with OSA, it can be difficult to decide which is best suited for e= ach individual patient. To make t= his decision, determination of the site or sites of obstruction, as well as the severity of OSA must be made. The usual levels of obstruction are: the nasal cavity/nasopharynx, the palate/o= ropharynx, and the base of tongue/hypopharynx. This information can be obtained via physical exam, with the Mü= ller maneuver being particularly helpful, and cephalometric analysis.
Next, the severity of the patient’s OSA sh= ould be determined by polysomnography. Patients with mild OSA have an RDI of less than 20 and a lowest saturation of oxygen greater than 85%.&nbs= p; Patients with moderate OSA have an RDI between 20 and 40 and a lowest saturation of oxygen of greater than 80%.&= nbsp; Patients with moderate/severe OSA have an RDI between 40 and 60 and a lowest saturation of oxygen of greater than 70%.
Finally, patients with severe OSA have an RDI le=
ss than
60 and a lowest saturation of oxygen less than 70. Generally, as the severity of OSA
increases, so should the invasiveness or aggressiveness of the procedure.
Protocol for Surgical Management
A specific protocol was developed at the
Based on this protocol, a prospective study was completed that had 135 patients with mild to moderate OSA, and 42 patients = with severe OSA. Their goal was to minimize surgical interventions and avoid unnecessary surgery while achievi= ng a cure. Success in the study was defined as an RDI reduction of at least 50% or an absolute drop of at least 20. The study was completed i= n two phases. In phase I, all patie= nts were placed into one of three groups. Group 1 was determined to have obstruction at the level of the oropharynx and received a UPPP. Group 2 had combined obstruction at the oropharynx and hypopharynx a= nd received a genioglossus advancement, a hyoid suspension, and a UPPP. Group 3 only had obstruction at the= hypopharynx and received a genioglossus advancement and a hyoid suspension. Of note is that a= hyoid suspension was not performed if intraoperatively the patient was considered= to have achieved adequate enlargement of the hypopharynx with genioglossus advancement alone, or if airway edema was considered to be likely after the genioglossus advancement was completed.&nb= sp; Patients who did not have success in phase I as determined by a 6 mo= nth postoperative sleep study moved onto phase II, which was maxillomandibular advancement. The success rate= s for phase I were 71-78% for mild to moderate OSA and 42% for severe OSA. For phase II of the study, the suc= cess rate for patients that failed phase I was 100%. As evidenced by the high success r= ate of the study, the Stanford protocol was recommended as a method of achieving a cure for OSA via surgical intervention.
Conclusion
There is a large amount of literature concerning= the surgical treatment of OSA. Ma= ny of the procedures have variable success rates that may make physicians wary of= performing them as a method of treatment. In light of this, more prospective studies are needed that specifically compare these procedures alone or in combination.&= nbsp; Additionally, the studies should be based on procedures that are specifically tailored to the sites of airway obstruction in the patient.
Also of note is that the accepted definition of success is often not acceptable clinically. If a patient has an RDI of 35 and = it drops to 15 with intervention, this is considered a success. However, the patient still has an increased overall mortality based on their RDI. Additionally, the RDI does not cor= relate completely with the amount of daytime sleepiness or decrease quality of life they are experiencing. Quanti= tative measures that have been found to better correlate with these symptoms are t= otal oxygen desaturation time, number of desaturation episodes below 90%, and the lowest oxygen saturation value.
Finally, in research studies and in clinical pra= ctice, patients often feel subjectively better after surgical intervention and are reluctant to undergo further studies. It should be emphasized to patients that postoperative sleep studies= are always important to access the effect of their procedure. Overall, OSA is an underdiagnosed = and undertreated disease that affects a large portion of the population. As the population becomes more obe= se, so will the number of people with OSA, thus making it imperative that further research be conducted to discover practical and effective therapy.
DISCUSSION:
Andrew, that was a very nice review of a topic that’s becoming increasingly relevant and recognized. I have several comment= s on it: first of all we can never forget the fact that CPAP cures all apnea.= It really does. There = are issues with treatment with CPAP as whether you are going to have a patient = who is going to be compliant. Compliance has been studied some and to a degree this is correlated = with the amount of pressure required to overcome the collapse and in others it’s just behavioral. F= or example, some people travel a lot and others simply don’t want to be bothered with a hose and a mask every night. The numbers out there are about 50= % for compliance. In my personal pr= actice I tailor my surgery around the patient’s disposition towards CPAP.
On another separate note, it’s clearly imp= ortant to have a gradation of surgical results so you can have a method if followi= ng just how much of a contribution the surgical procedure(s) have made to the patient’s health and comfort. The Stanford group is probably the most experienced group in dealing with sleep apnea in the country. &nbs= p; I will argue, however that from a clinically relevant perspective, reducing the RDI to less than fifty percent of their pre-intervention value= s is not necessarily correlative with clinical results. You can have someone with an RDI o= f 35 and you reduce it to 15, and they may still be somnolent enough that they m= ay be at high risk for injury at work or while driving. Again, it’s important to understand that in order to g= auge what benefits particular interventions can bring about it is one thing to t= hink about research and clinical relevance.
In my practice I consider anybody who has an RDI greater than 10 to have an abnormal RDI.&n= bsp; And it’s unusual that I see anybody show up in the office with= out symptoms having a value lower than that.&n= bsp; So at that point in time, anything with a value greater than 10 calls for an intervention, at least the most behavioral based intervention such as weight loss or potential treatment of nasal allergy to improve patency of n= asal airway at night that can perhaps improve their quality of life.
As you have pointed out, the RDI is kind of a bl=
unt
instrument, very objective and quantitative but at the same time blunt in
describing disease. In my act=
ual
practice I talk to patients about CPAP as well as severity of disease. In my mind there is really two
classes: mild-to-moderate, and
severe. Mild-to-moderate is
anywhere between 10 to 30. Gr=
eater
than 30 I call severe. It mat=
ters
greatly that people with RDI’s between 10 and 30 can be treated with
anything. You can treat them =
with
CPAP and they’ll get better. &n=
bsp;
You can have someone who says “I don’t want to use CPAP-
I’ve tried it and I hate it…” and you can offer them a number of relatively benign,
well-tolerated surgical interventions and more often than not cure them.
The surgeries I’m referring to are low-complexity surgeries: nas= al altering surgeries- intranasal- septoplasties, turbinate reduction, UPPP’s, tonsillectomies, which in my mind their contribution aside fr= om tissue bulk reduction is really a secondary contribution and that is that w= hen you do your tonsillectomy and you do your “triple P” there̵= 7;s often a remodeling that occurs which tends to stiffen up the tissue increas= ing the benefit of the procedure.
I actually draw the line in terms of low complex=
ity
surgery there because I think the next step, talking about tongue-reposition
maneuvers whether they be ton=
gue
base reduction maneuvers or genioglossal advancement procedures, both have
significant potential morbidity.
Whereas the previous procedures in the hands of well-trained individ=
uals
are rather well-tolerated with well-described complications that are relati=
vely
well-mannered. That cha=
nges
when you transcend into the next level.&nb=
sp;
As such I generally consider them as high-complexity surgeries toget=
her
with mandibular/maxillary advancement, and there are things that I won̵=
7;t
offer a patient generally until they have a true, sincere trial of CPAP eve=
n if
they come back and complain of their inability to tolerate it I will still
offer them low-complexity surgery with the aim not to do away with CPAP
compliance completely, but to improve their compliance by potentially
decreasing pressures and improving anatomy so that they are better supporte=
d. Only at that time, in a patient wi=
th
severe apnea, who has failed to tolerate CPAP, who has failed to benefit fr=
om
low-complexity surgery =
for
improved compliance, who still comes back and still has symptoms and potential
co-morbidities that I will engage in high-complexity surgical procedures.
References:
Couch= ME, Senior B. Nonsurgical and surgical treatments for sleep apnea. Anesthesiolo= gy Clin N Am. 2005 Sep;23(3):525-34, vii.
Cummi=
ngs
Otolaryngology: Head and Neck Surgery. Editors: Cumming CW, Haughey
BH, Thomas JR, Harker LA,
Head =
and Neck
Surgery Otolaryngology. Editors: Bailey BJ, Johnson JT,
Li KK= . Hypopharyngeal airway surgery. O= tolaryngol Clin N Am. 2007 Aug;40(4):845-53.
Li KK=
,
Li KK= , Powell NB, Riley RW, Troell R, Gu= illeminault C. Overview of phase II surgery for obstructive sleep apnea syndrome. Ear N= ose Throat J. 1999 Nov;78(11):851,854-7.
McMains KC, Terris DJ. Evidence-based medicine in sleep apnea surgery. Otolar= yngol Clin N Am. 2003 Jun;36(3)539-61, viii.
Prinsell JR.
Maxillomandibular advancement surgery for obstructive sleep apnea
syndrome. J Am Dent Assoc.
Riley= RW, Nelson NB, Guilleminault C. Obstructive sleep a= pnea syndrome: A review of 306 consecutively treated surgical patients. Otolaryngol Head Neck Surg. 1993 Feb;108(2):117-25.