Obstructive sleep apnea syndrome (OSAS) is a debilitating sleep and breathing disorder defined as the cessation of breathing for 10 seconds or more (an apnea) at least five times per hour of sleep. During sleep, the body's muscles relax, which can cause excess tissue to collapse into the upper airway (back of the mouth, nose and throat) and block breathing. When breathing is interrupted by an obstruction in the airway, the body reacts by waking enough to start breathing again. These arousals may occur hundreds of times each night but do not fully awaken the patient, who remains unaware of the loud snoring, choking and gasping for air that are typically associated with obstructive sleep apnea. Obstructive sleep apnea sufferers never get "a good night's sleep" because repeated apneas and arousals deprive patients of REM and deep-stage sleep, leading to chronic daytime exhaustion and long-term cardiovascular stress.
Obstructive sleep apnea has a profound impact on an individual's health. Excessive daytime sleepiness caused by disruption of normal sleep patterns leads to a significant increase in the rate of accidents for obstructive sleep apnea patients, including a sevenfold increase in automobile accidents. Over the long term, obstructive sleep apnea is associated with greater risk of hypertension and cardiovascular disease and the National Commission on Sleep Disorders Research estimates that 38,000 cardiovascular deaths due to sleep apnea occur each year.
In addition, loud snoring and intermittent breathing interruptions can affect the quality of sleep of the obstructive sleep apnea patient's bedpartner. Witnessing an apnea can be a frightening experience because the obstructive sleep apnea patient appears to be suffocating. Frequently, it is a sleep-deprived bedpartner who convinces the apneic patient to seek medical help.
Twenty-four percent of adult men and nine percent of adult women, or more than 20 million Americans, are estimated to have some degree of obstructive sleep apnea. Of these, six million are estimated to have cases severe enough to warrant immediate therapeutic intervention. However, obstructive sleep apnea was not well understood or recognized by primary care physicians until recently, and only a fraction of these 20 million obstructive sleep apnea patients have been diagnosed and treated by a physician. Somnus believes the number of patients currently undergoing treatment to be less than 500,000. With increased awareness in the physician and patient communities, a growing number of new patients are expected to be identified for treatment in the next few years.
While obstructive sleep apnea is commonly associated with obesity and male gender, it affects a broad cross-section of the population. Other risk factors include habitual snoring, which is often a precursor of more serious upper airway disorders such as obstructive sleep apnea. In fact, results from a recent study indicate that one in three men and nearly one in five women who snore habitually suffer from some degree of obstructive sleep apnea.
Traditional therapy for obstructive sleep apnea includes nightly use of continuous positive airway pressure (CPAP). During sleep, CPAP patients wear a face mask connected to a pump that forces air into the nasal passages at pressures high enough to overcome obstructions in the airway and stimulate normal breathing. CPAP is effective, but many patients find the mask uncomfortable, claustrophobic or embarrassing. CPAP patients often suffer from side effects related to forced air delivery including nasal congestion, sore eyes, headaches and abdominal bloating, and about half of CPAP patients discontinue treatment. Since CPAP is not a cure and must be used every night for life, non-compliant patients experience a full return of obstructive sleep apnea and related symptoms.
Surgical methods for treating obstructive sleep apnea include uvulopalatopharyngeoplasty (UPPP), the surgical resection of the uvula, part of the soft palate, tonsils and possibly other excess tissue in the throat. UPPP is an invasive procedure that typically requires general anesthesia and an overnight hospital stay, and it does not address obstructions at the base of tongue. Other surgical methods for treating obstructive sleep apnea are invasive and involve reducing the size of the tongue through surgical resection, moving the tongue or the jaw forward, or bypassing the obstruction through a tracheostomy. A tracheostomy, or the opening of a collateral airway through the neck, is typically reserved for the most severe cases of obstructive sleep apnea, when other interventions are either ineffective or unacceptable. These treatments are invasive and expensive, may require general anesthesia and hospitalization, and result in a lengthy, painful recovery period.
The Somnoplasty procedure for obstructive sleep apnea, which is performed under local anesthesia, treats sleep apnea by shrinking soft tissue in the upper airway including the base of tongue, the source of obstruction that is most difficult to treat. Somnus' proprietary Somnoplasty™ System is designed to use radiofrequency (RF) energy to provide a minimally invasive and less painful treatment of upper airway obstructions under local anesthesia. The System includes an automated RF control unit with temperature monitoring capabilities and a suite of proprietary, single-use, disposable surgical handpieces that deliver controlled thermal energy into targeted areas to reduce tissue volume and stiffen soft tissue.
The Somnoplasty procedure for obstructive sleep apnea generates heat at approximately 85° C (185° F) to create finely controlled coagulative lesions at precise locations within the upper airway. An insulating sleeve at the base of the needle electrode is intended to protect the surface of the tissue from thermal damage, thereby minimizing post-operative discomfort. The lesions created by the procedure are naturally resorbed in approximately three to eight weeks, reducing excess tissue volume and opening the airway. Typically, the Somnoplasty procedure for obstructive sleep apnea takes 30 to 45 minutes, with only five to 10 minutes required for RF energy delivery. The procedure is performed on an outpatient basis and after being monitored overnight, patients can return to their normal activities the following day. Typically, more than one treatment is necessary to achieve optimal results.
The Somnoplasty procedure for obstructive sleep apnea is performed under local anesthesia in an outpatient setting. The protection of the delicate surface of the tissue, the controlled delivery of energy and the ability to maintain a constant, low temperature present a sharp contrast to conventional surgery. Patients undergoing traditional surgery can suffer significant pain and take narcotic medications for several weeks. After the Somnoplasty procedure for obstructive sleep apnea, patients may experience swelling and some discomfort, and take pain medications for two to three days.
Initial clinical results showed that the Somnoplasty System effectively treated obstructive sleep apnea by shrinking the base of tongue-the most difficult source of obstruction to treat-in moderately and severely affected patients. These results were presented at the Annual Meeting of the
All potential candidates should be evaluated by a physician to confirm the presence of obstructive sleep apnea (through an overnight sleep study) and identify the possible sites of airway obstruction.
Is the Somnoplasty procedure for obstructive sleep apnea commercially available throughout the U.S.?
More than 800 doctors in the
The Somnoplasty System has already been cleared by the FDA for use in the treatment of three conditions: habitual snoring (soft palate and uvula), chronic nasal obstruction (enlarged inferior turbinates) and OSAS/UARS. As of June 1999, more than 20,000 patients have been treated with Somnoplasty Procedures.