Introduction
Obstructive sleep apnea - hypopnea syndrome (OSAHS) is an important medical condition, affecting 2-4% of adult female population and 4-6% of adult male population(1,2). More recent studies show that OSAHS has a general prevalence of approximately 26% in individuals between 20-70 years of age(1,3).
The symptoms of OSAHS are represented by daytime sleepiness, loud snoring, witnessed breathing interruptions, or episodes of awakening due to choking or gasping for air. The pathophysiology of OSAHS is responsible for the signs, symptoms and consequences, and is represented by repetitive episodes of collapse of the upper airway. These episodes determine sleep fragmentation, hypoxemia, hypercapnia, marked swings in intrathoracic pressure and increased sympathetic activity(4). OSASH is known to be associated with an important risk of developing and aggravating cardiovascular disease such as hypertension, atrial fibrillation, cerebrovascular disease, heart attack and stroke(1,3-6).
The diagnosis of OASHS should be made through a multidisciplinary approach including specialists in Otolaryngology, Respiratory medicine and sometimes Cardiology, Neurology and Bariatric Surgery. The diagnostic criteria are based on clinical assessment and objective sleep testing such as polysomnography (PSG) or respiratory polygraphy using a portable monitor (PM)(7,8). These tests will give an objective diagnosis and evaluate the severity of the disease using the Apnea-Hypopnea Index (AHI).
The treatment of OSAHS should be approached as the treatment for a chronic disease, requiring a long-term multidisciplinary management. The treatment options are medical, surgical and behavioral, sometimes a couple or all of them being necessary for a good outcome. Conservative treatment using Positive Airway Pressure (PAP) either in continuous (CPAP), bi-level (BiPAP) or auto-titrating (APAP), is the treatment of choice for OSAHS as it is non-invasive and has good results in reducing AHI(7,9). Nevertheless, this type of treatment has difficulties, the most important one being the lack of compliance to treatment, which is observed in 46-85% of cases(10-11). In case this happens, surgical treatment is the key to a good result for reducing AHI, by itself, or by creating favorable conditions for the patient in order to continue PAP therapy.
Discussion
The surgical treatment for OSAHS and snoring has had a great increase in modern times, after a period when it was used only as a last resort. This was due to the fact that most surgeons would perform mostly only one type of surgery, uvulo-palato-pharyngoplasty (UPPP), which for unselected patients did not have a favorable outcome(8). The modern surgery has the advantage of being “tailor-made”, in particular for every single patient, after complete and complex diagnostic procedures.
It is well known that the obstruction of the upper airway that appears in OSAHS is determined by anatomical variations of the nose and pharynx, and even of the larynx, or by an abnormal elasticity of pharyngeal structures. The most common sites of obstruction are at the level of the nose and paranasal sinuses, soft palate and uvula, lateral pharyngeal walls, tongue-base, and even epiglottis(12). The surgical techniques for this type of pathology include minimally invasive and/or extensive surgery, depending on the type of pathology and the indication for each patient. Minimally invasive techniques include surgery with radiofrequency for the nose, soft palate and tongue base, with very good results if the indication is clear(13). They are usually used in cases of mild-moderate OSAHS and can be performed as multi-level techniques, either at the same time, or apart, depending on the patient. The main advantages of these techniques are related to the fact that they can be performed under local anesthesia, as outpatient procedures, and result in a good quality of life and fast healing.
The techniques that were studied in a very intense way were the ones targeting the soft palate and uvula, regions most frequently involved in the apparition of OSAHS. Starting from classic UPPP, a series of techniques were developed with the same outcome, to shorten and harden the soft palate, and to enlarge the dimensions of the oropharyngeal inlet. Some variations of UPPP such as expansion pharyngoplasty, transpalatal advancement pharyngoplasty, lateral pharyngoplasty, pillar implants and so on are currently used with very good results. One very popular technique is the radiofrequency somnoplasty, with good results for mild OSAHS and habitual snoring. Long-term results for this technique are even better when combined with surgery of the nose and tongue-base(13).
Tongue-base surgery has had very good results in improving AHI, probably due to the fact that the tongue is a very important factor in determining OSAHS. It can be performed as an outpatient procedure using radiofrequency or using more advanced surgical techniques. Tongue-base reductions using coblation or trans-oral robotic surgery (TORS) have probably the best results, but they are also associated with higher surgical risk and sometimes severe complications(14).
Nasal and sinus surgery have an important role in the treatment of OSAHS, especially for improving the compliance to CPAP therapy(15). Even tough there is a lack of evidence regarding the success of nasal surgery as an isolated treatment for OSAHS, improving nasal patency has a very important role as part of a multi-level treatment and relieving the symptoms of habitual snoring(16).
Aside from the usual types of surgery, some other more advanced surgical techniques can be performed in selected cases, such as hyoid suspension, tongue-base suspension, genioglosus advancement, or skeletal surgery such as mandibular advancement, maxilo-mandibular advancement or mandibular distraction osteogenesis(15). These types of surgery are used for selected cases and have the slight disadvantage of being invasive. The results shown by statistics are very good, offering an important reduction of AHI. They are however restricted for patients with clear indications and for surgeons with a higher experience in sleep surgery.
Another type of surgery, which has an “indirect” implication in the treatment of OSAHS, is bariatric surgery. It is stated that one very important factor contributing to development of this condition is obesity. In obese patients, bariatric surgery and a reduction of Body Mass Index can improve AHI with very good results(17-19).
Final considerations
Even though the first intention treatment for OSAHS is conservative using PAP, surgical treatment is important in some situations. One of the situations which are frequently encountered is for patients who need an improvement in nasal patency in order to continue using PAP. Another one is for patients who are not compliant to PAP therapy, for different reasons, and prefer surgical treatment. Last but not least, in cases of mild OSAHS or habitual snoring, sleep surgery could be considered as a first option of treatment. In any case, surgery for OSASH should be performed with a “tailor-made” strategy, keeping in mind that it could be a multi-level, multi-stage approach.