Sleep apnea is a common sleep disorder characterized by repetitive breathing stops, also called apneas. The apneas may either result from airflow reduction or blockage, or from the brain’s inactivity to activate breathing muscles contained in the chest area. Sleep apnea is a serious medical condition that may lead to a variety of unfavourable effects such as cardiovascular disease, hypertension, memory problems, stroke or death. The most common treatment methods involve surgery, the process of which can sometimes lead to health complications and death, too. There is a pressing need for pre-surgery screening, in order to assess the presence of contraindications and surgery risk levels in patients.
Types of Sleep Apnea
Depending on how often the apnea occurs, the type of sleep apnea may be classified as central, obstructive, or mixed. Obstructive sleep apnea is the most common type of the disorder. When people talk about sleep apnea, they normally refer to OSA.
Obstructive sleep apnea, characterized by at least 5 apneas per hour, generally occurs due to upper-throat tissues that collapse at various times while the person is asleep, which in turn blocks air passage. The disorder usually comes with snoring, sleepiness during the day, and disturbed sleep. Causes include structural abnormalities in the skull, face, or airways, weak surrounding airway muscles, soft palate problems, and obesity.
In central sleep apnea, the problem occurs in the central nervous system, with the most common links pointing to the brain’s failure to signal airway muscles. Heart failure proves to be the leading cause of central sleep apnea.
Mixed sleep apnea refers to a combination of central and obstructive sleep apneas.
Sleep apnea surgery risks
Major surgeries for OSA are associated with complications, due to the medications and the general anesthesia used. Anesthetic and analgesic agents are known to be CNS depressants, which can thus lead to upper airway collapse. CNS depressants have the potent capacity of affecting the body’s ventilator response, in relation to hypercapnea (increased carbon dioxide levels in the blood) and hypoxemia (decreased oxygen levels in the blood). Furthermore, an anesthetic can result in respiratory arrest.
The most commonly used corrective surgery for grave OSA cases is Uvulopalatopharyngoplasty (UPPP). Its aims are to increase airway width that is found at the opening of the patient’s throat, to improve the soft palate’s closure and movement, and to inhibit certain muscular actions so as to improve the airways capacity of remaining open. It stands as one of the most painful ways of treating the disorder, and poses several complications that can lead to fatality:
- Mucus found in the throat
- Problems in swallowing
- Impaired functionality of the soft palate and throat muscles
- Apnea recurrence
For children and adolescents, the commonly used operation includes surgically removing the patient’s adenoids and tonsils — a process called Adenotonsillectomy. The major complication that can arise is respiratory illness.
Contraindications for Sleep Apnea Surgery
Depending on the type of surgery to be employed, contraindications may vary. Reportedly, there is a low risk of developing grave complications due to surgery for sleep apnea but risks are heightened due to certain contraindications. With tonsillectomy and adenoidectomy for children, contraindications include:
- Velopharyngeal insufficiency in patients
- Having a sub-mucous cleft palate
- Being less than 3 years old
- Pre-existing complications due to OSA such as pulmonary hypertension
- Pre-existing medical or congenital conditions
Published by the Journal of the American Medical Association, a study led by Eric J Kerizian MD and MPH, revealed that contraindications for sleep apnea surgery using UPPP are the following:
- Pre-existing medical conditions or complications
- Undergoing non-nasal surgeries apart from UPPP
- High levels of body mass index
- OSA severity