Surgical options for obstructive sleep apnea (OSA)
Surgical options for obstructive sleep apnea (OSA)DR. GIRISH. S
American Academy of Sleep Medicine (AASM)
Definition of osaSleep disorder that involves cessation or significant decrease in airflow through the upper airway in the presence of breathing effort.Most common type of sleep-disordered breathing (SDB) Associated with recurrent oxyhemoglobin desaturations and arousals from sleep.
osasOSA associated with excessive daytime sleepiness (EDS) is commonly called obstructive sleep apnea syndrome (OSAS)also referred to as obstructive sleep apnea-hypopnea syndrome (OSAHS)with severe OSA more than hundreds of apnea can occur.
osasOSA is defined by five or more respiratory eventsapneas, hypopneas, or respiratory effort related arousalsin association with excessive daytime somnolence; waking with gasping, choking, or breath holding; or witnessed reports of apneas, loud snoring, or both.
Pathophysiology of osa
pathophysiologyUpper airway is a compliant tube and, therefore, is subject to collapse.
OSA is caused by soft tissue collapse in the pharynx.
Role of Three factorsa reduction in the dilating forces of the pharyngeal dilators, the negative inspiratory pressure generated by the diaphragm &abnormal upper airway anatomy, the element most effectively addressed by surgery.
TRANSMURAL PRESSURE - difference between intraluminal pressure and the surrounding tissue pressure.If transmural pressure decreases the cross-sectional area of the pharynx decreases. If this pressure passes a critical point (Pcrit), pharyngeal closing pressure is reached .The airway is obstructed. OSA duration is equal to the time that Pcrit is exceeded.
pathophysiologyThe three major areas of obstruction are the nose, palate, and hypopharynx.NASAL / RETROPALATAL / RETROLINGUAL
Nasal obstructionNasal obstruction contributes to increased airway resistance and may worsen OSA. Leads to open-mouth breathing during sleep, which increases upper airway collapsibility and may decrease the efficacy of dilator muscles.Snoring can be caused by nasal obstruction.
Pathophysiology of OSAFindings in Obstruction:Nasal ObstructionLong, thick soft palateRetrodisplaced MandibleNarrowed oropharynxRedundant pharyngeal tissuesLarge lingual tonsilLarge tongueLarge or floppy EpiglottisRetro-displaced hyoid complex
PATENT v/s COLLAPSED AIRWAY
DIAGNOSISHistoryPhysical examinationFIBEROPTIC NASOPHARYNGOSCOPYMultiple positionsIn awake & asleep patientsWith Mullers maneuver awake pt generates negative pressure by inhaling against a closed glottis with mouth & nose close triggers airway collapse.
Fiberoptic view of the hypopharyngeal airway before the Mller maneuverFiberoptic view of hypopharyngeal collapse during the Mller maneuver.
diseDrug-induced sleep endoscopy (DISE) - guide more effective surgical intervention. DISE involves the use of fiberoptic nasopharyngoscopy to evaluate the site of airway collapse during pharmacologically induced sleep.Useful tool for assessing the location, severity, and pattern of airway obstruction during sleep.
cephalometric radiograph2D representation of the airway, a standardized evaluation system with broad availability and relatively low cost.These films provide information on both the bony skeleton and the overlying soft tissues. Inferior displacement of the hyoid, a smaller posterior airway space, and longer soft palates.
AWAKE COMPUTED TOMOGRAPHYMRIFLUOROSCOPY / SOMNOFLOUROSCOPYNOCTURNAL PSG gold std for the diagnosis of OSA.
PSGSimultaneous recordings of multiple physiological signals during sleep.Electroencephalogram (EEG)Electrooculogram (EOG)Electromyogram (EMG)Electrocardiogram (ECG)Oronasal airflowChest wall effortSnore microphoneOxyhemoglobin saturation
Medical treatmentWeight loss Bariatric SurgeryContinuous positive airway pressure (CPAP) Gold std for moderate to severe OSAPneumatic splint prevents collapseProvides constant +ve intraluminal pressure during respiration.
Positive Airway Pressure
69. Sullivan CE, Issa FG, Berthon-Jones M, Eves L. Reversal of obstructive sleep apnoea by continuous positive airway pressure applied through the nares. Lancet 1981;1(8225):862-65.This slide depicts the therapeutic effect of continuous positive airway pressure (CPAP). In the panel on the left, you can see upper airway closure in an untreated sleep apnea patient. Note that the airway closure is diffuse, involving both the palate and the base of the tongue. In the second panel, CPAP is applied and the airway is splinted open by the positive pressure.
Medical treatmentBilevel positive airway pressure (BiPAP) delivers a separately adjustable, lower expiratory positive airway pressure and higher inspiratory positive airway pressure.Autoadjusting positive airway pressure (APAP) Autotitrate the pressure depending on the variations of airflow to select an effective level of CPAP.
Medical treatmentORAL APPLIANCES TRD, MPDPHARMACOLOGIC THERAY MODAFINIL
osasIncludes a wide variety of procedures that vary in their invasiveness and success rates. Generally, success is defined as a drop in the RDI by either 50% or 20 total points.
indicationFactors for surgical treatment of OSA include the patients wishes, CPAP tolerance, severity of symptoms, severity of disease, patient comorbidities,site and severity of upper airway collapse.
Clinical staging of osasIn earlier days the sole treatment option for OSAS was UPPP. Surgeons were planning treatment based on the severity of disease, avoided severe dse.Now we know that OSAS is a multilevel obstruction dse & UPPP is only useful for oropharyngeal obstruction.
Clinical staging of osasAn anatomically-based staging system is made to identify areas of obstruction, and helps in tailoring the appropriate surgical treatment for each individual.The severity of disease is a secondary factor, which plays a role in determining the need for treatment.
Friedman staging systemParametersTONGUE POSITION TONSIL SIZEBODY MASS INDEX
Friedman tongue position FTP I - the entire uvula, tonsils, and tonsillar pillars. FTP II allows visualization of the uvula, but not the tonsils. FTP III allows visualization of the soft palate, but not the uvulaFTP IV allows visualization of the hard palate only
Tonsil sizeTS 0 - post-tonsillectomy patients. TS 1 implies tonsils hidden within the pillars. TS 2 represents tonsils that extend to the pillars. TS 3 refers to tonsils that extend beyond the pillars, but not all the way to the midline,TS 4 tonsils (kissing tonsils) reach the midline.
Staging outcomesSuccessful treatment of OSAHS with UPPP was most likely achieved in stage I patients because of the predominant palatal and tonsillar component. Stage II and III patients were least likely to achieve a cure after UPPP, with an overall objective cure rate of 37.9 and 8.1%, respectively. Stage III patients have a predominant base of the tongue obstructive component, thus making single level surgery useless.
precautionsOSA patients are frequently overweight, hypertensive, and have other cardiac risk factors.These patients must be cautiously screened with a comprehensive medical examination before considering surgery.The surgical planning should include a discussion between the anesthesia team and the surgeon.
precautionsStepwise algorithm frequently used - using an oropharyngeal airway to prevent airway obstruction by the tongue, refraining from using paralyzing agents until the patient can be easily ventilated with a mask & preparing alternative methods of ventilation in case intubation is unsuccessful. Possibility of tracheotomy.
Surgical managementStaged, stepwise surgical protocol.site of obstruction - to determine the type and extent of surgical intervention.Before therapy is initiated, patients should be counselled regarding the possible need for multiple surgical procedures.Patients with laryngeal obstruction should be considered for tracheostomy if improvement is not achieved surgically or with CPAP.
Nasal surgery Nasal obstruction poor sleep quality, snoring, and OSA.Septoplasty, turbinate reduction, nasal valve surgery, and sinus surgery .However, nasal procedures are unlikely to significantly improve OSA when used alone.Improving nasal patency help to restore physiologic breathing and may allow for the use of nasal CPAP in patients previously unable to tolerate it. Initial step in OSA management so as to facilitate better CPAP adherence.
Palatal surgery1981 Fujita &colleagues 1st palatal surgery UPPPIkematsu: 1985 UPPPStiffens the soft palate & increases the space behind the soft palate.Complications : temporary nasal reflex ( 12-15%) , post operative bleeding, infection & rare altered speech.
89. Fujita S, Conway W, Zorick F, Roth T. Surgical correction of anatomic abnormalities in obstructive sleep apnea syndrome: uvulopalatopharyngoplasty. Otolaryngol Head Neck Surg 1981;89(6):923-34.This slide depicts the uvulopalatopharyngoplasty (UPPP) surgical technique.