Magnetic Resonance Imaging in Obstructive Sleep Apnea
This is a study from a funded SC CTSI grant application. There is an existing IRB-approved protocol for a data repository for DISE. DISE is being performed as part of clinical care. MRI is performed for research purposes only. This submission is for the MRI component of the research study only, which is being performed for research purposes.There is a fundamental gap in our ability to design effective surgical treatment of obstructive sleep apnea (OSA) for the 30-40% of patients who cannot tolerate non-surgical treatment. OSA surgery outcomes vary widely, with the chances of a successful outcome ranging from 5% to 65% for individual or combination procedures. To predict and thereby to improve outcomes, we must determine what predicts surgical success. This project will compare findings from two evaluations: drug-induced sleep endoscopy (DISE) and upper airway magnetic resonance imaging (MRI). DISE has demonstrated important benefits, but it has important limitations. Upper airway MRI is the most complete evaluation performed during wakefulness, making it conducive to broad application and less expensive than DISE, but there are no studies utilizing MRI as a surgical evaluation. We propose a cross-sectional analysis of 50 adult subjects with moderate to severe OSA. In addition to history, physical examination, and polysomnogram (sleep study), all subjects will undergo DISE and MRI to characterize the pattern of obstruction. We will examine the association between DISE and MRI, focusing on specific DISE findings that have been associated with surgical outcomes. We are well-prepared for this innovative research and future NIH submissions because our multidisciplinary team has substantial expertise and experience in OSA investigation, DISE, and upper airway MRI.
THE ROLE OF TONSILLECTOMY IN ADULTS WITH MARKED TONSILLAR HYPERTROPHY AND OBSTRUCTIVE SLEEP APNEA
Purpose: To determine if tonsillectomy eliminates symptoms of obstructive sleep apnea in
patients with obstructive sleep apnea and marked tonsillar hypertrophy with normal soft
palate and uvula length.
Specific Aims: 1. To determine if tonsillectomy eliminates obstructive sleep apnea as
determined by polysomnography. 2. To determine if tonsillectomy eliminates excessive daytime
sleepiness and other obstructive sleep apnea symptoms.
Rationale: Current surgical procedures for obstructive sleep apnea include tonsillectomy with
soft palate surgery (including uvulopalatopharyngoplasty). Tonsillectomy alone may provide
sufficient benefit in adults with marked tonsillar hypertrophy and normal soft palate and
uvula length, avoiding the need for additional soft palate surgery.
Intervention: Tonsillectomy will be performed as standard of care, in patients who would be
undergoing said surgery regardless of study. Study intervention includes multiple home sleep
studies to determine effect of tonsillectomy in impacting symptoms of sleep apnea.
Study Population: Inclusion criteria: Subjects must be at least 18 years old, have documented
obstructive sleep apnea; be willing to undergo 3 home sleep studies; and have markedly
hypertrophic (3+ or 4+) tonsils. Exclusion criteria: Subjects must not have any craniofacial
abnormality; normal soft palate length (<4 cm) and uvula length ((<2 cm); must have no
history of chronic obstructive pulmonary disease, untreated psychological disorder, restless
leg syndrome, alcohol or drug abuse; must have a body mass index <35; must not plan to use
continuous positive airway pressure during the study period, and lack significant nasal
obstruction. The subjects will serve as their own control.
Methods and Follow Up: This two-center prospective study will include evaluation of
demographics, clinical symptoms, extent of tonsillar hypertrophy, sleep habits, and home
sleep studies. All subjects will undergo a 4-8 week period of watchful waiting (standard
minimum delay for scheduling surgery), followed by tonsillectomy alone, with values at
baseline compared to a period of watchful waiting and post-tonsillectomy.
Outcomes: Primary outcome is apnea-hypopnea index (from home sleep study). Exploratory
outcomes include other sleep study results and subjective assessments (sleep-related quality
of life with the Functional Outcome of Sleep Questionnaire and daytime sleepiness with the
Epworth Sleepiness Scale).
Statistics and Plans for Analysis: The minimum sample size is 44 subjects, with an enrollment
target of 60 subjects that will accommodate a 25% dropout rate. Standard statistical tests
(e.g., paired t-tests for continuous measures) will evaluate potential differences between
outcome measures at baseline vs. post-watchful waiting and baseline vs. post-tonsillectomy.
Similarly, standard and appropriate statistical tests (e.g, t-tests for continuous measures)
will compare changes with watchful waiting vs. tonsillectomy (e.g., baseline vs.
post-watchful against baseline vs. post-tonsillectomy).
Drug-Induced Sleep Endoscopy for Upper Airway Evaluation in Obstructive Sleep Apnea
The purpose of this study is to create a data repository about drug-induced sleep endoscopy done in the context of clinical care. The purpose of this data collection is to improve the surgical evaluation of obstructive sleep apnea by examining the technique of drug-induced sleep endoscopy and its association with surgical outcomes. Traditional evaluation techniques are static during wakefulness, whereas drug-induced sleep endoscopy provides a dynamic evaluation under sleep-like conditions. This prospective cohort data collection study will evaluate drug-induced sleep endoscopy in adults with obstructive sleep apnea who are considering surgical treatment or who are undergoing surgical treatment of obstructive sleep apnea. Adults will undergo unconscious sedation in the operating room using intravenous propofol, and oOutcomes will include the distribution of findings, association with other evaluation techniques, and a comparison of drug-induced sleep endoscopy findings with surgical outcomes. Data collection will include All subjects will undergo history, physical examination, and sleep study before and after surgery. Statistical analyses will include a combination of t-tests, chi-squared tests, and regression analyses, as appropriate.