The use of nasal airway stent (Nastent R) in patients with sleep-disordered breathing (SDB) including snoring and/or obstructive sleep apnea (OSA).

Within the spectrum of sleep-disordered breathing (SDB), obstructive sleep
apnea (OSA) is highly prevalent.[1] OSA is caused by recurring collapse of the
upper airway during sleep, resulting in complete (apnea) or partial (hypopnea)
cessation of airflow.[2] This leads to micro-arousals and sleep
fragmentation.[3] OSA severity is expressed by the apnea-hypopnea index (AHI),
defined as the number of apneas and hypopneas per hour of sleep.[4] Snoring is
common among people who suffer from OSA, however, it can also be present in the
non-OSA population (primary snoring) with various reports of its prevalence
(15-54%).[5] Besides its considerable impact on social life and its disturbing
nature, snoring is associated with several side effects. It has an established
link with both patients* and their partners* hyper-somnolence which can lead to
more severe consequences such as traffic and work place accidents. Therefore,
snoring is indeed a socioeconomic burden.[6] There have been some studies which
claim that snoring can lead to chronic hearing loss, especially in the
partner*s ears.[7-9] Snoring can also be a cause for local pharyngeal
neurogenic lesions and muscular deformations which can give rise to a
progressive upper airway collapsibility and a more severe disease over
time.[10] Also, carotid artery atherogenesis and plaque rupture, due to the
transmitted local energy from the constant vibrations and the resultant trauma
have been associated with snoring.[11]
Several attempts throughout the years have been made for the treatment of
primary snoring, including lifestyle changes such as weight reduction,
avoidance of nighttime use of caffeine, alcohol and other stimulant substances.
Various surgical techniques on different levels of the upper airway from nose
to epiglottis have been carried out. In recent years, the use of mandibular
advancement devices (MAD) or modified MADs (mandibular obturators), sleep
position therapy (SPT) and myofuctional exercise therapies [12] have also been
proposed for treatment of snoring.
Pathophysiology of snoring is diverse and therefore, not one treatment suits or
is tolerated by all. Bearing in mind that each therapy has limitations, such as
the anatomical multilevel nature of snoring in some patients which is a
negative predictor for surgical therapies, temporomandibular joint problems and
dental issues that can limit the use of MAD, there is always room for novel
treatment measures in this area.
In 1972, Walsh and colleagues for the first time tried the insertion of a nasal
tube, which was usually used for maintenance of an open airway in burn and
trauma patients, as a treatment modality for OSA. They reported good results
with a reduction in arousals and hyper-somnolence.[13] Over the years various
groups of researchers have tried different methods of using a form of stent or
tube for patients with OSA. [14-16] The concept of using a nasal stent has been
recently re-visited by OSA experts as another possible treatment option in
these patients, in particular for those with a narrow velopharynx. To date,
this treatment option has shown good results.[17] Nasal stents can be a simple
and readily available treatment option for snoring in patients with SDB.

Study aims
The aim of the current study is to assess the effect of a nasal airway stent
(Nastent R) as a treatment modality in patients with snoring and/or OSA.
Hypothesis
Nastent R, a distally perforated soft silicon nasal tube, is a mechanical
splint that might prevent collapse of the upper airway at multiple levels. It
also might reduce the vibrations caused by fluttering of various parts of the
upper airway which leads to snoring. Finally, it also might be able to secure a
patent upper airway throughout the night.

Study design
Description study design
- Patients from the ENT department who meet the inclusion criteria will be
recruited and informed about the study. Informed consent will be obtained from
the patient.
- A baseline portable sleep monitoring evaluation at home using WatchPAT*300
will be carried out.
- After a thorough clinical ENT examination, the right side of the nose (left
or right) for each patient will be determined.
- To determine the right size and position, the following protocol is done:
o A Nastent R classic (165mm) is inserted endo-nasally. Throughout the
insertion of the stent, the upper airway is being observed under awake
fiberoptic nasolaryngoscopy (which is routinely performed during ENT
examination of patients with sleep disordered breathing (SDB) in the outpatient
clinic) until the end of the nasal stent reaches the base of the tongue and
eventually is in contact with the epiglottis. After insertion, a mark is set on
the tube to show how much of the tube shaft is still out of the nostril. Based
on this marking, the right size and position of the Nastent R can objectively
be determined (165mm - protruded part in mm = correct size in mm).
o After length determination, the correct instructions for insertion by the
patients themselves will be given in detail and each patient will receive a
Nastent R Starter kit (containing 6 different stent sizes, 130, 135, 140, 145,
150 and 155mm). This kit is for patients to gradually increase the sizes each
day until they reach the right determined size for them and to get accustomed
to the stent by going from small to large to reach their size.
- After this one-week period of using the starter kit, the patient will return
to discuss their evaluation on the Nastent R, including an assessment of
tolerability and acceptance and to check whether the patient has been able to
reach the calculated size by using the starter kit.
o if yes, then a Nastent R classic kit (containing 7 stents (each can be used
for two consecutive nights) of the same length (as determined during the
previous visit or shorter if the patient has not reached the calculated size)
will be prescribed to be used by the patient for 14 nights.
o if not, the reason will be investigated.
Some patients might have gotten a response in the form of resolution of their
snoring and apneas on a shorter size than predicted while trying out various
sizes of the starter kit. In this case, the shorter size should be prescribed
for them.
- During the last night of this 14 days period with the Nastent R inside the
nostril, the patient will undergo a control portable sleep monitoring
evaluation at home using WatchPAT*300.
- Final visit, after this 14-day period:
To discuss patient acceptance and to decide on the final choice of going ahead
with this treatment modality.

Study procedures
• After patient inclusion, a baseline portable sleep monitoring at home
(WatchPAT*300) for 2 consecutive nights will be performed.
• During the next visit the objective size and position of the stent will be
determined under direct visualization using fiberoptic nasolaryngoscopy.
Subsequently, the patients will receive a Nastent R Starter kit (containing 6
different stent sizes of Nastent R, 130, 135, 140, 145, 150 and 155mm) to
gradually get accustomed to the stent and to find the right size for them.
• During the following consultation, a Nastent R classic kit (containing 7
stents of the same size, each can be used for two consecutive nights) will be
given to the patients to be used for 14 consecutive nights.
• During the last two nights of this 14-night period, a follow-up home portable
sleep monitoring evaluation (WatchPAT*300 ) will be performed with Nastent R in
situ.
• Afterwards, during the final visit at the outpatient clinic, acceptance of
the therapy with Nastent R by the patients will be evaluated, and the decision
of whether to continue the therapy and to proceed to the purchase of this
product as a long-term treatment for the patient or not, will be made.

Benefits and risks assessment, group relatedness
There are little or no risk associated with this study and based on the work of
previous researchers, no side effects were observed after long term follow up.
Possible advantages and disadvantages of the therapy
Advantages:
-fast, easy and accessible treatment
-little or no complications
disadvantage
-It might be difficult for some patients to perform the insertion on their own
which should be minimized by proper patient education

Incentives
The participants receive no compensation for participating in this study, apart
from the fact that they receive the treatment for free during the duration of
the study as the Nastent during the study period is provided for free by the
company without any additional costs for patients. In addition, there are no
extra costs for the patients either.