ㅁ 연구목적 및 배경 : 
Eustachian tube dysfunction has no standardized diagnostic criteria in clinical otology, but it is a common disease. It has symptoms including hearing disturbance, aural fullness, otalgia, uncontrollable middle ear pressure, tinnitus, and dizziness. Chronic Eustachian tube dysfunction is a key factor of recurrent middle ear disease like otitis media with effusion and adhesive otitis media. The prevalence of Eustachian tube dysfunction is estimated to be around 1% of the total population. Various conservative treatments including medication or treatment for nasal cavity disease are currently conducted for these patients, but much of them didn’t respond to the treatment. Past several decades, myringotomy and ventilation tube insertion have been considered almost the only effective treatment. After the development of balloon catheter for balloon Eustachian tuboplasty(BET) with transnasal-approach in 2010, there have been reported more than 20,000 clinical trials. According to these studies, BET is considered as a safe and effective treatment for chronic Eustachian tube dysfunction. Although the internal carotid artery is adjacent to Eustachian tube, there is no way of real-time confirmatory methods for catheter insertion site and depth. 
The aim of this study is to evaluate the safety and the efficacy of Navigation guided BET (Ballooning of Eustachian tuboplasty) for patients with chronic Eustachian tube dysfunction. 

ㅁ 포함된 대상자와 진행될 중재, 측정할 결과변수: 
Out of the patients with chronic Eustachian tube dysfunction, we randomly divided them into two group; one group is treated with Navigation guided-BET (NAVIBET), and the other group is treated with previous conservative medication therapy. 
After the treatment, we will check their vital sign and symptoms indicating complications for safety evaluation.
For efficacy evaluation, the patients were evaluated by the questionnaire (named ETDQ-7), audiometric tests (pure tone audiometry, tympanometry), and ability to do Valsalva maneuver.

ㅁ 연구 가설:
We expect the patients who are treated with NAVIBET will show the relatively improved symptom score (in ETDQ-7 questionnaire) and less complications than the patients treated with previous conservative medication therapy.

Others

(The aim of this study is to evaluate the safety and efficacy of Navigation guided BET (Ballooning of Eustachian tuboplasty) for patients with chronic Eustachian tube dysfunction.)

Experimental group – Navigation guided Eustachian Tube Balloon Dilatation
1)	 Under nasal endoscope, find the orifice of Eustachian tube in lateral side of nasopharynx and insert the balloon catheter into the Eustachian tube.       
2)	Dilate the balloon with 12 atm and keep that pressure for 2 minutes.         
3)	6 weeks later, check the Eustachian tube function.

Active comparator – Conservative medication therapy (current standard treatment)
(1) drug information
   1) Fluticasone (Avamys Nasal Spray): in the morning, spray once a day, twice each nostril.
  2) Antihistamines (Bepotastine Besilate Tab. 10mg, Twolion Tab. 10mg): 1 tab twice a day.
  3) Preventive medicine for peptic ulcer (PPI or H2-blocker; Cimetidine, Famotidine, 
Lafutidine): 1 tab twice a day.
(2) period: administration for 6 weeks after the prescription

Arm Label

Target Number of Participant

Arm Type

Arm Description

1)	Under nasal endoscope, find the orifice of Eustachian tube in lateral side of nasopharynx and insert the balloon catheter into the Eustachian tube.       
2)	Dilate the balloon with 12 atm and keep that pressure for 2 minutes.         
3)	6 weeks later, check the Eustachian tube function.

Arm Label

Target Number of Participant

Arm Type

Arm Description

(1) drug information
   1) Fluticasone (Avamys Nasal Spray): in the morning, spray once a day, twice each nostril.
   2) Antihistamines (Bepotastine Besilate Tab. 10mg, Twolion Tab. 10mg): 1 tab twice a day.
   3) Preventive medicine for peptic ulcer (PPI or H2-blocker; Cimetidine, Famotidine, Lafutidine): 1 tab twice a day.
(2) period: administration for 6 weeks after the prescription

Gender

Age

Description

* Subjects must meet all the following criteria.
(1) Male or female over the age of 19
(2) Chronic Eustachian tube dysfunction patients with one or more of the criteria below
   a) Those who have three or more of the following symptoms for 12 months or longer; ear pain, ear pressure, tinnitus, cracking or popping in ears, muffled hearing, feeling that ears are clogged. 
   b) Those with otitis media with effusion whose symptoms persist even after medication. 
   c) Those with adhesive otitis media whose symptoms persist even after medication.                           
(3) Patients who voluntarily agreed in writing to participate in this clinical trial.

* Subjects who meet any of the following criteria cannot participate in this study.
(1) Those with proved dehiscence of internal carotid artery near the Eustachian tube in computed tomography (CT) scan. 
(2) Patients with patulous Eustachian tube.
(3) Patients with tympanic membrane perforation or ventilation tube insertion state. 
(4) Patients who have Meniere’s disease or chronic sinusitis.
(5) Those who have anatomy that are difficult for transnasal-approach to Eustachian tube.   
(6) Those who have history of major head or neck surgery within 4 months.  
(7) Patients with active chronic or acute otitis media.
(8) Pregnant, nursing, or childbearing-age women that have plan to get pregnant during the study period. 
(9) Those with clinically significant liver disease (ALT or AST results are more than 2.5~3 times the normal upper limit in screening test).
(10) Those with clinically significant kidney disease (serum Creatinine result is more than 2.0 mg/dL in screening test) or with hemodialysis.
(11) Those who have history of malignancy including leukemia and lymphoma within past 5 years. 
(12) Those who have experience of other clinical trial within past 4 weeks before this study.  
(13) In case that researcher judged that participation in this clinical trial is not appropriate.

Primary efficacy evaluation: Difference in average score of ETDQ-7 after 6 weeks compared to baseline score.

Efficacy evaluation: after 6 weeks from the baseline.

Safety evaluation: complication case, laboratory test, vital sign.

At every visit: visit 1(-4~0 week), visit 2(0 week), visit 3(6week ± 7day)

Secondary efficacy evaluation: difference of average score of ETDQ-7 and score of each item of ETDQ-7, tympanometry, change of hearing threshold in pure tone audiometry(500, 1000, 2000, 3000Hz), change of ability of Valsalva maneuver.

After 6weeks from the baseline.