Eustachian tuboplasty and shrinkage of ostial mucosa with new devices : Including a proposal of a classification system

The rat eustachian tube: Anatomical, histological, and radiological features

Purpose

This study investigated the anatomical and histological characteristics of the rat Eustachian tube (E-tube) and the feasibility of Eustachian tubography in a rat model.

Materials and methods

Fifteen male Wistar rats were used in this study, and the bilateral E-tubes of each rat were examined. Ten E-tubes were used for anatomical studies, another ten for histological analysis, and the other ten for Eustachian tubography. Five rats were euthanized and decapitated, and ten E-tubes were dissected to describe the anatomy of the E-tube. Ten E-tube specimens obtained from five other rats were sectioned to investigate E-tube histology. Eustachian tubography was performed on the bilateral E-tubes of the other five rats using the trans-tympanic approach.

Results

The rat E-tubes consisted of bony and membranous parts. Cartilage and bone tissue covered only the bony part. The E-tubes' mean diameter and overall length were 2.97 ​mm and 4.96 ​mm, respectively. The tympanic orifices' mean diameter was 1.21 ​mm. The epithelium of E-tubes was mainly composed of pseudostratified ciliated and goblet cells. Eustachian tubography was successfully performed on both sides of the E-tube for each rat. The technical success rate was 100%, the average running time was 4.9 ​min, and no procedure-related complications occurred. On tubography images, the E-tube, tympanic cavity, and nasopharynx could be identified because of the visualization of bony landmarks.

Conclusion

In this study, we described the anatomical and histological features of rat E-tubes. With the aid of these findings, E-tube angiography was successfully performed using a transtympanic approach. These results will facilitate further investigation of E-tube dysfunction.

Eustachian tube dysfunction in patients with house dust mite-allergic rhinitis

Background

One of the important pathogeneses of eustachian tube dysfunction (ETD) is nasal inflammatory disease. The prevalence of allergic rhinitis (AR) in adults ranges from 10 to 30% worldwide. However, research on the status of eustachian tubes in AR patients is still very limited.

Methods

This prospective controlled cross-sectional study recruited 59 volunteers and 59 patients with AR from Sun Yat-sen Memorial Hospital. Visual analogue scale (VAS) scores for AR symptoms and seven-item Eustachian Tube Dysfunction Questionnaire (ETDQ-7) scores were collected for both groups. Nasal endoscopy, tympanography and eustachian tube pressure measurement (tubomanometry, TMM) were used for objective assessment. All AR patients underwent 1 month of treatment with mometasone furoate nasal spray and oral loratadine. Then, the nasal condition and eustachian tube status were again evaluated.

Results

TMM examination revealed that 22 patients (39 ears, 33.1%) among the AR patients and 5 healthy controls (7 ears, 5.9%) had abnormal eustachian pressure. Twenty-two AR patients (37.3%) and 9 healthy controls had an ETDQ-7 score ≥ 15. With regard to nasal symptoms of AR, the VAS scores of nasal obstruction were correlated with the ETDQ-7 scores, and the correlation coefficient was r = 0.5124 (p < 0.0001). Nasal endoscopic scores were also positively correlated with ETDQ-7 scores, with a correlation coefficient of 0.7328 (p < 0.0001). After 1 month of treatment, VAS scores of nasal symptoms, endoscopic scores and ETDQ-7 scores were significantly decreased in AR patients (p < 0.0001), and TMM examination also suggested that eustachian tube function was significantly improved after treatment (p < 0.0001).

Conclusions

AR patients, especially those with severe nasal obstruction, could have ETD. The local conditions of the pharyngeal orifices of the eustachian tubes are closely related to the symptoms of ETD. After treatment with nasal glucocorticoids and oral antihistamines, eustachian tube function can significantly improve as nasal symptoms subside.

Trial registration Chinese Clinical Trial Registery (ChiCTR2000029071) Registered 12 January 2020—Retrospectively registered, http://www.chictr.org.cn/edit.aspx?pid=48328&htm=4

Surgical Parameters for Minimally Invasive Trans-Eustachian Tube CSF Leak Repair: A Cadaveric Study and Literature Review

BACKGROUND

Cerebrospinal fluid rhinorrhea from a lateral skull base defect refractory to spontaneous healing and/or conservative management is most commonly managed via open surgery. Approach for repair is dictated by location of the defect, which may require surgical exploration. The final common pathway is the eustachian tube (ET). Endoscopic ET obliteration via endonasal and lateral approaches is under development. Whereas ET anatomy has been studied, surgical landmarks have not been previously described or quantified. We aimed to define surgical parameters of specific utility to endoscopic ET obliteration.

METHODS

A literature review was performed of known ET anatomic parameters. Next, using a combination of endoscopic and open techniques in cadavers, we cannulated the intact ET and dissected its posterior component to define the major curvature position of the ET, defined as the genu, and quantified the relative distances through the ET lumen. The genu was targeted as a major obstacle encountered when cannulating the ET from the nasopharynx.

RESULTS

Among 10 ETs, we found an average distance of 23 ± 5 mm from the nasopharynx to the ET genu, distance of 24 ± 3 mm from the genu to the anterior aspect of the tympanic membrane and total ET length of 47 ± 4 mm.

CONCLUSIONS

Although membranous and petrous components of the ET are important to its function, the genu may be a more useful surgical landmark. Basic surgical parameters for endoscopic ET obliteration are defined.

Fluoroscopy-guided balloon dilation in patients with Eustachian tube dysfunction

OBJECTIVES

To prospectively evaluate the technical feasibility and safety of fluoroscopy-guided balloon dilation in patients with Eustachian tube (ET) dysfunction.

METHODS

Patients who could not do a Valsalva manoeuvre for more than 6 months and diagnosed with chronic otitis media or ET dysfunction were prospectively enrolled. A 0.035-in. guide wire and 6-mm long balloon catheter with a diameter of 2 mm were used to dilate the cartilaginous portion of the ET under fluoroscopic guidance. The balloon was inflated by manual injection twice for 1 min each time. Clinical outcomes were assessed by the patient's ability to perform a Valsalva manoeuvre, and symptoms were assessed using the 7-item Eustachian Tube Dysfunction Questionnaire (ETDQ-7) score.

RESULTS

Balloon dilation was attempted in a total of ten adult patients from October 2016 to March 2017. Technical success was achieved in all procedures (10/10). Ninety percent (9/10) of the balloons were fully dilated without waist deformity. There were no major complications. All patients were able to perform a Valsalva manoeuvre at the time of their last visit and/or improvement of at least one ETDQ-7 score.

CONCLUSION

Fluoroscopy-guided balloon dilation seems to be technically feasible and safe in the treatment of ET dysfunction.

KEY POINTS

• Fluoroscopy-guided balloon dilation without general anaesthesia was well-tolerated in all patients. • Location of the balloon catheter can be monitored during the procedure. • Inflation state of the balloon catheter can be monitored during the procedure. • Using guide-wire during the procedure would prevent false passage creation. • All patients had clinical improvement within 3 months after balloon dilation.