Endolymphatic Duct Blockage as a Surgical Treatment Option for Ménière's Disease

Summary

Endolymphatic duct blockage is a relatively new surgical method for patients suffering from Ménière’s disease. Following a regular mastoidectomy, the endolymphatic duct is identified and ligated using a regular titanium hemoclip. The effectiveness of this procedure is currently being assessed in a randomized trial.

Abstract

Endolymphatic duct blockage is a relatively new treatment option for Ménière’s disease, aiming to reduce vertigo attacks while sparing hearing and equilibrium. After a regular mastoidectomy, the posterior semicircular canal is identified, and Donaldson’s line is determined. This is a line through the horizontal semicircular canal, crossing the posterior semicircular canal. The endolymphatic sac is usually found at this site under the posterior semicircular canal. The bone of the endolymphatic sac and the dura are thinned until the sac is skeletonized, after which the endolymphatic duct is identified. The duct is then blocked with a titanium clip. Using a computerized tomography (CT) scan, the position is confirmed. Follow-up visits take place 1 week, 6 weeks and 1 year after surgery. To this day, only one prospective trial assessing this method has been conducted, comparing this new method to endolymphatic sac decompression. Results of the duct blockage are promising, with 96.5% of the patients free of vertigo after 2 years. However, further research is required.

Introduction

Ménière's disease (MD) is an incapacitating disease characterized by vertigo bouts, aural symptoms, and hearing loss¹. Endolymphatic hydrops in the inner ear is present in patients with MD, but the exact aetiology of the disease remains unclear. In most patients, the symptoms resolve over time²; despite this, the majority of patients seek active treatment because of the unpredictable pattern of attacks.

Treatment for MD aims to reduce vertigo attacks. In the past century, different treatment modalities have been proposed, both surgical and non-surgical. Destructive surgical interventions, such as labyrinthectomy or vestibular neurotomy, are effective in controlling vertigo but cause deafness and a loss of vestibular function on the operated ear^3,4. Surgeries on the endolymphatic sac (ES) have been studied, such as decompression and shunting of the sac, but neither of the proposed interventions have been proven to be more effective than placebo surgery⁴.

In 2015, Saliba et al. published the results of a randomized controlled trial comparing a new technique, endolymphatic duct blockage (EDB), to endolymphatic sac decompression (ESD)⁵. The trial yielded promising results, with 96.5% of the patients in the EDB group being free of vertigo attacks after 2 years. The rationale behind this technique is that the ES is at least partially responsible for the disturbed homeostasis of endolymph and produces an overload of endolymph due to increased production. By blocking the endolymphatic duct (ED), the surplus of endolymph that is generated in the sac is hindered from flowing to the rest of the inner ear. This hypothesis is supported by histological studies^6,7,8.

Whether EDB is the appropriate treatment for an individual patient depends on various factors. The patient's preference and the surgeon's preference play a role, but local health care regulations may also influence treatment choice. In our center, EDB is only considered in patients who suffer vertigo attacks despite treatment with intratympanic (IT) injections with corticosteroids, and if vestibular migraine has been ruled out. EDB is especially suitable for patients with good hearing function who reject ablative treatment. This article describes the surgical steps of this new technique and discusses the literature that is currently available.

Protocol

This protocol is used for a randomized controlled trial that is currently being carried out in the Netherlands. The trial compares endolymphatic duct blockage (EDB) to endolymphatic sac decompression (ESD)9. The protocol was approved by the medical ethics committee METC Leiden-Den Haag-Delft (number P20.118) and the board of the hospital, as well as the hospital's research ethics committee (Haga Hospital Research Board, T20-108). All patients who participated in the trial where this protocol i…

Representative Results

Surgical factors This procedure was performed by one of the authors (HB) in both the Haga Hospital and the Antwerp University Hospital. Data from the Antwerp University Hospital could not be retrieved, but approximately 100 patients underwent EDB at that location. In the Haga Hospital, EBD is only allowed in the context of the aforementioned trial. In this trial, surgery was performed on 38 patients. Due to the blinded character of the trial, it is unknown how many and which of these patients under…

Discussion

EDB is a potential new treatment modality, aiming to reduce vertigo attacks while sparing inner ear function in patients with intractable MD. In the current literature, the results seem promising, but little data is available.

Rationale of the technique
Targeting the ES for relieving MD symptoms has been controversial for some decades. In the past, the general belief has been that the (ES) mainly has a role in the resorption of endolymph^13,</…

Materials

Adson Forceps, Delicate, Smooth, 1 x 2 teeth, 12 0mm	Aesculap BV	BD511R
Adson-Brown Tissue Forceps, 7 x 8 teeth, 120 mm	Aesculap BV	BD700R
Baby Adson Retractor, hinged, semi-S tip, 3 x 4 prongs blade end, 140 mm	Aesculap BV	BV085R
Baby Senn-Miller RetractorFlat Handle, SHARP tip, 3 PRONGS blade end, blade size 8 x 7/22 x 7, 165 mm	Aesculap BV	BT006R
Bien Air Nano Micromotor OsseoDUO + NANOmicromotor	Bien air	1700524-001	Electronic motor used for mastoidectomy
Bien air tubing set for peristaltic pump	Bien air	1100037
Coagulation Forceps	Aesculap BV	E700246	Used for hemostasis
Cord, bipolar, 4.5 m	Valleylab BV	E360150L
Diamond burrs 0.8x 70 to 7.0×70	Bien air
Ear Curette, Pointed, Double Ended, cup size LARGE, 170 mm	Aseculap BV	OG189R
Ethicon hechtdraad 3/0 sh-1 vicryl 70 cm	Ethicon	3006273	Suture for deeper tissue layers
Fibrin Sealant	Baxter BV	BE-90-01-040	Tissue glue used in case of liquor leakage
Gillies Skin Hook, Tip 0.5/6mm, jaw STR, SERR	Aesculap BV	OL611R
Gillies Tissue Forceps, Delicate, X-SERR tip, 1 x 2 teeth, 155 mm	Aesculap BV	BD660R
Halsted Mosquito Forceps, Delicate, CVD jaw, 125 mm	Aesculap BV	BH111R
Handpiece for burr	Bien air	1600830-001
Hartmann Ear Forceps , Tip 4 mm, jaw STR	Aesculap BV	OG329R
Hartmann-Wullstein Ear Forceps	Aesculap BV	OF410R
Hejek Mallet, Ø27 220 mm	Aesculap BV	FL044R
Horizon Metal Ligation System – Clips size MICRO, SMALL, MEDIUM	Teleflex Medical	1201, 2200, 5200	Titanium clip used for blockage of endolymphatic duct
House Ear Curette	Aesculap BV	OG182R	Double Ended, cup size (mm) 1.5/1.8, tip ANG
Lucae Bayonet Forceps	Aesculap BV	BD878R	SERR tip, 140mm
Lucae Bayonet Forceps	Aesculap	BD878R	SERR tip, 140mm
Lucae Ear Hook Button	Aesculap BV	OF278R	Hook end SMALL, tip SHARP, 130mm
Mayo Dissecting Scissors	Aesculap BV	BC587R	Round Blade, B/B tip, CVD blade, 165mm
Mayo Dissecting Scissors, Round Blade, B/B tip, CVD blade, 165 mm	Aesculap BV	BC587R
McIndoe Thumb Forceps, Delicate	Aesculap BV	BD236R	SERR tip, 150 mm
Micro Adson Forceps, Delicate, SERR with platform tip Tip, 12 cm	Aesculap BV	BD220R/425.112
Monocryl 4-0 FS-2. 70 cm	Ethicon	Y422H	Suture for skin
NIM response 3.0	Medtronic	NIM4CM01	Nerve monitoring system
OSSEODUO control unit	Bien air	1600513-001
Paired Subdermal electrodes with subdermal ground electrode and subdermal stim return, 2 channel	Medtronic Xomed	8227410
Scalpel Handle #3  F/ Blades	Aesculap BV	BB070R
Steel burrs 0.8x 70 to 7.0x 70	Bien air
Volkmann Curette, tip size 3.6 mm, 170 mm	Aesculap BV	FK631R
Watertight, 2-button multifunction pedal	Bien air	1600517-001
Williger Bone Elevator, blade 6, 160 mm	Aesculap BV	FK300R
Wire bending forceps, curved downards, 80 mm, jaw length 3.50 mm, with tubular shaft	McGee	OG359R	Used to close clip
Wullstein Retractor, sharp tip, 3 x 3 prongs blade end, 130 mm	Aesculap BV	BV076R