Balloon dilatation of the Eustachian tube for obstructive Eustachian tube dysfunction in adults

Eustachian tube dysfunction (ETD) causes symptoms and signs of pressure dysregulation in the middle ear, and is associated with tympanic membrane retraction, otitis media with effusion, and chronic otitis media. Interventions aiming to improve symptoms can be non-surgical or surgical, including balloon dilatation of the Eustachian tube, also known as balloon eustachian tuboplasty (BET) for obstructive ETD. However, existing published evidence for the effectiveness and safety of BET remains unclear.

To evaluate the effects of balloon dilatation of the Eustachian tube in adults with obstructive Eustachian tube dysfunction.

The Cochrane ENT Information Specialist searched the Cochrane ENT Register; Central Register of Controlled Trials (CENTRAL); Ovid M>DLINE; Ovid Embase; Web of Science; Clinicaltrials.gov; ICTRP and additional sources for published and unpublished trials. The final search was updated on 18th January 2024. There were no restrictions on language, publication date or study setting.

Randomised controlled trials were included if they allocated adult participants with chronic obstructive ETD to treatment randomly and compared BET with non-surgical treatment, no treatment, or other surgical treatment. Studies with other designs were excluded.

At least two review authors independently selected trials using predetermined inclusion criteria, assessed the risk of bias, extracted data, and rated the certainty of evidence (CoE) according to GRADEpro. Statistical analyses were performed using a random-effects model and interpreted according to the most recent version of the Cochrane Handbook. Predefined primary outcomes were obstructive ETD symptoms, Eustachian tube function (objective or semi-objective tests), or serious adverse events. Secondary outcomes were hearing, tympanic membrane abnormalities, quality of life, and other adverse events.

Nine trials were identified with 684 randomised participants across three comparisons: BET versus non-surgical treatment (five trials, 422 participants), BET versus no treatment (sham surgery; one trial, 17 participants), and BET versus other surgery (four trials, 275 participants). None of the studies were rated with an overall low risk of bias. Comparing BET to non-surgical treatment up to three months, there is low-certainty evidence showing that BET may reduce patient-reported ETD symptoms (change in ETDQ-7: mean difference (MD) -1.66 (95% CI -2.16 to -1.16; I² = 63%; 4 RCTs, 362 participants)). There is very low-certainty evidence that BET may improve ETD as assessed by objective or semi-objective measures (improvement in tympanometry: RR 2.51 (95% CI 1.82 to 3.48; I² = 0%; 3 RCTs, 369 participants). Between three and 12 months, the evidence is very uncertain whether BET reduces ETDQ-7: MD -0.55 (-1.31 to 0.21; 1 RCT, 24 participants). The evidence is very uncertain whether BET improves ETD as assessed by objective or semi-objective measures (improvement in tympanometry: RR 2.54 (95% CI 0.91 to 7.12)). Evidence was downgraded for risk of bias, imprecision, indirectness, or a combination of these. Comparing BET to no treatment (sham surgery trial) up to three months, there is very low-certainty evidence that BET improves ETD as assessed by patient-reported ETD symptoms (change in ETDQ-7: MD -0.54 (95% CI -2.55 to 1.47; 1 RCT, 17 participants)). Between three and 12 months, the evidence is very uncertain whether BET improves ETD as assessed by ETDQ-7 (MD 0.16 (95% CI -0.75 to 1.07; 1 RCT, 17 participants)). Evidence was downgraded for indirectness and twice for imprecision. Although there were no serious adverse events reported, these studies were underpowered to detect adverse events and were performed by highly trained and experienced investigators under strict study protocols. This could underestimate the true risk of adverse events by less experienced clinicians in everyday clinical practice. Evidence was rated as very low certainty, downgraded for risk of bias, imprecision, and indirectness.

BET may lead to a clinically meaningful improvement in ETD symptoms compared to non-surgical or no treatment (in the form of sham surgery) at up to three months. The effects of BET on ETD compared to non-surgical treatment are very uncertain beyond three months. However, the certainty of evidence ranged from low to very low, with the studies being underpowered to detect adverse events. The findings of this review should help to inform further BET research and guidelines. Future research should focus on longer-term outcomes and the incidence of adverse events or complications in real-world practice settings.