Introduction

Eustachian tube dysfunction is a physiological disorder. Eustachian tube dysfunction is further classified into three subtypes: dilatory (or obstructive), baro-challenge-induced and patulous Eustachian tube dysfunction.Reference Schilder, Bhutta, Butler, Holy, Levine and Kvaerner1 Eustachian tube dysfunction traditionally has been treated with pharmacological agents, mechanical devices and nasal surgery. However, the results have not been satisfactory.Reference Adil and Poe2,Reference Norman, Llewellyn, Harden, Coatesworth, Kimberling and Schilder3 Balloon Eustachian tuboplasty was first introduced to patients in 2010 for chronic obstructive Eustachian tube dysfunction.Reference Leichtle, Hollfelder, Wollenberg and Bruchhage4,Reference Ockermann, Reineke, Upile, Ebmeyer and Sudhoff5 The goal of balloon Eustachian tuboplasty is to prevent, reverse or stop the progression of these diseases by widening the cartilaginous part of the Eustachian tube, and thereby improving its function.Reference Leichtle, Hollfelder, Wollenberg and Bruchhage4

Balloon Eustachian tuboplasty is a promising treatment for both adults and children that has encouraging results.Reference Leichtle, Hollfelder, Wollenberg and Bruchhage4,Reference Ockermann, Reineke, Upile, Ebmeyer and Sudhoff5 Although balloon Eustachian tuboplasty is generally considered a low-risk procedure and several studies on the effect of balloon Eustachian tuboplasty have been published,Reference Randrup and Ovesen6it is a comparatively new intervention with limited evidence so far in terms of efficiency and risks.Reference Leichtle, Hollfelder, Wollenberg and Bruchhage4

Some studies have discussed complications associated with balloon Eustachian tuboplasty.Reference Krogshede S, Kirchmann, Peter Schjellerup Jørkov and Glad7–Reference Saniasiaya, Kulasegarah and Narayanan9 However, data are scarce and true figures are lacking to describe common and uncommon adverse events and their incidence. This is primarily important for clinicians to know these so that common and uncommon adverse events and their incidence can be discussed in the consenting process. It is also noteworthy that indications and outcomes of balloon Eustachian tuboplasty are neither fully proven nor widely accepted so far. Hence, balloon Eustachian tuboplasty still is an emerging procedure. This makes it even more vital for clinicians to inform patients about possible risks so they can weigh the benefits and the complications.

Therefore, we aim to conduct a systematic review of the literature, especially randomised, controlled trials (RCTs) and other sources of primary evidence to identify the possible complications and their approximate incidence based on published data. Simultaneously we also aim to investigate what pre-, peri- and post-operative measures should be taken to avoid possible complications.

Results

Initial search was made using our keywords. However, studies that had balloon Eustachian tuboplasty only were considered for final analysis. A total of 69 studies met our initial search using Google Scholar, Medline, Cochrane library, PubMed, and Embase databases. Of these 69 studies, 14 met our inclusion criteria and were selected for data extraction and analysis. These 14 studies included two randomised, controlled trials (RCTs),Reference Krogshede S, Kirchmann, Peter Schjellerup Jørkov and Glad7,Reference Poe, Anand, Dean, Roberts, Stolovitzky and Hoffmann8 two systematic reviews,Reference Randrup and Ovesen6,Reference Saniasiaya, Kulasegarah and Narayanan9 five retrospective studies,Reference Cheng, Saxby, Jufas, Kong and Patel10–Reference Dai, Guan, Jia, Li, Sang and Chang14 two case seriesReference Ockermann, Reineke, Upile, Ebmeyer and Sudhoff5,Reference Jurkiewicz, Bień, Szczygielski and Kantor16 and three case reports.Reference Chung, Shin, Cha and Lee17–Reference Shah, Thomas, Naples and Ruckenstein19 The study-selection process is illustrated in the flow chart in Figure 1.

Figure 1. Flow chart presentation of all studies.

Review of literature by the level of evidence Level IB

Two randomised, controlled trials (RCTs) were analysed. The two trials included a total of 309 patients. No life-threatening or major complications were reported. Following that, balloon Eustachian tuboplasty was considered as a safe and effective procedure for Eustachian tube dysfunction.Reference Ockermann, Reineke, Upile, Ebmeyer and Sudhoff5,Reference Krogshede S, Kirchmann, Peter Schjellerup Jørkov and Glad7,Reference Poe, Anand, Dean, Roberts, Stolovitzky and Hoffmann8

Level III

Five studies were analysed retrospectively. Of 2430 patients that were analysed, 10 patients developed post-operative emphysema, including three patients with extension into mediastinum and developed pneumomediastinum.Reference Cheng, Saxby, Jufas, Kong and Patel10–Reference Dai, Guan, Jia, Li, Sang and Chang14 Howard et al. concluded that balloon Eustachian tuboplasty was a relatively safe intervention with an overall complication rate of 4.7 per cent in a paediatric population.Reference Howard, Babu, Haupert and Thottam15 Similarly, Skevas et al. reported balloon Eustachian tuboplasty as a safe and effective procedure with major complication rates less than 1 per cent.Reference Skevas, Dalchow, Euteneuer, Sudhoff and Lehnerdt13

Level IV

Two case series were published. Twelve patients were included. No major or life-threatening complications were reported in any of the cases. Jurkiewicz et al. reported an overall improvement in symptoms post-balloon Eustachian tuboplasty.Reference Jurkiewicz, Bień, Szczygielski and Kantor16

Review of literature by type of complication

We divided the complications according to severity. We described major complications as being those requiring further therapy with an increase in the level of care or requiring hospitalization. Events not requiring any additional treatment or hospital admission were regarded as minor. Complications reported as a single case report are described under the heading of rare complications because it is difficult to ascribe procedure effects with single reports.

Major complications

The most commonly reported major complication was surgical emphysema. Of 3480 patients, 14 patients had surgical emphysema. In five patients, surgical emphysema was extending into the mediastinum leading to pneumomediastinum (0.14 per cent).Reference Skevas, Dalchow, Euteneuer, Sudhoff and Lehnerdt13,Reference Long, Obayemi and Rameau18,Reference Shah, Thomas, Naples and Ruckenstein19 The overall percentage for surgical emphysema was 0.40 per cent.

Miscellaneous complications

Some studies reported minor complications, including patients with slight tenderness, epistaxis, hemotympanum, temporary increase of tinnitus, serous otitis media, rhinitis, transient dysesthesia of the tongue secondary to chorda tympani compression, temporary patulous Eustachian tube and transient ischaemic attack (TIA) unrelated to balloon Eustachian tuboplasty at the fifth post-operative day.Reference Randrup and Ovesen6,Reference Saniasiaya, Kulasegarah and Narayanan9–Reference Skevas, Dalchow, Euteneuer, Sudhoff and Lehnerdt13 Their incidences, as per our review, are given in Table 3.

Table 3. Percentages of all reported complications post-Balloon Eustachian tuboplasty

Rare complications

There was one case of transient asystole during balloon Eustachian tuboplasty. This happened as soon as the balloon in the Eustachian tube was inflated, and it lasted for 13 seconds. The patient recovered sinus rhythm spontaneously. The balloon Eustachian tuboplasty was successfully performed after prophylaxis with vagolytic drugs. It is thought to be a neurally mediated vagal reflex, and both anaesthesiologists and otologic physicians should pay proper attention to monitoring during the procedure.Reference Chung, Shin, Cha and Lee17

Another case of TIA was reported in a retrospective case series of 62 patients, from our Australian colleagues.Reference Cheng, Saxby, Jufas, Kong and Patel10 However, TIA developed on the fifth post-operative day. The case was investigated further to find the cause; despite thorough investigations, Cheng et al. could not find a relationship to the procedure. All complications are summarised in Table 3.

Discussion

The present study systematically reviewed 14 articles for possible complications associated with balloon Eustachian tuboplasty. Out of 3480 post-balloon Eustachian tuboplasty patients (14 studies), 15 patients (0.43 per cent) had post-balloon Eustachian tuboplasty major complications. Other minor complications also were recorded. In all studies, patients were managed conservatively. Our findings are consistent with other studies published on balloon Eustachian tuboplasty complications. Balloon Eustachian tuboplasty seems to be a relatively safe procedure with a risk of major complications of less than 1 per cent.Reference Skevas, Dalchow, Euteneuer, Sudhoff and Lehnerdt13,Reference Ramakrishnan, D'Souza and Kadambi20

Different surgical procedures were developed to treat chronic Eustachian tube dysfunction until the introduction of balloon Eustachian tuboplasty.Reference Ockermann, Reineke, Upile, Ebmeyer and Sudhoff5 Although balloon Eustachian tuboplasty seems to be a relatively a safe procedure, possible adverse events have been documented. McCoul et al. reported a complication rate of 2 per cent for balloon Eustachian tuboplasty.Reference McCoul, Weinreich, Mulder, Man, Schulz and Shin21 Most complications were minor and self-limiting. Most complications found in our review also were minor. The overall complication rate in our study was 1.66 per cent (58/3480), all of which were managed conservatively.

Tucci et al. Reference Tucci, McCoul, Rosenfeld, Tunkel, Batra and Chandrasekhar22 reached a consensus regarding the risks associated with balloon Eustachian tuboplasty and pre-operative discussions with patients. They included bleeding, scarring, infection, development of PETD, and/or need for an additional procedure for consenting to balloon Eustachian tuboplasty.Reference Tucci, McCoul, Rosenfeld, Tunkel, Batra and Chandrasekhar22 However, we think that there are other important complications as well, which we divided into major and minor complications (Table 3). We recommend including these complications in the consenting process with a patient.

Surgical emphysema is a well-documented complication associated with balloon Eustachian tuboplasty.Reference Skevas, Dalchow, Euteneuer, Sudhoff and Lehnerdt13 Skevas et al. reported that post-operative emphysema was 0.27 per cent in their study.Reference Skevas, Dalchow, Euteneuer, Sudhoff and Lehnerdt13 Similarly, in our analysis, overall post-balloon Eustachian tuboplasty surgical emphysema was 0.40 per cent.

We also reviewed the literature to identify measures that can be taken to prevent post-balloon Eustachian tuboplasty complications. Based on our review we have divided them into three categories: (1) pre-operative assessment and patient selection, (2) peri- and intra-operative care and (3) post-operative care.

Pre-operative assessment and patient selection

It is crucial to select the correct patients for balloon Eustachian tuboplasty to prevent procedure-related complications. Cheng et al. reported pre-operative patient selection criteria in their study to carefully consider a patient for balloon Eustachian tuboplasty surgery.Reference Schilder, Bhutta, Butler, Holy, Levine and Kvaerner1,Reference Cheng, Saxby, Jufas, Kong and Patel10,Reference Zhou, Gopen and Poe23 Possible measures to prevent post-balloon Eustachian tuboplasty complications are noted in Table 4.

Table 4. Measures to prevent post-balloon Eustachian tuboplasty complications

Balloon Eustachian tuboplasty's success largely depends on proper patient selection. It is essential to select a candidate with true primary dilatory Eustachian tube dysfunction before offering balloon Eustachian tuboplasty. Because patulous Eustachian tube dysfunction and dilatory Eustachian tube dysfunction symptoms commonly crossmatch, lack of in-depth assessment may lead to poor outcomes and even harm in some cases.Reference Tucci, McCoul, Rosenfeld, Tunkel, Batra and Chandrasekhar22 In addition, Tucci et al. emphasized identifying the secondary causes of Eustachian tube dysfunction, such as allergic rhinitis, rhinosinusitis, and laryngopharyngeal reflux.Reference Tucci, McCoul, Rosenfeld, Tunkel, Batra and Chandrasekhar22 Targeted therapy will help in the symptomatic treatment of extrinsic causes.Reference Tucci, McCoul, Rosenfeld, Tunkel, Batra and Chandrasekhar22 The role of preoperative computed tomography scans also has been investigated to rule out carotid artery dehiscence by Abdel Aziz et al., however they did not find sufficient evidence to support its use to predict adverse events.Reference Abdel-Aziz, Schröder, Lehmann, Gehl, Ebmeyer and Sudhoff24

Peri- and intra-operative care

Mucosal injury of the Eustachian tube orifice during catheter adjustment for the correct position of the insertion instrument is thought to be one of the most plausible causes of post-interventional emphysemas. Another possibility is mucosal damage inside the Eustachian tube through a ‘kinking’ of the balloon catheter or even due to the relatively hard catheter itself, even though its form is regarded to be atraumatic. Thus, air can escape to the peri-tubal tissues, involve the soft tissues of the face and neck, and extend up to the mediastinum. Results from studies showing rupture of the mucosal barrier during balloon Eustachian tuboplasty reinforce the above assumptions.Reference Skevas, Dalchow, Euteneuer, Sudhoff and Lehnerdt13

Furthermore, it is thought that catheter material plays an important role as well. Rigid catheters can be difficult to insert and cause injury to the mucosa, which can lead to major complications. For example, Pau et al. raised concerns regarding possible mucosal ruptures inside the Eustachian tube secondary to a relatively inelastic catheter.Reference Pau25

Careful catheter insertion and less manipulation are key in preventing any adverse incident. In addition, extra care is needed in case of increased vulnerability of the mucous membranes of the upper airways. For instance, earlier radiation therapy, systemic diseases, or chronic infections with mucosal involvement may notably increase the risk of emphysematous complications. For example, Skevas et al.'s report of one patient with an eosinophilic disease supports this assumption, since the patient developed emphysemas after both balloon Eustachian tuboplasty procedures.Reference Skevas, Dalchow, Euteneuer, Sudhoff and Lehnerdt13

Two different balloon catheter systems for dilating the cartilaginous portion of the Eustachian tube have been described in the literature: (1) Acclarent sinus balloon catheter (Acclarent, Menlo Park, CA, USA), which is 5 mm wide and 16 mm long, and (2) Bielefeld balloon catheter (Spiggle & Theis Medizintechnik, Overath, Germany), which is 20 mm long with a diameter of 3.28 mm. The balloon sizes of the Acclarent system are wider compared to the Bielefeld catheter with diameters of 5–7 mm.Reference Hwang, Kok and Walton26 While the Acclarent system inflates the balloon at 12 atmospheres for between 30 seconds and 2 minutes, the Bielefeld system inflates the balloon at 10 atmospheres for 2 minutes. Despite this difference in dimensions and recommended pressure, emphysematous complications with the Acclarent system do not exceed the ones reported with the Bielefeld balloon.Reference Catalano, Jonnalagadda and Yu27,Reference Tisch, Maier and Maier28

Prophylactic antibiotic also has been recommended in cases of mucosal injury to prevent soft-tissue infections. Schröder et al. reported that catheter tips are potential sources of infection.Reference Schröder, Abdel-Aziz, Lehmann, Ebmeyer and Sudhoff29 They noted that catheter tips have a wide range of bacterial species including the normal flora of pharyngeal mucosa such as Corynebacterium, Staphylococcus hominis, Proteus mirabilis, Escherichia coli, Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pyogenes and Klebsiella oxytoca. Mucosal injury can provide a medium for organisms to spread into soft tissues and lead to infection, even sepsis in certain cases.Reference Schröder, Abdel-Aziz, Lehmann, Ebmeyer and Sudhoff29 Hence, the use of broad-spectrum antibiotics covering both gram-positive and gram-negative seems essential in the event of complications. Similarly, Skevas et al. recommended use of prophylactic antibiotics in case of mucosal injury.Reference Skevas, Dalchow, Euteneuer, Sudhoff and Lehnerdt13

Post-operative care

Post-balloon Eustachian tuboplasty, patients were told in the majority of the studies to perform the Valsalva manoeuvre immediately after the procedure.Reference Skevas, Dalchow, Euteneuer, Sudhoff and Lehnerdt13 However, it was found that the Valsalva manoeuvre, along with other factors, was actively responsible for post-balloon Eustachian tuboplasty emphysema.Reference Skevas, Dalchow, Euteneuer, Sudhoff and Lehnerdt13 Hussain et al.Reference Hussain, Hashmi and Qayyum30 reported that a patient advised to perform the Valsalva manoeuvre post-balloon Eustachian tuboplasty, developed extensive subcutaneous emphysema immediately after the Valsalva manoeuvre. They recommended delaying the Valsalva manoeuvre for 2 weeks post-operatively.Reference Hussain, Hashmi and Qayyum30 Similarly, Skevas et al. recommended delaying the Valsalva manoeuvre 3 weeks post-operatively.Reference Skevas, Dalchow, Euteneuer, Sudhoff and Lehnerdt13 Additionally, patients should be instructed to sneeze with an open mouth and consider the use of stool softeners in case of constipation in the immediate post-operative period. Patients also should be advised against heavy weightlifting, and straining.Reference Hussain, Hashmi and Qayyum30 Likewise, Shah et al. reported that their patient was sneezing vigorously and lifting heavy weights (30–40 lb at work), which subsequently led to bilateral extensive subcutaneous emphysema in the head, neck and chest, with significant pneumomediastinum.Reference Shah, Thomas, Naples and Ruckenstein19 Hence, they recommended strict avoidance of exertion post-operatively for at least 48–72 hours.

We recommend avoidance of the Valsalva manoeuvre, vigorous sneezing, coughing, constipation and lifting weights. We could not find any specifications in the literature that related lifting weights to balloon Eustachian tuboplasty. However, international consensus guidelines on spontaneous cerebrospinal fluid leak does mention less than 15 lb (7 kg), which seems reasonable for balloon Eustachian tuboplasty as well.Reference Georgalas, Oostra, Ahmed, Castelnuovo, Dallan and van Furth31

• Balloon Eustachian tuboplasty is a new and safe treatment modality addressing chronic obstructive dysfunction of the Eustachian tube

• Balloon Eustachian tuboplasty is still not very widely practised in the UK

• We found an overall complication risk of 1.68 per cent, with major complications of less than 0.42 per cent

• The most common major complication was surgical emphysema, which was 0.39 per cent

• Surgeons need to discuss possible complications with patients before balloon Eustachian tuboplasty, and take all possible measures to prevent these complications

• Preventive measures are divided into pre-operative assessment, peri- and intra-operative care, and post-operative care

In our study, it was difficult to thoroughly analyse all the balloon Eustachian tuboplasty success rates because different authors have adopted different parameters to determine a satisfactory result. However, the success rate is about 60–90 per cent.Reference Tich, Maier and Sudhoff32 We think this is an area of future research to exactly determine balloon Eustachian tuboplasty success in terms of resolution of symptoms for obstructive Eustachian tube dysfunction. This is crucial in the consenting process so that the patient can weight risks and benefits.