Extensive Subcutaneous Emphysema and Pneumomediastinum Following Eustachian Tube Dilation and PET Insertion: A Rare Complication

ABSTRACT

Introduction

Eustachian tube dilation (ETD) is an increasingly popular and seemingly safe method of treating ETD. We present a rare case of subcutaneous emphysema and pneumomediastinum following ETD.

Methods

Retrospective chart review. Patient consent was obtained for data collection, analysis, drafting, and publication of information.

Results

A 33‐year‐old male presented to the emergency department with acute facial swelling 1 day after treatment for bilateral eustachian tube dysfunction with bilateral ETD and pressure equalization tube (PET) insertion by an otolaryngologist at an outside facility. Symptoms began after he tried to pop his ears. He had extensive crepitus throughout his face, neck, and chest bilaterally with intact and patent PETs. Flexible laryngoscopy revealed a patent airway and no evidence of mucosal injury. Computed tomography demonstrated extensive subcutaneous emphysema extending from the chest to the skull base along with pneumomediastinum. The patient was admitted for observation given these findings and ultimately discharged without requiring any surgical intervention. No recurrent symptoms were noted in the subsequent post‐operative period.

Discussion

This case illustrates a rare but important complication of ETD, where mucosal injury within the Eustachian tube likely facilitated air dissection into deep cervical and mediastinal fascial planes. While subcutaneous emphysema and pneumomediastinum are typically self‐limiting, awareness of anatomical pathways, appropriate imaging, and conservative management strategies are essential for optimal patient care. As ETD gains wider acceptance, further research is needed to characterize risk factors and preventative measures for these complications.

Summary

• Significant findings:

  • ∘
    A rare case of extensive subcutaneous emphysema and pneumomediastinum following eustachian tube dilation and pressure equalization tube insertion, including diagnostic evaluation and clinical workup.
• What this study adds:

  • ∘
    Reviews relevant literature and delineates anatomical pathways that allow air to dissect into deep cervical and mediastinal planes after eustachian tube dilation.
  • ∘
    Provides insight into the pathophysiology, diagnostic approach, and conservative management of this uncommon complication.

1. Introduction

Eustachian tube dilation (ETD) is a growingly popular intervention utilized in the treatment of eustachian tube dysfunction, offering a minimally invasive alternative to traditional treatments such as pressure equalizing tubes (PET) and medical therapy [1]. While complications are uncommon, and typically minor, we report a rare case of subcutaneous emphysema and pneumomediastinum following ETD with PET insertion.

2. Case Presentation

A 33‐year‐old patient with a past medical history of bilateral congenital blindness status‐post bilateral enucleation, depression, anxiety, glottic insufficiency with functional voice disorder, and eustachian tube dysfunction presented to the emergency department with a chief complaint of acute facial swelling. On the previous day, the patient had undergone bilateral ETD and PET insertion by an otolaryngologist at an outside facility for treatment of his eustachian tube dysfunction. He reported acute onset facial swelling after he tried to pop his ears.

On physical examination, the patient was anxious but comfortably breathing on room air. He had extensive crepitus throughout his face, neck, and chest bilaterally (Figure 1). Otoscopy confirmed patent external auditory canals with bilateral PETs in place, with patent lumens, and clear middle ears. Bedside flexible laryngoscopy revealed a patent airway and no evidence of mucosal injuries.

Figure 1.

A picture showing the extent of acute facial swelling secondary to extensive subcutaneous emphysema following eustachian tube dilation with pressure equalization tube insertion.

Complete blood count and basic metabolic panel were within normal limits. A contrast‐enhanced CT scan of the neck and chest demonstrated extensive subcutaneous emphysema in the face and neck, extending up to the skull base and down to the chest (Figures 2, 3, 4), as well as pneumomediastinum (Figure 4).

Figure 2.

CT showing the extent of the extensive subcutaneous emphysema using a coronal view. Note the bilateral inferior extension of air from the face (A) down into the mediastinum (B).

Figure 3.

CT showing the extent of the extensive bilateral facial subcutaneous emphysema using an axial view.

Figure 4.

CT showing the extent of the extensive subcutaneous emphysema along with pneumomediastinum using an axial view. The various panels (A–D) demonstrate extensive inferiorly tracking subcutaneous emphysema extending all the way inferiorly to the mediastinum.

Given the extensive nature of his subcutaneous emphysema, the patient was admitted for observation. While inpatient, the patient had difficulty breathing and swallowing without changes in oxygen requirements. On further examination, he had stable crepitus, and repeat endoscopy did not demonstrate airway obstruction or mucosal injury. Upon further inquiry, patient reported persistent symptoms of aural fullness and continued popping of his ears.

Patient was counseled against popping his ears, straining, nose blowing, or sneezing with mouth closed, and without any worsening of exam findings, was discharged on hospital Day 2. His subcutaneous emphysema progressively resolved and he had no further episodes.

3. Discussion

Subcutaneous emphysema with pneumomediastinum is a rare but documented complication of ETD. A 2023 systematic review by Hussain et al. [2] reported subcutaneous emphysema in 0.40% of 3480 patients, with pneumomediastinum occurring in 0.14%. In contrast, a 2025 Cochrane review found no serious adverse events related to subcutaneous emphysema or pneumomediastinum in these patients [1], emphasizing the low incidence of these complications. With only a few reports having documented subcutaneous emphysema [3, 4, 5], cases of pneumomediastinum are even rarer [6, 7, 8]. For example, in one series of cervicofacial emphysema following bilateral ETD, only 3 of 10 patients (30%) with subcutaneous emphysema progressed to pneumomediastinum [8]. Similarly, analyses of the Manufacturer and User Facility Device (MAUDE) database report pneumomediastinum in 37.5% (3 of 8 cases) to 50% (3 of 6 cases) of patients with subcutaneous emphysema [9, 10]. As in our case, the majority of reports describe a benign course, with patients admitted for short‐term observation and treated with prophylactic antibiotics. Symptoms generally improve within days and resolve over several weeks, provided strict postoperative precautions—such as avoiding nose blowing, Valsalva maneuver, and forceful sneezing or ear popping—are followed. Almost all of these cases attribute the development of subcutaneous emphysema and pneumomediastinum to non‐adherence with these postoperative restrictions, highlighting the importance of thorough patient counseling as a key preventative strategy [2, 6, 7, 8].

As ETD gains popularity, understanding the pathophysiology of these complications is crucial. The cartilaginous portion of the eustachian tube is located within the parapharyngeal space (PPS) [11]. The PPS is an inverted pyramid‐shaped space extending from the skull base to the hyoid bone. It is bounded anteriorly by the pterygomandibular raphe, posteriorly by the prevertebral fascia, medially by the buccopharyngeal fascia, and laterally by the superficial (investing) layer of the deep cervical fascia that overlies the masticator space and the parotid gland. Within the PPS, the tensor vascular styloid fascia divides this space into pre‐styloid and retro‐styloid (carotid space) compartments. Importantly, the retropharyngeal space (RPS), which lies medial to the PPS, is separated by the buccopharyngeal fascia [12]. During ETD, mucosal injury can lead to air dissection into adjacent spaces. If the buccopharyngeal fascia is breached, air may track into the RPS and descend inferiorly to the thoracic vertebral level, where the alar fascia fuses with the middle (pre‐tracheal) layer of deep cervical fascia, allowing pneumomediastinum to develop [6]. Additionally, air spreading deep to the superficial (investing) layer of deep cervical fascia can result in extensive deep cervical emphysema, while direct violation of this fascia allows air to enter the subcutaneous tissue, causing true subcutaneous emphysema [7]. As postulated by Hussain et al. [2], the etiology of mucosal injury likely stems from instrument manipulation into the eustachian tube orifice or mucosal trauma within the eustachian tube itself from balloon kinking or from the rigidity of the catheter itself, despite the catheter designed to be atraumatic [2]. An understanding of pathophysiology of this rare but potentially serious complication warrants further study and better understanding of risk factors, prevention strategies, and long‐term outcomes.

Author Contributions

Scott E. Mann and Emily Ambrose were equally responsible for project conception. Mihai A. Bentan and Nam K. Lee were equally responsible for data collection. All authors were equally responsible for manuscript drafting and proofing.

Funding

The authors received no specific funding for this work.

Ethics Statement

All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards.

Conflicts of Interest

The authors declare no conflicts of interest.

Data Availability Statement

All available data has been shared with readers in the format of this case report.