Acute shortness of breath due to reoccurrence of an intrapericardial bronchogenic cyst

Introduction

We present our unit's case of an unusual diagnosis of causation of dysphagia and acute shortness of breath with successful surgical resolution.

Case Report

A 71‐year‐old woman presented to a peripheral hospital with a six‐week history of dysphagia and acute onset shortness of breath. A clinical diagnosis of aspiration pneumonia was made based on clinical imaging and pathology results. Chest x‐ray did not demonstrate any mediastinal shadow consistent with a bronchogenic cyst. The patient was commenced on intravenous antibiotic therapy. The patient was also in fast atrial fibrillation, and a nasojejunal tube was inserted for feeding under direct vision on gastroscopy. During gastroscopy, compression of the middle third of the oesophagus was evident.

Her surgical history included a prior thoracotomy for a bronchogenic mesothelial cyst 19 years prior to the current admission. This previous operation was performed at an overseas institution. Previous medical history included a transient ischaemic attack in 2017 with no residual deficit, type II diabetes mellitus with diet control, and osteoarthritis. She was otherwise an ex‐smoker and independent in all activities of daily living.

Computed tomography imaging at the time of referral to the specialist cardiothoracic surgical centre demonstrated a large, thin‐walled hypoattenuating mass within the posterior mediastinum splaying the carina, measuring 69 × 70 × 74 mm. It was also displacing the adjacent mediastinal structures. At this time, antibiotics had already been utilized to treat the aspiration pneumonia (Video S1, Supporting Information). There was a small number of peripheral surgical clips reflecting previous resection procedures. There was no associated lymphadenopathy. A barium swallow test was performed to confirm no anatomical communication between the oesophagus and the cystic mass.

Due to the residual adhesions from the previous thoracotomy and size and anatomical complexity of the bronchial cyst, it was determined that endovascular drainage was not suitable, and thus, the patient underwent a medium sternotomy for bronchial cyst resection. A thoracotomy was not performed as this was a redo procedure, and the inherent scar tissue with a cyst in close proximity to the heart and great vessels deemed a median sternotomy to be the safer approach. An intraoperative echocardiogram did not present any other identifiable cause for atrial fibrillation. Cardiopulmonary bypass was on standby if decompression of the heart and great vessels was required. Both pleura were divided, with dense adhesions found on the right. The mass was unable to be palpated behind the right ventricle or through the pleura. With manipulation of the heart, the subcarinal region was explored safely. The mass was located behind the right atrium and was intrapericardial (Fig. 1). An extensive resection was performed as the mass was densely adhered to the left atrium, oesophagus, trachea, and pulmonary vessels (Fig. 2). The cyst originated from the pericardium with invasion of surrounding structures and no attachment to the bronchus. Due to the nature of the friable tissue, the bronchogenic cyst ruptured during the resection. Repair of the left atrium and pulmonary vessels was required. No cardiopulmonary bypass was required. A pericardial drain was left in situ, positioned into the post‐resection space. This was gradually removed postoperatively to drain fluid that collected in the remaining space. The patient was in sinus rhythm at the time of discharge from the cardiothoracic specialist service.

Figure 1

Intrapericardial bronchogenic cyst with stitch in situ. Right atrium and ascending aorta retracted.

Figure 2

Excised macroscopic bronchogenic cyst.

Discussion

Intrapericardial bronchogenic cysts are a rare form of congenital cystic lesions in the mediastinum arising from the primitive foregut 1. It is hypothesized that, at 21 days after fertilization, the cardiac primordia are in close proximity to the foregut and or primitive tracheobronchial tree, and thus, at this time, abnormal budding of the tracheobronchial tree can arise in a myocardial location 2.

The clinical symptoms of the patient will often be a direct result of the size of the cyst and the local invasion and or compression 3. In this particular case, the external compression of the oesophagus by the intrapericardial bronchogenic cyst is considered to be the precipitating cause of the aspiration pneumonia. Furthermore, the atrial fibrillation is hypothesized to be due to the compression of the left atrium. The acute shortness of breath was due to aspiration pneumonia as a direct result of oesophageal compression.

Although uncommon, bronchogenic cysts can reoccur after initial resection. Redo mediastinal surgery requires careful consideration and planning. Methods of redo thoracotomy and video‐assisted thorascopic surgery have been described for the resection of recurrent bronchogenic cysts 4. Irrespective of the method of approach, the mainstay of therapy must be complete resection in order to minimize the chance of recurrence and relieve symptoms, eliminating risk of infection and malignant degeneration 5. This case report highlights the complexity associated with acute shortness of breath and the potential wide‐ranging list of diagnoses.

Supporting information