CASE 14286 Published on 15.12.2016
0

A rare surgical outcome - post pneumonectomy syndrome

Section

Chest imaging

Case Type

Clinical Cases

Authors

Fernando Matos, Pedro Azevedo, Bernardete Rodrigues, Joana Rodrigues, Daniel Cardoso, Filipa Costa, Cristina Santiago, Duarte Silva

Centro Hospitalar Tondela-Viseu - Viseu, Portugal; Email:fjmatos@msn.com
Connected authors
Fernando Matos Portugal
Patient

47 years, female

Categories
Area of Interest Thorax ; Imaging Technique Conventional radiography, CT, CT-Angiography
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Clinical History
A 47-year-old female presented with intermittent cough, dyspnoea and asthenia over 5 months. The previous history revealed right-sided pneumonectomy 8 years ago due to lung carcinoid. A chest radiograph was performed.
Imaging Findings
The chest radiograph revealed a hypotransparency of the lower half of the right hemithorax and rightward deviation of the trachea. The cardiac silhouette did not occupy its usual place and its contour was not seen. There was evidence of aired lung in the right hemithorax.
A CT study was performed in order to investigate the anatomical alterations and to assess the possible cause of the symptoms. The left lung was well ventilated, hyperinflated and completely herniated to the right. Also, the heart and mediastinum shifted excessively towards the side of the pneumonectomy and underwent counterclockwise rotation. The major vessels also rotated significantly. There was no evidence of pneumothorax or pleural effusion. The distal trachea and the left main bronchus were stretched and pushed against the vertebral body by the pulmonary artery. Partial endobronchial filling was more evident in the lower left lobe but also in the lower lingular bronchus.
Discussion
It is expected that anatomical changes occur in a procedure as radical as a pneumonectomy. Typically, the postoperative pneumonectomy space is filled by air which is gradually replaced by liquid over the following weeks or months. Complete opacification on chest radiograph occurs in most patients [1].
Our case refers to a post pneumonectomy syndrome, a very rare condition affecting approximately 1 in 640 cases [2]. After either right or left pneumonectomy, the remaining distal trachea and/or main bronchus can become compressed against the vertebral column or aorta by the pulmonary artery [3]. This results in symptomatic central airway compression and dynamic airway obstruction [4, 5].
The degree of mediastinal shift depends on the compliance and hyperexpansion of the remaining lung. According to literature, young women and children have a greater tendency to develop this syndrome due to their increased capacity of expanding the lung [6]. Postpneumonectomy syndrome seems to be more common after right pneumonectomy [2].
Since this patient presented with obstructive symptoms, she should be closely followed up and examined through bronchofibroscopy to better assess the degree of airway obstruction. In this particular case, the presence of mucus within the bronchi is already a reflection of a partially obstructed bronchial tree. There is a risk of developing even more serious symptoms such as inspiratory stridor and recurrent infections in the remaining lung [7]. If obstruction or symptoms are demonstrably severe, surgery to reposition the mediastinum should be considered. Silicone breast implants are an option that has been used in the postpneumonectomy space to prevent rotational shifting after pneumonectomy in children, a method that has brought good results [2].
To study the postpneumonectomy space, the positioning of the major vessels and the trachea, CT scan should be the first choice exam to assess the anatomical changes that occur after such procedure [3].
Differential Diagnosis List
Post pneumonectomy syndrome
Recurrence of lung carcinoid
Chronic pulmonary thromboembolism
Final Diagnosis
Post pneumonectomy syndrome
Case information
URL: https://eurorad.org/case/14286
DOI: 10.1594/EURORAD/CASE.14286
ISSN: 1563-4086
License

This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.

Figure 1

Chest radiograph

Chest radiograph
Right deviation of the trachea. Hypotransparency of the lower half of the right hemithorax. Displacement of the cardiac silhouette. There is evidence of aired lung in the right hemithorax since vascular markings are clearly seen.
Figure 2

CT scan - axial view

CT scan - axial view
Left pulmonar artery (red arrow) compressing the distal trachea (blue arrow) against the vertebral body.
Figure 3

CT scan - axial view

CT scan - axial view
Counterclockwise rotation of the mediastinum and hyperinflation and herniation of the left lung. Note the stretching of the left bronchus (red arrow).
Figure 4

CT reconstruction coronal view

CT reconstruction coronal view
Narrowing of distal trachea due to compression of the left pulmonary artery. Shift in major vessel positioning.
CT reconstruction coronal view
Cardiac silhouette shifted to right hemithorax. Left main bronchus is stretched but not completely obstructed.
Figure 5

CT scan - axial view

CT scan - axial view
Presence of mucus within the bronchus (red arrow). Crowding of ribs: The interspace between ribs on the right is narrower compared to the opposite side.
Figure 6

Usual imaging findings after a pneumonectomy

Usual imaging findings after a pneumonectomy
Chest radiograph. After a pneumonectomy, the resulting resection cavity fills with fluid. No aerated lung is depicted in the right hemithorax. The cardiac silhouette shifted rightwards to fill the space vacated by the removed lung.
Usual imaging findings after a pneumonectomy
CT scan - axial view. Right hemithorax cavity filled with fluid after right pneumonectomy. There is mild rightward deviation of the mediastinum and hyperinflation of the remaining lung.