CASE 560 Published on 24.10.2000

Macklin effect in blunt chest trauma

Section

Chest imaging

Case Type

Clinical Cases

Authors

M. Wintermark, P. Schnyder

Patient

43 years, female

Categories

No Area of Interest ; Imaging Technique CT

No Procedure ; No Special Focus ;

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Clinical History

Fall from a height

Imaging Findings

43-year-old female patient who jumped through a window and fell from a 9-m height to commit suicide

Discussion

Pneumomediastinum, also known as mediastinal emphysema, stands for free air collections surrounding mediastinal structures . It occurs in up to 10% of blunt chest trauma. In over 95% of cases, pneumomediastinum results either from extension of a subcutaneous emphysema or from alveolar rupture related to primary lung trauma or positive--pressure mechanical ventilation. Alveolar rupture is followed by centripetal dissection of the released alveolar air through the pulmonary interstitium and along the peribroncho-vascular sheaths into the mediastinum, this pathophysiological process being classically described as the “Macklin effect”. In the remaining cases, pneumomediastinum results from lesions of the trachea, bronchi or esophagus

Differential Diagnosis List

Blunt traumatic Macklin effect extending into the mediastinum as a pneumopericardium

Final Diagnosis

Blunt traumatic Macklin effect extending into the mediastinum as a pneumopericardium

References

[1] Jabra AA, Fishman EK, Shehata BM, Perlman EJ.
Localized persistent pulmonary interstitial emphysema: CT findings with radiographic-pathologic correlation.
AJR Am J Roentgenol. 1997 Nov;169(5):1381-4. (PMID: 9353462)

[2] : Satoh K, Kobayashi T, Kawase Y, Mitani M, Nakano S, Takahashi K, Takashima H, Ohkawa M, Tanabe M, Kojima K.
CT appearance of interstitial pulmonary emphysema.
J Thorac Imaging. 1996 Spring;11(2):153-4. (PMID: 8820025)

[3] Wintermark M, Wicky S, Schnyder P, et al
Blunt traumatic pneumomediastinum: using CT to reveal the Macklin effect.
AJR 172:129-130 (1999). (PMID: 9888752)

[4] Wintermark M, Wicky S, Bettex D, et al Trauma of the Mediastinum. In: Schnyder P, Wintermark M. Radiology of Blunt Trauma of the Chest. Springer, Berlin Heidelberg New York, pp 71-134 (2000).

Case information

URL:	https://www.eurorad.org/case/560
DOI:	10.1594/EURORAD/CASE.560
ISSN:	1563-4086

Figure 1

Macklin effect, pneumomediastinum and pneumopericardium

The Macklin effect features a pulmonary interstitial emphysema, i.e. numerous aeric lucencies (arrows) contiguous to small pulmonary vessels on both lung fields

A Macklin effect can definitely be diagnosed only when the chest CT allows for the identification of a triad bronchus-pulmonary vessel-surrounding air collection (arrows)