Marked ventilation impairment due to progression of diffuse pleural thickening after cardiac surgery

Abstract

A 64-year-old Japanese man presented with dyspnea and shortness of breath during exertion. Chest computed tomography revealed bilateral pleural effusion. He was drowsy because of CO₂ storage and died due to ventilatory impairment. His past medical history included a thymectomy and adjuvant radiotherapy with thymoma. He had undergone cardiac surgery and permanent pacemaker implantation. The autopsy examination revealed extensive bilateral pleural adhesions and diffuse visceral pleural thickening. An inspection of multiple lung sections failed to detect any asbestos body formation or mesothelioma. The patient's pleural effusion and diffuse pleural thickening may have exacerbated after cardiac surgery. In this case, the progression and pathophysiology of the pleural thickening could be traced by imaging and an autopsy, and we were able to estimate the factors that exacerbated the pleural thickening and ventilation impairment.

Keywords: Cardiac surgery; Diffuse pleural thickening; Pleural effusion.

Fig. 1

(A) Chest X-ray taken after the patient's cardiac surgery 30 years prior to this admission, showing density indicating right-sided and left-sided pleural effusion. (B) At this admission: chest X-ray showing the placement of a drainage tube (DT) in the left thoracic cavity. Arrows: pleural effusion. MAV: mechanical aortic valve, MMV: mechanical mitral valve.

Fig. 2

(A) Chest CT from before the patient's earlier cardiac surgery. (B) CT revealing moderate pleural effusion and DPT in the posterior right lung after that cardiac surgery. Arrow: pleural thickening.

Fig. 3

Autopsy findings of the pleura. Gross findings revealed severe thickening of the right pleura, which adhered to the diaphragm and pericardium. Arrows: thickened pleura. D: diaphragm P: pericardium.

Fig. 4

Microscopic findings of the right parietal pleura. Victoria blue staining shows DPT in the right parietal pleura (>3 mm). Arrows: thickened pleura. 1.25 × magnification.

Fig. 5

Microscopic findings of the left lower pleura. Victoria blue staining shows paucicellar hyaline collagen plaques, fibrous tissues, and elastic fibers. 12.5 × magnification.