Ultrasound analysis of cervical thoracic duct for patients with constrictive pericarditis and chylothorax.

Purpose: To analyze ultrasound features of cervical thoracic duct for patients with constrictive pericarditis and chylothorax.

Methods: Patients were retrospectively assessed. The patients were divided into a non-pleural effusion (PE) group (n = 54), a chylothorax group (n = 23), and non-chylothorax group (n = 28). Conventional ultrasound was used to obtain the maximum inner diameter and collapse of the inferior vena cava, the inner diameter of left cervical thoracic duct, and the frequency of opening of the valve at the end of the left thoracic duct. Contrast ultrasonography was used to score the reverse flow of the thoracic tube.

Results: The percentage of PE was 48.5%, and the percentage of chylothorax was 21.9%. The three groups had significant differences in five parameters. The inner diameter of left cervical thoracic duct was correlated with the degree of central venous pressure. Contrast ultrasonography was effective in quantitative assessment of the degree of intravenous-thoracic cord reverse flow which correlated with all parameters of central venous pressure.

Conclusion: Thoracic duct dilation and regurgitation secondary to central venous pressure can lead to chyloreflux disorder and may be the mechanism of chylothorax occurrence in constrictive pericarditis.