The preventive role of thoracic duct ligation on cerebral fat embolism in lung injury: an experimental study.

Abstract

BACKGROUND: Cerebral fat embolism constitutes a major problem in intensive care units and treatment methods are highly controversial. Cerebral fat embolism has been thought to result from the migration of bone marrow fragments to the brain. However, the present authors observed that cerebral fat embolism is not possible unless the bone marrow particles cause alveolar wall destruction due to pulmonary artery occlusion. Thoracic duct ligation is essential for improved patient survival under such conditions. The aim was to investigate whether thoracic duct ligation plays a preventive role in cerebral fat embolism in lung injury. MATERIAL/METHODS: Pulmonary contusion was established with chest wall trauma in 20 male hybrid rabbits (n=20), with thoracic duct ligation being administered to half (n=10). Ten days after the procedure, all the rabbits were sacrificed. Brain specimens were taken using the frozen-section method, stained with Sudan Black, and examined microscopically. RESULTS: In the frozen brain sections the number of branches occluded by fat particles in both the central cerebral arteries was 15.5+/-3.02 in eight animals of the non-ligated group (GI) compared with 4.7+/-2.45 in two animals of the ligated group (GII). The number of occluded branches of the middle cerebral arteries was significantly higher in GI than in GII (p<0.001). CONCLUSIONS: The number of branches of both central cerebral arteries occluded by lipid particles was greater in the non-ligated than in the ligated animals. It is believed that thoracic duct ligation provides significant protection against fat embolism in cases of thoracic trauma.