Importance of morphostructural changes observed in cortical microvessels in patients died after a severe head injury

Introduction. The development of secondary lesions in traumatic head injuries seems to be a determinative factor for the survival of these patients. Endothelium damage of cortical microvessels could be fundamental in the main secondary lesions as cerebral ischemia and intracranial hypertension. Objectives. To investigate which are the main morphological changes that can be observed in cortical microvessels from these patients. Material and methods. We have studied 15 fresh human brains from subjects died after a severe head injury. The study has been carried out by scanning electron microscopy of vascular corrosion casts and confocal microscopy of histological sections after immunocytochemistry, as well as detection of apoptosis by TUNEL technique. Results and conclusions. The most significant structural alterations were observed mainly on arterioles and capillaries of the middle and deep vascular zones of the cerebral cortex. Corrosion casts showed vessels with longitudinal folds, sunken surface with craters and flattened vessels with reduced lumen. Histological sections immunostained with MAS-336 also showed vessels with longitudinal folds and thinning of their vascular lumen, the presence of cytoplasmic round bodies and a thickening of endothelial cell membrane. TUNEL method revealed a positive staining of some endothelial cells. The structural alterations observed seem to reveal a situation of cellular damage of endothelium in the human cortical microvessels from these patients. It can be thought that this kind of lesions, as well as the secondary functional injury of the blood brain barrier, could play an important role in the development of secondary damage.