Seven patients died, and postmortem analysis of GI tissues displayed fibrinoid necrosis of terminal arterioles
within the deep mucosa, extravasation of fragmented red blood cells (RBCs) around affected vessels, and extensive crypt depletion in the tip of mucosal folds.
It has therefore become apparent that the presence of an ADAMTS13 deficiency and the resulting excess of circulating UL-VWFs leads to disseminated platelet-rich thrombi, which block terminal arterioles
Autopsy findings included hyaline thrombi in the terminal arterioles and capillaries of the heart and kidney.
Hyaline thrombosis of the terminal arterioles and capillaries: a hitherto undescribed disease.
The wall of the terminal arterioles is formed by flattened endothelial cells, and the fixed phagocytes are attached to the outer surface of the endothelium (Factor & Naar 1990).
The uptake of particles by large numbers of fixed phagocytes of the digestive gland cannot be analyzed in this way, as the manual technique for separating the terminal arterioles from the digestive gland tissue is laborious, and methods for separating the individual fixed phagocyte cells from the arterioles and perforated membranes are not available.
Reduced tissue oxygen pressure induces relaxation of terminal arterioles
and precapillary sphincters, causing them to open when the oxygen concentration falls to low levels.