[The azygos or vertebro-parietal venous anastomotic system].

This experimental work, realized on a group of 25 monkeys, aims at determining the correct circulatory direction in rachis veins and the importance of the vertebral veinous circulation in the general return circulation. Radiophysiological tests defined the azygopetal direction of the vertebral circulation, the role of the intercavous shunt of this circulation with or without obstacle, and the possibility, under certain conditions, for pelvic blood to accede to cranial sinuses. Physiopathological tests (with iode 131 and BSP) contributed to prove that vertebral veinous circulation drains 5 to 10% of lower extremity, pelvic and sus-mesocolic visceral and cranial contents circulation.