US Patent 11839540 Vena-caval apparatus and methods

Apparatus and methods are described including identifying a subject as suffering from a condition that causes the subject to have elevated central venous pressure. In response thereto, a device is placed inside the subject's vena cava, and the device is deployed inside the subject's vena cava, such that, in a passive manner, the device reduces blood pressure within the subject's renal veins relative to the subject's central venous pressure. Other applications are also described.