Wireless pressure sensors are being used to warn doctors that a blood vessel is liable to burst. On Monday, the Michael E. DeBakey VA Medical Center announced that it had implanted the Endosure sensor in patients who were receiving stents to protect against aortic aneurysms. The device, made by CardioMEMS Inc., is implanted in the aneurysm sac. When activated by an external device, it transmits information about pressure inside the aneurysm. aneurysms are typically repaired by inserting a stent into the affected blood vessel. This takes the pressure off the aneurysm by creating a new route for blood to flow. But since the stents can leak and cause the aneurysm to rupture, they require regular check-ups. The sensor, which is implanted into the aneurysm sac, provides a new way to monitor the pressure.