RALEIGH, N.C. — Some fighter jet pilots keep track of fuel levels through a small pressure sensor in the tank. That concept got some vascular surgeons thinking they could use the same thing, only smaller.

EndoSure is a tiny pressure sensor that helps doctors check on patients who have had a stent graft procedure to fix an aneurysm. Within the plastic core are two metal plates that respond to pressure.

The Food and Drug Administration approved EndoSure for use last October. Rex Hospital was the first in the state to place one inside a patient.

The device provides an added bit of assurance for patients like Steve Van Westendorp. During a routine physical exam, his doctor asked about his family's medical history.

"I let him know that my mother died of an abdominal aneurysm rupture," Van Westendorp said. "(They said,) 'Oh, in that case, we'd better get a check on you.' That's what started the whole ball rolling."

Just like his mom, Van Westendorp had an abdominal aortic aneurysm. It is 80 percent more common in men than in women. The artery walls weaken and expand like a balloon.

"It expands and gets bigger and bigger and bigger to the point that it can pop," said vascular surgeon Dr. Jim Fogartie, of Rex Hospital.

Fogartie used a stent graft inside the artery to redirect blood flow and take pressure off the weak artery walls. But there's no guarantee blood won't find its way back into the sac and cause more problems.

Instead of using expensive CAT scans and contrast dye that could harm the kidneys, Fogartie can use EndoSure to make sure the stent is still working.

Through a catheter, the sensor is placed in the artery sac. The surgeon deploys the stent graft, trapping the sensor.

"It's evaluated by sending radio frequency waves to this pressure transducer and the waves are reflected back and, in essence, gives us a beautiful pressure reading of what's going on inside the sac," Fogartie said.

What Fogartie looks for are flat waves that show the graft seal still holds and blood is not getting into the sac.

Patients who have had the procedure still have to go in once a year to have the pressure sensor checked.