Angioplasty

Tiny balloons open clogged arteries

For more than 30 years, heart catheters were used chiefly for diagnosis. The idea for using a balloon-tipped catheter to open clogged coronary arteries came from European physicians who tried it first in peripheral and renal arteries. Swiss physician Andreas Gruntzig used the technique successfully on coronary arteries in 1977.

The technique—called balloon angioplasty—is much less traumatic than coronary bypass surgery. Instead of surgically opening the chest, doctors make a tiny incision at the hip or elbow.

This catheter has two long chambers within it. One delivers radio-opaque dye to the arteries so physicians can see the blockage using angiography. The other is used to inflate the balloon. A doctor steers the deflated balloon into place with a tiny guide wire, inflates it to stretch the artery walls and flatten the plaque deposits, then deflates and removes it.

Miniature scaffolding for arteries

One problem with balloon angioplasty is that a tough, scar-like mass of tissue often forms at the site where plaque was removed. This process, called restenosis, can eventually restrict the artery as much as the plaque did before the procedure.

Devices like these, called stents, were introduced in 1987 to prevent restenosis. A stent is a tiny scaffold that holds an artery open. The wire-mesh tube is inserted over a balloon at the end of a thin tube. Inflating the balloon locks the stent into place.