Coronary cleanup stops jams downstream

12 December 1998

WHEN heart surgeons insert metal supporting devices to open up blocked heart
veins, they risk dislodging dangerous particles of debris. These can block
smaller blood vessels downstream—with potentially fatal results.

To solve the problem, a company called PercuSurge of Sunnyvale, California,
has developed a catheter that sucks out the debris—or “plaque”—to
stop it travelling down the vein. Plaque blockage occurs in 5 to 15 per cent of
patients who have the supports—called stents—put into their veins.
The problem is particularly common in people who have the stent inserted into
deteriorating heart-bypass grafts.

Once the smaller vessels are blocked, there is little the doctor can do to
restore blood flow to the heart. “It’s as if you repaired a clog in a water main
but then the clog goes to each of the taps in your house,” says Donald Baim of
Harvard Medical School in Cambridge, Massachusetts, who recently performed the
first operation in the US using the new catheter.

The surgeon threads a balloon mounted on the end of a guide wire through the
vein and inflates it briefly to block blood flow and stop any material from
travelling downstream while the stent is put in place. Then the catheter is
inserted and used to pump out the blood and plaque particles, which can be up to
1 millimetre across.

Trials show that fewer than 3 per cent of patients experienced complications
after surgery. “Even though this is a simple concept, it’s the first practical
device to treat the problem,” says Baim. “It seems to virtually eliminate what
is sometimes a nasty and untreatable problem.”