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C HAPTER 2 3 / Interventional Cardiology Techniques: Percutaneous Coronary Intervention 539
■ Figure 23-1 Mechanism of intracoronary balloon angioplasty. (A) A balloon catheter is introduced into the
coronary artery through a guide catheter in the aorta. (B) A guidewire is advanced across the area of narrowing.
(C) The balloon catheter is advanced over the wire across the lesion. (D) The balloon is inflated. (E) Coronary
artery after PTCA. (Courtesy of Boston Scientific Corporation, Maple Grove, MN.)
in plague compression and less vessel wall expansion. This type of Clinical trials have shown no improvement in long-term results
dilatation may reduce the force needed to dilate an obstructed le- with these devices; many atherectomy devices no longer are
sion. The cutting balloon has specific, limited indications: lesions used. 18,19
that are resistant to dilatation by traditional angioplasty balloons,
such as calcific, elastic, and fibrotic lesions; and in-stent restenosis Atherectomy
(ISR) to avoid slipping-induced vessel trauma during PCI. 16,17
The cutting balloon may be used alone or in combination with Directional Coronary Atherectomy
stents. The directional coronary atherectomy (DCA) catheter (Guidant
Corporation, Santa Clara, CA) consists of a catheter-mounted,
cylindrical metallic housing unit (collection chamber, window,
CORONARY ATHERECTOMY, and cup-shaped cutter) and a small balloon attached to the hous-
ATHEROABLATIVE, AND ing. When the catheter is placed at the lesion, a balloon is inflated
THROMBECTOMY DEVICES

Coronary atherectomy (directional and rotational) and excimer
laser coronary angioplasty (ELCA) were developed and approved
by the FDA for coronary artery use in the late 1980 to 1990s, with
hopes of resolving the limitations of PTCA. Atherectomy device
technique involves reduction of the severity of coronary blockage
by removal of atheromatous plaque rather than compressing
and/or fracturing the plaque, or stretching the arterial wall. In the-
ory, this approach was developed to permit a more controlled vas-
cular injury, minimize the degree of arterial mural stretch, create
a smoother surface by debulking the vessel, and removal of ather-
osclerotic plaque that is frequently resistant to balloon dilatation.
Atherectomy devices have been used successfully to remove
atherosclerotic plaque but were associated with increased compli-
cation rates and restenosis rates similar to PTCA from neointimal
hyperplasia. Atherectomy devices now account for less than 3% of ■ Figure 23-2 The cutting balloon. (Courtesy of Boston Scientific
current PCI and are being used in very specific subsets of patients. Corporation, Maple Grove, MN.)