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Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_3597_Библиотеки_им_академика_М_И_Перельмана
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Interventional Cardiology Procedures
Pressure-derived FFR
FFR = Pd/Pa = 105/133 = 0.78
Aortic (Pa)
Coronary (Pd)
A
B
Coronary velocity
Adenosine
66-year-old woman D1 stent 2 years ago with new angina
II
II
III
III
Pd
Pd
Pa
Pa
Pd
Pd
Pa
66-year-old woman, post-PTCA of LAD artery
II
III
FFR = 74/102 = 0.72
FFR = 74/102 = 0.72
CVR = 2.2
Pd
Pa
Pd
Pa
C
Figure 10-7
pressure (Pa) and distal coronary pressure (Pd) and coronary flow velocity
at rest and after intracoronary (IC) adenosine (bottom arrow). Hyperemia
widens gradient and decreases Pd when velocity is maximal (coronary
vasodilatory reserve [CVR] = 2.2), FFR = Pd/Pa = 105/133 = 0.78, above
the ischemic threshold value (0.80). B, Patient example: Before percutane ous coronar y intervention (PCI), FFR = 0.72. C, After PCI, FFR = 0.98.
LAD, Left anterior descending; PTCA, percutaneous transluminal coronary
angioplasty.
Use of fractional flow reserve (FFR). A, Proximal guide catheter
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Interventional Cardiology Procedures 433
Box 10 -2 Diagnostic and Imaging Adjuncts to Percutaneous
Coronary Intervention
Fractional Flow Reserve
Indication: Coronar y lesion assessment (any location) when hemodynamic
significance is unknown or in doubt. Angiographic lesions, especially
eccentric or of intermediate severity (40% to 70% diameter narrowed) are
the most commonly assessed.
Derivation: FFR, Q
same artery without stenosis. Q, Flow; sten, stenotic ar tery.
sten/Qnormal
Hence,
Complete derivation includes venous pressure (Pv) because:*
Features: Nonischemic threshold range >0.75 to 0.80, normal value of 1.0
for every artery and every patient, epicardial lesion specific, linear
relation with relative maximum blood flow, independent of hemodynamic
alterations, value that accounts for total myocardial blood flow, including
collater als, highly reproducible, high spatial resolution (pressure pull
back recording).
Coronar y Flow Velocity Reserve
Indication: Used to assess microcirculation when insignificant epicardial
lesions do not explain chest pain syndromes.
Derivation: CFVR, Q
unchanged during hyperemia.
Features: Nonischemic threshold range of CF R >2.0; coronary flow reserve
in unobstructed vessels assesses microvascular integrity, useful for
studies of coronar y endothelial function, accur ate estimation of
volumetric flow when vessel cross-sectional area is available.
Intravascular Ultrasound Imaging and Optical Coherence Tomography
Indications:
• Evaluation of lesion severity at a location difficult to image by
angiography, in a patient with a positive functional study and a
suspected flow-limiting stenosis.
• Assessment of a suboptimal angiographic result after PCI
• Diagnostic and management of coronary disease after cardiac
transplantation
• Assessment of the adequacy of deployment of coronary stent, including
the extent of stent apposition and determination of the minimal luminal
diameter within the stent
• Determination of plaque location and circumferential distribution
• Determination of the mechanism of stent restenosis or thrombosis
(inadequate expansion vs. neointimal proliferation) and to enable
selection of appropriate therapy (plaque ablation vs. repeat balloon
expansion)
• Preinter ventional assessment of lesion characteristics of haz y lesions
(e.g., calcification) as a means of selecting an optimal revascularization
device
at maximal hyperemia; normal, theoretically
Q P /resistance
= ,
sten sten sten
Q P /resistance then
= ,
normal aorta sten
Q /Q P /P
sten normal sten aorta
hyperem ia/Qbase
=
FFR P /P
=
distal to stenosis aorta
FFR P Pv P Pv
= − −
distal to stenosis aorta
. Q, Velocity if cross -sectional area
CFR, Coronary vasodilatory reser ve; CF VR, coronary flow velocity reserve; FFR,
fractional flow reserve; PCI, per cutaneous coronar y intervention.
*See Pijls et al.
diagnostic techniques during PCI is presented in Box 10-2. Remember
that IVUS or optical coherence tomographic imaging measures
anatomy, not flow and can be used to assess the anatomic (but not
physiologic) severity of the stenosis; and confirms optimal stent
implantation.
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B
C
Figure 10-8 Stent designs.
Stent Implantation
Stents are used in nearly all PCIs. Decisions regarding drug coated,
bare metal, or bioabsorbable stents are individually tailored. There are
several different designs for stents (Fig. 10-8).
Compared with balloon angioplasty, stenting produces a larger
minimal luminal diameter, maintains arterial patency, and reduces
restenosis with excellent long-term results. Stents improve long-term
results compared with balloon angioplasty in nearly every angiographic subset examined. Stenting reduces the incidence of acute
recoil, abrupt vessel closure, and the need for emergency CABG previously associated with “plain old” balloon angioplasty. Drug-eluting
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Interventional Cardiology Procedures 435
stents reduce the rates of restenosis compared with bare metal stents
and are generally used if there are no contraindications for prolonged
dual antiplatelet therapy.
Bioabsorbable stents have promising characteristics and likely
will become widely available in the United States within the next 5
years.
Contraindications to Stenting
Contraindications are divided into two types: clinical and anatomic
factors. Relative contraindications based on patient factors include the
following:
1. Inability to take dual antiplatelet therapy.
2. Inability to fully dilate the lesion.
3. Hypersensitivity to stent material.
4. History of bleeding or other conditions that preclude anticoagula-
tion during PCI.
5. Noncardiac surgery required within 2 weeks.
Figures 10-9 and 10-10 are case examples of PCI.
Coronary Atherectomy
Because atherosclerotic plaque remains in the artery after balloon
dilation, physical removal of the plaque from inside the coronary
artery was thought to improve procedural and clinical results. Only
two devices are still in use for this purpose: the high-speed rotablator
for coronary calcified plaque (Fig. 10-11) and directional atherectomy
catheter (DCA) for peripheral vascular disease.
Figure 10-9 Single -vessel stenting. Top, Left anterior descending (LAD)
artery with a 90% narrowing, significant hemodynamic gradient, and low
fractional flow reserve (FFR) before percutaneous coronary intervention (PCI).
Bottom, Post- PCI result with 0% angiographic residual and normalization of
translesional pressure. (Courtesy of Drs. Bernard De Bruyne and Nico Pijls.)
Resting
gradient
FFR = 0.55
Hyperemia
FFR = 0.98
HyperemiaResting gradient
99% subtotal LAD with fresh thrombus
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A
99% LAD with thrombus
B
LAD after stent
with 0% stenosis
C
Figure 10-10 Percutaneous coronary intervention (PCI) for acute
ST-segment elevation myocardial infarction (STEMI) of left anterior descending (LAD) artery. A, LAD in right anterior oblique (RAO) cranial projection
showing thrombotic narrowing. B, LAD in anteroposterior (AP) cranial projection. C, Post-PCI of LAD after stenting for STEMI.
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Interventional Cardiology Procedures 437
A
B
C
Figure 10-11
calcified left main ar tery. C, After rotational atherectomy, final angiographic
results af ter percutaneous coronary inter vention (PCI) with drug-eluting
stent.
A, Severe stenosis of the ostial left main artery. B, Heavily
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Figure 10 -12
blades.
A, Rotablator burr. B, Cutting balloon with microatheratome
Rotational Atherectomy (Rotablator)
The rotablator is made of an olive-shaped steel burr (1.25 to 2.5 mm
in diameter; Fig. 10-12, A) that is embedded with microscopic diamond
particles in the front half and rotated on a torque wire at up to
200,000 rpm by an external air turbine. The device is inserted through
6-F to 9-F guiding catheters over a special 0.009-inch stainless-steel
guidewire. Continuous pressurized heparinized saline (with or without
emulsifiers) is infused through the device to aid lubrication and heat
dissipation. After the burr is placed just proximal to the lesion, the
system is activated, and the burr is advanced through the lesion in a
slow, steady “pecking” manner. The abrasive surface of the burr selectively ablates (pulverizes) hard calcified plaque while sparing the
softer normal wall (differential cutting). Several burr passes are performed up to 30 seconds per each run before removal of the burr and
a decision for a larger burr or balloon inflation is made. Definitive
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therapy with stenting is almost always performed. The maximum burr
diameter should be no larger than 70% of the normal arterial luminal
diameter.
The rotablator is most suitable for rigid calcified and long lesions
in which stent delivery success is likely to be low. The goal of rotational
atherectomy is plaque modification of resistant lesions. Randomized
comparisons for use of rotablator indicate no restenosis advantage but
better procedure success in the calcified small vessel or long lesion
subset.
A specific complication of the rotablator is a temporary no-reflow
phenomenon, with creatinine kinase enzyme or troponin increase in
some patients. This problem may necessitate insertion of a prophylactic pacemaker wire, especially for dominant right coronary lesions.
Other potential complications are coronary artery dissection and
perforation.
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Interventional Cardiology Procedures 439
Cutting Balloon
The cutting balloon is equipped with microatherotomes to incise the
plaque at three or four points along its circumference (see Fig. 10-12,
B). This scoring or cutting of the plaque is purported to produce more
controlled and better dilation. The cutting balloon is commonly used
for ostial lesions or in-stent restenotic lesions.
Thrombus Aspiration Systems
IC thrombus can be aspirated manually with several available manual
aspiration catheters (Fig. 10-13) or a high-pressure mechanical rheolytic thrombectomy system (AngioJet, Boston Scientific, Maple Grove,
MN). The AngioJet catheter uses high-pressure water jets directed
backward into the catheter to create a strong suction at the space
near the tip, which effectively evacuates and macerates thrombus
(Fig. 10-14).
The clinical efficacy of manual aspiration thrombectomy catheters is mixed, with one trial (TAPAS) showing reduced mortality in
patients with MI who undergo primary PCI. Another trial showed no
benefit (INFUSE AMI). A full discussion of these devices can be found
elsewhere (see Suggested Readings at the end of this chapter).
Peripheral Arterial Balloon Angioplasty
Peripheral arterial disease is a common manifestation of atherosclerosis and often present in patients who undergo cardiac catheterization for coronary artery disease. Generally, peripheral arterial disease
can be managed conservatively, although some patients require revascularization therapy (either via surgery or peripheral intervention).
Two circumferential
Figure 10-13 Manual thrombus aspiration catheters.
side holes
Larger inner lumen
New shape
Shorter tip
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B
C
Figure 10-14
Scientific, Maple Grove, MN). A, High-pressure water jet is directed from the
tip back into the catheter lumen. B, Jet creates Venturi suction at the top
and (C) can aspirate material.
Rheoly tic thrombus aspiration catheter (AngioJet, Boston
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Profunda femoris
Superior mesenteric
Inferior mesenteric
Common iliac
External iliac
Common femoral
Superficial femoral
Popliteal
Anterior tibial
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Interventional Cardiology Procedures 441
Celiac
Renal
Internal iliac
(hypogastric)
Tibioperoneal
Posterior tibial
Peroneal
Figure 10-15 Peripheral vascular interventional sites of the lower extremi-
ties. (Courtesy of CJ White, SR Ramee, and TJ Collins, Ochsner Health
System, New Orleans, LA.)
Certain anatomic considerations often make a patient a better candidate for one procedure as opposed to the other. In peripheral arterial
disease, discrete localized lesions are usually treated best by balloon
angioplasty (See Chapter 5), whereas diffuse disease and long total
occlusions are often treated better with bypass surgery. A team
approach involving input from the vascular interventionalist and vascular surgeon results in optimal treatment for the patient. Nomenclature for the peripheral vessels below the diaphragm is shown in
Figure 10-15.
Indications
Indications for peripheral arterial revascularization include (1) intermittent (lifestyle-limiting) claudication for more than 6 months and
(2) critical limb ischemia (pain at rest, nonhealing ulcer, and tissue
loss). Revascularization is elective in nondiabetic patients and those
who smoke with intermittent claudication, because (1) it does not
affect long-term survival and (2) the incidence of severe limbthreatening ischemia is low because of distal vessel patency.
Vascular Access Technique for Lower
Extremity Angioplasty
1. Antegrade, common femoral: The common femoral artery is
entered above the midpoint of the femoral head. Most superficial
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