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Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_3720_Библиотеки_им_академика_М_И_Перельмана
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Encounters With Thrombus and Thrombosis in a Major Academic Center Chapter | 22 325
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FIGURE 22.5 Suspicion of an acute mural thrombus in a patient with acute coronary syndrome and absence of obstructive coronary artery
disease on coronary angiography. A patient with acute coronary syndrome (non-ST-segment elevation myocardial infarction) with ST-segment changes
in the anterior leads underwent coronary angiography. On coronary angiograms, there were no obstructive lesions. Given the clinical presentation,
intravascular ultrasound (IVUS) assessment of the left anterior descending coronary artery was performed. The arrow on the left angiogram corresponds to
the cross-sectional view on the right IVUS image. A mural thrombus was suspected at six o’clock (t) and, based on the bright appearance, felt to reflect the
acute phase of thrombosis (platelet aggregation). The arrows on the cross-sectional IVUS image (right) delineate the luminal site of the vessel wall.
FIGURE 22.6 Intracoronary thrombus visualized a few days after acute clinical presentation. A patient with non-ST-segment elevation myocardial
infarction underwent coronary angiogram a few days following the initial clinical presentation. The coronary angiogram (top) revealed a picture indicative
of a non-flow-limiting thrombus in the proximal left anterior descending artery (arrow). Intravascular ultrasound (IVUS) was performed for further
investigation of the underlying pathology (bottom). In comparison with the patient presented in Fig. 22.5, this IVUS shows a darker, more echo-lucent and
homogeneously structured acute thrombus (t). The boundary with the underlying fibrous plaque is indicated by the arrows (right).
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FIGURE 22.7 Intracoronary thrombus detected by intravascular ultrasound (IVUS) a few days after the acute clinical presentation, previously
invisible to angiography. Arrows in the crossectional view (middle right) indicate the transition of thrombus with soft plaque. Arrow in the bottom view
indicate the thrombus in the distal coronary left main stem proximal from the bifurcation with the left cirxumflex artery (cx). A patient with acute coronary
syndrome underwent coronary angiogram and IVUS assessment of the left main coronary artery. Coronary angiography (top) did not show any evidence
of a thrombotic event, yet IVUS was suggestive of the presence of a thrombus (t) above a soft plaque (arrows right cross-sectional view, middle, right). On
the longitudinal reconstruction (bottom), the delineation of the thrombus inside the lumen can be appreciated.
implantation. Color Doppler, biplane imaging, and pulsed-wave Doppler echocardiography often provide important
complementary data in addition to 2D echocardiography.
Transthoracic echocardiography is the first-line imaging modality in detecting left-ventricular apex thrombus. Contrast
echocardiography is especially useful in this scenario as the transthoracic apical window is not always optimal. Color
Doppler echocardiography could also be helpful in confirming these findings.
Figs. 22.15e22.22 represent a seri es of typical intracardiac thrombus cases as visualized with echocardiography and
catheter-based thrombectomy under the guidance of transesophageal echocardiography.
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FIGURE 22.8 Adequate stent implantation on angiography but an unexpected finding on intravascular ultrasound (IVUS). A patient with acute
coronary syndrome underwent intracoronary stent implantation of the distal right coronary artery (arrow, left). IVUS revealed correct apposition of the
stent struts (middle). Yet, closer examination indicated that the stent struts were opposed to thrombotic material overlaying a soft plaque (transition
thrombus; plaque indicated by arrowheads). Further stent dilatation was performed to avoid malposition after thrombus (t) resorption.
FIGURE 22.9 Protruding thrombus between stent struts. An ST-segment elevation myocardial infarction patient underwent stent implantation in a
distal lesion of a degenerated saphenous vein graft. Intravascular ultrasound (IVUS) (bottom) reveals correct stent apposition to the vessel walls.
Nevertheless, there is evidence of underlying thrombus, as the cross-sectional IVUS images reveal echogenic spots between the stent struts suggestive of
thrombus protruding between the stent struts (arrows, right).
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(A)
FIGURE 22.10 Thrombus or plaque protrusion. (A) Thrombus protrusion after stent implantation results in echo-dense spots overlapping more struts
(arrowheads), while (B) tissue protrusion by soft plaque stays between two struts (arrowhead).
(B)
FIGURE 22.11 Assessment of thrombus at follow-up. Intravascular ultrasound (IVUS) assessment 18 months after stent implantation and accom-
panying thrombectomy in the context of acute coronary syndrome. On IVUS, malposition of the stent between one and seven o’clock with organized
thrombus is demonstrated, as depicted by the black mass behind the stent (arrows).
FIGURE 22.12 An organized thrombus. Intravascular ultrasound cross section with subacute and organized thrombus. The cross section on the right
shows the organized thrombus border as indicated by arrows. Note that the organized thrombus is attached to the vessel wall as well as the transition
between plaque and thrombus.
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(A)
(B)
FIGURE 22.13 (A) A red thrombus with corresponding optical coherence tomography (OCT) cross-sectional image and light attenuation curve. (B) A
white thrombus with corresponding OCT cross-sectional image and light attenuation curve. White thrombus has a rich signal with moderate attenuation,
which allows easier visualization of the underlying anatomical structures [6].
(A) (B) (C)
FIGURE 22.14 Optical coherence tomography (OCT) assessment of thrombus. Arrows indicate the acute thrhombus that surrounds the catheter
(A), evidence of red thrombus (B), white thrombus at 6 o’clock (C). (A) An acute white thrombus on a guidewire and OCT catheter [3]. Histologic
examination revealed platelets, fibrin, and some erythrocytes (Fig. 22.1, top). (B) From a patient with acute coronary syndrome in whom OCT revealed a
red thrombus with strong signal attenuation. (C) White thrombus after thrombectomy in a patient with acute coronary syndrome caused by in-stent
thrombosis. The difference in the appearance of the thrombus as depicted by OCT in (B) and (C) consists of a later phase of thrombus formation,
while the one shown in (A) consists of a more acute phase of thrombus formation. This phenomenon is caused by the lines of Zahn as a result of the fibrin/
red blood cell ratio present in the lines of Zahn.
TABLE 22.2 Difference between Antemortem and Postmortem Thrombus.
Thrombi (Antemortem) Postmortem Clots
Dry and friable Gelatinous
Gray Dark purple-red
Attached to vessel wall Free in blood vessel
Conform to vessel shape Do not conform to vessel shape
Lines of Zahn No lines of Zahn
(A) (B)
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FIGURE 22.15 Left-atrial appendage thrombus. Transesophageal echocardiographic assessment of mitral regurgitation. (A) While focusing on mitral
regurgitation, the small left-atrial appendage thrombus was not seen (arrow), but (B) was clearly visualized during further interrogation in the framework
of MitraClip planning (arrows).
FIGURE 22.16 Left-atrial appendage thrombus. Left-atrial appendage thrombus visualized with 2D and color Doppler transesophageal echocardi-
ography. The color flow envelops the thrombus.
FIGURE 22.17 Left-ventricular apical aneurysm and thrombus. Left-ventricular apical aneurysm and thrombus (arrows) due to large anterior
myocardial infarction as visualized with transthoracic echocardiography in the apical views. 2CH, two-chamber view; 3CH, three-chamber view; 4CH,
four-chamber view.
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FIGURE 22.18 Left-ventricular thrombus. Left-ventricular thrombus in the apex visualized with 2D, color Doppler, and 3D transthoracic echo-
cardiography in the apical views. The color flow envelops the thrombus sitting in the apex. 2CH, two-chamber view; 3CH, three-chamber view; 4CH,
four-chamber view.
(A)
(B)
FIGURE 22.19 Left-ventricular thrombus missed on routine echo. (A) Thrombus in the apex of the left ventricle was not seen in the apical views
during routine transthoracic echocardiography, but (B) visualized with contrast echocardiography. 2CH, two-chamber view; 4CH, four-chamber view.
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(A)
(B)
FIGURE 22.20 Right-atrial thrombus. (A) Right-atrial thrombus (arrows) in a patient posteFontan circulation due to tricuspid atresia, as visualized in
the preprocedural transthoracic echocardiography and (B) by intraprocedural transesophageal echocardiography. Spontaneous contrast in the right atrium
was also seen in the latter. SVC, superior vena cava.
THROMBOSIS FOLLOWING CATHETER-BASED STRUCTURAL HEART INTERVENTIONS
(FIGS. 22.23e22.25)
Thrombosis Following Transcatheter Aortic Valve Replacement
A 62-year-old patient with bicuspid aortic stenosis received a 29-mm CoreValve Evolut R bioprosthesis. Because of low
implant positioning associated with severe paravalvular regurgitation a second Evolut R valve was implanted, which
corrected the regurgitation. The patient was discharged with dual antiplatelet therapy (acetylsalicylic acid 80 mg, clopidogrel 75 mg) after a short and uneventful postoperative course. As part of a clinical research project in patients with
bicuspid aortic stenosis, multislice computed tomography was perfor med 30 days after the index transcatheter aortic valve
replacement. A radiolucent area was seen during diastole and systole at the level whereby the inflow of the second
implanted valve touched the first implanted valve (Fig. 22.26, left green frame on cross-sectional images, Fig. 22.26, right
longitudinal section).
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(A)
(C)
(B)
FIGURE 22.21 Thrombus suction was performed using the AngioVac venous drainage system as shown under the guidance of transesophageal
echocardiography. (A) The suction cannula (arrows, left) on top of the thrombus (arrows, right). (B) Thrombus fragments were collected in the filter of the
system. (C) The residual base of the thrombus after the suction is shown (arrows). SVC, superior vena cava.
FIGURE 22.22 The procedure was followed by MitraClip implantation and atrial septal defect occlusion. Predischarge transthoracic echocardiography
showed all the devices in situ (arrows) and no prominent thrombus was seen in the right atrium. ASD, atrial septal defect.
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FIGURE 22.23 Intrathoracic bleeding due to failed application of a plug-based vascular closure technique after the implantation of a CoreValve Evolut
R valve via the left axillary artery. Access to the axillary artery was achieved via echo-guided puncture. After successful valve implantation, the vascular
plug was applied using standard technique but failed to achieve hemostasis. The activated clotting time was immediately corrected (with intravenous
protamine 50 mg), while an occlusive balloon was advanced via the right femoral artery into the left subclavian artery and inflated for 2 5 min. Because
of incomplete hemostasis, an 8 38-mm covered stent was implanted, leading to complete hemostasis.
FIGURE 22.24 Thrombosis distal to the access site was suspected, as the anesthesiologist reported a sudden loss of oxymetry reading (the pulsed
oxymeter was connected to the left little finger) that was confirmed by selective contrast angiography, which demonstrated fresh thrombus in the left ulnar
artery distal to the elbow (upper left). A percutaneous coronary intervention guidewire was advanced into the ulnar artery after which thrombus aspiration
was performed (utilizing an Export catheter) combined with the reinstitution of heparin therapy (upper right and lower left and right). A large fresh red
thrombus was successfully retrieved leading to reconstitution of antegrade flow and uneventful postoperative course (Fig. 22.25).
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