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Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_3676_Библиотеки_им_академика_М_И_Перельмана
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10 Cardiac CTA in the Evaluation of CABG
https://t.me/med1917
Fig. 10.14 (a) Volume
rendering. Multiple
patent grafts (long
arrows). Stump in the
ascending aorta from an
occluded SVG in the left
circumflex (short
arrow). Chronic left
ventricular infarct
(double arrow). (b–d)
Volume rendering,
cMPR, stretched.
Occluded PDA beyond
the distal anastomosis
(arrows). There is
retrograde flow into the
proximal PDA (c, short
arrow)
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C. Smuclovisky
10.15 Case 14
10.15.1 History
An 86-year-old male presented with a history of
an inferior wall fixed defect on a nuclear perfusion scintigram and status post two times CABG
in the previous 30 and 12 years.
10.15.2 Findings
There is a patent LIMA to the distal LAD and a
patent RIMA to the distal RCA. There is a patent
sequential right gastroepiploic artery conduit
(GEA) to circumflex branches. There were
chronic occluded SVGs in the ascending aorta
from the first CABG (Fig. 10.15a–e).
10.15.3 Diagnosis
Repeat CABG demonstrates patent internal
mammary arteries and a GEA.
may not be possible to reach the posterior surface of the heart with the internal mammary as
either a pedicle or a free graft. The right GEA,
which was first implanted as a direct bypass
graft in 1974 by Edwards, is occasionally used
as a graft to the distal right coronary artery, the
posterior descending artery and as in this case,
to the distal circumflex branches [1, 2]. This is
a technically difficult operation to perform
that has not become a popular bypass graft but
has a high likelihood of good long-term
patency when used in the proper situation, and
in some patients represents a significant
advantage over vein grafts. Harvesting of the
GEA necessitates an abdominal extension of
the sternal incision, which may cause additional postoperative pain and may be a potential site for herniation and/or adhesion
formation. Additional possible complications
include postoperative ileus, pancreatitis, and
intra-abdominal hemorrhage. In addition,
there was an old inferior wall MI (not shown)
that accounted for the abnormality reported on
the nuclear study.
10.15.4 Discussion
The internal mammary arteries are commonly
used for direct coronary revascularization; it
10.15.5 Pearls and Pitfalls
It is important to look below the diaphragm in
order to confirm that a GEA was harvested.
10 Cardiac CTA in the Evaluation of CABG
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Fig. 10.15 (a–d) Axial, oblique maximum intensity pro-
jection, cMPR, and volume rendering. Sequential GEA to
circumflex branches (arrows). (e) Axial. IMAs and one of
the stumps in the ascending aorta from an occluded SVG
from previous revascularization (arrows)
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C. Smuclovisky
10.16 Case 15
10.16.1 History
An 84-year-old asymptomatic male presented
with a history of an ascending aortic aneurysm
and CABG in the previous 15 years.
10.16.2 Findings
There is an ascending aortic aneurysm measuring
maximally 6.8 cm, containing a localized dissection in the right lateral wall. There is a patent
saphenous vein graft (SVG) with a limb to the
distal and sequential to circumflex branches.
There is occluded LIMA to the first diagonal and
also an occluded SVG to the distal RCA. In addition, there was mild mediastinal adenopathy and
a new 4.5-cm peripheral spiculated soft tissue
mass in the right upper lobe (Fig. 10.16a–d).
10.16.3 Diagnosis
10.16.4 Discussion
Aortic dissection can be caused by cardiac
surgery, including aortic and mitral valve
replacements, CABG surgery, or percutaneous
catheter placement (e.g., during cardiac catheterization and percutaneous coronary intervention). Aortic dissection occurs when the
layers are split in the process of cannulation or
aortotomy.
Since the proximal anastomosis of the SVG
to the RCA could not be identified, it is reasonable to assume that the dissection in this case
may be secondary to the previous aortotomy
site. A CT scan of the chest in the previous
12 months did not demonstrate any abnormality in the area of the current mass or adenopathy. Although the mass had a CT appearance
consistent with a primary carcinoma, it would
be most unusual for a neoplasm to have grown
from undetectable to 4.5 cm in 1 year. The
CT-guided or biopsy confirmed the diagnosis
of sarcoidosis.
The diagnosis was large aneurysm of the ascending aorta with a localized dissection; occluded
SVG to the distal RCA and LIMA to the first diagonal; patent vein grafts to the LAD and circumflex
branches; and new onset of mild mediastinal adenopathy and a peripheral mass in the right upper
lobe, which was biopsy-proven sarcoidosis.
10.16.5 Pearls and Pitfalls
It is important to inspect an ascending aortic
aneurysm for the presence of dissection and also
the entire field-of-view for additional extracardiac abnormalities.
10 Cardiac CTA in the Evaluation of CABG
https://t.me/med1917
Fig. 10.16 (a) Axial.
Localized dissection in
the right lateral wall of
an ascending aortic
aneurysm (long arrow).
Occluded LIMA graft
(short arrow). (b)
Volume rendering.
Patent SVG with two
surgical limbs to the
LAD and circumflex
branches (arrows). (c, d)
Sarcoidosis. Axial
mediastinal and lung
windows. Peripheral soft
tissue mass in the right
upper lobe (long arrow).
Mild mediastinal
adenopathy (short
arrows)
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10.17 Case 16
10.17.1 History
A 75-year-old male presented with a history of
chronic ischemic heart disease and three prior
coronary revascularizations, first in the 1960s
and the last in the previous 18 years.
10.17.2 Findings
A large low-density ovoid mass is seen anterolaterally in the mediastinum with adjacent metal
artifact that extends into a stump in the ascending
aorta (Fig. 10.17a). There is a dissection in the
pulmonary artery trunk (Fig. 10.17b, c). There
are three stumps in the ascending aorta from old
occluded grafts (Fig. 10.17d). There are chronic
total occlusions of the LAD, left circumflex, and
RCA (not shown). There is a sequential LIMA
graft to the distal LAD, which has extensive surgical clip artifact. The distal anastomosis contains a stent that could not be adequately evaluated
(Fig. 10.17e). There is a saphenous vein graft
with a proximal anastomosis to the descending
aorta and distally to circumflex branches
(Fig. 10.17f, g). The graft appears to be patent but
could not be adequately assessed due to surgical
clip artifacts. The RIMA is atretic and distally
has been surgically tunneled into the free wall of
the right ventricle (Fig. 10.17h–k). There are
extensive chronic infarcts in the left ventricle
(Fig.
10.17l) and COPD (Fig. 10.17m).
10.17.3 Diagnosis
1. Status post embolization with coils of an SVG
pseudoaneurysm
2. Chronic dissection of the main pulmonary
artery trunk, with COPD and chronic pulmonary arterial hypertension
3. Multiple occluded grafts in the ascending
aorta
4. Sequential LIMA graft to the distal LAD and
SVG from the ascending aorta to circumflex
branches
5. Previous Vineberg’s procedure
6. Multiple chronic infarcts in the left ventricle
10.17.4 Discussion
This complicated case demonstrates findings
related to multiple prior cardiac surgical revascularizations and intervention over a period of four
decades. Due to the length of time, the surgical
history was incomplete but the findings on the
CTA are compelling and worthwhile to review.
The patient had unstable angina and under-
went a Vineberg’s procedure in the 1960s. Arthur
M. Vineberg (Canadian thoracic surgeon) developed the procedure of direct implantation of the
internal mammary artery into the ventricles for
relief of myocardial ischemia. Although the procedure had merit, it never received broad acceptance from the medical and surgical communities.
The procedure consisted of dissecting the IMA
free from the chest wall and tunneled into the
superficial myocardium. He founded this procedure on the belief that the myocardium contains
relatively large venous sinusoids that could
absorb the flow from the bleeding mammary vessels and consequently improve myocardial perfusion. Thousands of patients underwent this
procedure and although it had mixed results, it
was considered at that time to be the best available alternative and benefited many patients. In
this procedure, primarily the left internal mammary was tunneled into the left ventricular wall.
RIMAs to the right free ventricular wall were
also performed. It was unknown whether in this
case the LIMA was previously implanted and
then removed from the left ventricle and reused
as a sequential graft.
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The patient continued to have unstable angina
and was subsequently reoperated with grafting of
multiple saphenous vein conduits. One of the
grafts developed a pseudoaneurysm that was subsequently embolized successfully with percutaneous intervention and placement of coils.
Remarkably, the pulmonary artery dissection was
known to the patient for more than 20 years.
Pulmonary arterial dissection is usually a lethal
complication of congenital (e.g., Eisenmenger’s
syndrome) or acquired chronic pulmonary hypertension. The condition usually manifests as cardiogenic shock, sudden death, and is typically
diagnosed postmortem. There are isolated
reported cases of patient’s surviving pulmonary
artery dissection, as in this case.
Pseudoaneurysms occurring as a complication
from surgical revascularization are well documented
in the literature and most commonly occur as a
result of suture breakdown in the area of anastomosis. Prior to the availability of covered stents, percutaneous embolization with coils or a reoperation
was usually necessary.
10.17.5 Pearls and Pitfalls
Complex anatomy requires a patient wellorganized step-by-step approach to completely
and accurately assess the study. And brace yourself for having to spend a long time in front of the
workstation.
Fig. 10.17 (a) Axial and coronal: Proximal occlusion of an
SVG (long arrow). Embolization coil (short arrow).
Thrombosed pseudoaneurysm (arrow heads). (b, c) Axial and
coronal. Chronic main pulmonary artery dissection (arrows).
(d) Volume rendering. Stumps from occluded grafts in the
ascending aorta (triple arrow). Thrombosed pseudoaneurysm
(single arrow). (e) cMPR. LIMA–LAD. Extensive surgical
clip artifact and distal stent not adequately visualized (lower
arrow). (f, g) SFVG from the ascending aorta to circumflex
branches (arrows). (h–k) Axial and cMPR. Atretic RIMA
tunneled into the free wall of the right ventricle: Vineberg’s
procedure in the 1960s (arrows). (l) Sagittal oblique. Multiple
chronic LV infarcts (arrows). (m) Axial lung window.
Advanced COPD
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Fig. 10.17 (continued)
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10.18 Case 17
10.18.1 History
A 78-year-old female presented with a history of
an inconclusive nuclear perfusion scintigram and
CABG in the previous 15 years.
10.18.2 Findings
There is dextrocardia with situs inversus
(Fig. 10.18a). There is a patent RIMA graft to the
LAD and a saphenous vein graft (SVG) to the
ramus intermedius. The circumflex is small caliber and was not grafted. There is an occluded
SVG to the distal RCA (Fig. 10.18b–d). The
native RCA is dominant and has scattered calcified nonobstructing plaques (Fig. 10.18e).
10.18.3 Diagnosis
The diagnosis is situs inversus with dextrocardia.
The status was post CABG, with a patent RIMA
to the LAD and SVG to the ramus intermedius
artery. There is an occluded SVG to the RCA
likely from competitive flow from a patent native
RCA.
10.18.4 Discussion
Situs describes the position of the cardiac atria
and viscera. The prevalence of situs inversus is
estimated at 0.01% of the population. Situs solitus
is the normal position, and situs inversus is the
mirror image of situs solitus. Cardiac situs is
determined by the atrial location. In situs inversus, the morphologic right atrium is on the left,
and the morphologic left atrium is on the right.
The normal pulmonary anatomy is also reversed
so that the left lung has three lobes and the right
lung has two lobes. In addition, the liver and gallbladder are located on the left, whereas the spleen
and stomach are located on the right. The remaining internal structures are also a mirror image of
the normal. Situs inversus totalis is associated
20% of the time with primary ciliary dyskinesia
and known as Kartagener’s syndrome (not in this
case). Kartagener’s syndrome consists of the
triad: bronchiectasis, sinusitis, and situs inversus.
Because of the dextrocardia, the RIMA was
used, instead of the LIMA, to bypass the left
anterior descending coronary artery. Typically,
after a coronary artery is grafted, there is accelerated development of disease proximal to the
anastomosis in the native coronary. If the grafted
native artery remains patent, competitive flow
may cause the graft to fail and occlude early.
10.18.5 Pearls and Pitfalls
The recognition of situs inversus is important for
preventing surgical mishaps that result from the
failure to recognize reversed anatomy.
Competitive flow between a native coronary
artery and a graft may cause an early occlusion of
the graft.
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Fig. 10.18 (a) Dextrocardia with situs inversus. (b)
Volume rendering. Dextrocardia and post CABG. (c, d)
cMPR. Patent RIMA to the LAD and SVG to the ramus
intermedius. (e) cMPR. Calcified nonobstructing calci-
fied plaques in the proximal to mid-large dominant RCA.
(f–h) Coronary angiogram of the patent RIMA to the
LAD, SVG to the ramus intermedius, and widely open
native RCA
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