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Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_3811_Библиотеки_им_академика_М_И_Перельмана
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1 Echocardiography inAdult Cardiac Surgery
ab
c
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Fig. 1.21 Type II AR with (a, c) slightly dilated Ao sinuses, ail of right coronary cusp and (b) eccentric regurgitant
jet directed from prolapsing cusp
In majority of type I or type II cases, valve repair
Quantitation ofAR
may be considered and often may be successfully
performed, though AV repair is still underused.
However, if cusp tissue quality is poor (type III
AR) or there is mixed stenotic and regurgitant
valve disease, the valve is generally considered
unrepairable and replacement strategy should be
No single measurement or Doppler parameter is
precise enough to quantify AR in individual
patients. Integration of multiple parameters is
required. Criteria for the denition of severe AR
is presented in Table1.6 [13].
chosen if surgical treatment is indicated [24].
24
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R. Ordiene et al.
a
b
Fig. 1.22 Type III AR—aortic valve tissue destruction
because of infective endocarditis causing severe aortic
regurgitation (a, b)
Table 1.6 Echocardiographic criteria for severe AR
Quantitative
Measures Specic Criteria
EROA ≥30mm2
Regurgitant
volume≥60ml
Regurgitant fraction
≥50%
a
Denitely severe if ≥4 specic criteria
Flail leaet
VC width>0.6cm
Central jet, width≥65% of
LVOT
Large ow convergence
PHT<200ms
Prominent holodiastolic ow
reversal in the descending aorta
Dilated with normal function LV
a
Consequences ofAR onLV Size
andFunction andTiming forSurgery
LV remodelling is a consequence of chronic
severe AR and may be a specic marker of regurgitation severity. The timing for surgery is based
on symptoms, severity of AR and changes of LV
systolic function, as well as dimensions. Surgery
is indicated in symptomatic patients with severe
AR, or in asymptomatic patients with severe AR
and LV dysfunction at rest (LVEF≤50%). In
asymptomatic severe AR without LV dysfunction, LV enlargement with LV EDD >70 mm or
LVESD >50mm or>25mm2/m2, guide for surgical AR correction. Echocardiographic parameters obtained by three-dimensional (3D)
echocardiography, tissue Doppler and strain rate
imaging may be useful, particularly in patients
with borderline left ventricular ejection fraction
(LVEF), where they may help in the decision for
surgery [19]. Recently a study focused on prognosis demonstrated that asymptomatic severe AR
patients with dilated LV and GLS>−19.5% were
more likely to have a shorter survival without
aortic valve replacement [13]. In patients with
dilated aorta, the rationale for surgery has been
dened by aetiology and extent of aortic dilatation. Surgery should be considered in patients
with maximal ascending aortic diameter≥45mm
in the presence of Marfan syndrome and additional risk factors, ≥50mm in the presence of a
bicuspidal valve, and ≥ 55 mm for all other
patients. When surgery is indicated for the aortic
valve, replacement of the aortic root or ascending
part is considered when aortic diameter is
≥45mm, particularly in bicuspid valve [19].
The Role ofEcho inGuiding AV Repair
Intra-operative TOE provides a road map and
predicts techniques to be used for an effective
and durable repair. Pre-pump intra-operative
1 Echocardiography inAdult Cardiac Surgery
25
echocardiography protocol includes the main
objectives to be assessed:
• Valve type and geometry. Valve type is dened
by number of cusps, which is based on the
number of functional commissures (a tricuspidal valve with three fully developed commissures, a bicuspid valve (BAV) with two
developed commissures and 0 or one raphe on
the fused cusp, a unicuspid AV with one fully
developed commissure and two raphes and
quadricuspid valve with four commissures).
Commissure orientation, which varies
between 120° (tricuspid) and 180° (bicuspidal
symmetrical conguration) and the aortic
annulus must be assessed. Additional measurements are of great importance in planning
valve reconstruction: the effective height
(eH)—the distance from the annulus to the
middle of the free margin of the cusp (normal
value is close to 9mm), the geometric height
(gH) (also called cusp height)—the distance
between the cusp nadir and the middle of the
free margin (cusp retraction when gH is
16mm or less), the coaptation height (cH) or
coaptation length—the distance of cusp apposition in diastole with normal range 4–5mm.
(Fig.1.23). The motion of the cusps and the
jet direction must be evaluated [25]. 3D has
STJ
cH
eH
Annulus
Fig. 1.23 Denitions used in aortic valve repair: STJ
sinotubular junction, eH effective height, cH coaptation
height, gH geometric height
gH
several advantages in individualizing each
cusp and in detail measurement of eH and
gH. Restriction per se is not considered an
absolute contraindication for valve repair,
however combination with valve retraction is
a predictor of poor repair result. Another
lesion with surgical implications is the presence of fenestrations, seen as lament—like
structures on the free margins of the leaets.
The complexity of repair increases if these
fenestrations are multiple, big size and
fragile.
• Aortic diameters, that enables to diagnose aortic phenotype: normal root with aortic diameters <40mm, aortic root dilatation, aorta at the
sinuses of Valsalva >45mm, ascending aortic
aneurysm—aortic root < 40 mm, ascending
aorta > 45mm.
• LV diameters and function, as well as evaluation of other valves.
After AV repair postoperative TOE including 3D
imaging is mandatory to evaluate the surgery
result. It is ideal when the valve is competent
without any or trace residual AR, without cusp
restriction and mean transvalvular gradient
<10mmHg, with coaptation length≥4mm, with
individual cusps eH≥9mm (by 3DE), with aortic annulus <25 mm. These measurements are
important determinants of good long term postoperative results [25, 26].
Aortic valve Stenosis (AS) [19, 27]
AS is one of the most common valvular disorders leading to valve replacement procedure.
Despite the chosen technique—TAVI (transcatheter aortic valve implantation) or surgical aortic
valve replacement, detailed information is
required. By the time the patient arrives to the
cardiac theatre, the diagnosis usually has been
made according to clinical symptoms, signs and
by TTE as it’s the rst line diagnostic method in
aortic stenosis. Additional information (e.g.
invasive hemodynamics, low dose dobutamine
stress echocardiography, computed tomography)
can be important for decision making. 2D and
3D TOE should be considered for: better ana-
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R. Ordiene et al.
tomic assessment, underlying morphology
(bicuspid vs tricuspid), extent and distribution of
calcication, assessment of annulus dimension
in discording grading of stenosis severity, measurement of aortic valve area planimetry in cases
of coexisting subvalvular stenosis, in severe
valve calcication and “low gradient, low ow”
patients with LV dysfunction.
Echocardiographic Factors
intheEvaluation ofAS
• Assessment of valve anatomy and morphology.
• Conrmation of aetiology of aortic stenosis is
mandatory. Calcic degenerative aortic stenosis is the commonest valve lesion in the ageing
Western world population. It is identiable as
trileaet and calcied, with reduced cusp
opening and mobility. Bicuspid aortic valve is
another cause of isolated aortic stenosis in the
younger age group with or without echocardiographic signs of aortopathy. Rheumatic
aortic stenosis can be recognized by commissural fusion and thickening, reduced leaet
motion. Mitral valve can also be affected
(Fig.1.24).
• Severity of AS
• AS is considered severe when peak jet velocity is >4m/s, transvalvular mean pressure gradient >40mmHg, valve area is less than 1cm2
(or<0.6cm2/m2) by continuity equation, LV
outow tract/AV velocity/VTI ratio ≤ 0.25
(Fig.1.25). Discording of grading is common
in clinical practice (20–30%). 3D guided 2D
planimetry of the aortic valve in systole may
be used to evaluate the precise AV area, also in
perioperative setting this method is preferred
over the gradients, as the severity of AS may
not necessarily follow a high gradient
(Fig.1.26). AV calcium scoring is a quantitative and ow independent method of assessing
AS severity. Severe AS is likely when calcium
score by CT is more than 2.000 in men and
more than 1.200in woman [27].
• Current evidence suggests that a low gradient
cannot exclude the presence of severe AS.
“Low ow, low gradient” severe AS with
decreased LV systolic function is diagnosed
when AVA < 1 cm2, mean pressure < 40 mmHg, LVEF <50% and systolic
volume index SVi<35ml/m2. In these cases
low dose dobutamine stress echo provides
info on contractile response and helps to differentiate severe AS, causing LV dysfunction
and moderate AS with another cause of LV
dysfunction. Paradoxical “low gradient, low
ow” AS with preserved LV systolic function
is a challenging situation when AVA <1cm2,
mean pressure < 40 mmHg, a peak velocity < 4 m/s with maintained LV EF and
SVi<35%. This refers to patients with hypertrophied, small ventricles. Technical mistakes
in AVA calculation have to be excluded. AV
replacement might improve outcome of this
group of patients [27, 28].
• Intervention (AV replacement or TAVI) is recommended is symptomatic patients with
proven severe AS. Prognostic markers to
impact decision for surgery in asymptomatic
severe AS is velocity> 5,5 m/s, severe valve
calcication with rapid increase in transvalvular velocity (>0,3m/s/y) and increase transvalvular gradient with exercise more than
20mmHg [27].
• Associated Findings
– Changes of LV geometry and function. LV
hypertrophy is the consequence of pressure
overload and can lead to severe diastolic
dysfunction and pulmonary hypertension
in AS patients with poor outcomes of the
surgical treatment. Global longitudinal
strain (GLS) in severe AS may detect
impairment of LV systolic function when
ejection fraction is still normal and may
predict prognosis in this group of patients.
– Changes of aortic root and ascending
aorta—echocardiography may provide
information on the extent of aortic dilatation, severe calcication and the presence
of mobile atheromas, indicative of
increased risk of embolism or aortic cannulation. Extensive aortic calcication
1 Echocardiography inAdult Cardiac Surgery
Fig. 1.24 3D image of
congenitally bicuspid
aortic valve with
moderate stenosis and
continuous ow Doppler
through the valve
27
(porcelain aorta)—is a considerable contraindication to AV replacement.
– Evaluation of other valves and unexpected
lesions.
During surgery for AS some notes for pre- and
postoperative echocardiographic examination are
important—.
Selection of the prosthetic valve type and size
preoperatively. Echocardiographically derived
small aortic annular dimensions may lead towards
the selection of a stentless bioprothesis or aortic
root enlargement to prevent the patient-prothesis
mismatch.
Postoperative evaluation includes the assessment of transvalvular gradients, intra- and/or
paravalvular regurgitation, LV function and
integrity of the aortic wall.
Tricuspid Valve
The tricuspid valve (TV) is often called the ‘forgotten’ valve as it is relatively understudied in
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Fig. 1.25 Illustration of AV area calculation
comparison to the other heart valves and the
imaging of this valve is more difcult by TTE and
TOE due to the inability to visualize its structures
in one cross-sectional view (e. g. imaging of all
three TV leaets) (Fig. 1.27). However, recent
advances in 3D TTE and TOE has enabled to
visualize the TV anatomy, dene the mechanism
of tricuspid regurgitation, measure the size and
geometry of the tricuspid annulus, analyze the
anatomic relationships between TV apparatus and
surrounding cardiac structures, to assess volumes
and function of the right atrium and ventricle, and
to plan surgical repair or guide and monitor transcatheter interventional procedures [29].
Echocardiography allows differentiation of
functional (dilatation of RV and/or tricuspid
annulus leading to malcoaptation of the leaets
due to RV dysfunction, pulmonary hypertension,
or left heart disease) and organic TR causes
(infective endocarditis, congenital anomalies,
rheumatic disease, carcinoid syndrome, prolapse,
trauma, iatrogenic complications), as well as
diagnosing different morphologic types of TR
(leaet damage, annular dilation, and distinct
patterns of right—heart remodelling) (Fig.1.28).
TV repair is indicated when primary and secondary TR is severe in patients undergoing left
heart surgery or in pts. with progressing RV dilation/dysfunction [19]. No single Doppler and
echocardiographic parameter is precise enough,
therefore integration of multiple parameters is
required. In poor TTE quality or when parameters are discordant TOE or CMR for quantitation
could be used (Table1.7).
1 Echocardiography inAdult Cardiac Surgery
Fig. 1.26 3D guided
2D planimetry of the
aortic valve area in
systole
29
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R. Ordiene et al.
ab
Fig. 1.27 3D image of a tricuspid valve “en face” in diastole (a) and in systole (b) with visible three cusps: A anterior,
P posterior and S septal
Signicant annular dilatation is dened by an
end-diastolic diameter ≥ 40 mm or > 21 mm/
m2in the four-chamber transthoracic view and it
is the indication for secondary TR surgical correction during left sided surgery even in the
absence of substantial TR as this demonstrated to
provide reverse RV remodelling and to improve
functional status of the patients [19]. 3D echocardiography allows more detail evaluation tricuspid annulus size and geometry (Fig. 1.29).
Assessment of TV deformation parameters is
important as it was shown that marked leaet
tethering (coaptation height > 1 cm) was
associated with failed annuloplasty repair. In
these patients adjunctive repair techniques or
valve replacement maybe required [30].
Evaluation of RV geometry, function and pulmonary systolic pressure should be carried out in
TR patients. Parameters of RV systolic function
helps to detect the deterioration of RV muscle
function. A tricuspidal annular excursion measurement <16 mm and an RV fractional area
change <35% are suggestive of RV dysfunction
[13]. In severe TR indices of longitudinal RV systolic function can be misleading. CMR or 3D RV
volumes and ejection fraction provides more
accurate information for quantication of RV
geometry and function. Preoperative pulmonary
hypertension has the impact on postoperative
outcomes and must be carefully assessed in this
group of patients.
Tricuspid stenosis is often combined with tricuspid regurgitation, most frequently of rheumatic origin. Echocardiographic evaluation of
the anatomy of the valve and its subvalvular
apparatus is important to assess valve repairability. A mean transvalvular gradient ≥5mmHg at a
normal heart rate indicates signicant tricuspid
stenosis and requires intervention [19].
Articial Valves
Prior to evaluating the patient with an articial
valve, it is imperative to know the type and size
of the valve, as different types of prosthetic
valves have different ow characteristics.
Comprehensive echocardiographic assessment of the prosthetic valve function comprises
the evaluate on of valve leaet/occluder morphology and mobility, peak and mean transvalvular
gradients, effective orice area (EOA) calculation, assessment of any transvalvular or paravalvular regurgitation and, nally, evaluation of LV
dimensions and function and systolic pulmonary
artery pressure [31]. These parameters obtained
1 Echocardiography inAdult Cardiac Surgery
31
Fig. 1.28 2D TOE images of traumatic TV anterior cusp ail and severe TR
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R. Ordiene et al.
in operating theatre tend to change after the
effects of GA wear off and the associated hyperdynamic state resolves. A baseline postoperative
TTE assessment of prosthetic valve function is
recommended to be performed before hospital
discharge or 3–12weeks after the operation.
Table 1.7 Echocardiographic criteria for severe TR [13]
Quantitative Measures,
whenever possible Specic Criteria
EROA ≥40mm2
Regurgitant
volume≥45ml
VC width≥0.7cm
Flail leaet or dilated
annulus with no valve
coaptation
VC width>0.7cm
Central jet, >50% of right
atrium
PISA radius>0.9cm
Dense, triangular CW jet
Systolic reversal of hepatic
vein ow
Dilated RV with preserved
function
Normal gradients through articial valves are
slightly higher than the gradients of normal native
valves. Doppler echocardiographic parameters
are presented for the normal prosthetic valves
and suspected stenotic prosthetic valve dysfunction. (From Version 2015) Abnormally high
velocities and gradients through a prosthetic
valve may be indicative of valve stenosis, patientprosthesis mismatch (PPM), high ow states,
regurgitation or localised high velocity central jet
in bileaet prostheses. TTE imaging is often difcult, especially in mechanical valves, due to
reverberation and shadowing artefacts, therefore,
TOE has marked superiority in prosthetic valve
assessment. Valve type and size should be taken
into consideration and effective orice area
(EOA) of the type and size of the implanted valve
should be indexed to the patient’s body surface
area (BSA). In the early postoperative period,
stentless bioprostheses, especially if implanted
by subcoronary technique, may have higher gra-
Fig. 1.29 3D TTE evaluation of tricuspid annulus size and geometry
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