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Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_3737_Библиотеки_им_академика_М_И_Перельмана
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Transcatheter Aortic Valve Replacement
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Positioning ofValve inValve Bioprosthesis
Along with uoroscopic and angiographic determination of the sewing ring position, echocardiography is useful especially in non-radiopaque
SHV.When positioning and deploying the THV,
appropriate uoroscopic angles should be perpendicular to the basal ring of the SHV with angles
determined by pre procedural CT/angiography or
intraprocedurally [95]. High implantation is associated with risk for embolization and coronary
obstruction in both self and balloon expandable
valves but has an advantage of reduced gradients
[96]. Low implantation of balloon- expanding
valves are at risk for paravalvular regurgitation
and bioprosthetic SHV leaet overhang (unlikely
in the longer S3) with risk of anterior mitral leaet
impingement and suboptimal lower annular position in self expanding valves [96]. Note should be
made that coplanar uoroscopic views do not correlate with long axis views on echo [96]. Optimal
positioning on TEE is achieved with the THV
implanted within 5mm from the inferior margin
of the suture ring for SE valves and 10% below
the suture ring for BE valves [96]. Fluoroscopic
and echocardiographic landmarks are different
[96]. Manufacturer recommendations are for the
central marker on the balloon to be aligned with
the base of the right coronary cusp during Sapien
implantation [110]. Ramanathan etal. describes a
100% success rate with no new pacemaker
requirement, procedure related death or valve
embolization when the lucent line at the inow of
the Sapien valve was aligned with the radiopaque
basal ring [110]. The larger height of third generation BE THV’s (compared to any SHV) require
echocardiographic conrmation of the upper margin positioned below the STJ and above the SHV
leaets with automatic appropriate positioning of
its lower margin below the suture ring [96].
Following valve implantation echocardiographic assessment for valve position, leaet
motion, gradients, valve area, intra and inter valvular regurgitation, ventricular function and size
and new or increasing size of any pericardial
effusion should be performed [96]. Table7 show-
ing role of Multimodality Imaging in aortiv valve
in valve implantation.
Post Procedural Assessment
Immediate post procedural transthoracic echocardiogram demonstrated a well seated trans
catheter heart valve, however leaet motion was
not well seen. The AVA measured 0.7cm2, indexed
AVA=0.42cm2/m2 Vmax measured 3.5m/s with
a peak gradient of 49mmHg and mean gradient
was 26mmHg. Left ventricle demonstrated mild
concentric hypertrophy with an ejection fraction
of 60%. Trivial PVL was present. Elevated gradients and velocities post procedure, while
improved as compared to pre-procedure, likely
represent PPM due to the use of a 20mm SAPIEN
valve (Fig. 36).
To rule out leaet abnormality, a post procedure CT was obtained and demonstrated an
under expanded Sapien 3 valve with an area of
2.44cm2 at the stent inow, 2.02mm2 at the mid
Table 7 Valve-in-valve multimodality imaging
Valve in valve Echocardiography Fluoroscopy Computed tomography MRI
Preprocedure
imaging
Intraprocedural
imaging
Postprocedural
imaging
First line for diagnostic
assessment of a prosthetic
valve and quantication of
severity
TEE is of greater
intraprocedural utility in
stentless valves. Can assist in
determining risk of coronary
obstruction
Same as AS (case 1)
Visualization of
indwelling valve
optimizes
deployment
Essential in determining
risk of coronary artery
obstruction and
determining size and type
of SHV (if information
not already provided)
Limited due to
metal artifact from
degenerated
bioprosthetic valve
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abc
Fig. 36 Post contrast CT at 30days following TAVR VIV with coplanar images at the inow (a), mid (b) and outow
(c) demonstrating an under expanded S3 with the areas obtained less than expected for a 20mm S3
portion of the stent and 271mm2 at the stent outow. No evidence of HALT or leaet thrombosis.
30-day TEE revealed a well seated transcath-
eter heart valve and poorly visualized leaet
motion, AVA of 0.7cm2, Vmax of 3.5m/s and a
mean gradient of 28mmHg. There was concentric
left ventricle hypertrophy with an ejection fraction of 65%. This was essentially unchanged as
compared to the immediate post-procedure TTE.
Complications Following VIV TAVR
Leaet Thrombosis andThickening
Computational modelling demonstrates relative
increase in blood stasis within the neo sinus as a
potential mechanism to leaet thrombosis following VIV TAVR [98]. Other causes of leaet
thickening and altered motion include incomplete valve frame expansion, endocarditis, HALT
and leaet degeneration [58, 111].
Elevated Gradients andPPM
PPM results from a normally functioning bioprosthetic valve with an EOA relatively smaller
than required for the patient’s body size with subsequent elevated post procedural gradients [92].
An indexed EOA of <0.65cm2/m2 denes severe
PPM.Post TAVR valve in valve mean gradients
are higher than mean gradient post native TAVR,
averaging 12.4–16mmHg [104]. A gradient of
greater than 20mmHg following TAVR VIV is
associated with poor clinical outcomes and 1year
mortality rates [95]. Supra annular morphology
of the core valve, inner versus externally mounted
leaets, higher implantation depth (allowing for
better coaptation and leaet motion, unrestricted
by the basal ring of the SHV [98]) and larger
THV sizes confer lower valve gradients [104].
The effective orice area is not necessarily larger
with a larger THV choice with invitro results
demonstrating different EOA in similar sized
THV by different SHV manufacturers [98]. Pre
dilation of the bioprosthetic valve to increase the
inner diameter in the setting of calcication,
thickened leaets and brotic pannus is an available option but seldom used due to the risk of
embolization or haemodynamic compromise following acute aortic regurgitation [104].
Appropriate THV choice (supra annular valve in
SE THV) should be considered with smaller
SHV [96]. VIV THV in small SHV (e.g. 19mm
SHV) should be avoided [96] with poor outcomes
in SHV’s less than 21mm due to persistent high
gradients [95]. Valve fracture, in the appropriate
setting, and post implantation dilatation are further available options to minimise risk of patient
prosthesis mismatch [104].
Permanent Pacemaker Requirements
The stable and rm nature of the surgical valve
limits injury and compression to the conduction
system with reduced post procedural pacemaker
requirements [104], especially with new generation devices with no signicant difference
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between the balloon or self-expandable valves
[112]. Pre-existing RBBB, increased age and
larger THVs have increased pacemaker requirement risks [112].
Paravalvular Leak
The rm and regular surface provided by the surgical valve reduces the risk of PVL and annular
rupture, unless balloon expansion is aggressive
[104].
Clinical Controversies andPearls
• In stented valves measure VTC, if the ostium
is below or at the level of the tip of the stent
post, and a VTS at the tip of the stent posts
should be measured. A VTC <4 mm is high
risk for obstruction, intermediate risk when
4–6mm and low risk when >6mm.
• If the SHV valve lies above and in close proximity to the STJ, a valve to STJ distance should
be measured and is signicant if circumferentially below normal. A valve to STJ less than
3mm is high risk for coronary obstruction.
Key Points
– A key assessment in evaluation of
degenerative bioprosthetic aortic valve
disease is the risk of early or delayed
coronary obstruction, which is largely
based on CT measurements.
– Outcomes of valve-in-valve after implan-
tation of a TAVR valve of 21mm or less
are suboptimal, likely due to elevated gradients and patient-prosthesis mismatch.
– With the exception of the risk for coronary
obstruction, early outcomes after valve-invalve (TAVR in SAVR) are generally
superior to native valve TAVR because of
the presence of a regular, rigid structure
(degenerated bioprosthetic valve) upon
which to expand the TAVR valve.
Valvuloplasty
Case Study 1
An elderly patient presented with signicant shortness of breath on mild exertion
worsening in the last 6–8months (NYHA 3)
without syncope or pre syncope. The clinical examination revealed a systolic ejection murmur, loudest in the right
parasternal region.
Background andDenitions
Initial optimism for standalone balloon valvuloplasty for AS in the pre-TAVR era was tempered
by recurrence of symptoms and restenosis with
mortality rates equivalent to those in patients
managed conservatively [113]. With the advent
of TAVR there has been a resurgence of balloon
valvuloplasty procedures with up to 40% of
patients progressing from balloon valvuloplasty
to TAVR [114].
Balloon valvuloplasty serves as a bridge to
more denitive TAVR and SAVR in haemodynamically unstable patients and may be utilised
in patients requiring urgent noncardiac surgery
but have comorbid severe aortic stenosis [82,
113, 115]. Both the self-expandable valve
(Evolut R generation) and balloon expandable
valve (Sapien 3, Edwards Life Sciences) demonstrate similar outcomes with non-inferiority
of the direct to TAVR procedures when compared to pre TAVR valvuloplasty [116]. It
should be noted however that during direct to
TAVR procedures, 5.8% of procedures had to
be preceded by balloon valvuloplasty due to
difculty in traversing the aortic valve in the
presence of severe valve calcication, small
valve area and variant valve morphology e.g.
bicuspid valves [116].
Balloon valvuloplasty may be used to determine the contribution of severe AS to the presence and severity of symptoms in a patient with
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multiple co morbidities with any co morbidity as
a possible cause to symptoms [113, 114]. Patients
with advanced co morbidities, low left ventricular systolic function, chronic obstructive pulmonary disease and signicant frailty whom develop
improved transvalvular gradient post balloon valvuloplasty are likely to demonstrate improvement in left ventricular function following TAVR
[113].
Currently, balloon valvuloplasty is the preferred treatment option of young adults and children with congenital aortic stenosis in the absence
of severe calcication [115]. Balloon valvuloplasty may also be utilised post THV deployment. Balloon dilation improves apposition of
the prosthetic valve with the annular wall and
generally increases the smallest diameter by
1.9mm [113] subsequently enlarging the effective orice area, minimising PVL and reducing
the risk of PPM [113, 116]. Risk of annular rupture and post dilation requirements should be balanced when using a non-compliant balloon which
should subsequently be at least 1 mm smaller
than the average annular diameter obtained from
pre procedural CT and the procedure continued
depending on patients response [113, 116].
Complications associated with balloon post dilatation include annular rupture, stroke, left bundle
branch block [116] and valve embolization [117].
Both TEE and uoroscopy can identify valve
infolding requiring post deployment valvuloplasty, which has been described with the Core
valve and Evolut R [118, 119]. In valve in valve
procedures, balloon valvuloplasty may improve
the effective orice area and transvalvular gradients by cracking the implanted surgical prosthetic
valve [116].
Diagnoses andPreprocedural
Assessment
Initial TTE revealed a moderately thickened
trileaet aortic valve with severely restricted
cusp motion. The aortic valve area measured
0.8 cm2 with a peak velocity of 4.2 m/s and a
mean gradient of 43mmHg with trivial valvular
regurgitation. The left ventricular ejection fraction was 60%.
A pre prosthetic valve work up CT was performed. The patient has a tricuspid calcied aortic valve with an annular area of 413mm2, with
moderate annular calcication and a mildly protruding nodule below the left coronary sinus.
Risk for coronary obstruction was low and trans-
femoral was route chosen as the preferred access
site (Fig. 37).
Cardiac catheterization demonstrated mild
coronary artery disease with no revascularization requirements. The aortic valve and
aortic root were moderately calcified. No significant coronary artery disease was present,
but the patient had moderate pulmonary
hypertension and borderline femoral dimensions for large sheaths at 6mm in narrowest
diameter (Fig. 38).
abc
Fig. 37 (a) Annulus is drawn ensuring to be oblivious to
calcium during measurement. Leaets are moderately calcied with a protruding nodule below the left coronary
cusp. Annulus area of 429mm
2
and perimeter of 74.4mm
suggests use of a 23 mm S3 valve. (b) LM height of
14.5mm. (c) RCA Height of 24.4mm. Suggests low risk
for coronary artery obstruction
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a
b
Fig. 38 Conventional cardiac catheterization via transfemoral access. (a) The aortic root is normal with mild calcica-
tion. (b–d) Left main coronary artery and (e) Right coronary artery demonstrated mild coronary artery disease
Dierential Diagnosis
The patients’ symptomatology followed by echocardiogram conrmed severe AS and concurrent
pulmonary arterial hypertension. No exacerbating lung pathology or superimposed pneumonia
was present. No clinical, biochemical or ECG
features of heart failure or myocardial ischemia.
Heart Team Approach andDiscussion
In view of her age and co morbidities in the setting of severe symptomatic AS trans catheter aortic valve replacement with a 23mm Sapien valve
was the treatment of choice.
Heart Team Decision
Indications for balloon valvuloplasty in relation
to TAVR.
Balloon Valvuloplasty Prior toTAVR
Balloon valvuloplasty may be performed immediately prior to transcatheter valve placement to
c
assist with the valve delivery system negotiating
the annulus and valve orice [113, 116]. Balloon
valvuloplasty increases the aortic valve area
ensuring a uniform and consistent shape of the
orice allowing for equable prosthetic expansion
and reducing the risk of valve malposition and
PVL [116]. Improved radial force and delivery
system proles of the later generation valves,
institution expertise with direct TAVR and preprocedural annular sizing with CT and/or TEE
has limited the need for balloon valvuloplasty
[120].
Annular Sizing
Intra procedural balloon sizing of the annulus
provides complementary information when
annular sizing by MDCT is not conclusive but
rather borderline between two consecutive valve
sizes [113, 121]. Condado etal. described similar
rates of mild PVL, annular rupture, and acute
kidney injury when annular sizing is done by CT
or balloon valvuloplasty, however balloon valvuloplasty demonstrates a slightly higher (7% versus 5.7%) rate of moderate PVL [121]. Babilaros
et al. described balloon valvuloplasty as an
important, safe and efcient supplement to TEE
d
e
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sizing of the annulus with no coronary obstruction, THV embolization or annular damage and
in 26% of patients an alternate THV was used
based on balloon valvuloplasty ndings [44].
Annular sizing is usually performed with rapid
pacing, following injection of iodine contrast
with opacication at the aortic root and simultaneous maximal insufation of an appropriately
sized balloon, consistent with pre procedural
imaging derived annular dimensions [28]. Under
sizing is described as the balloon not reaching the
annular hinge points or if there is signicant contrast leak around the balloon into the left ventricle [28]. There should be precautionary
preparation for expedited TAVR placement post
valvuloplasty in the event of acute aortic regurgitation with haemodynamic compromise [28].
Coronary Occlusion
Concurrent balloon valvuloplasty, inated to a
size similar to the predicted TAVR valve, and
root aortography can help determine risk of coronary artery occlusion [113] by simulating leaet
displacement and position relative to the coronary ostia, as if the TAVR valve was utilised [28].
Crossing theValve
Pre TAVR balloon valvuloplasty may assist in
certain situations which predispose to difculty
in crossing the valve with the delivery device.
Situations include highly calcied leaets with
high calcium scores and low AVA [116].
Echocardiographic ndings for an unfavourable
direct TAVR procedure include severe leaet calcication, presence of calcication nodules, AVA
less than 0.4cm2 and an irregular valve orice
[116].
Bicuspid Aortic Valve
Pre TAVR dilation occurs with balloon valvuloplasty in almost all patients with bicuspid aortic
valves to minimise asymmetrical valve expansion and valve migration [116].
Contraindications toBalloon
Valvuloplasty
Balloon valvuloplasty is contraindicated in the
absence of severe AS [113] and in the presence of
infective endocarditis [113, 115], moderate [115]
to severe aortic valve regurgitation [113, 115],
presence of LV thrombus [113], signicant left
main coronary artery stenosis [113], tumour
[115], or life limiting non cardiac co morbidities
[113, 115]. Furthermore, exclusive valvuloplasty
in the presence of a mechanical or bioprosthetic
valve can be complicated by prosthesis fragmentation [113]. Valvuloplasty in patients with
reduced intravascular volumes and concentric LV
hypertrophy may exhibit persistent hemodynamic instability [28]. Annular dimensions not
compatible with balloon specications, i.e. signicantly smaller or signicantly larger, and
active bleeding preclude the use of intraprocedural heparin and are also a contraindication
[113].
Intra andPost Procedural Assessment
Right femoral access was achieved as per protocol and pre deployment valvuloplasty was performed. (Fig. 39, Video 22). This was uneventful
with no evidence of haemodynamic instability.
The bio prosthesis was then advanced and
deployed under rapid pacing at nominal volume
with a good result. (Fig. 40).
Whilst still on the table, patient complained of
nausea and ECG showed ST elevation. An urgent
coronary angiogram was performed showing a
lling defect in the left main, presumably thrombus, with slow ow in the LAD and circumex
arteries. A balloon was then inated in the LAD
and circumex with no visualized thrombus ow
was reestablished at the end of the procedure.
The patient was transferred to the intensive care
unit on dual antiplatelet therapy (Fig. 41).
A same day post procedural echo showed a
well seated 23mm Sapien 3 trans catheter heart
valve with trivial valvular and mild paravalvular
regurgitation. The peak velocity was measured at
1.8m/s, the peak gradient was 13mmHg, with a
mean gradient of 7mmHg and a VTI of 36cm. A
3 × 10 mm mobile echogenic structure of
unknown origin was visualized in the aortic root
(Fig. 42, Video 23).
To further investigate the mobile echogenic
structure in the aortic root, a CT scan was performed. CT showed a linear lling defect extend-
ab
ab
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Fig. 39 Intra procedural, pre deployment valvuloplasty shows (a) Balloon waist at the site of the valve with (b) expan-
sion of the balloon waist post successful valvuloplasty
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Fig. 40 Transfemoral catheterization of the aortic root. (a) Intraprocedural contrast injection with the THV advanced
and (b) deployed under rapid pacing. Adequately positioned and expanded valve
abc
Fig. 41 Urgent on intra procedural conventional coronary angiogram. (a) Patent RCA. (b) Thrombus in the left
main with slow ow in the LAD and circumex arteries.
A balloon was then inated in the LAD and circumex
with no visualized thrombus. (c) Reestablished ow at the
end of the procedure
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ing from the non-coronary/left coronary
commissure traversing through the sinus of
Valsalva and into the left main coronary artery
and LCX ostium (Fig. 43). There was at least a
moderate degree of luminal narrowing of the left
main with subtotal occlusion of the LCX ostium.
The valve was well expanded with no hypo atten-
Fig. 42 Zoomed Long axis TTE with an echogenic ap
distal to the THV outow
uating leaet thickening (HALT) or leaet thrombus (Fig. 44).
During an urgent coronary angiogram, a
lling defect in the LM and LCX was
appreciated.
PCI with DES’s from the LM to CX and from
the LM to LAD (simultaneous kissing stents)
were deployed (Fig. 45).
Complications Post Isolated BAV andPre
TAVR BAV
In this patient, a post balloon valvuloplasty (and
TAVR) echocardiogram showed an echogenic
mobile structure corresponding, on CT, to a lling defect in the aortic root extending into the left
main coronary artery, with subtotal occlusion of
the left circumex artery. Possible considerations
include focal dissection or a torn leaet extending into the coronary ostium. Prior descriptions
of coronary ostial occlusion by a perforated leaflet following balloon valvuloplasty have been
described. The incidence is extremely low and
with an unfavourable 30 day mortality rate of
41% [122]. Clinical features include hypotension
with ECG and biochemical features of ischemia
[122, 123], ventricular arrhythmias or cardiac
c
Fig. 43 (a–c) Linear lling defect (open arrow) (viewed in orthogonal planes centred on the lling defect) seen extend-
ing from the Sinuses of Valsalva into the left main coronary artery
ab
cd
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Fig. 44 (a) Sapien 3 ultra 23mm valve with expansion measured at (b) inow, (c) mid and (d) outow demonstrating
good valve expansion
57
abc
Fig. 45 Emergency post procedural coronary angiogram
performed. (a) Shows a lling defect in the LM and LCX.
(b) PCI with DES’s from the LM to CX and from the LM
arrest [123], and should be treated with emergency percutaneous intervention or bypass graft
[122, 123]. Although uncommon, coronary ostial
occlusion by an avulsed leaet, aortic root dissection, mural haematoma or embolised leaet
material do occur [123, 124]. Common predictors
of coronary artery occlusion risk during the
TAVR procedure are a narrowed sinus of Valsalva
in combination with a low lying coronary height
and bulky leaet calcication which are easily
detectable on CT and MRI [123].
Other complications associated with balloon
valvuloplasty include stroke, ventricular perfora-
to LAD (simultaneous kissing stents) were performed. (c)
Flow was reestablished in the LM and LCX
tion, annular rupture [113–115], aortic regurgitation [114, 115], death [113, 114], dysrhythmias
[113, 115], myocardial infarction, acute mitral
regurgitation [113] and contrast allergies [115].
Haemodynamic instability may occur as a result
of rapid pacing or severe aortic insufciency following leaet and commissural separation [116].
Severe aortic insufciency occurred in 1–2% of
patients when balloon valvuloplasty was used in
isolation to treat AS, prior to the TAVR era [116].
Echocardiographic assessment of hemodynamic
instability is directed at identifying AR, annular
rupture and cardiac tamponade with aortofemoral
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angiograms accessing for the presence of contrast extravasation in aortofemoral injury [113].
Other potential complications include vascular
and access site complications (pseudo aneurysm,
dissection, vascular ischemia [113–115]) and
access site haematomas and infection [115].
There are increased rates of new conduction disorders, often persistent following valvuloplasty
[116]. Periprocedural stroke is thought to result
from excessive native valve manipulation with
rates of stroke at 30days post procedure ranging
from 2 to 4% [116]. There is no signicant
increase in stroke rates with pre procedural valvuloplasty however higher rates are described
with balloon post dilation [116]. Contrasting evidence currently describes reduced PVL in
patients with and without preprocedural balloon
valvuloplasty, with one school of thought stating
that patients who do not have pre TAVR balloon
valvuloplasty have reduced PVL due to better
prosthetic valve anchorage, and the other that
patients with pre TAVR valvuloplasty have
reduced PVL due to circular valve expansion and
lower incidence of under expansion [116].
Case Study 2: VIV Valvuloplasty
An elderly patient presented with productive cough, shortness of breath, orthopnea
and effort intolerance (NYHA III) for
2 weeks. Prior history was signicant for
CABG and SAVR.On physical examination
the patient had pitting sacral oedema and a
non-radiating early systolic murmur at the
left upper sternal border. Troponin:
0.04ng/mL, ECG: atrial brillation with-
out ischemic changes.
Background andDenitions
Bioprosthetic valve fracture (BVF) and
remodelling.
Bioprosthetic valve fracture is performed to
reduce transvalvular gradients and increase the
effective aortic valve area [103] reducing the risk
of PPM and possible leaet pin wheeling (which
may result in premature leaet degeneration of
an under expanded THV) [125, 126]. Patient
prosthetic mismatch, when dened as a post procedural gradient >20mmHg, occurs more commonly after VIV TAVR and is due to under
expansion of the TAVR valve which is limited by
the true inner diameter of the failing surgical
valve [125, 126]. Following VIV TAVR, 1year
mortality rates in patients with small (≤21mm)
valves was signicantly higher at 25% when
compared to intermediate (18%) and large (7%)
surgical prosthetic valves with PPM hypothesised as a possible contributory factor [125,
126]. Bioprosthetic valve fracture entails frac-
turing the valve by insufation of a non-compliant high pressure balloon, placed across the
valve during rapid pacing [98]. Visual sudden
expansion at the balloon waist with a reduction
in ination pressure and/or an audible click
occurs with successful fracture [95]. On the
other hand sudden reduction in pressure with
deation of the balloon is regarded as an unsuccessful fracture with balloon rupture [95].
The risk of annular injury as a consequence of
the valve fracture procedure is low and explained
by most SHV’s positioned in a slight supra
valvular location [125, 126]. In the setting of an
intra annular implantation, SHV fracture should
be avoided [125, 126].
BVF prior to TAVR deployment facilitates the
use of a larger TAVR valve and limits potential
injury to the new TAVR valve leaets [98]. BVF
post deployment has the advantage of a reduced
risk of particulate embolization, greater valve
expansion and limits the risk of haemodynamic
compromise [98].
In patients with increasing gradients with initially normal valve haemodynamics, and no evidence of leaet thrombosis, balloon valve fracture
may also be performed within 1year post VIV
procedure [125, 126]. Most but not all SHV’s are
amenable to remodelling or fracture [125, 126].
Aortic surgical valves that can be fractured
include the Magna (Edwards Lifesciences),
Magna Ease (Edwards Lifesciences), Perimount
2800 (Edwards Lifesciences), Mitroow (Sorin
Group), Mosaic (Medtronic), and Biocor Epic
(Abbott) [125, 126]. Surgical valves that can be
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