Добавил:
Sekretar
kiopkiopkiop18@yandex.ru
t.me/Prokururor I Вовсе не секретарь, но почту проверяю
Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз:
Предмет:
Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_3737_Библиотеки_им_академика_М_И_Перельмана
.pdf
266
https://t.me/med1917
A. Desai et al.
is rapid and complete whiteout of the left sided
chambers. To augment venous return and thus
accentuate the opening of the PFO, a Valsalva
maneuver or cough can be helpful to reveal PFOs
that at rest may not be apparent.
The timing of bubble arrival on the left side
can be used to delineate whether the shunt is truly
intra-cardiac. It is thought that bubbles arriving
later (>6 beats after arrival on the right side) may
represent extracardiac shunting. However, there
may be exceptions to this such as low cardiac output states, Valsalva (which during the strain phase
lowers venous return), deep inspiration or cough
[5]. Alternatively, if the source of bubbles seen on
the left side can be ascertained (emanating from a
pulmonary vein vs. emanating from the interatrial
septum), then this can be used in lieu of the number of beats to differentiate intracardiac vs. extracardiac shunting. Then, certain anatomic features
can help identify higher risk features such as atrial
septal aneurysms (Fig. 2), Chiari networks and
prominent Eustachian ridges (Fig.3) [6, 7].
Given the presence of intracardiac shunting on
TTE, a TEE is performed for the purpose of identifying high risk features associated with cryptogenic stroke and whether challenges for device
closure may be present. Challenges to percutaneous closure include: redundant tissue, fenestrations, thicker/lipomatous septum secundum,
small retroaortic rim, the presence of chiari networks and atypical pulmonary vein anatomy. Of
note, PFO size is typically measured by TEE in
its maximum diameter with color ow Doppler
(Fig.4), however, this underestimates defect size
relative to sizing balloon because PFOs typically
remain closed during imaging and gentle ination with a sizing balloon more closely approximates the PFOs true shape and size [8]. On TEE
with color doppler, there is intermittent ow
across the PFO (Fig.5). A small shunt is seen on
TEE bubble study (Fig. 6 and Video 2) no
Valsalva is performed. TEE will typically
underestimate the degree of shunting due to the
effect of sedation on degree of shunting and its
effect on lling pressures and provocative maneuvers. As a result, we primarily use TTE for the
assessment of the degree of shunting while relying on TEE to visualize the PFO and detect atrial
septal aneurysm. No other intra-cardiac thrombi
are noted on the TEE.No atrial septal aneurysm
was identied, the retro-aortic rim was >5mm
and the septum secundum appeared to be of normal thickness. The Eustachian ridge was prominent, but no Chiari networks were seen. Assuming
four pulmonary veins, the pulmonary veins were
all seen and noted to connect to the left atrium.
There were no fenestrations noted in the interatrial septum and there was a clear tunnel that
measured about 10mm (measured as the length
of overlap between the ap and the septum secundum). No aortic dilation was noted (Video 3).
Given the high likelihood of PFO (rather than a
true atrial septal defect), consideration was given
to directly proceeding with PFO closure and intracardiac echocardiography at the time of the procedure and forgoing preprocedural TEE.However,
our institutional operator preference is to undertake pre-procedure TEE to not only ensure the cor-
Fig. 2 Transesophageal
image of interatrial
septum demonstrating
interatrial septal
aneurysm with bowing
of the septum toward the
left atrium. LA left
atrium; IASA interatrial
septal aneurysm; RA
right atrium
IASA
RA
LA
Aorta
Patent Foramen Ovale andAtrial Septal Defect
https://t.me/med1917
Fig. 3 Transesophageal
image of prominent
Eustachian ridge. LA left
atrium; RA right atrium
Eustachian
Ridge
267
LA
Fig. 4 Intracardiac echo
image of interatrial
septum with color
Doppler over patent
foramen ovale, and
maximum diameter
measured
RA
Aorta
rect defect is identied but also for device selection
purposes. There have been cases where a PFO was
suspected but during the procedure, a complex
fenestrated defect was found or a secundum ASD
was found, which can dramatically change the
procedural plan and device selection. Additionally,
TEE has increased sensitivity for other potential
sources of cardiac emboli such as left atrial or ventricular thrombi, myxoma, papillary broelas-
toma, endocarditis and Lamble’s excrescence.
Lastly, the in-hospital evaluation for mechanism is
often incomplete for many reasons. There is rarely
sufcient length of telemetry monitoring to rule
out paroxysmal atrial brillation and thrombophilia workups are delayed in the setting of acute
clot as well and are often not back prior to discharge. For these reasons, closure during the index
hospitalization is rare.
268
a
b
https://t.me/med1917
Fig. 5 (a) TEE bicaval view of PFO on the left image and (b) TEE bicaval view of PFO with color Doppler on right
image showing resting right to left shunt
A. Desai et al.
LA
IAS
RA
Fig. 6 Transesophageal echocardiogram of interatrial septum obtained in mid esophagus in 2 orthogonal planes
ASD: For secundum atrial septal defects
(Video 4) in particular, pre-procedure imaging
plays an important role in determining whether
a defect is appropriate for trans-catheter closure. Our practice is to obtain 3D TEE measurements of the defect as this has been shown
to correlate closely with 2D balloon sizing
(Fig.7). Additionally, even large defects (up to
44 mm) have been closed with transcatheter
techniques, particularly if the defect is oval
with a shorter minor axis and adequate rims.
During pre- procedure assessment of secundum ASDs, important issues to pay attention
to are ensuring all four pulmonary veins are
visualized as there is an association of partial
anomalous pulmonary venous return with
secundum ASDs. A sinus venosus defect can
be seen in the midesophageal bicaval (120°)
view. Ideally, rims should be visualized (as
discussed in the intra-procedural guidance
section). The degree of mitral regurgitation
should be assessed as post-ASD closure, this
LA
IAS
RA
Patent Foramen Ovale andAtrial Septal Defect
https://t.me/med1917
269
Fig. 7 3D rendering of atrial septal defect with orthogonal B-mode image slices in top 2 panels and short axis of atrial
septal defect measured in bottom left panel
can increase due to the increase in left sided
volumes and can worsen significant mitral
valve disease.
Cross sectional imaging (gated cardiac CT
and MRI) is not particularly helpful in evaluation
of PFOs but can be helpful in understanding the
three-dimensional anatomy of atrial septal
defects as well as investigating congenital anomalies associated with them. This can be particularly useful in the identication of complex ASDs
that may require multiple devices or lead to signicant interaction with surrounding cardiac
structures, such that surgical closure might be
more effective and safer. While CT has superior
spatial resolution and can be used to plan for closure with virtual placement of devices as well as
3D printing of complex defects to assist with case
planning, MRI can be used for these purposes as
well as hemodynamic evaluation of ASDs
through calculation of cardiac output, shunt fractions, and Qp/QS via phase contrast imaging.
Anatomically precise 3D reconstructions of ASD
anatomy through pre-procedure cross-sectional
imaging have also allowed for increasing use of
intraprocedural intra-cardiac echocardiography
rather than TEE for guidance of closure. Overall,
specically for the purposes of initial PFO and
ASD evaluation, echocardiography in its various
forms remains the mainstay of diagnostic evaluation as well as procedural guidance during percutaneous closure procedures.
PFO: Importantly, two main scores assessing
the likelihood that a cryptogenic stroke was due
to a PFO have been developed. The initial Risk of
Paradoxical Embolism (RoPE) score was developed and internally validated from 3023 patients
in 12 combined databases of patients with cryptogenic stroke [9]. The resulting parsimonious
bedside model incorporates six features of patient
history and demographics to determine stroke
relatedness to the PFO with a small observational
study indicating a cutpoint of 7 (PFO-attributable
270
https://t.me/med1917
A. Desai et al.
stroke was 0% [95% CI 0–7.5] for RoPE <7 and
71.1% [95% CI: 35–87.3] for ROPE >7). The
model has subsequently been validated for the
relative risk reduction of device vs. medical therapy [10]. Importantly, the RoPE score does not
take into account known “high risk” features of
PFOs, including atrial septal aneurysm (dened
as ≥10mm excursion of the atrial septum from
the midline) or hemodynamic consequence (large
shunt was dened as >20 bubbles in the left
atrium on TEE). The PASCAL classication system combines the ROPE score with presence or
absence of these high-risk features and was
derived and validated from a cohort of 3740
patients in six randomized clinical trials of PFO
closure plus medical therapy versus PFO closure
alone in patients aged 18–60. The PFOAssociated Stroke Causal Likelihood (PASCAL)
Classication System improved upon the ROPE
score’s ability to discriminate those that were
most likely to benet from PFO closure, indicating the potential importance of high-risk imaging
features in determining the potential benet that
may be derived from percutaneous PFO closure.
Heart Team Approach
andDiscussion
The patient was seen in the multi-disciplinary
PFO/stroke clinic to discuss the etiology of her
stroke as well as management options. Vascular
neurology reviewed her brain imaging and agreed
that the location of the stroke as typical of a
cardio- embolic stroke and she had no other compelling data to suggest an alternative cause such
as vasculitis, early atherosclerosis, a hypertensive
stroke or that there was an arterial hypercoagulable state that may have contributed. Her RoPE [9,
10] score was calculated at eight and her PASCAL
classication [11] was probable given RoPE
score of 8 and presence of a large shunt. Taken
together, these scores suggests that (1) there is an
increased likelihood of her stroke being “PFOrelated” and (2) she would derive substantial
reduction in recurrent stroke rate with PFO closure and a low risk of peri-procedural atrial brillation. Given this, it was felt reasonable to
proceed with closure of the patent foramen ovale
to decrease her risk of recurrent stroke with a
lower risk of peri-procedure atrial brillation.
The interventional cardiologist then met with
the patient to discuss percutaneous closure vs.
medical management. At this point, given the
variety of percutaneous closure devices available
as well as the clinical trial data in support of percutaneous PFO closure over antithrombotic or
anticoagulant therapy, surgical closure of PFOs is
rarely appropriate. The patient and interventional
cardiologist discussed the compelling data supporting that the patient experienced a stroke due
to paradoxical embolization via the patent foramen ovale was probable. The options of antiplatelet therapy alone or anticoagulation were
discussed as part of a shared decision-making
process. Given the patients young age and potential for future pregnancies as well as desire to not
be on life-long anticoagulation, percutaneous
PFO closure was decided upon.
The role of medical therapy in PFO is minimal
in patients otherwise deemed appropriate for
PFO closure. Current guidelines recommend
against anti-thrombotic or anti-coagulation therapy instead of PFO closure in patients with PFO
related stroke [12]. RESPECT [13] and REDUCE
[14, 15] led to the approval of the two currently
commercially available devices based on their
long-term results. Specically, in longer-term
follow up, it was shown that PFO closure reduced
the rate of recurrent ischemic strokes. It was a
patient-level data meta-analysis [16] that have
led to a understanding of the treatment effect
with a relative risk of recurrent stroke of 0.42.
This and many other similar meta-analyses led to
the eventual shift from the term “cryptogenic
stroke in the presence of a PFO” to “PFO-related
stroke”. Additionally, this meta-analysis showed
that there was an increased risk of atrial brillation with device closure. Though no RCT exists,
this data has been extended to cover peripheral
paradoxical embolization as well.
The other clear indication for PFO closure is
hypoxemia with exertion or upright position that
cannot be explained by another etiology,
platypnea- orthodeoxia syndrome. The mechanism is with upright or standing position, intra-
Patent Foramen Ovale andAtrial Septal Defect
https://t.me/med1917
271
thoracic and intracardiac conditions cause a PFO
to be in an open position, and shunting across the
PFO increases, leading to systemic hypoxemia
and dyspnea. This is typically also caused by
abnormalities that cause the PFO to be deformed
such that it is opened to a greater degree or
“slides” open; for example: aortic aneurysm,
atrial enlargement, paralyzed hemi-diaphragm or
mediastinal shifting. Other conditions that lead to
increase right atrial pressures may also cause
increased right to left shunting via the PFO [17,
18]. In our experience, these shunts are often
massive on TTE and if only a small shunt is
noted, one should question the diagnosis of
platypnea-orthodeoxia syndrome.
Decompression sickness (DCS) with scuba
diving may be more prevalent in divers with
PFOs and that closure may reduce this risk. The
pathophysiology of DCS causing neurologic
symptoms is the formation of nitrogen gas bubbles in the systemic venous circulatory system
during rapid ascent some of which can bypass the
lung ltering mechanism when a PFO is present,
and subsequent arterial manifestations can
include neurologic symptoms, cutaneous changes
(Cutis marmorata) and joint “bends”. The current
recommendation is counseling on the increased
risk of DCS with PFO and avoidance of high-risk
diving. SCAI guidelines recommend against PFO
closure for prevention of DCS given no clear evidence to suggest benet [12] though allow for
closure if the patient and physician participate in
a shared decision making process.
Perhaps the most controversial condition associated with PFO is migraine. Migraines are disabling and can be incredibly challenging to treat
so this has led to many different procedural solutions, one of which is PFO closure. PFO stroke
study sub-group analyses rst discovered a
reduction of migraine days among PFO closure
patients. There are many proposed mechanisms
by which PFOs are thought to contribute to
migraine including chemicals crossing the PFO
instead of being blocked by the blood brain barrier, micro-emboli and cerebral hypoxia.
However, three RCTs testing device closure for
treating migraine headaches (MIST [19],
PREMIUM [20] and PRIMA [21]) were unable
to achieve their primary outcomes. Despite this,
there remains signicant hope that PFO closure
might benet this difcult to treat entity. A new
study, RELIEF [22], is currently recruiting
patients to test whether the Gore CARDIOFORM
PFO occluder in patients that have migraines
responsive to P2Y12 therapy may derive benet
from PFO closure.
ASD: True atrial septal defects can have a signicant degree of left to right shunting and are
associated with right sided volume overload;
therefore, right sided chamber dilation, pulmonary hypertension and atrial arrhythmias can be
seen. The indication for ASD closure include the
presence of RVE, suggesting signicant left to
right shunting, even in the asymptomatic child.
Some patients with long-standing untreated
ASDs will develop pulmonary vascular disease,
that when severe can reverse shunting leading to
cyanosis. Decision-making regarding closure is
more complex and if pulmonary vascular resistance is greater than 8 Woods’ units or two-thirds
systemic vascular resistance or mean PA pressure
greater than two-thirds of systemic blood pressure, closure is not pursued in favor of treating
underlying pulmonary hypertension rst [23–25].
Iatrogenic ASD’s following different procedures
involving transeptal catheterization may spontaneously close but if it causes substantial shunting, including systemic hypoxemia, closure is
indicated.
There are some ndings during initial evaluation that are contraindications to PFO and ASD
closure until there is resolution. Percutaneous
closure should not be pursued in patients who
have active thrombi in the ileo-femoral venous
system, inferior vena cava or atria as there is risk
of embolization. Additionally, active infection is
a contraindication due to the risk of device
endocarditis.
PFO: There are two commercially available
devices in the United States specically for PFO
closure. The Abbott Amplatzer PFO Occluder
and Gore Cardioform PFO Occluder. PFOs with
concomitant septum primum fenestrations can
also be treated with the Abbott Amplatzer
Cribiform Occluder. Very large PFOs may be
amenable to closure with the Abbott Amplatzer
272
https://t.me/med1917
A. Desai et al.
Septal Occluder used for ASDs. Gore also has
developed an ASD occluder which can treat large
PFOs as well.
Device selection for PFO and ASD closure is
determined by multiple factors including the size
and characteristics of the septal defect, the
devices that are approved by the regulatory system of the country, operator experience and preferences, and some patient-specic features
related to potential complications such as device
erosion, nickel allergy, and potential need for
future transseptal access to the left atrium. Atrial
septal defect sizing often involves balloon sizing,
i.e. inating a sizing balloon across the defect
until shunting ceases and the “waist” on the balloon is measured by ultrasound or X-ray. PFO
sizing to select the size of device to be used can
utilize balloon sizing but often a stiff wire across
the defect holds the septum primum in an open
position and allows echocardiographic measurement of the PFO size. Atrial septal aneurysms of
the septum primum and lipomatous septum
secundum are further modiers of PFO device
selection. Long tunnels can often be closed by
both devices unless the tissue is non-compliant,
preventing tunnel collapse and deforming the
devices. Under-sizing of the device needed for
both ASD and PFO closure can lead to incomplete closure and even device embolization.
Device sizing recommendations are included
in the instructions for use for the Amplatzer
device. PFOs that are “simple” with a nonprominent atrial septal aneurysm (<20mm excursion), tunnel length <10 mm, and normal
thickness septum secundum (<10 mm) can be
closed with a 25mm device. Those that do not
meet those criteria, will likely require a larger
device. All these measurements are easily found
on a thorough TEE.
Device selection for PFO closure is based on
experience and availability. There are no randomized data comparing the two PFO closure devices
available in the US and they performed well in
their respective clinical trials. Some ner points
of device selection have been identied. In the
presence of a small aortic rim, the Cardioform
device may be safer given it is more exible and
without rigid edges. Device erosion, often associ-
ated with decient rims, by the Amplatzer PFO
Occluder is very rare, more so than with the
Amplatzer ASD Occluder. To date, there have
been no case reports of erosion with the
Cardioform PFO device though there are reports
of wire fracture causing tamponade [26].
However, the Cardioform may come with a
slightly greater increased risk of atrial brillation
in the early post-procedure period after PFO closure [15]. Given the lack of a randomized comparison involving patients with a diversity of
PFO anatomy, it is not possible to say whether
the two devices differ in terms of the completeness of PFO closure.
The last consideration may be a nickel allergy.
Our practice is to counsel the patient regarding
the unsettled nature of whether a cutaneous nick
allergy is even relevant to the risk of an allergic
reaction to an intravascular device. The suspicion
of nickel allergy is often uncovered with a
through history. Skin patch testing for nickel
allergy is standard but does not accurately predict
if a systemic reaction may occur from an
implanted device containing nitinol, an alloy of
nickel and titanium. Therefore, a nickel allergy is
not an absolute contraindication to percutaneous
device closure but given case reports of systemic
reactions after PFO or ASD closure, careful
counseling is recommended prior to proceeding
with percutaneous PFO closure in patients with
signicant nickel allergies. Surgical closure can
be entertained in this patient population if there is
enough concern and the patient desires PFO closure without nickel containing materials [27].
New techniques of PFO closure using a transcatheter suture deployment system may be considered, although complete data are not yet
available on other outcomes versus devicemediated closure techniques.
The role of PFO closure in patients with
hypercoagulable states is less clear. The newest
SCAI guidelines do suggest PFO closure in
patients with a PFO related stroke, even with
thrombophilia requiring anticoagulation [12].
However, the determination of whether a stroke
is PFO related versus not in patients with a signicant thrombophilia, such as anti-phospholipid
antibody may be quite challenging. Given this, it
Patent Foramen Ovale andAtrial Septal Defect
https://t.me/med1917
273
would be reasonable to involve vascular neurology as well as hematology experts to provide
individualized recommendations to patients.
PFO closure may be reasonable as an “additive”
therapy given there may be instances during
which patients who would otherwise be on longterm anticoagulation cannot be on it, but this
would need to be weighed against the risk of
device related thrombosis.
Heart Team Decision: Percutaneous
PFO Closure
In patients who do not have other indications for
cardiac surgery, percutaneous closure of patent
foramen ovale is recommended as it was in this
patient’s case. Surgical closure of a PFO requires
surgical access to the heart (sternotomy), cardiopulmonary bypass, and a prolonged recovery versus device-closure often being performed with
conscious sedation on an outpatient basis with
minimal recovery.
Intraprocedural Imaging Modalities
andMeasurements, (Discussion
Between Members oftheHeart
Team)
Intraprocedural imaging for closure is usually
done with intra-cardiac echocardiography or
transesophageal echocardiography. Less frequently, the procedure is performed with TTE
and angiographic guidance. Though limited in
use, uoroscopy only guided closure of PFOs has
been shown in small studies to be safe and effective [28, 29].
Trans-esophageal echo cardiography offers
the ability to both perform the screening TEE and
therapeutic procedure in a single setting but typically this requires deep sedation or general anesthesia. Intracardiac echocardiography (ICE)
allows the performance of the closure procedure
to be done with conscious sedation, which may
allow for same-day discharge due to faster recovery. Studies have shown the two methods to be
equivalent [30–32].
Typically, if the procedure is performed with
ICE guidance, the interventionalist manipulates
the catheter and has catheterization laboratory
staff operate the imaging console with capture of
key images. However, with the advent of 3D ICE,
the presence of an echocardiographer experienced in acquiring 3D datasets and interpretation
can be quite helpful. Regardless of modality, the
procedural imaging follows the same general
cadence. The use of uoroscopy is also useful to
the interventionalist who can see the position of
the device relative to cardiac borders and ensure
the discs are deployed fully.
First, a repeat assessment of key cardiac structures is performed to ensure no other possible
sources of emboli (in the case of stroke patients)
are found. TEE offers the advantage of once
again assessing for the presence of LA and LV
thrombi, which may not be as easily visualized
with ICE. On TEE, the inter-atrial septum is
imaged in a bicaval and short axis view. On ICE,
a septal view is obtained by retroexion and
clockwise rotation from the “home” view with
the catheter in the right atrium (Video 5) The
catheter is then advanced slightly cranial, which
shows the SVC rim. Then, a short axis view
which is like the TEE short axis view (other than
in ICE the right atrium is at the apex of the imaging cone whereas in TEE the left atrium is at the
apex of the imaging cone) is obtained by rotating
clockwise and then retroexing further with
slight leftward deection or using newer catheters, with bi-plane of the septal view. This shows
the aortic rim in detail [33].
The PFO is then assessed at rest, paying attention to key features: the aortic rim, the presence
and excursion of an atrial septal aneurysm, tunnel
length, thickness of the septum secundum and
degree of shunting by bubble. Not infrequently, if
lower extremity injection was not performed as
part of the screening TTE or TEE, with a bubble
injection into the femoral vein, the degree of
shunting becomes far more impressive.
After this, the defect is crossed, often without
much effort with a standard J-tipped guidewire
and multi-purpose diagnostic catheter. Imaging
guidance can assist if there is difculty in ensuring the guidewire is positioned in the tunnel to
274
https://t.me/med1917
A. Desai et al.
cross the PFO (Video 6). If despite visualization
of the J-wire in the tunnel, the wire is unable to
cross, this may lead one to consider that the PFO
may be too small to be the cause of a cryptogenic
stroke or certainly, hypoxemia. One can try with
hydrophilic guidewires or different shaped catheters if there is a strong indication for closure.
After crossing, echo guidance can help position the wire and catheter in the left upper pulmonary vein, which provides the best trajectory for
insertion of the delivery sheath. Once positioned
in the vein, the wire is exchanged for a stiff
guidewire. Echo is used to ensure the wire is
indeed in the pulmonary vein as uoroscopically,
the left atrial appendage is in a similar position.
Should the wire be in the LAA, this can be a
cause of perforation given the thin-walled nature
of the LAA.At this point, the PFO is maximally
“propped” open (Video 7). Measurements of the
PFO width are performed by measuring the width
of the color jet on the right atrial side (Fig. 8).
The tunnel length often also becomes more
apparent as one can measure the length of the
septum primum from the right atrial entrance to
the tip of the primum on the left atrial side. A
general rule is the right atrial disc width should
be at least two times the width of the PFO or tunnel length. This is because the PFO devices are
not self-centering since the central portion is con-
necting pin rather than a true disc and therefore,
when sizing, one must assume that the device
may be pushed entirely into one corner of the
defect and therefore, the radius of the device
must be large enough to close the defect.
Once a device is chosen, echo guidance is
used to ensure the delivery sheath tip is free in the
left atrium (Video 8). Then, the left atrial disc is
unsheathed and then pulled back such that it is
pulled against the inter-atrial septum without
prolapsing into the tunnel (Videos 9 and 10).
Echo guidance is key for this step as if the LA
disc falls into the tunnel, the device can be easily
recaptured and torqued to allow the LA disc to sit
against the septum. Then, while maintaining
some tension, the right atrial disc is deployed and
pushed against the septum. Again, echo guidance
allows for visualization to ensure the entirety of
the right atrial disc is on the right atrial side
(Videos 11 and 12). At this point, the device is
evaluated to ensure that there is no interaction
with the aorta or SVC (Video 13), which if seen,
is a marker for erosion. Fluoroscopically, in the
LAO cranial view, the discs of the device should
be separate and there may even be motion of the
discs, reecting the motion of the tissue in
between the two discs. A push-pull test is performed to demonstrate stability. If a disc is seen
within the tunnel, then the device should be
Fig. 8 ICE image with
color Doppler, wire over
interatrial septum with
measurements of the
PFO width performed
by measuring the width
of the color jet on the
right atrial side
Patent Foramen Ovale andAtrial Septal Defect
https://t.me/med1917
275
upsized. If the device is felt to be well positioned
and sized, the device is released. Often, with
release, there is dramatic shifting in the device as
it orients to the natural lie of the inter-atrial septum. The device is re-inspected to ensure both
discs remain well positioned. A repeat bubble
study can be performed to verify closure. Repeat
color doppler should also be performed of the
inter-atrial septum to document that there were
no “missed” small atrial septal defects.
ASD: In contrast, atrial septal defect closure
guidance at our center remains largely guided by
TEE except in the cases of well dened, small
ASDs with large rims on pre-procedure imaging;
most often iatrogenic ASDs. Rims are best
assessed with 2D views. For each ASD, we recommend measuring rims in the following views:
SVC and IVC rims in the mid-esophageal 90°
view (Fig.9), aortic and posterior rims in the 45°
mid-esophageal view (Fig.10), mitral and atrial
rims in the 0° mid-esophageal view (Fig. 11).
Most commonly, as in the case demonstrated
here, aortic rims are decient and this is not a
contraindication to percutaneous closure. Often,
particularly with external referrals, these measurements are done on the table at the time of the
closure procedure.
During the procedure, the defect size is conrmed using 3D TEE.Then after crossing, bal-
loon sizing is performed (Fig. 12). The 34 mm
balloon can be used for all ASDs since it is longer
and will shift less with ination so many tend to
only use this size but care must be taken to not
over-inate the balloon and rupture the interatrial septum.
After sizing, the delivery catheter is advanced
into the LA and TEE can be used to ensure the
catheter is in the left upper pulmonary vein
(Fig. 13). The LA disc is deployed and pulled
against the septum (Fig.14), then the RA disc is
deployed (Fig. 15). Before release, views are
obtained to ensure no signicant leaks (Fig.16)
and that there has been no impact on the surrounding structures: SVC and IVC ow, mitral
valve function and the aortic root. A gentle tug
test is performed to ensure stability and if so, the
device is released and further evaluation for leaks
is performed (Fig. 17) as with shifting of the
device, new leaks may be identied as tension
from the delivery cable is released.
Both available devices in the United States
have been reported to close defects up to
40-44mm in diameter though strictly labeled, the
Amplatzer can treat defects up to 38mm and the
Gore up to 35mm by stop ow balloon sizing.
Typically, with the Amplatzer device, a 5mm rim
of tissue is needed for device stability and to
decrease the risk of erosion. The major risk fac-
Fig. 9 ICE image of
measurements of SVC
and IVC rims of ASD in
the mid-esophageal 90°
view
Соседние файлы в папке Библиотека им академика М.И. Перельмана