2. ASD
• Small ASDs with diameter <5 mm and no evidence of RV volume
overload may not require closure as these do not usually impact the
natural history.
• Unrepaired ASDs with significant shunting can result in right-sided
volume overload, with progressive heart failure, arrhythmias,
hemodynamically significant tricuspid regurgitation,
pulmonary hypertension, and reduced survival.
• Current guidelines recommend ASD closure in the presence of right-
sided volume overload, that is, right ventricular or right atrial dilatation
in a symptomatic or asymptomatic patient.
SEYYED REZA MIRI.MD, Pediatric Cardiologist, Interventionist
2
3. ASD
An ASD other than secundum ASD should be repaired surgically.
Closure of ASD may be considered in some patients regardless of
evidence of right-sided enlargement due to risk of paradoxical
embolism:
in professional divers
patients undergoing pacemaker implantation
prior to pregnancy
SEYYED REZA MIRI.MD, Pediatric Cardiologist, Interventionist 3
4. ASD
• Closure in presence of symptoms or right-sided heart enlargement
prevents further deterioration and helps normalize the right-sided
dilatation.
• Natural history studies of ASD closure show reduced survival after
closure in patients older than 24 years of age or with pulmonary
hypertension (systolic PAP ≥ 40 mm Hg)
• Also closure in patients over 40 years of age, while improving symptoms
and mortality compared with a medically managed group, did not
reduce the risk of atrial arrhythmias.
SEYYED REZA MIRI.MD, Pediatric Cardiologist, Interventionist 4
5. ASD closure indications
Class I
Transcatheter secundum ASD closure is indicated in patients with hemodynamically significant
ASD with suitable anatomic features
Class IIa
It is reasonable to perform transcatheter secundum ASD closure in patients with transient right-to-
left shunting at the atrial level who have experienced sequelae of paradoxical emboli such as
stroke or recurrent transient ischemic attack
It is reasonable to perform transcatheter secundum ASD closure in patients with transient right-to-
left shunting at the atrial level who are symptomatic because of cyanosis and who do not require
such a communication to maintain adequate cardiac output
Class IIb
Transcatheter closure may be considered in patients with a small secundum ASD who are
believed to be at risk of thromboembolic events (eg, patients with a transvenous pacing system or
chronically indwelling intravenous catheters, patients with hypercoagulable states)
SEYYED REZA MIRI.MD, Pediatric Cardiologist, Interventionist 5
6. ASD
Class III
Transcatheter secundum ASD closure is not indicated in patients with a
small secundum ASD of no hemodynamic significance and with no other
risk factors
Transcatheter ASD closure should not be performed with currently
available devices in patients with ASDs other than those of the secundum
variety. This would include defects of septum primum, sinus venosus
defects, and unroofed coronary sinus defects (Level of Evidence: C).
Transcatheter ASD closure is contraindicated in the management of
patients with a secundum ASD and advanced pulmonary vascular
obstructive disease
SEYYED REZA MIRI.MD, Pediatric Cardiologist, Interventionist 6
7. ASD closure:Procedural Details
A complete right heart catheterization is first performed to measure shunt
fraction, pulmonary artery pressures, and pulmonary capillary wedge pressure.
In patients older than 40 years, a coronary angiogram is also performed,also
perform pulmonary angiogram with levo phase imaging to assess drainage of all
four pulmonary veins into the left atrium.
Some operators perform right upper pulmonary vein angiogram in 35-degree
LAO cranial projection, which provides an angiographic roadmap of the
interatrial septum to facilitate closure.
The ICE catheter is advanced into the right atrium and the interatrial septum
adequately interrogated for assessment of various rims, measuring defect size
and confirming pulmonary venous drainage.
A rim is considered to be deficient if its length is <5 mm, and absent if it is ≤1
mm. The rims should not be deficient (except anterior rim, as many patients
lack the anterior rim and it is not a contraindication). The directions include a
“warning” that a deficient aortic rim may incur increased risk of erosion, but
data are insufficient as discussed later.
8. Management and Indications for Atrial Septal Defect Closure
In patients with PAH, pulmonary vasodilator testing to assess for reversibility
and test occlusion of ASD should be performed. Inhaled nitric oxide is used
commonly as a pulmonary vasodilator.
A positive vasoreactivity response is defined as a reduction of mean PAP of
>10 mm Hg with resultant mean PAP of 40 mm Hg or less, without fall in
cardiac output.
Closure in such patients may be performed if there is net left-to-right
shunting, PA pressure <2/3 systemic levels, PVR <2/3 SVR, or when
responsive to either pulmonary vasodilator testing or test occlusion.
A favorable response is indicated by a fall in mean pulmonary artery
pressure with test occlusion with no decrease in cardiac output and no rise
in right atrial pressure.
9. Management and Indications for Atrial Septal Defect
Closure
In patients with PAH, when pulmonary vasodilator
testing has unfavorable response, pulmonary vasodilator
therapy should be initiated and hemodynamics
reassessed a few months later.
ASD closure is also indicated in presence of paradoxical
embolism and documented platypnea orthodeoxia. An
absolute contraindication (Class III) for closure is
irreversible PAH and no evidence of left-to-right shunt.
10. ASD
hemodynamic features influence difficulties of transcatheter ASD closure.
Candidates for ASD closure have a hemodynamically significant atrial shunt or the presence
of right ventricular volume overload, and/or clinical symptoms of dyspnea, reduced
exercise capacity, or paradoxical embolism.
Pulmonary vascular resistance <5 Wood units/m2 and the peak pulmonary artery
pressure ≤70% of the systemic blood pressure are also important conditions for ASD closure.
Although most pediatric patients with ASD fulfill the hemodynamic criteria, the incidence
of pulmonary artery hypertension is significantly increased in adult populations. It is well
known that the natural course in patients with ASD and pulmonary hypertension is
significantly worse than in patients without pulmonary hypertension
transcatheter closure without cardiopulmonary bypass can be performed even in such high-
risk patients, and Importantly, the more significant reduction of pulmonary artery pressure
can be achieved even in severe pulmonary hypertension.
Even if the initial hemodynamic parameter appears to be untreatable (or contraindicated)
for ASD closure, catheter closure of ASD may be performed if such pulmonary vascular
resistance can be considered as responder for pulmonary artery specific vasodilators .Long-
term follow-up is mandatory especially in these high-risk populations
SEYYED REZA MIRI.MD, Pediatric Cardiologist, Interventionist 10
11. ASD in he elderly patients
In the elderly patients with ASD, hemodynamic features are significantly
different from those in children and young adults. Elderly patients with
ASD frequently present with hemodynamic abnormalities such as
pulmonary hypertension, atrial arrhythmias, and valvular regurgitation,
which causes congestive heart failure
As the incidence of pulmonary hypertension significantly increases with
age in ASD patients, the decision of ASD closure is sometimes difficult
especially in patients with severe pulmonary hypertension. Moreover,
various comorbidities, such as systemic hypertension, chronic obstructive
pulmonary disease, coronary artery disease, chronic kidney disease,
and left ventricular diastolic dysfunction often complicate the clinical
features in this population. Left ventricular diastolic dysfunction, which is
also seen as part of normal aging and frequently occurs in elderly
individuals with hypertension or increased arterial stiffness, may cause
acute congestive heart failure after ASD closure
Previous studies have suggested that development of acute congestive
heart failure is due to abrupt elevation in left
ventricular preload following transcatheter ASD closure, especially in
elderly patients with impaired left ventricular systolic or diastolic
function
SEYYED REZA MIRI.MD, Pediatric Cardiologist, Interventionist 11
12. ASD in he elderly patients
impaired left ventricular diastolic function estimated by decreased e′ and
increased E/e′, pre- and periprocedural anticongestive medication is
important and effective for preventing congestive heart failure after ASD
closure in elderly patients
monitore pulmonary capillary wedge pressure (PCWP) during the procedure
to avoid the acute congestive heart failure caused by ASD closure in elderly
patients. If mean PCWP increased > 10 mmHg from the baseline value
during balloon occlusion of the defect (test balloon occlusion), or PCWP
increased >20 mmHg, such ASD closure could lead to the development of
pulmonary edema and the procedure should be abandoned
Especially in patients who had a history of heart failure, we considered to be
hemodynamically high-risk patients. Creation of a fenestration hall in the
device may avoid the abrupt hemodynamic change after the transcatheter
closure of ASD. However, the optimal fenestration size has not been
evaluated, and the experiences are still limited
SEYYED REZA MIRI.MD, Pediatric Cardiologist, Interventionist 12
13. Special groups who may be suitable for consideration of balloon occlusion trial
1. RV dilatation
2. significant PAH’ but responsive to PVT
3. Significant LV impairment ,off-loading across ASD which may
decompensate once ASD closed
SEYYED REZA MIRI.MD, Pediatric Cardiologist, Interventionist 13
14. ASD ECHO
transesophageal echocardiography (TEE) has long been the standard
modality for ASD closure.
However, intracardiac echocardiography (ICE) is gradually replacing
the role of TEE recently.
Transthoracic echocardiography (TTE) may also be used especially in
patients with good windows for echocardiography such as small
children
SEYYED REZA MIRI.MD, Pediatric Cardiologist, Interventionist 14
15. ASD ECHO
SEYYED REZA MIRI.MD, Pediatric Cardiologist, Interventionist 15
PSAX- IAS separates Rt & lt atrium and runs posteriorly from NCC of aortic valve.
L Not seen in entirety as a result of drop out artefact
APICAL 4C- Posterior aspect of I nteratrial septum is clearly delineated in this
view but drop out artefact is seen in region of fossa ovalis.
Pulmonary venous drainage- 3 veins draining to LA
APICAL 5C VIEW- Anterior aspect of interatrial septum
16. when to suspect ASD in 2d echo
SEYYED REZA MIRI.MD, Pediatric Cardiologist, Interventionist 16
• right ventricular dilation
• abnormal motion of IVS: brisk anterior movement in early systole or
flattened movement throughout diastole
• SUB COSTAL 4C VIEW- is useful in patients with COPD and ventilated patients, viewed
with breath held in inspiration- index marker in 3o' clock position. No IAS drop outs
• SUB COSTAL SHORT AXIS- Index marker at 12o'clock position and sweeping the
transducer from midline to Rt side of patient
17. SEYYED REZA MIRI.MD, Pediatric Cardiologist, Interventionist 17
The Relative Atrial Index (RAI)
If you detect IAS drop out in apical 4c view ,then determine
RELATIVE ATRIAL INDEX
A Simple, Reliable, and Robust Transthoracic Echocardiographic
Indicator of Atrial Defects
18. ASD ECHO
SEYYED REZA MIRI.MD, Pediatric Cardiologist, Interventionist 18
I
En face view in 2D
First the apical 4c view was taken.
The image index marker was at approximately kept at 1
o'clock.
Keeping the atrial septum and ASD in the region of
interest, the transducer was rotated counterclockwise
approximately 45° to 60°.
19. ASD ECHO
SEYYED REZA MIRI.MD, Pediatric Cardiologist, Interventionist 19
For contrast echocardiography APICAL 4C VIEW is used
AGITATED SALINE USED- 5m1 in each 10m1 syringe. 0.5m1 of air taken in the syringe
and agitated to create microbubbles.
arrow shows negative contrast effect ,a direct evidence of shunt(non contrast
blood in RA)
Extent of shunting tend to focus on numbers of bubbles seen in a single still
frame in the left atrium.
Shunt grading incorporates :
Grade 1: 5 bubbles
Grade 2: 5 to 25 bubbles
Grade 3: >25 bubbles
Grade 4: Opacification of chamber
21. ASD ECHO Other important views
SEYYED REZA MIRI.MD, Pediatric Cardiologist, Interventionist 21
• To visualize SVC: Suprasternal short axis -index marker in 4 o'clock
position
• L-SVC is seen from left supraclavicular fossa or suprasternal short
axis
• Suprasternal short axis :to visualise the the pulmonary veins draining
into left atrium
• Cleft mitral valve in AVCD in 12o'clock position in PSAX
22. ASD ECHO :RIMS OF ASD
SEYYED REZA MIRI.MD, Pediatric Cardiologist, Interventionist 22
the rims of a secundum ASD are labeled as:
1. aortic (superoanterior)
2. atrioventricular (AV) valve (mitral or inferoanterior)
3. superior venacaval (SVC or superoposterior)
4. inferior venacaval (IVC or inferoposterior),most important
5. posterior (from the posterior free wall of the atria, coronary sinus rim).
24. ASD RIMS
By conventional definition, a margin 5
mm is considered to be adequate.
Podnar et al. defined 10
morphological variations of defects,
the most common type being the
defect with deficient aortic rim
(42.1%).
The other variants included central
defects (24.2%), deficient
inferoposterior rim (12.1%),
perforated aneurysm of the septum
(7.9%), multiple defects (7.3%),
combined deficiency of mitral and
aortic rims (4.1%), Deficient SVC rim
(1%), and deficient coronary sinus rim
(1%).
SEYYED REZA MIRI.MD, Pediatric Cardiologist, Interventionist 24
25. The locations of rim deficiencies
(A) aortic rim, (B) IVC rim, (C) SVC rim deficiency, (D)
posterior rim, (E) atrioventricular valve rim.
SEYYED REZA MIRI.MD, Pediatric Cardiologist, Interventionist 25
Specific rims of the sASD are measured on 2D imaging
Consideration should be given to the integrity of the rim tissue. Thin flimsy tissue is unlikely to have the
strength to hold the device disc despite appearing an adequate length.
26. ASD rims
Traditional teaching allows the aortic rim to be absent since the ASD
closure device is able to anchor using both left and right discs by splaying
across the aortic root. a number of erosions resulting in cardiac
perforations have led to caution in such ,usually arises within the first 12
months although has been reported as late as 8 years post procedure.
High risk features appear to include absent or limited aortic and superior
vena cava rims ,compounded by significant device oversizing, and motion
(‘see-saw’ movement) where the waist of the device (or the disc edges
protrude into the aortic wall) is in continual contact with the aortic root,
perhaps causing distortion of its wall
SEYYED REZA MIRI.MD, Pediatric Cardiologist, Interventionist 26
27. The locations of rim deficiencies
In atrioventricular valve rim deficiency,
encroachment of device onto the mitral
and/or tricuspid valve is a potential
problem.
This is a concern especially in infants and
young children because of the inherent
design of Amplatzer-type devices which
have a relatively larger disk-rim width in
smaller devices.
In case of device encroachment onto the
valve, it is generally recommended not to
implant a device. There is an extremely
rare documented case of erosion on
mitral valve
SEYYED REZA MIRI.MD, Pediatric Cardiologist, Interventionist 27
28. The rim deficiencies
Deficiency in the surrounding rim(s) is frequently associated with large defects, and
may potentially increase the risk of complications such as device embolization,
erosion and encroachment of device onto nearby cardiac structures.
Aortic rim (antero-superior rim, Figure 1A) deficiency is most common rim
deficiency and device implantation is frequently interfered by LA disk prolapse.
Erosion risk is higher in aortic rim deficiency as well as device oversizing , thus
device selection has to be refrained from undue oversizing.
IVC rim (posteroinferior rim, Figure 1B) deficiency is second most common among
rim deficiencies and associated with higher risk of device embolization . In case
with this rim deficiency, under-sizing of the device may further increase the risk of
device embolization, and should be avoided. It is difficult to visualize IVC rim with
TEE guidance, so ICE is preferable imaging modality in patients with IVC rim
deficiency ,however, so called ‘modified retroflexed view’ may be helpful to
visualize IVC rim with TEE guidance
Superior vena cava (SVC) rim (posterosuperior rim, Figure 1C) deficiency is a rare
condition and may interfere with device positioning
When the rim deficiency is extended from SVC rim to aortic rim, this indicates the
defect is located superiorly in the atrial roof and may carry higher risk of erosion
In case with posterior rim (Figure 1D) deficiency, the feasibility of device closure
may be decided by the extent of rim deficiency (Figure 2). In the presence of rim
deficiency in large area from IVC to posterior rim, the risk of device embolization is
very high and this condition may preclude device closure.SEYYED REZA MIRI.MD, Pediatric Cardiologist, Interventionist 28
29. 3D echo for ASD
3D echo provides instantaneous appreciation of defect position,
orientation, size and spatial relationships to surrounding structures and
may offer a superior approach to ASD measurements.
Correct anatomical orientation of the 3D image is essential and ideally
performed and presented for viewing in a standardised manner.
a major advantage of 3D echo, is its ability to simultaneously align
anatomical understanding between team members (interventional,
surgical and imaging) enabling more effective dialogue and an efficiently
performed procedure. 3D multi-plane reconstruction allows a detailed
assessment of the ASD rims ,simplifying the 2D incremental 10°–15° sweep
performed to assess the precise nature of each rim region. Accurate
orientation of the 3D defect in its true long and short axis can be rapidly
achieved .
3D TEE ASD measurements appear to be more accurate when compared to
2D since they allow precise orientation with the defect axes
SEYYED REZA MIRI.MD, Pediatric Cardiologist, Interventionist 29
30. TEE for ASD
A systematic approach includes a scout at 0 degrees in transverse plane,
imaging the AS through its entire length (high, mid, low esophageal levels
allowing a quick overview of the defect) then rotating through 0°–180°
preferably in 10°–15° increments where specific rim assessments are viewed
at 45°, 90°, 135°.
Limitations of TEE imaging should be remembered and include poor echo
windows; especially low esophageal views where the inferior border of the AS
moves away from the esophageal wall and may be difficult to image.
LA size effects the angle of view and ensuring the patient is appropriately
volume loaded is essential to optimize the widest angle of view as possible.
Where image quality remains poor or esophageal intubation is contra-indicated
or where the TEE probe cannot be tolerated (e.g., general anaesthesia not
advisable) then ICE imaging may be considered.
SEYYED REZA MIRI.MD, Pediatric Cardiologist, Interventionist 30
31. Multiple ASD
understanding the accurate anatomy and properties of
surrounding/intervening rims of multiple defects is the cornerstone of
successful device closure.
To overcome these problems, proper use of real time 3-dimensional
(RT3D) echocardiography may be helpful
RT3D echocardiography enables visualization of the wide ranged
septum in a single view in the echocardiography and provides
instantaneous understanding of the anatomy as well as identification
of complex morphology and spatial relationship between multiple
defects
Temporary balloon occlusion test may also be useful to investigate
compliance of surrounding rims and intervening septum, as well as to
predict changes of the defects and rims after device implantation.
Also, a careful observation of fluoroscopic images with balloon sizing
may provide additional information on the spatial relationship
between the defects and intervening septum
SEYYED REZA MIRI.MD, Pediatric Cardiologist, Interventionist 31
32. Check list for assessing ASD for device closure
a) Confirm defect is secundum type
b) Would surgery be a better option?
a) Presence or anomalous pulmonary venous drainage
b) Significant mitral valve pathology necessitating surgical intervention
c) Detailed assessment of defect
a) Defect size
b) Number of defects
c) Surrounding rims
d) Alrial septal aneurysm
d) Is there a risk for interference during device placement
a) Eustachian valve (less commonly Eustachian ridge)
b) Chiari network
SEYYED REZA MIRI.MD, Pediatric Cardiologist, Interventionist 32
33. ASD closure
Suitable for closure
RV dilatation with or without symptoms
with L-R shunt and without significant
PAH
Paradoxical embolism
Platypnoea / orthodeoxia Syndrome
Suitable anatomy (adequate n‘ms.
detect 535 mm. LA size allows device.
no associated lesions)
Eisenmenger syndrome with lit-L shunt.
significant PAH unresponsive to PVT
Unsuitable for closure
Current Sepsis
Contra-indication to anti-
platelet therapy
Nickel allergy
Unsuitable anatomy
inadequate rims
defect >36 mm
LA size too small
associated lesions‘
SEYYED REZA MIRI.MD, Pediatric Cardiologist, Interventionist 33
34. balloon sizing (BS) at the time of the procedure is an option.
However unless the defect opens (folds back) noticeably once the guide wire is
placed, reliance can be placed on echo measurements without the need for BS.
If BS is employed then this should be a ‘stop-flow’ technique .This approach
ensures sizing in line with TEE avoiding oversizing and its subsequent risks
.When performed correctly the method relies on TEE imaging.
The shaft of the balloon, as it is inflated, is visualized through its entirety
(confirming alignment through the central long axis for accurate sizing) and
monitored using CFD. When the flow on CFD stops balloon inflation ceases
This method prevents oversizing and a prominent balloon waist is avoided
(suggesting over-inflation). The narrowest central portion of the balloon is
measured on TEE and compared to fluoroscopy. The measured diameter
equates to the device size. It is recommended not to oversize more than 2–4
mm in the case of deficient anterosuperior rim due to an increased risk of
erosion.
SEYYED REZA MIRI.MD, Pediatric Cardiologist, Interventionist 34
35. ASD ECHO
There has been debate on the necessity of balloon sizing for selection of device
size.
Balloon sizing may be skipped in suitable defects with sufficient surrounding
rims ,however, it has long been regarded as an essential step of the procedure
.Indeed, balloon sizing may provide more information than averaged size of the
defect including compliance of surrounding rims and presence of additional
defect.
While the balloon stretched diameter or balloon occlusive diameter were used
in balloon sizing in the past, currently stop flow diameter (SFD) is
recommended as the standard measurement to avoid oversizing
In self-centering devices such as the Amplatzer Septal Occluder (ASO) the
recommended device size is the same or slightly larger (<2 mm) than the SFD.
In cases with aortic rim deficiency, the usual recommendation is to avoid an
“oversized” device because of the potential risk of erosion
in cases with inferior vena cava (IVC) rim deficiency with higher risk of device
embolization, use of an “undersized” device should be avoided.
In case of using a non-self-centering device such as the Gore Septal Occluder
(GSO) ,a device twice the size of the defect is recommended and the GSO is not
recommended for defects >18 mm
SEYYED REZA MIRI.MD, Pediatric Cardiologist, Interventionist 35
36. Illustration of feasible (A), borderline (B) and unfeasible (C) defect for device closure in
posterior rim deficiency. For the defects with posterior rim deficiency, the extent of rim
deficiency determines feasibility of device closure, so the clear anatomic definition is very
important
SEYYED REZA MIRI.MD, Pediatric Cardiologist, Interventionist 36
37. Multiple ASD
In case of device closure of multiple defects using multiple devices, the optimal
combination of devices based on the comprehensive information from RT3D
echocardiography and balloon occlusion test is required to prevent unfavorable
interference between multiple devices
Usually, a small additional defect adjacent to a larger defect (<7 mm in distance)
can also be closed by implantation of a single device in the major defect
When the additional defect is also sizable or defects are in distance each other,
use of multiple devices is required. For multi-fenestrated defects with a large
septal aneurysm, patch-like closure using a non-self-centering device may be a
good option
Several discrete defects may necessitate multiple device implantations or
fenestrations (multiple small ‘pepper pot’ defects) may warrant a large device
with a narrow waist placed as centrally as possible on the AS to ensure coverage of
the entire fossa ovalis (FO).
SEYYED REZA MIRI.MD, Pediatric Cardiologist, Interventionist 37
38. ASD closure History
Transcatheter closure Initially attempted in adult dogs
,Work expanded to human patients in1976
Amplatzer device first implanted in humans,in 1995, by
Hijazi Z
39. ASD device History-1
King and Mills, in 1974, originally described and subsequently demonstrated feasibility
of closing ASD using a device.
Their device consisted of Dacron-covered stainless steel umbrellas, but it required a
large delivery sheath and complicated maneuvering during deployment.
William Rashkind in 1977 developed a device that Single disk anchoredby “fish
hooks”14-16f delivery sheath, size 25, 30 and 35mm
initially had 3 stainless steel arms covered with medical grade foam and subsequently
a device with 6 arms, all of which ended with miniature hooks.
Due to difficulty in deploying the double-umbrella, Lock et al. modified the Rashkind
device in 1989 into a clamshell occluder by introducing a second spring in the arms.
Rome et al. and Hellenbrand et al. reported clinical experience with this device in the
1990s.
40. ASD device History-2
In 1990, Sideris et al. described a buttoned device that consisted of an occluder and a counter-
occluder
In 1993, Pavenik et al. designed a monodisk device, which consisted of a stainless steel ring
covered with 2 layers of wire mesh and hollow pieces of braided stainless steel wire.
Babic et al. in 1991, Siveret et al. in 1995, and Hausdorf in 1996 described the use of a double
umbrella device called an ASD occluding system deployed via an arterio-venous wire loop.
In 1993, Das et al. described a self-centering device delivered transvenously called Das Angel
Wing with a subsequent modified device that was called Guardian Angel Wing.
When the clamshell device was withdrawn due to stress fractures of the stainless steel arms,
the device was modified by using MP35N, a nonferrous alloy, with an additional bend in the arms
and the device was called Cardio-SEAL (2nd generation:Clamshell) in 1996.
41. ASD device History-3
In 1997, Amplatz developed a self-expanding prosthesis made of nitinol (nickel
and titanium alloy) wire mesh with 2 round disks and a connecting short waist.
This device was called Amplatzer septal occluder (ASO) and was approved by
the FDA in December 2001.
In 1998, the device was further modified by using a self-centering mechanism
with microsprings between the umbrellas and the device was called STARFlex
The Helex occluder is made of a 0.012-inch nitinol wire covered with an ultra-
thin expanded polytetrafluoroethylene membrane, and once deployed, the
device forms 2 round flexible disks on either side of the septal defect. The FDA
approved the Helex occluder in 2006.
The STARFlex device was subsequently further modified by using bioabsorbable
material to replace the Dacron, and the devices were called BioSTAR (NMT
Medical Inc.) and BioTREK (NMT Medical Inc.)
43. Asd closure steps
Step 1: TTE Assessment
Step 2: TEE or ICE imaging
Step 3: Hemodynamic assessment
• venous access - 8Fr sheath (+/- Arterial line)
• Right heart cath: qp:qs; pvr etc
Step 4: Balloon size and device selection “stop flow”
waist +/- 2 mm
Step 5: Load device, advance across ASD and open
Step 6: Assess by ECHO and “Wiggle”
Step 7: release and reassess
enhanced atrial to septal alignment using a modified Mullins sheath achieving good septal apposition during
delivery of both components
44. Aspirin 325 mg is usually administered before the
procedure and Clopidogrel 600 mg loading dose at the
end of the procedure.
Femoral venous access is obtained in bilateral groins (or
2 sheaths in the same vein), one of which ,9 Fr 35-cm
sheath is for the ICE catheter to easily traverse the iliac
vein into the inferior vena cava, particularly for left
femoral vein insertion.
Heparin is administered to maintain ACT >250 seconds
and a dose of intravenous antibiotic is administered
prior to device deployment.
45. ASD closure is usually performed in the cardiac
catheterization laboratory with conscious sedation and
fluoroscopic +/- ICE guidance
For complex septal anatomy, such as multiple ASDs, TEE
may be preferred.
Advantages of ICE over TEE include no need for general
anesthesia or additional cardiologists to perform the
procedure, better views of the posteroinferior part of
the interatrial septum, and shorter procedure times.
Most operators use the AcuNav ICE catheter
46. Management and Indications for Atrial Septal Defect Closure
In patients with PAH, pulmonary vasodilator testing to assess for reversibility
and test occlusion of ASD should be performed. Inhaled nitric oxide is used
commonly as a pulmonary vasodilator.
A positive vasoreactivity response is defined as a reduction of mean PAP of
>10 mm Hg with resultant mean PAP of 40 mm Hg or less, without fall in
cardiac output.
Closure in such patients may be performed if there is net left-to-right
shunting, PA pressure <2/3 systemic levels, PVR <2/3 SVR, or when
responsive to either pulmonary vasodilator testing or test occlusion.
A favorable response is indicated by a fall in mean pulmonary artery
pressure with test occlusion with no decrease in cardiac output and no rise
in right atrial pressure.
47. Management and Indications for Atrial Septal Defect
Closure
In patients with PAH, when pulmonary vasodilator
testing has unfavorable response, pulmonary vasodilator
therapy should be initiated and hemodynamics
reassessed a few months later.
ASD closure is also indicated in presence of paradoxical
embolism and documented platypnea orthodeoxia. An
absolute contraindication (Class III) for closure is
irreversible PAH and no evidence of left-to-right shunt.
48. Procedural Details ASD
closure
Balloon sizing is the next step and is usually performed with an AGA
sizing balloon or NuMed sizing balloon.
Under fluoroscopic and ICE guidance, the balloon catheter is placed in
the defect over the extra-stiff guidewire and the balloon is gently
inflated until no flow is visualized by color Doppler on ICE imaging.
It is very important to stop inflating when flow ceases (stop-flow
diameter) to avoid oversizing the defect. This diameter is measured on
ICE as well as fluoroscopy.
For ASO, device size should be equal to but no larger than 1 to 2 mm
above the stop-flow diameter.
Helex septal occluder size should be at least twice the stop-flow
diameter.
For defects >18 mm, ASO is preferable over Helex device.
49. Sizing the ASD
Two major approaches exit, TEE sizing or balloon sizing (BS).
2D TEE provides high-resolution images where the defect measures slightly smaller
than the actual size required for device sizing. Colour flow Doppler (CFD) clearly
demonstrates flow and the boundaries of the ASD, being comparable to surgical and
device sized measurements
When the measurements in all four TEE planes [0, 45, 90, 135] are similar (1–2 mm)
the largest is taken as the ASD size.
If the measurements are significantly different (≥3 mm) a mental reconstruction will
allow an understanding of the overall 3D shape, although 3D TEE has superseded this
requirement.
When the defect is circular a single diameter measurement is taken. When oval in
shape the short and long axes are averaged and correlate with device sizing.
The device size chosen is the measured ASD size plus 20% ,If additional features exist
[such as atrial septal aneurysm (ASA) or absent aortic rim] ,it is advised usually add
25% to the measured size of the defect thereby allowing for adequate grip of the
surrounding rims.
50. Procedural Details
1. the intravenous administration of heparin (100 U/kg)
2. the stretch diameter of the ASD is measured with sizing balloon, either OBW
by Meditech (20, 27 ,33 mm) or AGA Medical Corporation (24 , 34 mm)
3. Introduction into the left atrium is accomplished coaxially via catheter
exchange with a guide wire located in the left superior pulmonary vein.
4. The balloon is filled in the left atrium with contrast material diluted with
physiological serum until it reached a volume greater than the diameter of
the defect, and is slowly removed under TEE-color Doppler control until the
short circuit disappear entirely.
5. The balloon is then slowly deflated and drawn toward the right atrium until
the jump of the balloon to the right atrium is noted. The stretch diameter is
that of the balloon when the balloon passes from the left to the right
atrium, occluding the ASD.
6. Once the balloon is outside the patient, the diameter of the balloon was
tested by inflating it with the same amount in millimeters of contrast
solution, assuming the stretch diameter to be that of the orifice through
which the balloon passes with a certain degree of difficulty, according to
the template recommended by the manufacturer.
51. Procedural Details ASD closure
ICE assessment should include Doppler flow, which may still demonstrate
flow through the waist (but should not be present around the disk), and
evaluation for obstruction of adjacent structures including
atrioventricular valves.
If the positioning is unsatisfactory or there is impingement of adjacent
structures, the device is retracted back into the delivery sheath and
redeployed or replaced with a new device as appropriate.
Device positioning can also be confirmed by angiography in LAO cranial
projection, which allows separation of the left and right atrial disks. In
cases where the device impinges or indents on the aortic root, there may
be higher risk of erosion. Once satisfactory positioning is confirmed, the
device is released by attaching the plastic vise to the delivery cable and
rotating it counterclockwise.
52. ASD closure steps
After completion of hemodynamic assessment, angiography, and ICE
assessment, a Goodale-Loubin (GL) catheter is advanced with a 0.035-inch
J-tipped guidewire into the SVC.
The GL catheter is moved in a caudal direction and then directed toward
the interatrial septum and the ASD crossed with or without the 0.035-inch
J-tipped guidewire using ICE and fluoroscopic guidance.
The catheter and guidewire are placed in the left superior pulmonary vein,
taking care to ensure that the wire tip is not in the left atrial appendage
to avoid perforation. The 0.035-inch J-tipped guidewire is exchanged for a
0.035-inch 1-cm Amplatz super-stiff wire, again taking care to ensure that
the tip is not in the appendage.
53. ASD closure
The next steps depend on the device used.
For the ASO device, delivery sheath size ranges from 6 Fr to 12 Fr depending on device size
chosen.
The balloon-sizing catheter is removed, leaving the 0.035-inch wire in place. The delivery
cable is passed through the loader and the device is screwed to the tip of the delivery cable.
The device and loader are immersed in sterile saline solution and the device is pulled into the
loader while flushing through the side arm. The delivery sheath is prepped and the dilator is
inserted into the sheath. The short sheath in the femoral vein is removed and the delivery
sheath/dilator is then advanced over the 0.035-inch wire, which has been placed in the left
upper pulmonary vein.
The dilator is removed once it reaches the right atrium and the sheath is de-aired. The sheath
is then advanced over the wire into the left atrium, taking care to avoid suction of air in the
system.
The guidewire is removed and the sheath is flushed carefully. The loading device is then
attached to the delivery sheath. Under fluoroscopic guidance, the device is advanced,
carefully watching for any sign of air in the system. Once the device is at the tip of the
delivery sheath in the left atrium, under fluoroscopic and echocardiography guidance the left
atrial disk is deployed by retracting the sheath over the delivery cable.
The device is gently pulled against the interatrial septum and with tension on the delivery
cable; the sheath is retracted further to deploy the right atrial disk. After deployment, the
position is checked by ICE and, if needed, a gentle “to and fro” motion (Minnesota wiggle) can
be performed with the delivery cable to assure stable positioning