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_3590_Библиотеки_им_академика_М_И_Перельмана
.pdf
26—COARCTATION AND PDA CLOSURE 299
https://t.me/medicina_free
A
C
Fig. 26.1 A-D Echocardiographic-Doppler findings in 12-year-old male with severe juxtaductal coarctation of the
aorta with a prominent posterior ridge. The color flow images in B illustrate the turbulence a the coarctation posterior
ledge. The continuous wave Doppler (C) confirms a mean systolic gradient of 36 mmHg and the abdominal pulsed
Doppler (D) demonstrates the typical low velocity delayed-continuous flow consistent with severe aortic obstruction.
B
D
Fig. 26.2 CT provides the most rapid and high resolution imaging of the anatomy of the coarctation site.
This gothic type aortic arch also has some arch hypoplasia.
300 8—ACHD INTERVENTIONS
https://t.me/medicina_free
three-dimensional printed models (Fig. 26.3, Video 26.1). Such imaging can be particularly helpful to allow structural visualization and interventional planning.
The site of coarctation, severity, proximity to other vascular structures such as subclavian or
carotid vessels, and the presence of arch hypoplasia are all anatomic features which will determine
the interventional procedure. When the coarctation involves the origin of the left subclavian artery, some have suggested minor surgical transfer of the subclavian to the left carotid would
preclude concerns for obstruction of the subclavian.
Published reports of multicenter study of coarctation intervention results have indicated that
age, severity of coarctation, and presence of previously surgical intervention or vascular injury (aneurysm) would significantly affect decision-making concerning the type of procedure and type of
stent to be considered. They defined a discrete coarctation anatomically as a stenosis #
5 mm and
aortic aneurysm as a 10% increase in the aortic dimension from the adjoining aortic lumen. In
particular, they noted that the risk of encountering a technical complication increased in patients
over the age of 40 years.
1-3
. Thus the use of covered stents would be an important technical consid-
eration for the older population of patients.
AHA Guidelines
Surgical repair or catheter-based stenting is recommended for
I B-NR
adults with hypertension and significant native or recurrent
coarctation of the aorta
Balloon angioplasty for adults with native and recurrent coarcta-
Iib B-NR
tion of the aorta may be considered if stent placement is not
feasible and surgical intervention is not an option
(From Stout KK, Daniels CJ, Aboulhosn JA, Bozkurt B, Broberg CS, Colman JM, Crumb SR, Dearani JA, Fuller
S, Gurvitz M, Khairy P, Landzberg MJ, Saidi A, Valente AM, Van Hare GF. 2018 AHA/ACC guideline for the
management of adults with congenital heart disease: executive summary: a report of the American College of
Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. J Am Coll Cardiol 2018.)
ABC
Fig. 26.3 A. CT angio image of a 12-year-old male with severe juxtaductal coarctation of the aorta clearly defined
in the 2D image. There also is mild arch hypoplasia present. B,C. 3D images of CT angio in a 49-year-old female
with associated bicuspid aortic valve. Note the extreme severity of the coarcted segment with multiple collateral
vessels present.
26—COARCTATION AND PDA CLOSURE 301
https://t.me/medicina_free
Workup for Transcatheter Intervention
Prior to catheter intervention, 3D rotational angiography has been particularly helpful to define
the anatomy of the coarctation site, its length, and severity. Fig. 26.4 and Video 26.2 illustrates a
3D rotational angiography obtained during catheterization. These images assist the interventionist
to better understand the location, length, and severity of the coarctation, which in this example is
a more diffuse lesion over several centimeters. In addition, some arch hypoplasia is evident. Hemodynamic study prior to intervention also represents a significant part of the assessment documenting gradient and LVEDP. Studies have defined significant resting coarctation gradient as
20 mmHg. In addition, LVEDP 12 mmHg is supportive in recognizing significant long-term
coarctation hemodynamic effects.
Interventional Techniques
During intervention, initial wire placement may provide better stability by placing the wire in the
opposite subclavian artery. A simple juxtaductal coarctation that is distant from the arch and is
approximately a 50% stenosis is demonstrated in Fig. 26.5 in a teenage patient with associated
bicuspid aortic valve. The coarctation had been balloon dilated 6 years previously. The obstruction
and gradient were completely eliminated with placement of a 36-mm bare metal stent dilated to
approximately 16 mm. For a larger patient, subsequent stent redilation may be necessary to accommodate further growth. With native coarctation, a bare metal stent can be considered when complete dilation of the coarctation site may be limited by the dilation pressure necessary. Some investigators have considered 6 atms a reasonable pressure limit for initial dilation to avoid significant
aortic wall injury.
ABC
Fig. 26.4 A,B. 3D reconstruction of a rotational angiogram obtained in the catheterization laboratory in a
15-year-old male who had coarctation repair in infancy with a left subclavian flap technique. The reconstruction demonstrates the severity of a long segment of obstruction consistent with the type O repair used.
There is also mild arch hypoplasia. C illustrates a rotational reconstruction after placement of a 36-mm bare
metal stent and dilated to 15 mm to completely relieve the obstruction.
302 8—ACHD INTERVENTIONS
AB
CD
https://t.me/medicina_free
Fig. 26.5 A,B. Anterior-posterior and lateral views of placement wire located in the right subclavian artery for
stent intervention. C illustrates an A-P view of the juxtaductal coarctation that represents approximately a
50% stenosis. D shows an A-P view of a 36-mm bare metal stent dilated to 15 mm with no evidence of
residual aortic obstruction and no evidence of aortic wall unjury.
Procedural Steps
Trancatheter aortic coarctation repair may require general anesthesia for hemodynamic stability
and because of significant pain associated with aortic dilation. Femoral arterial access is established with ultrasound guidance. Patients are heparinized with 100units/kg, aiming for an
ACT.250s.
The sheath size is determined by the anticipated final diameter to be achieved with the stent
dilation; however, a 14 Fr sheath may be reasonable in instances where a covered stent may be
necessary.
26—COARCTATION AND PDA CLOSURE 303
https://t.me/medicina_free
Fig. 26.6 Depending on the anatomy and severity of the
aortic coarctation, we select a pigtail (for less severe
stenosis) or multipurpose or JR4 6F catheter and an
0,035” angle glide wire to cross the coarcted segment.
This is advanced into the aortic root.
Fig. 26.7 A. Aortic angiography or rotational angiography
is performed to accurately delinate the aortic anatomy.
The left ventricular pressure is recorded. A simultaneous
gradient across the coarctation can be measured using
the pigtail catheter in the ascending aorta and the sheath
in the descending aorta.
Fig. 26.8 A stiff exchange wire (e.g., Amplatzer extra
stiff) is inserted. During intervention, initial wire place-
ment may provide better stability by placing the wire in
the opposite subclavian artery. If the stenosis is severe,
predilation may be required before the sheath and stent
can be advanced through the coarcted segment.
304 8—ACHD INTERVENTIONS
https://t.me/medicina_free
Fig. 26.9 A long Mullin’s type sheath is advanced
across the coarctation. This is used to deliver the
stent.
Fig. 26.10 The stent is carefully placed across the
coarctation. Multiple small hand injections during un-
sheathing of the stent may be necessary to accurately
adjust the stent position prior to deployment. Often a BIB
type balloon delivery system (NuMED Inc., New York) is
utilized to deploy the balloon in the coarcted segment. The
BIB balloon most often is rated at 4–5 atms for dilation. A
variety of stents can be considered for stent placement,
including the Cordis Palmaz, EV3 Instrastent LD Max, or
the Cheatham Platinum covered stent. Higher-pressure
balloons can be considered for postdilation, especially if a
covered stent has to be utilized. If some segments of the
stent remain poorly configured with the aortic wall, these
stent segments may be flared to approximate the wall with
lower pressure and larger balloons. Rapid ventricular pacing is often employed to assist appropriate stent delivery
by reducing cardiac output and stroke volume during stent
deployment. Also holding the ventilation during deployment may help to reduce stent movement.
Fig. 26.11 Once the stent is deployed, the pigtail
catheter can be readvanced over the exchange wire
and positioned in the aortic root to measure pressure and assess for any residual gradient. If a residual
gradient exists, postdilatation may be performed or a
determination may be made to wait several months for
a safer further dilation later.
26—COARCTATION AND PDA CLOSURE 305
https://t.me/medicina_free
More complex coarctation is illustrated in Fig. 26.12. The patient is a 21-year-old male with
biscuspid aortic valve and previously coarctation surgical repair at age 1 week. His hemodynamic
cath demonstrates a 50 mmHg gradient primarily evident in the mid arch distal to the left carotid
artery. The transverse aortic arch was 15-18 mm in diameter while the area of recoarctation was
7.5 mm in diameter. The descending aorta was 22 mm in diameter. A 36-mm open cell bare metal
stent (eV3 Intrastent LD. max) was implanted in the coarctation with a 16-mm high-pressure
balloon and dilated with up to 6-8 atms in pressure. The stent ends were flared with a 20-mm
low-pressure balloon to approximate the stent to the aortic wall. The right subclavian artery
originated anomalously at the stenosis and was dilated to 7-mm through an open stent cell. The
nearly occluded left subclavian, which originated above the stenosis, was also dilated through an
open stent cell with a 7-mm balloon. After stent placement there was a residual 7-mmHg gradient
and mild stenosis as observed in the post-catheter CT angiogram reconstruction. Although advised to consider redilation of the stent, this was not performed, and 5 years post intervention he
remains normotensive and on no medication.
Fig. 26.13 illustrates a saccular aortic psuedoaneurysm in a 44-year-old woman after coarctation
repair at age 4 years, which is treated with three covered CP stents dilated on a 20-mm balloon. At
CT angiogram reconstruction demonstrated that a moderate aortic psuedoaneurysm was present at
the inferior surface of the aorta just distal to the origin of the left subclavian artery. In addition, there
is moderate aortic stenosis of the aorta at the same site. We previously had asked a vascular surgeon
to reimplant the left subclavian artery into the left carotid artery in order to allow appropriate placement of a covered stent to eliminate the pseudoaneurysm. We noted that the aortic arch measures
approximately 20 mm in diameter and the descending aorta approximately 25 mm in diameter. We
initially placed a 34-mm covered CP stent on a 20-mm Zmed. BIB balloon at the aneurysm site.
This appear to effectively cover the aneurysm, but the subsequent rotational study showed a residual
proximal portion of the aneurysm remained. Fig. 26.13C also illustrates the ability to superimpose
or overlay a previously obtained 3D rotation reconstruction on the fluoroscopic image of the patient
to allow easier and more accurate placement of the covered stents. Therefore a second 34-mm
covered CP stent was placed more proximally and a third 28-mm CP covered stent in the mid segment to completely eliminate the pseudoaneurysm. The follow-up 3D CT angiogram demonstrated complete elimination of any residual narrowing and aortic pseudoaneurysm. The patient
remains well and symptom free.
These examples of coarctation stent intervention are consistent with the multicenter trial studies
cited. Simple, moderate, native coarctation can often be easily managed with bare metal stent implantation. Because of its flexibility, we often prefer an open cell stent design, which may also allow
dilation of jailed vessels. Initial efforts are often directed to partial elimination of the coarctation
obstruction with minimal residual gradient, often with plans for subsequent dilation on a later return
visit. Usually the initial dilation pressure may be limited to 6 atms or less for the dilation. For more
complex, severe obstruction with associated aortic aneurysm or in patients older than 30–40 years, a
covered stent may be the safer choice. In addition, if one anticipates an attempt to fully dilate a coarcted segment at the initial procedure with higher atmospheric pressures, the covered stent may be
the most reasonable choice to use. Arch obstructions can be considered in patients if the subclavian
vessels can be salvaged through an open cell stent or by surgical reimplantation if a covered stent is
necessary. Long-term follow-up of coarctation stent in necessary to determine potential complications such as aneurysm formation, in-stent stenosis, stent fracture, or embolization.
Complications
Complications include stent migration (,4%), damage to the aortic wall (dissection, hematoma,
aortic rupture), access site injury, and stroke. Aortic perforation is very rare but may be fatal. Covered stents should be kept available in case of aortic rupture. Restenosis is rare if post-procedural
306 8—ACHD INTERVENTIONS
DE
https://t.me/medicina_free
A
B
Fig. 26.12 A,B. CT angio in a 21-year-old male who had surgical repair of coarctation of the aorta at age
1 week. There is severe obstruction in the aortic arch just distal to the left carotid artery, and there is near occlusion of the left subclavian artery at the site of obstruction. There is anomalous origin of the right subclavian
artery just distal in the descending aorta. C presents the hemodynamics measured at catheterization demonstrating a 50 mmHg gradient across the coarctation. D illustrates the angiographic definition of the major site
of obstruction and its relationship to the subclavian arteries.
C
26—COARCTATION AND PDA CLOSURE 307
https://t.me/medicina_free
F
Fig. 26.12 cont’d
arteries. G presents a follow-up CT angio after stent placement showing relief of the arch obstruction and
widely patent access to both subclavian arteries.
E, F illustrates selective dilation of opened stent cells for the right and left subclavian
G
gradients are ,10 mmHg. Up to 20% of patients may have late aneurysm formation and surveillance aortic imaging should be performed.
Conclusions
n
Aortic coarctation repair is recommended for adults with hypertension and significant native
or recurrent coarctation of the aorta.
n
Transcatheter techniques are well established with a high success rate and low procedural
complications.
n
Preprocedure planning is essential, with CT or MRI to assess the aortic anatomy and posi-
tion of great vessels relative to the coarctation site.
n
Covered stents should be considered if there is a higher risk for aortic injury with severe
coarctation or in patients over 40 years of age.
n
Long-term follow-up of coarctation stent in necessary to determine potential complications
such as aneurysm formation, in-stent stenosis, stent fracture, or embolization
Patent Ductus Arteriosus
Patent ductus arteriosus (PDA), as a communication between the aorta and the main pulmonary
artery, represents a normal and necessary part of the fetal circulation. Therefore the presence of a
PDA in the early neonatal period can be considered a nearly universal phenomenon. While ductal constriction usually leads to functional and anatomic closure, partial or limited closure may
occur in some cases. The previous discussion on coarctation of the aorta noted that the constrictive tissue present in the ductus arteriosus may in fact result in constriction or coarctation of the
aorta or the left pulmonary artery. Isolated patent ductus arteriosus reportedly represents 5% to
10% of congenital cardiac defects.
tal period is much more common among preterm neonates than among term infants.
tiny asymptomatic PDA may also be more prevalent in older children and adults and remain
unrecognized clinically except for occasional recognition by echocardiography requested for other
reasons.
4
Persistent patency of the ductus arteriosus beyond the neona-
5
However,
A
CD
https://t.me/medicina_free
B
E
Fig. 26.13 A illustrated 3D reconstruction of a CT angiogram in a 44-year-old woman who had surgical repair of
coarctation of the aorta at age 4 years. There is a moderate pseudoaneurysm present on the under surface of
the aorta just below the left subclavian artery. In addition, there is a moderate stenosis at the aneurysm. B illustrates 3D reconstruction of rotational angio that demonstrates the placement of a 34-mm covered CP stent dilated on a 20-mm balloon. The left subclavian artery has been previously surgically transposed to the left carotid
artery. C illustrates the previous 3D reconstruction superimposed on the fluoroscopic image to allow better positioning of a second 34-mm covered CP stent at 20 mm. D illustrates placement of a final 28-mm covered CP
stent in the mid segment to complete coverage of the entire arch segment beyond the left carotid as seen
in post-catheterization CT angio shown in E.
Соседние файлы в папке Библиотека им академика М.И. Перельмана