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_3913_Библиотеки_им_академика_М_И_Перельмана
.pdf
[15] Tanaka J, Izumo M, Fukuoka Y, et al. Comparison of two-dimensional versus real-time three-dimensional transesophageal echocardiography
for evaluation of patent foramen ovale morphology. Am J Cardiol 2013;111(7):1052e6.
[16] Faletra FF, Pedrazzini G, Pasotti E, et al. 3D TEE during catheter-based interventions. JACC Cardiovasc Imaging 2014;7(3):292e308.
[17] Fok H, Jiang B, Chowienczyk P, Clapp B. Microbubbles shunting via a patent foramen ovale impair endothelial function. JRSM Cardiovasc
Dis 2015;4. 2048004015601564.
[18] Zhao E, Cheng G, Zhang Y, Li Y, Wang Y. Comparison of different contrast agents in detecting cardiac right-to-left shunt in patients with a
patent foramen ovale during contrast-transthoracic echocardiography. BioMed Res Int 2017;2017:6086094.
[19] Fan S, Nagai T, Luo H, et al. Superiority of the combination of blood and agitated saline for routine contrast enhancement. J Am Soc Echo-
cardiogr 1999;12(2):94e8.
[20] Mojadidi MK, Zhang L, Chugh Y, et al. Transcranial Doppler: does addition of blood to agitated saline affect sensitivity for detecting cardiac
right-to-left shunt? Echocardiography 2016;33(8):1219e27.
[21] Gevorgyan R, Perlowski A, Shenoda M, Mojadidi MK, Agrawal H, Tobis JM. Sensitivity of brachial versus femoral vein injection of agitated
saline to detect right-to-left shunts with transcranial Doppler. Cathet Cardiovasc Interv 2014;84(6):992e6.
[22] Lao Annabelle Y, Sharma Vijay K, Tsivgoulis G, et al. Detection of right-to-left shunts: comparison between the International Consensus and
Spencer Logarithmic Scale criteria. J Neuroimaging 2008;18(4):402e6.
[23] Clarke NR, Timperley J, Kelion AD, Banning AP. Transthoracic echocardiography using second harmonic imaging with Valsalva manoeuvre
for the detection of right to left shunts. Eur J Echocardiogr 2004;5(3):176e81.
[24] Mojadidi MK, Mahmoud AN, Elgendy IY, Agarwal N, Tobis JM. Transesophageal echocardiography for the detection of patent foramen
ovale. J Am Soc Echocardiogr 2017;30(9):933e4.
[25] Danie
¨
ls C, Weytjens C, Cosyns B, et al. Second harmonic transthoracic echocardiography: the new reference screening method for the detec-
tion of patent foramen ovale. Eur J Echocardiogr 2004;5(6):449e52.
[26] Souteyrand G, Motreff P, Lusson J-R, et al. Comparison of transthoracic echocardiography using second harmonic imaging, transcranial
Doppler and transesophageal echocardiography for the detection of patent foramen ovale in stroke patients. Eur J Echocardiogr 2006;7(2):
147e54.
[27] Thanigaraj S, Valika A, Zajarias A, Lasala JM, Perez JE. Comparison of transthoracic versus transesophageal echocardiography for detection
of right-to-left atrial shunting using agitated saline contrast. Am J Cardiol 2005;96(7):1007e10.
[28] Nemec JJ, Marwick TH, Lorig RJ, et al. Comparison of transcranial Doppler ultrasound and transesophageal contrast echocardiography in the
detection of interatrial right-to-left shunts. Am J Cardiol 1991;68(15):1498e502.
[29] Mojadidi MK, Winoker JS, Roberts SC, Msaouel P, Gevorgyan R, Zolty R. Two-dimensional echocardiography using second harmonic imag-
ing for the diagnosis of intracardiac right-to-left shunt: a meta-analysis of prospective studies. Int J Cardiovasc Imaging 2014;30(5):911e23.
[30] Belkin RN, Pollack BD, Ruggiero ML, Alas LL, Tatini U. Comparison of transesophageal and transthoracic echocardiography with contrast
and color flow Doppler in the detection of patent foramen ovale. Am Heart J 1994;128(3):520e5.
[31] Katsanos AH, Psaltopoulou T, Sergentanis TN, et al. Transcranial Doppler versus transthoracic echocardiography for the detection of patent
foramen ovale in patients with cryptogenic cerebral ischemia: a systematic review and diagnostic test accuracy meta-analysis. Ann Neurol
2016;79(4):625e35.
[32] Scacciatella P, Meynet I, Giorgi M, et al. Angiography vs transesophageal echocardiography-guided patent foramen ovale closure: a propen-
sity score matched analysis of a two-center registry. Echocardiography 2018;35(6):834e40.
[33] Seiler C. How should we assess patent foramen ovale? Heart 2004;90(11):1245.
[34] Overell JR, Bone I, Lees KR. Interatrial septal abnormalities and stroke. Neurology 2000;55(8):1172.
[35] Mojadidi MK, Elgendy AY, Elgendy IY, et al. Transcatheter patent foramen ovale closure after cryptogenic stroke: an updated meta-analysis of
randomized trials. JACC Cardiovasc Interv 2017;10(21):2228e30.
[36] Wahl A, Krumsdorf U, Meier B, et al. Transcatheter treatment of atrial septal aneurysm associated with patent foramen ovale for prevention of
recurrent paradoxical embolism in high-risk patients. J Am Coll Cardiol 2005;45(3):377e80.
[37] Schneider B, Zienkiewicz T, Jansen V, Hofmann T, Noltenius H, Meinertz T. Diagnosis of patent foramen ovale by transesophageal echocar-
diography and correlation with autopsy findings. Am J Cardiol 1996;77(14):1202e9.
[38] Mojadidi Mohammad K, Bogush N, Caceres Jose D, Msaouel P, Tobis JM. Diagnostic accuracy of transesophageal echocardiogram for the
detection of patent foramen ovale: a meta-analysis. Echocardiography 2013;31(6):752e8.
[39] Schuchlenz HW, Weihs W, Beitzke A, Stein J-I, Gamillscheg A, Rehak P. Transesophageal echocardiography for quantifying size of patent
foramen ovale in patients with cryptogenic cerebrovascular events. Stroke 2002;33(1):293.
[40] Bunch TJ, Day JD. Examining the risks and benefits of transesophageal echocardiogram imaging during catheter ablation for atrial
fibrillation. Circ Arrhythm Electrophysiol 2012;5(4):621.
[41] Rana BS, Thomas MR, Calvert PA, Monaghan MJ, Hildick-Smith D. Echocardiographic evaluation of patent foramen ovale prior to device
closure. JACC Cardiovasc Imaging 2010;3(7):749e60.
[42] Spencer MP, Moehring MA, Jesurum J, Gray WA, Olsen JV, Reisman M. Power m-mode transcranial Doppler for diagnosis of patent foramen
ovale and assessing transcatheter closure. J Neuroimaging 2004;14(4):342e9.
[43] Medford BA, Taggart NW, Cabalka AK, et al. Intracardiac echocardiography during atrial septal defect and patent foramen ovale device
closure in pediatric and adolescent patients. J Am Soc Echocardiogr 2014;27(9):984e
90.
[44] Newton JD, Mitchell ARJ, Wilson N, Ormerod OJ. Intracardiac echocardiography for patent foramen ovale closure: justification of routine
use. JACC Cardiovasc Interv 2009;2(4):369.
[45] Hildick-Smith D, Behan M, Haworth P, Rana B, Thomas M. Patent foramen ovale closure without echocardiographic control: use of
“Standby” intracardiac ultrasound. JACC Cardiovasc Interv 2008;1(4):387.
[46] Van H, Poommipanit P, Shalaby M, Gevorgyan R, Tseng CH, Tobis J. Sensitivity of transcranial Doppler versus intracardiac echocardiography
in the detection of right-to-left shunt. JACC Cardiovasc Imaging 2010;3(4):343e8.
[47] Lu
¨
thy E, Rutishauser W, Hegglin R, Hegglin M. U
¨
ber das Verhalten des arteriellen Sauerstoffgehaltes und der Farbstoff-Verdu
¨
nnungskurven
bei verschiedenen kongenitalen Vitien. Cardiologia 1959;35:355e64.
II. DIAGNOSIS AND IMAGING ASSESSMENT OF PFO
REFERENCES 27
https://t.me/med1917
[48] Karttunen V, Ventila M, Ikaheimo M, et al. Ear oximetry: a noninvasive method for detection of patent foramen ovale: a study comparing dye
dilution method and oximetry with contrast transesophageal echocardiography. Stroke 2001;32:448e53.
[49] Billinger M, Schwerzmann M, Rutishauser W, et al. Patent foramen ovale screening by ear oximetry in divers. Am J Cardiol 2013;111:286e90.
[50] Kim YJ, Hur J, Shim CY, et al. Patent foramen ovale: diagnosis with multidetector CT–comparison with transesophageal echocardiography.
Radiology 2009;250(1):61e7.
[51] Kara K, Sivrioglu AK, Ozturk E, et al. The role of coronary CT angiography in diagnosis of patent foramen ovale. Diagnostic and interven-
tional radiology (Ankara, Turkey) 2016;22(4):341e6.
[52] Hamilton-Craig C, Sestito A, Natale L, et al. Contrast transoesophageal echocardiography remains superior to contrast-enhanced cardiac
magnetic resonance imaging for the diagnosis of patent foramen ovale. Eur J Echocardiogr 2011;12(3):222e7.
[53] Mohrs OK, Petersen SE, Erkapic D, et al. Dynamic contrast-enhanced MRI before and after transcatheter occlusion of patent foramen ovale.
Am J Roentgenol 2007;188(3):844e9.
[54] Nusser T, Hoher M, Merkle N, et al. Cardiac magnetic resonance imaging and transesophageal echocardiography in patients with transcath-
eter closure of patent foramen ovale. J Am Coll Cardiol 2006;48(2):322e9.
[55] Mojadidi MK, Gevorgyan R, Tobis JM. A comparison of methods to detect and quantitate PFO: TCD, TTE, ICE and TEE. In: Amin Z, Tobis J,
Sievert H, Carroll J, editors. Patent foramen ovale. London, UK: Springer; 2015. p. 55e65.
II. DIAGNOSIS AND IMAGING ASSESSMENT OF PFO
2. ECHOCARDIOGRAPHY, TRANSCRANIAL DOPPLER, AND OXIMETRY FOR IMAGING AND QUANTIFICATION OF PFO-MEDIATED SHUNTS28
https://t.me/med1917
https://t.me/med1917
CHAPTER
3
Angiography, Transthoracic, Transesophageal,
and Intracardiac Echocardiography:
Periprocedural Assessment and Guidance
During PFO Closure
Fabian Nietlispach
1
, Felix C. Tanner
2
, Bernhard Meier
3
1
Cardiovascular Center Zurich, Hirslanden Klinik im Park, Zurich, Switzerland;
2
University Heart Center,
University Hospital Zurich, Zurich, Switzerland;
3
University Hospital Bern, Bern, Switzerland
OUTLINE
Introduction 29
Imaging Stages 30
Preprocedural Imaging 30
Screening 30
Assessing and Characterizing the PFO 32
Device Selection 32
Procedural Guidance 34
Angiography 34
Postprocedural Assessment of Device Position 37
Follow-Up Imaging 37
Special Situations 38
Role of Intracardiac Echocardiography 38
PFO Closure Without Prior (Transesophageal)
Echocardiography
38
In-Hospital Complications
38
PFO Occluder Embolization
39
Reclosure in Case of a Significant Residual Shunt
40
PFO Closure after Left Atrial Appendage Occlusion
40
Left Atrial Ablation, Left Atrial Appendage
Closure, or Other Left Atrial Catheter
Intervention after PFO Closure
40
Supplementary Materials
41
References
41
INTRODUCTION
As for most structural interventions, imaging is paramount for successful closure of the patent foramen
ovale (PFO). Fluoroscopy, angiography, transthoracic echocardiography (TTE), and transesophageal
echocardiography (TEE) are the most important imaging modalities. Some operators also use intracardiac ec hocar-
diography (ICE) for procedural guidance. TEE plays the dominant role in diagnosing and characterizing the PFO
and, in some centers, for a long-term follow-up control after PFO occlusion. Intraprocedurally, fluoroscopy is domi-
nant and used exclusively by many operators and for all PFO closure devices.
Table 3.1 weighs the importance of each imaging modality for the respective steps of PFO closure.
29
PFO Closure for Stroke, Myocardial Infarction, Peripheral Embolism, Migraine, and Hypoxemia
Copyright © 2020 Elsevier Inc. All rights reserved.https://doi.org/10.1016/B978-0-12-816966-7.00003-8
https://t.me/med1917
IMAGING STAGES
Preprocedural Imaging
Most of the time, the presence of a PFO is considered after a systemic embolic event (cerebrovascular event,
embolic myocardial infarction, peripheral arterial occlusion). However, knowing the potential devastating effects
of a PFO such as a cerebral or cardiac embolic event, screening for PFO should be considered under a variety of cir-
cumstances [1,2]. Such circumstances include situations that increase the risk for clot formation (hypercoagulability,
immobilization, major surgery), activities with frequent Valsalva maneuvers, as well as conditions that are
associated with PFO (e.g., migraine with aura or hypoxemia out of proportion to pulmonary disease) (Table 3.2).
Screening
A TTE is well suited for PFO screening. It is widely available, is noninvasive (except for the application of agitated
saline or other echocardiographic contrast medium for a bubble test), and can reliably diagnose a relevant PFO (e.g.,
PFO with a large shunt or hypermobile septum primum; Videos 3.1 and 3.2). During TTE, the patient is not sedated
and able to perform strong and sustained Valsalva maneuvers at the end of which the contrast needs to fill the right
atrium near the interatrial septum. This increases the sensitivity of the method (Fig. 3.1).
In most echocardiography laboratories, contrast bubbles are produced by mixing 9 mL of saline with 1 mL of air
and 1 mL of blood (rapidly squeezing the fluids back and forth between 2 Luer-lock syringes connected by a 3-way
stopcock). Rapid injections into the antecubital vein are important. Some laboratories use well shaken commercial
echocardiographic contrast media (colloids).
In some patients with a large Eustachian valve, the bolus of contrast medium injected through the arm is deflected
away from the interatrial septum and away from the PFO by the Eustachian valve and the non-contrast stained
blood coming from the lower extremities (Chapter 2). This is identified by the “negative contrast sign,” where
venous blood from the lower extremities washes out the contrast at the site of the PFO. In these patients, a
TABLE 3.1 Role of Imaging for PFO Closure: A ¼ Dominant Role; B ¼ May Play a Role; C ¼ No Role.
Fluoroscopy
*
TTE TEE Other
PREPROCEDURAL IMAGING
Screening for PFO B A B Transcranial Doppler: A, ear oximetry: B
Imaging of defect (PFO, ASD) B B (ASD) A
Shunt quantification B A A Transcranial Doppler: A, ear oximetry: B
Characterization of PFO B C A
Additional structures (Chiari network, Eustachian valve) B C A
DEVICE SELECTION
Presence of an atrial septal aneurysm B B A ICE: B
Thickness of septum secundum B C A ICE: B
Length of PFO tunnel B C A ICE: B
Presence of additional defects (ASD) B B A ICE: B
PROCEDURAL GUIDANCE
Correct positioning A C A ICE: B
Stable position A C A ICE: B
POSTPROCEDURAL IMAGING
Confirm stable device position before discharge B A A Computed tomography: B
Follow-up (device thrombus, complete closure) B B A Computed tomography: B
ASD, atrial septal defect; ICE, intracardiac echocardiography; PFO, patent foramen ovale; TEE, transesophageal echocardiography; TTE, transthoracic
echocardiography.
*Combined with contrast medium injections.
3. ANGIOGRAPHY, TRANSTHORACIC, TRANSESOPHAGEAL, AND INTRACARDIAC ECHOCARDIOGRAPHY30
II. DIAGNOSIS AND IMAGING ASSESSMENT OF PFO
https://t.me/med1917
TABLE 3.2 Conditions That Justify Screening for PFO and
Consideration of PFO Closure.
• Therapeutic
- Migraine (particularly with aura)
- Exercise desaturation
- Platypnea orthodeoxia
- Sleep apnea
• Secondary prevention
- Stroke
- Transient ischemic attack
- Embolic myocardial infarction
- Peripheral embolism
- Decompression illness in divers
- High-altitude pulmonary edema
• Primary prevention
- High-risk PFO attributes
- Atrial septal aneurysm
- Eustachian valve
- Chiari network
- Hypercoagulable state
- Deep venous thrombosis
- Pulmonary embolism
- Pacemaker/defibrillator electrodes
- Major surgery
- General
- Orthopedic
- Cerebral in sitting position
- Planned pregnancy
- Carcinoid tumor
- Special congenital situations
• Setting, occupation, or hobby
- Person living at high altitude
- Brass musician
- Glass blower
- Tile setter
- Military or acrobat pilot, astronaut
- Commercial driver or pilot
- Deep sea diver
- Mountain climber
FIGURE 3.1 Agitated saline (or contrast medium) bubble test for detection of an interatrial shunt. Left side: a patient with a large Eustachian
valve and a “negative contrast sign” (contrast applied from the antecubital vein is washed away by non-contrast stained blood coming from the
lower extremities being diverted towards the fossa); right side: same patient after a more strenuous Valsalva maneuver. The contrast medium
reaches the PFO and some bubbles pass to the left atrium.
II. DIAGNOSIS AND IMAGING ASSESSMENT OF PFO
IMAGING STAGES 31
https://t.me/med1917
particularly sustained Valsalva maneuver should be tried (Fig. 3.1; Videos 3.3 and 3.4) or contras t medium should be
injected from a lower extremity vein, to be directed toward the PFO by the Eustachian valve.
A more sensitive screening method for right-to-left-shunt, but without the ability to localize the shunt, is by
transcranial Doppler [3,4]. The simplest method for detecting a large right-to-left shunt is ear oximetry [5].It
requires no venous access or contrast medium and appears fit for screening in school classes or shopping malls,
but it is not well validated yet.
Once diagnosed, the PFO should be characterized (with small vs. large shunt; with vs. without atrial septal aneu-
rysm [ASA], Eustachian valve, or Chiari network; thickness of the septum secundum) to plan future closure and for
device selection.
Assessing and Characterizing the PFO
The differential diagnosis of a right-to-left-shunt includes interatrial and very exceptionally interventricular
shunts, as well as shunts in the pulmonary vasculature, the latter being poorly researched. They can be distinguished
from a PFO-induced shunt by the time required for the bubble contrast to reach the left atrium; however, this distinc-
tion can be difficult with central pulmonary arteriovenous shunts. TEE is the method of choice to:
- Establish the diagnosis of a PFO (Videos 3.5e3.7)
- Diagnose additional defects, such as atrial septal defects (ASDs)
- Characterize a PFO according to the presence of
B Eustachian valve
B Chiari network
B ASA
B Large or a small shunt
B Long or a short PFO tunnel (Videos 3.7e3.10)
- Assess for other causes of stroke such as left atrial appendage thrombus or aortic atheroma
For a TEE, patients are often sedated and therefore unable to perform strong and sustained Valsalva maneuvers.
In that case, it is recommended to compress the inferior vena cava by applying abdominal pressure below the liver
during the contrast injection, with release of pressure immediately before complete right atrial opacification [6]
(Chapter 2). Alternatively, the patient can be asked to cough, which they are usually able to do despite the sedation.
Both, the Eustachian valve and Chiari network direct venous return from the lower extremities toward the PFO.
The presence of an ASA is usually associated with a large PFO and large shunt. An ASA leads to frequent openings
of the PFO, not uncommonly with every heartbeat, and its movements are strongly dependent on respiration. If a large
shunt, ASA, or Eustachian valve is present, the risk of paradoxical embolism increases substantially (Video 3 .2). In a
large randomized trial, the relative risk reduction of PFO closure in patients with a substantial shunt was 82% (HR 0.18
[0.04e0.81]) and in patients with an ASA 81% (HR 0.19 [0.04e0.87]) when compared to medical therapy [7].
Quantification of the shunt size relies on the number of contrast bubbles crossing the PFO. A moderate or large
shunt is defined as 10e20 bubbles crossing the PFO or >20 bubbles with intense opacification of the left atrium,
respectively. This method, however, is semiquantitative, as the number of bubbles in most instances is determined
by two-dimensional imaging.
Device Selection
The most common devices used for PFO closure are Amplatzer (Abbott; Chicago, Illinois) and Amplatzer-type
occluders with a left atrial anchoring disc and an interconnected right atrial disc. Such devices need to be appropri-
ately sized to ensure a stable posi tion and to prevent embolization or partial embolization into the PFO channel.
Therefore, the most important factors for device selectio n based on a preprocedural TEE are:
- Thickness of the septum secundum
- Presence of an ASA
- Length of the PFO tunnel
- Size of PFO opening
- Coexisting ASD
A thick and round or cone-shaped septum secundum requires a larger right atrial disc (Chapter 16). Otherwise
the right atrial disc may slide off the septum secundum and flip into the PFO channel (Fig. 3.2; Video 3.11).
II. DIAGNOSIS AND IMAGING ASSESSMENT OF PFO
3. ANGIOGRAPHY, TRANSTHORACIC, TRANSESOPHAGEAL, AND INTRACARDIAC ECHOCARDIOGRAPHY32
https://t.me/med1917
This occurs typically after release of the device and can be detected by a “negative Pacman sign.” While the risk for
embolization to the arterial side is small, the effective closure rate will be reduced to presumably <50%.
This phenomenon is even more likely to occur if a large ASA is present and the PFO tunnel is very short (little
overlap of the septum primum and secundum to stabilize the device position).
As a rule (Chapter 16), the presence of 1 or 2 of the above risk factors (thick septum secundum, ASA, and short or
no tunnel) should trigger selection of the larger PFO occluder (e.g., an Amplatzer 35 mm PFO Occluder), whereas the
presence of all 3 risk factors mandates selection of the larger PFO Occluder (Fig. 3.3). A long tunnel or a small PFO
opening renders a thick septum secundum or an ASA less important and may still allow a standard device to be used
in their presence.
The use of “sizing balloons” is never required for PFO closure. The additional information gained from a sizing
balloon across the PFO is minimal (width and length of the PFO tunnel). The use of gauging balloons increases cost
and carries a small risk for complications (e.g., tearing of a thin septum primum).
In summary, for device selection, information gained from a preprocedure TEE is the gold standard. A TTE can
diagnose an atrial septal aneurysm and in some patients with good TTE quality, the thickness of the septum secun-
dum can also be characterized. Under certain circumstances where no ultrasound imaging is available, angiography
can answer these questions (e.g., if echocardiographic pictures are not accessible or in case of ad hoc PFO closure; see
below; Video 3.12).
FIGURE 3.2 Follow-up angiogram through a multipurpose catheter directed into the foramen ovale. The device was too small and the right
atrial disc prolapsed into the PFO channel (negative Pacman sign). Repositioning had been unsuccessful as the device unhinged again off the
septum secundum (SeS) due to excessive mobility of the hypermobile (aneurysmal) septum primum (SeP). An additional larger device (not
shown) was successfully implanted.
FIGURE 3.3 Presence of an atrial septal aneurysm (ASA) and a very short PFO tunnel (left panel) led to implantation of a 35 mm Amplatzer
PFO Occluder with a 35 mm right and a 25 mm left atrial disc (right panel). SeS, septum secundum.
II. DIAGNOSIS AND IMAGING ASSESSMENT OF PFO
IMAGING STAGES 33
https://t.me/med1917
Procedural Guidance
PFO closure is considered one of the simplest procedures in interventional cardiology, with a short learning curve.
In many centers, PFO closure is therefore exclusively guided by angiography. However, several important details for
angiographic guidance should be respected (Chapter 16).
Angiography
Crossing the PFO: The first step is crossing the PFO with the guidewire. Since minimal resistance is expected to
cross the PFO with the delivery sheath, a standard 0.035
00
guidewire is used. A stiff-tip guidewire should be avoided,
since it could potentially cause trauma (e.g., when accidentally placed in an atrial appendage).
Correct crossing of the PFO by the guidewire can be confirmed by fluoroscopy (Fig. 3.4). The guidewire is then
placed in either a pulmonary vein or, preferably, the left atrium. The left atrial appendage should be avoided
although perforation with a regular U-tip 0.035
00
wire is not really a threat.
Advancing the delivery sheath: The delivery sheath is advanced to the right atrium. No resistance is to be expected as
the sheath advances over the guidewire to the atrium after entering the groin. A kink in the guidewire would typi-
cally occur when introducing the sheath through the skin. Instead of using blind force, the sheath should be contin-
uously torqued (screwed) with a simultaneous to and fro motion of the guidewire, or even followed by fluoroscopy,
confirming the absence of wire kinking (otherwise vascular damage can occur).
The PFO is then crossed, again by fluoroscopic guidance and tactile feedback. Resistance can occur in a PFO with
a long tunnel and without ASA. In these patients, turning the sheath slightly counterclockwise will direct it supe-
riorly and may help to cross the septum.
Positioning the sheath in the left atrium: Ideally, the delivery sheath should not be advanced in a pulmonary vein. A
common landmark for placing the sheath on fluoroscopy is the intersection of the guidewire in the left atrium with
the left border of the spine in a posteroanterior view. Once in the left atrium, the introducer and guidewire are
removed. The proximal end of the she ath must be held low relative to the body of the patient, to avoid aspiration
of air. The position of the sheath’s tip should be noted with regard to fluoroscopic landmarks (e.g., spine;
Fig. 3.5) and held in place until the left disc of the respective device is deployed.
Deployment of the device: Once the left disc is deployed, the device and the sheath are pulled back as a unit to the
interatrial septum where resistance is felt. For this, the left anterior oblique position is ideal as it reliably shows when
the left disc gets stopped and erected by the septum (Fig. 3.6). By further pulling on the sheath, the right disc is
deployed while applying tension, which prevents accidental forward movement of the device that could result in
deployment of the right disc in the left atrium.
Confirmation of stable and correct device position: Device position can be reliably confirmed by angiography. It is
mandatory to visualize the device in a perfectly perpendicular view without disc overlap. Typically, these views
are to be found in a left anterior oblique with cranial angulation of the X-ray tube or (rarely needed) in a lateral-
caudal view (Fig. 3.7).
FIGURE 3.4 Confirmation that the guidewire crossed the PFO correctly: left: posteroanterior view with the guidewire pointing to the upper
right of the screen and beyond the border of the heart into the left upper pulmonary vein or left atrial appendage; right: lateral view with the
guidewire staying posteriorly (close to the spine) in the “atrial plane.”
II. DIAGNOSIS AND IMAGING ASSESSMENT OF PFO
3. ANGIOGRAPHY, TRANSTHORACIC, TRANSESOPHAGEAL, AND INTRACARDIAC ECHOCARDIOGRAPHY34
https://t.me/med1917
FIGURE 3.5 Position of the sheath tip in the left atrium with regard to fluoroscopic landmarks (e.g., spine) should be noted until the left-sided
disc is deployed.
FIGURE 3.6 Deployment of the right-sided disc while pulling the left disc toward the septum (always in left anterior oblique projection).
FIGURE 3.7 Angiographic views to confirm correct device position, Left: left anterior oblique cranial view; right: lateral-caudal view. There is
also a device in the left atrial appendage.
II. DIAGNOSIS AND IMAGING ASSESSMENT OF PFO
IMAGING STAGES 35
https://t.me/med1917
Соседние файлы в папке Библиотека им академика М.И. Перельмана