Email address of authors:
Javid Raja : javidraj86@gmail.com
Ganesh Kumar M : mganeshkumar19@gmail.com
Sachin Mahajan : sachinkriti111@gmail.com
Total number of images: 2
Total Word count: 1257
Data availability statement: The data that support the findings
of this study are available from the corresponding author, upon
reasonable request.
Authors’ Note:
This statement is to confirm that permission was granted by the
patient’s parents to publish this report.
Source(s) of support: No assistance taken from anybody for this work
Presentation at a meeting: NIL
Conflicting Interest (If present, give more details): No Conflicts of
Interest
Acknowledgement: No assistance taken from anybody for this work
Abstract:
The arterial switch operation (ASO) is the procedure of choice for the
management of d-transposition of the great arteries (TGA). However, the
surgical management of infants older than 6 weeks with TGA and intact
ventricular septum (IVS) remains contentious. We report a case of late
presenting TGA, IVS with Systolic anterior motion(SAM) of mitral valve
with preserved left ventricle(LV) and its management.
Key words: Transposition of great arteries, Arterial switch operation,
Systolic anterior motion
Introduction:
Patients with TGA, IVS presenting after the neonatal period are at high
risk for ASO in view of concerns regarding the preparedness of LV to
support the systemic circulation. In such cases, either an atrial switch
operation or a rapid two-stage arterial switch procedure has been
usually performed, though the former is inferior to ASO[1,2]. Some
centers advocate a primary ASO with standby extracorporeal membrane
oxygenation (ECMO) support[3]. We report our experience with a 2
year old girl with TGA, IVS with preserved LV mass and its management.
Case report:
This 2-year-old girl presented with the complaints of breathlessness and
cyanosis and was diagnosed to have cyanotic heart disease and referred
to our centre for management. On examination, her height was 65 cm, body
weight 5 kg, pulse 124/ min, BP 103/64 mm Hg, and respiratory rate
35/min. There was clinical cyanosis, clubbing, but no pallor or
jaundice. Oxygen saturation was 70% in room air. Echocardiography
revealed normal situs, atrioventricular concordance and
ventriculoarterial discordance, two fossa ovalis atrial septal defect 8
mm and 4 mm each, muscle bundle seen bulging into left ventricular
outflow tract(LVOT) causing Systolic Anterior Motion(SAM) of anterior
leaflet of mitral valve with peak gradient 12 mmHg (Fig. 1) and normal
bi-ventricular function. Since the LV posterior wall thickness and LV
mass was normal(Fig. 2) and there was circular cross-sectional
appearance of LV in the short-axis view, patient was planned for primary
ASO.
With parental consent, a primary ASO was performed with closure of the
ASD. Cardiopulmonary bypass time was 241 min and ischemic time of 127
min with two doses of del Nido cardioplegia and moderate hypothermia.
The child was successfully weaned from CPB with supports of milrinone
0.8 micrograms/kg/min, norepinephrine 0.1 micrograms/kg/min, epinephrine
0.05 micrograms/kg/min and returned to ICU with sternum left open in
view of severe LV systolic dysfunction. ECMO was kept standby, However,
by the simple intervention of vasodilatation and accepting low systemic
blood pressure (mean BP of 45 mm Hg), its use was avoided. Chest closure
was done on day 2. The poorly contractile LV necessitated prolonged
ventilation and sedation along with extended inotropes and vasodilator
infusion. She was extubated on postoperative day 7 and was discharged on
14th postoperative day and is on regular follow-up.
Discussion:
In spite of many published reports, little is understood about the
origin of left ventricular outflow tract obstruction in simple TGA, IVS.
Aziz and colleagues[4] described two types of obstruction in TGA and
IVS namely, ”fixed” in which there was no SAM of the mitral valve and
in which the diameter of the LVOT was reduced compared with the diameter
of the pulmonary artery through out the cardiac cycle and ”dynamic”,
in which the left ventricular outflow tract was wide open during
diastole but narrowed in systole and was associated with SAM of the
mitral valve. In the index case there was solely dynamic obstruction of
LVOT that has contributed in preservation of LV mass.
In TGA with IVS, LV cavity appears ellipsoid at birth but becomes banana
shaped sooner corresponding to a decline in PVR[5]. The assessment
of adequacy of LV to tolerate systemic circulation is one of the major
evaluation criteria for ASO. LV end-diastolic volume calculated using
area length method (Bullet method) on Transthoracic Echocardiography in
subcostal or parasternal short axis and subcostal or apical long axis
view is useful in calculating LV mass.[5] LV mass of <60%
of predicted or of <35 gm/m2 with respect to body surface area
suggests a regressed LV. Posterior wall thickness of LV measured at the
mid-cavity level if <4 mm is also suggestive of regressed
LV.[6] Furthermore, assessment of LV cavity from subcostal short
axis views of the heart at end-systole can yield additional information
on favourable LV for single-stage repair. LV geometry was classified as
“favourable” or type I if the superoinferior/ anteroposterior
dimension ratio was <2; “acceptable” or type II if the ratio
was between 2 and 3 and “unfavorable” or type III if the ratio was
>3.[7] In the present case it was favourable and LV
posterior wall thickness was >4 mm.
ASO is found to be a better operation in patients of TGA, IVS with
dynamic obstruction of LVOT unlike atrial repairs in which dynamic LVOT
obstruction is likely to persist or progress, and can even develop
postoperatively in some patients [8,9]. The other important thing is
that the child was managed with adequate inotropes and vasodilator
infusion without the use of ECMO. Very few cases have been reported in
late presenting TGA, IVS in which the LV mass is preserved solely due to
dynamic LVOT obstruction caused by SAM of mitral valve.
Conclusion:
Our experience supports the notion that the LV in TGA-IVS maintains the
potential for systemic work well beyond the neonatal period even with
dynamic LVOT obstruction. Though transient postoperative LV dysfunction
almost always results in a prolonged postoperative course, its always
reversible and therefore primary ASO should be the first surgical option
in such cases.
References:
- M. Lo Rito, I. Raso, A. Saracino, et al. Primary arterial switch
operation for late presentation of transposition of the great arteries
with intact ventricular septum. Semin Thorac Cardiovasc Surg (2020),
10.1053/j.semtcvs.2020.11.030 Google Scholar
- Williams WG, McCrindle BW, Ashburn DA, Jonas RA, Mavroudis C, Black-
stone EH, Congenital Heart Surgeon’s Society. Outcomes of 829 neonates
with complete transposition of the great arteries 12—17 years after
repair. Eur J Cardiothorac Surg 2003;24(1):1—9.
- Bisoi AK, Sharma P, Chauhan S, et al. Primary arterial switch opera-
tion in children presenting late with d-transposition of great
arteries and intact ventricular septum. When it is too late for a
primary arterial switch operation? Eur J Cardiothorac Surg.
2010;38:707–13.
- Aziz KU, Paul MH, Muster AJ. Echocardiographic assessment of left
ventricular outflow tract in d-transposition of the great arteries. Am
J Cardiol 1978; 41:543-51.
- Schiller NB, Shah PM, Crawford M, DeMaria A, Devereux R, Feigenbaum H,
et al. Recommendations for quantitation of the left ventricle by
two-dimensional echocardiography. American society of echocardiography
committee on standards, subcommittee on quantitation of
two-dimensional echocardiograms. J Am Soc Echocardiogr 1989;2:358-67.
- Salih C, Brizard C, Penny DJ, Anderson RH. Transposition. In: Anderson
RH, Baker EJ, Penny DJ, Redington AN, Rigby ML, Wernovsky G, editors.
Paediatric Cardiology. 3rd ed.. Philadelphia: Churchill Livingstone,
Elsevier; 2010. p. 794-817.
- Foran JP, Sullivan ID, Elliott MJ, de Leval MR. Primary arterial
switch operation for transposition of the great arteries with intact
ventricular septum in infants older than 21 days. J Am Coll Cardiol
1998;31:883-9.
- Yacoub MH, Arensman FW, Keck E, Radley-Smith R. Fate of dynamic left
ventricular outflow tract obstruction after anatomic correction of
trans- position of the great arteries. Circulation 1983;68:56—62.
- Kang N, de Leval MR, Elliott M, Tsang V, Kocyildirim E, Sehic I, Foran
J, Sullivan I. Extending the boundaries of the primary arterial switch
operation in patients with transposition of the great arteries and
intact ventricular septum. Circulation 2004;110:123—7.
FIGURES: