Re-intervention and Late Events
No late deaths occurred during the follow-up. Recoarctation occurred
only in one patient who underwent percutaneous aortic balloon
angioplasty 13 months after the initial surgery. No false or true aortic
arch aneurysms were detected in patients undergoing patch reconstruction
(Fig. 1). Three neoaortic valves showed moderate regurgitation and were
under close follow-up. Mild pulmonary stenosis was observed in one
patient. None of the patients had an RVOT pressure gradient
>30 mmHg. At the last follow-up, no reoperation was
required for neoaortic valve dysfunction or right-sided obstructions.
One tricuspid valve showed more than moderate regurgitation. This was
noted in patient 7 who had DORV with a non-committed VSD and type B IAA.
The patient has no significant symptoms and remained under close
monitoring. For the two patients who had 5 mm VSD fenestrations, a 2 mm
and 4 mm residual shunt could still be detected at the latest follow-up
echocardiograms.
All surviving patients were in New York Heart Association (NYHA) class
I, except for patient 10, who was 4-year-old and had reserved VSD
fenestrations at the initial surgery. The patient’s condition remained
NYHA class II, and the patient was still receiving bosentan orally for
postoperative PHT. No cardiac medication was required for the other
patients.
Discussion:
Only a few case reports and series, including single-digit patient
numbers, exclusively documented the surgical procedures in the
transposition complex associated with IAA.3–5 Pigott
et al. first reported the single-stage strategy for TGA with aortic arch
obstruction (AAO) in 1987.6 Moreover, in 1993, Planché
et al. demonstrated superior outcomes of the single-stage repair over
the two-stage repair for TGA, VSD, and AAO.2 The
advantages of the single-stage repair may be due to the early
reestablishment of the physiological circulation and aversion of
detrimental effects of the pulmonary artery banding. Moreover, the
hypoplastic aortic arch, coarctation, and interruption can be treated
efficiently through a median sternotomy incision with mild tension on
the anastomosis at the time of the ASO.7 Since 2000,
single-stage repair for ventriculoarterial discordance associated with
IAA has become the treatment of choice at our center.
Compared to other series, the age of the patients at the initial repair
was significantly older in this series, which is closely related to the
social and economic developmental factors in our country. Because of
poor medical and health conditions at the grass-root level, most of the
patients in this series were beyond the neonatal period when they were
first referred to our center; moreover, there were two patients, a 4-
and 6-year-old. To some extent, these patients were somewhat “naturally
selected.” This may explain why the incidence of coronary artery
anomaly was obviously low, and no right ventricle hypoplasia was
detected preoperatively in our series, both of which remain important
risk factors for this complex subgroup of patients, as stated in the
report by Pocar et al.8 To complete accurate coronary
artery transfer during ASO, coronary reimplantation after neoaortic
reconstruction was recommended by some previous
studies.9 In our series, the trap-door technique was
used, but coronary malperfusion did not seem to be the direct cause of
death. Of the three early deaths, only one had abnormal coronary artery
anatomy, which was a single coronary artery originating from sinus 1.
The premature neonate died of severe capillary leakage subsequently. In
the other two patients, the direct causes of death were sepsis and
treatment withdrawal because of multiple organ dysfunction.
Although coronary artery anomalies were uncommon, there were other risk
factors in our series. Compared to patients with noncomplex TGA or TGA
with arch coarctation, PHT is more common and persistent in this
population, with complex forms of TGA associated with IAA. Postoperative
PHT has been believed to be correlated with a prolonged stay in the ICU
among patients with coexisting VSD,8 and implantation
of a fenestrated atrial or ventricular septal patch or a one-way valved
atrial patch has been advocated in patients with hypoplastic right
ventricle (RV) or PHT.10,11 In our series,
postoperative inhaled nitric oxide and oral sildenafil and bosentan were
used to reduce pulmonary artery pressure in three patients who were
>1 year old, among whom VSD fenestration was performed in
two older children. In two of these three children, medications were
stopped for a satisfactory decrease in pulmonary artery pressure and
good exercise tolerance. This shows that PHT is reversible, even in
older
children with complex anomalies. However, a 4-year-old child at the time
of operation required
continued
oral bosentan for persisting PHT. This demonstrates the complexity and
diversity of PHT.
Size discrepancy between the great arteries has been reported to
significantly complicate surgery and influence early and late outcomes,
especially neoaortic valve regurgitation. The fate of the neoaortic root
and valve is of particular concern after the ASO.12 A
higher postoperative neoaortic root/ascending aorta ratio may be a risk
factor for neoaortic regurgitation evolution at
follow-up.13 Anastomosis of a dilated neoaortic root
with a diminutive ascending aorta may cause supravalvular aortic
stenosis, which has been reported as a cause of early death after an
ASO.14 In previous studies, several procedures have
been performed to overcome the mismatch in size, such as V-shaped
resection of the posterior sinus,13 extensive patch
enlargement of the entire arch and ascending aorta,7and relocation of the right coronary above the aortic
anastomosis.15 Herein, sinus plasty after transfer of
the coronary arteries was performed in 7 of the 11 patients. Without
using additional material in the anastomosis of the neoaorta, the
probability of major distortion and bleeding of the reconstructed
sinotubular junction was minimized through a simple procedure. The
integrity of the neoaortic root and apparent diminutive size of the
ascending aorta could pose a concern. However, no supravalvular aortic
stenosis or neoaortic root dilation was found on postoperative or
follow-up echocardiography. Although three patients developed moderate
neoaortic valve regurgitation, no reoperation was necessary.
Transpulmonary VSD closure has also been reported to be a significant
risk factor for neoaortic valve regurgitation.13Moreover, in a previous study, it was believed that it was possible to
close the VSDs through the tricuspid valve in nearly all
cases.16 However, in our series, we closed the VSD
through the right atrium in two patients with TGA, through the right
atrium and the original pulmonary valve in seven patients with TBA, and
through an infundibulotomy incision in one patient with TBA and one
patient with DORV and non-committed VSD. The high probability of
transpulmonary VSD closure in our series may be the reason for the
relatively high rate of aortic valve regurgitation (3 of 8 surviving
patients). However, we believe that a decent approach route depends on
anatomic features, and irrespective of the route used, it is essential
to carefully trim the VSD patch to avoid interference with the neoaortic
valve.
In a report from Australia, the end-to-side arch repair was performed in
four of five patients with transposition complex and
IAA.5 The authors suggested that pericardial patch
augmentation of the arch should be avoided, because it may result in
dilation of the neoaorta and subsequent neoaortic valve
insufficiency.5 However, in a series from France,
extended end-to-end anastomosis was reported to be a risk factor for
recoarctation; in another report from England, augmentation of the arch
with a homograft patch was advocated for IAA repair.7Repair procedures performed for IAA at our center varied over time. In
the first three cases before 2012, extended end-to-end anastomosis was
performed. Since then, glutaraldehyde-treated autologous pericardial
patch enlargement has been performed in the following eight patients,
except for the 6-year-old child in whom a 16-mm interposition graft was
implanted; therefore, this approach is our preferred choice for IAA
repair in patients with associated anomalies. We believe that this
approach may significantly reduce the tension of the anastomosis and the
distortion of the neoaortic root.
In our series, we often completed IAA repair prior to ASO; hence, it is
extremely important to tailor the patch to provide less of an acute
angle of the arch, especially after performing the Lecompte maneuver and
moving the ascending aorta posteriorly. Sometimes, two separate patches
are required, with one moving up the ascending aorta and one moving down
the descending aorta to create a smoother curve. Re-intervention for
recoarctation was necessary for only one patient in whom percutaneous
balloon angioplasty was performed uneventfully 13 months after the
initial surgery, in contrast to the findings of several previous series
with a high rate of re-intervention.7,13 Differences
in surgical technique and thresholds of balloon dilation for
recoarctation may explain such differences.