Email address of authors:
Sachin Mahajan : sachinkriti111@gmail.com
Javid Raja :
javidraj86@gmail.com
Neha Bharti : nehabharti198@gmail.com
Ganesh Kumar M : mganeshkumar19@gmail.com
Total number of images: 4
Total Word count: 1156
Source(s) of support: No assistance taken from anybody for this work
Ethical approval : Not applicable
Informed consent: Permission was granted by the patient’s parents to
publish this report
Clinical trial registration: Not applicable
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
Pseudoaneurysm of the right ventricular outflow tract(RVOT) is an
uncommon yet catastrophic complication after intracardiac repair of
Tetralogy of Fallot(TOF). We describe a patient diagnosed with RVOT
pseudoaneurysm in the immediate postoperative period after complete
repair for TOF with single pulmonary artery. The pseudoaneurysm was
repaired successfully. This case is reported to emphasise the importance
of a high degree of suspicion of this rare entity in these patients for
its early diagnosis and management.
Key words: Pseudoaneurysm, Tetralogy of Fallot, Single pulmonary artery,
Surgical correction
Case report:
A 3 year old male child was admitted with complaints of recurrent
cyanosis for the past six months. He was diagnosed with Tetralogy of
Fallot(TOF) and planned for surgical repair. Echocardiography and
cardiac catheterisation confirmed the diagnosis of Situs solitus,
Levocardia, TOF with absent left pulmonary artery and severe
infundibular stenosis. Left lung being supplied by smaller
Aortopulmonary collaterals. His pre-operative hemogram, renal function
and liver function were within normal limits.
After obtaining parental consent, child was taken up for surgical
correction. Bi-ventricular repair was done that include Dacron patch
closure of ventricular septal defect, resection of hypertrophied septal
and parietal bands, reconstruction of right ventricular outflow
tract(RVOT) with autologous pericardial patch. The pericardium was
treated using 0.6 % glutaraldehyde for eight minutes and was fixed
using 6-0 prolene single layer full thickness suture. Pulmonary annulus
was accepting Hegars no.11(Z score -2) thereby the native tricuspid
pulmonary valve was preserved. Post repair, pressure ratio of Right
ventricle to left ventricle was 0.6 and gradient across pulmonary valve
was 32 mmHg. Child underwent tracheal extubation on day 2, mediastinal
drains were removed on day 3 and remained hemodynamically stable.
Child remained asymptomatic but started developing ill-defined opacity
in left hemithorax on x-ray from the fifth postoperative day(figure 1).
Since it was persisting even after 48 hours and was gradually increasing
in size, Contrast Enhanced Computed Tomography(CECT) was done that
described a large Pseudoaneurysm of size 55x35 mm arising from RVOT,
occupying almost two thirds of left pleural cavity(figure 2). After
explaining the risks, child was shifted for Pseudoaneurysm repair. Right
Femoral vessels were exposed and redo sternotomy was done,
Cardiopulmonary bypass(CPB) was initiated with aortic and right atrial
cannulation. After moderate hypothermic cardioplegic arrest, RVOT patch
was found to be completely disrupted and blood was seeping into the
aneurysmal cavity. The previous patch and the aneurysmal tissue(figure
3) were completely excised, edges freshened up and was reconstructed
using bovine pericardium in two layers. The patient was weaned off CPB
with minimal inotropic support and was on mechanical ventilatory support
for 48 hours.
Child underwent extubation on day 3 and had an uneventful postoperative
course thereafter. The occurrence of RVOT Pseudoaneurysm in a
postoperative patient of TOF with absent left pulmonary artery is due to
its atypical morphology and has not been reported in literature so far.
Discussion:
Pseudoaneurysm of the RVOT is an uncommon postoperative complication of
pediatric cardiac surgeries that involve both a right ventriculotomy and
RVOT reconstruction with patch repair or conduit replacement [1-3].
The various mechanisms of pseudoaneurysm formation has been described as
related either to elevated residual right ventricular systolic pressure
or obstructive RVOT, leading to mechanical strain at the proximal suture
line and the use of patches, homografts, or conduits to reconstruct the
outflow tract, with dehiscence of surgical sutures being the aetiology
of the pseudoaneurysm. However, other factors such as suturing
technique, trauma, complete heart block, and infection have also been
rarely implicated[1-3]
Regardless of the aetiology, a pseudoaneurysm arises from the small
dehiscence of a portion of the reconstructed RVOT, permitting blood
seepage into the surrounding pericardial or pleural cavity [3,4]. In
the index case, after excluding infection, heart block, and surgical
technique, the pseudoaneurysm might have been caused by the exceptional
morphology that is, absent left pulmonary artery with unusually high
position and acute angulation of pulmonary valve with RVOT(figure 4)
supplemented partly by RV hypertension.
Pseudoaneurysms usually remain asymptomatic and are found incidentally
on follow-up[3]. However, they may present rarely with secondary
symptoms due to compression of adjacent mediastinal structures,
thromboembolism and infection [3,4]. In the present case, it was an
incidental finding on chest x-ray. Though transthoracic echocardiography
is a reliable method for diagnosing pseudoaneurysms[5] it does not
yield definitive information regarding the extent and relationship of it
with the surrounding structures. CECT and Magnetic resonance imaging
[6] are more precise in furnishing the size, extent and location of
the pseudoaneurysm, its anatomical relationships and retrosternal
anatomy. Once diagnosed, surgery is the treatment of choice.
Conclusion:
A pseudoaneurysm in a surgically reconstructed RVOT is rare. It should
always be suspected in patients with unusual morphology such as TOF with
Single pulmonary artery and those with RV hypertension and such patients
must be followed up with high suspicion even in the immediate
postoperative period and long term.
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Figure legends
Figure 1: Chest x-ray AP view showing opacity in the left hemithorax
Figure 2: Coronal sections of cardiac CT showing a large Pseudoaneurysm
arising from RVOT
Figure 3: Intra-operative image showing disrupted RVOT patch
Figure 4: Transesophageal echocardiography aortic short axis view
showing relatively the higher position of the pulmonary valve with its
continuation into the right pulmonary artery