Case Report
An eight months old male child weighing 4.5 Kg presented with complains
of breathlessness, repeated respiratory tract infections and failure to
thrive. The child was malnourished and had tachycardia and tachyopnea.
He had mild cyanosis with an oxygen saturation of 85% on room air. An
ejection systolic murmur was heard over the pulmonary area on
auscultation. Chest radiogram revealed cardiomegaly and differential
pulmonary vascularity with features of increased pulmonary blood flow on
the right lung field. The electrocardiogram suggested bi-ventricular
hypertrophy. Echocardiogram examination revealed anomalous origin of
right pulmonary artery (AORPA) from ascending aorta and hypoplastic
pulmonary annulus. The main pulmonary artery (MPA) continued as left
pulmonary artery. The interatrial septum was intact and there was a
large mal-aligned ventricular septal defect. The obstruction in the
right ventricular outflow tract was predominantly deemed to be valvular.
A decision to disconnect right pulmonary artery (RPA) from aorta and
create pulmonary confluence, close the VSD and enlarge the pulmonary
outflow was made.
Surgical approach was median sternotomy. During intra-operative
inspection, the pulmonary annulus was found to be severely hypoplastic
and a large coronary artery was found crossing the pulmonary annulus.
(Figure 1) It was a branch from right coronary artery crossing the right
ventricular outflow tract and running parallel to the inter-ventricular
groove as an accessory left anterior descending artery (LAD). Pulmonary
arteries were extensively mobilised upto the lobar branches..
Cardiopulmonary bypass was initiated after aorto-bicaval cannulation.
RPA was snared immediately prior to initiation of CPB. The ligamentum
ductus was divided. Del Nido’s Cardioplegia at 30ml/ Kg was administered
to achieve cardiac arrest. RPA was disconnected from the side of aorta.
Defect in the aorta was sutured primarily in two layers. RPA was
anastomosed to MPA directly and pulmonary confluence was created. The
ventricular septal defect (VSD) was routed to aorta using bovine
pericardial patch. MPA was opened longitudinally without cutting across
the pulmonary annulus in order to preserve the anomalous coronary
artery. A tri-leaflet valved conduit was created using bovine
pericardium (St. Jude Medical) and 0.1 mm Polytetrafluoroethylene
(Gore-Tex, WL Gore and Associates Inc, Flagstaff, Ariz). The valve
leaflets are created with 0.1mm PTFE membrane which is sutured to a
sheet of bovine pericardium. The bovine pericardial sheet is rolled into
a tube to make the valved conduit. The internal diameter of the conduit
was 12mm and it was interposed between the right ventricle and MPA.
(Figure 2) The native right ventricular outflow tract was also preserved
making a double barrel right ventricle outflow tract. The postoperative
course was uneventful. The child was weaned from mechanical ventilation
and extubated after 48 hours and was discharged on sixth postoperative
day. The child is asymptomatic at 36 months after surgery. The native
pulmonary valve has grown from 6 mm to 8 mm in diameter and the RV to PA
conduit is functioning well with mild regurgitation.