Pentalogy of Fallot with total anomalous pulmonary venous drainage (a case report).
Tetralogy of Fallot may be associated with other intracardiac lesions like atrial septal defect, patent ductus arterious, aortopulmonary window, and common atrioventricular canal., However, the association of tetralogy of Fallot with total anomalous pulmonary venous drainage is rare and only eight cases have been reported till now., We narrate here our experience with one such case.
R.S., an 11 year old boy, was admitted on 7-4-1984 to the cardiothoracic surgical ward with the history of cyanosis since one year of age, which had been progressively increasing on crying and playing. He had grade II effort intolerance. There was no history of any anoxic spell or fever.
On examination, he had intense central cyanosis. His jugular venous pressure (JVP) was 4-5 cm of H2O with prominent 'a' wave. There was grade III clubbing. The pulse was 88/minute, regular and of good volume with blood pressure 110/80 mm of Hg. Cardiovascular examination revealed silent precordium with apex beat in the left fourth interpass inside the left midclavicular line. Loud single S2 and gr. III/VI ejection systolic murmur were heard in the pulmonary area.
His chest skiagram revealed a 50% cardiothoracic ratio, bootshaped heart with pulmonary bay, right aortic arch, left superior vena cava and oligemic lung fields. Electrocardiogram showed normal sinus rhythm with junctional ectopics, right axis deviation, right ventricular hypertrophy and right atrial enlargement with transition zone in V2.
Two-D-echocardiographic study demonstrated mitral aortic continuity with a large subaortic ventricular septal defect and interatrial septal drop-outs. The great vessel relationship was normal.
He was catheterised by left and right heart catheters. The right heart catheter revealed the presence of an atrial sepal defect with bidirectional shunting demonstrated by oxygen saturation data. The aortic oxygen saturation was 60%. The catheter could not be passed into the main pulmonary artery. Cine-angiogram of the right ventricle disclosed classic tetralogy of Fallot with right aortic arch. Left superior vena cava draining into coronary sinus was also demonstrated.
He was operated on 25-4-1984. On gross examination of the heart, after median sternotomy, the aorta was seen to be large, the main pulmonary artery normal in size and the right ventricle hypertophied. Presence of ASD was confirmed by palpation. Mitral valve on palpation was normal.
Total correction of tetralogy of Fallot with repair of atrial septal defect was carried out under cardiopulmonary bypass. Inflow was through aortic cannulation and venous drainage via right superior vena cava (SVC) and inferior vena cava (TVC) cannulation through right atrium (RA). Left SVC was cannulated separately through coronary sinus via a purse string on RA. Venting was through atrial septal defect (ASD) and later through main pulmonary artery (MPA).
Infundibular resection and ventricular septal defect (VSD) closure was carried out through longitudinal right ventriculotomy. RA was opened by a longitudinal incision. There was a minimal leak of blood around the left SVC catheter. The ASD was closed with a double velour Dacron patch. The right ventricular outflow tract (RVOT) was then closed with an autogenous pericardial patch.
Each time an attempt was made to wean the patient off bypass, there was bradycardia, hypotension with distension of the right atrium and ventricle with vigorous contractions on bypass. Hence it was thought that the subannular patch was inadequate and a new transannular patch was sutured. This was of no benefit and the patient died due to failure to come off bypass.
The post mortem examination of the specimen revealed tetralogy of Fallot with intracardiac type of total anomalous pulmonary venous drainage into the coronary sinus via the left vertical vein connecting to the left superior vena cava and atrial septal defect of ostium secundum type. [Fig. 1A], [Fig. IB], [Fig. 2A] and [Fig. 2B].
When tetralogy of Fallot and total anomalous pulmonary venous drainage coexist,
the clinical presentation appears to be that of the former. When pulmonary flow is decreased, the clinical signs of pulmonary venous obstruction may be absent and pulmonary venous pressure may not be unduly elevated. After a systemic pulmonary shunt is established surgically, the obstruction is exaggerated and pulmonary venous pressure rises precipitously resulting in pulmonary edema with all of its manifestations.
When there is severe infundibular stenosis, it is difficult to enter the main pulmonary artery at cardiac catheterisation. Hence the angiographic study of the left heart is frequently done during the laevophase of the right ventricular injection. The pulmonary venous phase will essentially depend upon the pulmonary blood flow. If the obstruction is severe, the blood flow is poor and hence the left sided lesions may be missed as in the present case. Of the eight cases, reported in the literature, the pre-operative diagnosis was established in three cases only.,
These patients are usually taken for operation with a diagnosis of tetralogy of Fallot. So was ours. As the patient had left superior vena cava, this was cannulated via coronary sinus. This cannula in our case drained the left side of the upper half of the body and also the pulmonary venous return. This coupled with a PA venting, there was hardly any drainage around the left SVC cannula. Hence no clue to this additional anomaly was available even after right atriotomy for closure of the atrial septal defect. It is a routine practice to palpate the mitral valve through the atrial septal defect. It is unusual to attempt to locate pulmonary veins via the atrial seplal defect unless anomalous venous drainage is suspected.
Of the eight cases reported in the literature, successful operative correction was achieved in three cases only.,, The former two were recognised during the operation while in the third, pre-operative angiography had revealed the anomaly.
It is obvious that systemic pulmonary shunt alone in such cases is not advisable for fear of pulmonary edema and right ventricular failure. The choice of the procedure depends upon the size of the left ventricle. If adequate, one-stage total correction of both anomalies is recommended while if the left ventricle is under developed, two-stage procedure involving correction of total anomalous pulmonary venous drainage with systemicopulmonary shunt at the first stage and correction of tetralogy of Fallot at a later date is advised.
We are grateful to the Dean, K.E.M. Hospital, Bombay, for allowing us to publish this paper.