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20
Total Anomalous Pulmonary Venous Connection
In a total anomalous pulmonary venous connection, there is no direct continuity between the pulmonary veins
and left atrium. For the neonate to survive, there must be some mixing of circulation through a small atrial septal
defect or a patent foramen ovale. The pulmonary veins converge to form a pulmonary venous confluence that in
turn connects to the systemic venous system and right atrium. This confluence lies posterior to the pericardial
sac behind the heart. The common pulmonary vein may rarely be atretic, a condition that results in death after a
short time. Anomalous pulmonary venous connection may also be partial (see Chapter 19).
In approximately 25% of patients with total anomalous pulmonary venous connection, the drainage is directly into
the right atrium or coronary sinus. The drainage in these cases is therefore exclusively intracardiac. In another
25% of patients, the drainage is through infracardiac connections, that is, the hepatic and portal veins. In 45% of
patients, a common pulmonary venous channel drains into an anomalous vertical vein joining the innominate vein
or superior vena cava, thereby reaching the right atrium in a supracardiac manner. In approximately 5% of cases,
the drainage is mixed, occurring through all three or any combination of two of these connections. Very rarely,
there is no connection to either atrium except through some collateral vessels, a condition referred to as common
pulmonary vein atresia.
Two-dimensional echocardiography can usually delineate the anatomy and demonstrate any associated
anomalies. Rarely is cardiac catheterization or magnetic resonance imaging necessary for patients who have not
undergone previous cardiac surgery.
Some surgeons are now employing modifications of the sutureless technique in unoperated patients with
pulmonary vein abnormalities or in patients who are at high risk for developing pulmonary vein stenosis. All of
these techniques are based on the premise that anastomosing the left atrium to the pericardium surrounding the
opening on the pulmonary veins and confluence, rather than to the edges of the veins themselves, will prevent
the development of intimal hyperplasia and stenosis.
TECHNIQUE
Most patients are neonates with unstable cardiorespiratory status. Those who present with pulmonary venous
obstruction are true surgical emergencies. In neonates, the procedure is usually carried out during a period of
deep hypothermic circulatory arrest, although some have advocated performing the operation at mild to modest
hypothermia. Continuous cardiopulmonary bypass using bicaval cannulation with aortic cross-clamping and
moderate systemic hypothermia is used in older patients.
A median sternotomy is performed. The pericardium is opened, and the distal ascending aorta is cannulated. If
hypothermic arrest is to be used, a single cannula is introduced into the right atrium through the right atrial
appendage. Cardiopulmonary bypass is initiated, and the patient is cooled for 15 to 20 minutes. The aorta is
crossclamped, and cardioplegic solution is administered into the aortic root. Pump flow is discontinued, and after
draining blood from the infant, the venous cannula is clamped and removed.
Ligation of the Ductus
The ductus must be dissected and occluded with a tie or metal clip before the initiation of cardiopulmonary
bypass.
Intracardiac Type
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A generous right atriotomy is made, somewhat below and parallel to the atrioventricular groove. The edges are
retracted with fine sutures to provide maximal exposure. The inside of the right atrium is assessed carefully to
delineate the precise anatomy. A patent foramen ovale or an atrial septal defect is always present. There may be
a common pulmonary vein orifice opening into the right atrium, or the pulmonary veins may drain directly into the
coronary sinus. In the latter case, the orifice of the coronary sinus is somewhat enlarged. The pulmonary venous
return is rerouted into the left atrium by enlarging the atrial septal defect and using a pericardial patch to baffle
the anomalous veins through the atrial septal defect.
Size of the Atrial Septal Defect
The defect in the septum must be large enough to allow an unobstructed flow of pulmonary venous return. Most
commonly, it is enlarged by extending its inferior margin toward the inferior caval or common pulmonary vein
orifice.
Cannulation
This type of repair may be performed a mild hypothermia, but it is important to cannulate the inferior vena cava
low toward the diaphragm so as not to interfere with exposure of the coronary sinus.
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FIG. 20.1 Intracardiac type of total anomalous pulmonary venous drainage. A: Schematic illustration of the
defect. B: Schematic illustration of the correction of the defect. C: Operative view of the extension of the atrial
septal defect to incorporate the coronary sinus orifice. D: Correction of the anomaly by roofing the septal defect
and rerouting the pulmonary venous drainage into the left atrium.
Drainage into the Coronary Sinus
Whenever the common pulmonary vein returns to the coronary sinus, its orifice is extended superiorly to reach
the atrial septal defect. This incision must be well away from the anterior margin of the coronary sinus to prevent
damage to the atrioventricular node and the conduction system (Fig. 20.1). In addition, the incision in the roof of
the
coronary sinus should be extended to the posterior wall of the heart, often, with further resection of the margins
of the incision along the roof of the coronary sinus, thereby creating a V-shaped incision. The resulting defect in
the atrial septum is closed with an autologous pericardial patch using 6-0 Prolene suture.
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Suturing Inside the Coronary Sinus
The continuous suturing of the patch must incorporate the wall of the coronary sinus well below its anterior rim to
avoid the conduction system. Alternatively, only very shallow bites of endocardium are taken along the anterior
rim of the coronary sinus.
When the patch is satisfactorily sewn in place, the atriotomy is closed with a continuous 6-0 Prolene suture. The
heart is filled with saline, the venous cannula is replaced, cardiopulmonary bypass is recommenced, and the
patient is warmed. The aortic cross-clamp is removed, and the cardioplegic site is allowed to bleed freely.
Infracardiac Type
This type is usually associated with obstruction and represents a true surgical emergency. During the cooling
phase of cardiopulmonary bypass, the heart is elevated upward and to the right to expose the anomalous
descending vertical vein. A 5-0 Prolene suture is placed at the apex of the left ventricle to simplify retraction of
the heart. The posterior pericardium is opened, and a vertical incision is made in the anomalous vein to
decompress the pulmonary veins (Fig. 20.2). The heart is replaced in the pericardial well until complete cooling
is achieved. A marking suture is placed on the tip of the left atrial appendage and reflected leftward to maintain
its orientation. The aorta is cross-clamped, and cardioplegia is given. After emptying the circulating volume into
the pump, the venous cannula is removed. The heart is again lifted out of the pericardial well, and the previous
incision on the anomalous vertical vein is extended longitudinally along the length of the pulmonary confluence.
A matching incision is made on the posterior left atrial wall and is extended onto the left atrial appendage. The
suture previously placed on the left atrial appendage helps to expose and position the left atrium for
anastomosis. It is of paramount importance for the atriotomy to fall directly on the common pulmonary vein
opening when the heart is allowed to resume its normal position.
The superior (rightward) aspect of the anastomosis is performed first with a continuous 7-0 Prolene suture. The
inferior (leftward) aspect is similarly completed (Fig. 20.2C).
A small right atriotomy is now performed to close the atrial septal defect, usually a patent foramen ovale. If
primary suture closure appears to compromise left atrial size, an autologous pericardial patch should be used
(see Chapter 19). Cardiopulmonary bypass is started again, and the patient is warmed.
Enlargement of the Common Pulmonary Vein Opening
The vertical incision on the common pulmonary vein channel may be extended slightly onto the left upper
pulmonary vein to allow for a larger anastomosis. However, some surgeons advocate a “no touch” technique,
staying well away from individual pulmonary venous ostia to reduce the incidence of postoperative pulmonary
vein stenosis. Therefore, it may be preferable to enlarge the anastomosis using the divided vertical vein (see
subsequent text).
Vertical Vein Draining below Diaphragm
It is often useful to ligate and divide the vertical vein and use this tissue to create a wider anastomosis. After
dividing the vertical vein at the diaphragm, it is opened longitudinally as described in the preceding text. This
creates a hood-type opening of the pulmonary venous confluence, which is then anastomosed to a similar-sized
opening on the posterior left atrium and left atrial appendage.
Anastomotic Leak
A secure, leakproof anastomosis must be ensured. Suture reinforcement in this area is most difficult and may
disrupt or distort the anastomosis.
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Supracardiac Type: Superior Approach
Another technique for dealing with the supracardiac type is the superior approach. The aorta is retracted
leftward, and the dome of the left atrium is exposed. A marking suture is placed on the left atrial appendage and
reflected leftward to maintain orientation. The posterior pericardium just superior to the dome of the left atrium is
incised, and the pulmonary venous confluence is identified. A longitudinal incision is made along the entire length
of the confluence and extended into a pulmonary vein orifice, if necessary, to create a patulous opening. A
matching incision is made on the posterior aspect of the top of the left atrium, placing gentle traction leftward on
the left atrial appendage (Fig. 20.3). The suture line is started at the leftward extent and carried along the
superior edge of the atriotomy and the inferior edge of the venous confluence. It is completed by joining the two
remaining edges.
Closure of the Atrial Septal Defect
A patent foramen ovale or a small atrial septal defect, which is invariably present, must be closed in the usual
manner through a right atrial incision.
Ligation of the Ascending Vertical Vein
The ascending vertical vein is encircled with a heavy tie during cooling. After rewarming, this vein may be kept
open as cardiopulmonary bypass is discontinued. This can serve as a pop-off if left atrial pressures are too high.
After stable hemodynamics are achieved, the vein is ligated as far away from the venous confluence as possible.
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FIG. 20.2 Infracardiac type of total anomalous pulmonary venous drainage. A: Schematic illustration of the
defect. B: Schematic illustration of the correction of the defect. C: Operative technique for the correction of the
defect.
FIG. 20.3 Superior approach to the supracardiac type anastomosing the posterior aspect of the dome of the left
atrium to the pulmonary venous confluence. Ao, aorta; PA, posterior aspect; SVC, superior vena cava.
PULMONARY VENOUS OBSTRUCTION
Pulmonary venous obstruction may occur as an isolated lesion, but most often is encountered following repair of
total anomalous pulmonary venous connection. Occasionally, it is seen after other congenital heart procedures.
The pathology involves a fibrous intimal hyperplasia with some medial hypertrophy. It may be limited to an
anastomotic stenosis between the pulmonary venous confluence and the left atrium, or it may involve the ostia of
one or more of the pulmonary veins themselves. The diagnosis is usually made with two-dimensional and
Doppler echocardiography. Magnetic resonance imaging can be especially useful in visualizing patent pulmonary
veins with atretic ostia.
Conventional Technique
An isolated anastomotic stenosis is approached through a right atriotomy and vertical incision on the atrial
septum. The narrowed anastomosis is enlarged by removing as much of the tissue as possible between the
posterior left atrium and the pulmonary veins (Fig. 20.4). If good adherence between these two structures is
present, no suturing may be required. However, if there is any question about the integrity of the adhesions, the
endocardium of the left atrial wall and pulmonary venous confluence should be reapproximated with a running 6-
0 or 7-0 Prolene suture. If ostial stenosis of one or more pulmonary veins is present, it has been traditionally
repaired by endarterectomy excision of the scar tissue or by incising and patching the pulmonary vein using
pericardium, Gore-Tex, or atrial tissue. The results of these procedures have been disappointing with high rates
of restenosis. More recently, a sutureless technique has been shown to have improved outcomes.
Sutureless Technique
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The operation requires that the adhesions between the left atrium and pericardium be left intact. Circulatory
arrest may be used, but some surgeons prefer bicaval cannulation. The superior vena cava is cannulated as
high as possible and standard aortic and inferior vena caval cannulation is performed. Following aortic cross-
clamping and cardioplegia delivery, a left atrial incision is made just posterior to the interatrial groove. The
stenotic pulmonary venous ostia are identified. For right pulmonary venous involvement, as much scar tissue as
possible is completely excised from the left atrium and by transecting the pulmonary veins beyond the narrowed
area. Alternatively, incisions are made across the stenotic areas up to the pericardial reflection (Fig. 20.5A). A
posteriorly based flap of pericardium is mobilized and sewn to itself and the
right atrial wall above the left atrial opening, avoiding any sutures on the pulmonary venous tissue. This creates
a neo-left atrial pouch, allowing unobstructed drainage of the open right pulmonary veins into the left atrium (Fig.
20.5B).
FIG. 20.4 Repair of anastomotic pulmonary vein stenosis through a right atriotomy and transseptal incision.
Resection of scar tissue between the left atrium and pulmonary venous confluence results in an unobstructed
communication.
When left pulmonary veins are involved, the repair can be performed from within the left atrial cavity. A portion of
left atrial wall is excised around the stenosed vein(s) (Fig. 20.5A). Through the resultant opening, the pulmonary
vein(s) is dissected out to the left pericardium and divided beyond the stenosed segment (Fig. 20.6). If there are
adequate pericardial adhesions, no suturing is required and the left pulmonary vein(s) drains into the left atrium
through the closed posterior pericardial cavity. When pericardial adhesions are insufficient, the pericardium must
be sutured to the left atrial wall away from the pulmonary venous ostium. This can be performed from inside the
left atrium or from the outside by elevating the apex of the heart toward the right side. Alternatively, the left
pulmonary veins can be dealt with from the outside by elevating the apex of the heart and opening the left atrium
and stenotic pulmonary veins as described for right pulmonary vein stenosis. A pericardial flap is mobilized and
sewn to itself and the left atrial wall as described in the preceding text.
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Identifying Pulmonary Venous Ostia
The orifices of the stenotic pulmonary veins may be reduced to pinholes and can be difficult to identify.
Phrenic Nerve Injury
The suture lines for both the right-sided repair and the outside approach for left pulmonary vein repair come
close to the phrenic nerves. Often in a reoperation, the course of the phrenic nerve cannot be appreciated from
within the pericardial space. Therefore, it is best to open the pleural space(s) to check the location of the nerve
before placing the sutures in the pericardium. Superficial bites over the nerve may be taken, or in some cases,
the nerve with its pedicle can be mobilized away from the pericardium (Fig. 20.5B).
Sutureless Technique as Primary Procedure
Many have advocated for sutureless repair as a primary approach toward total anomalous pulmonary
venous return, in particular for patients with heterotaxy syndrome, mixed total anomalous pulmonary venous
return, and those with unusual orientation of the common confluence. Here, the development of a
pericardial well around the confluence and veins affords an adjustment for orientation abnormalities. The
plane between the pericardium and the pulmonary veins must be developed carefully, as this provides
exposure to the veins as well as limits the borders (“well”) of the “neo-atrium” (Fig. 20.7).
Bleeding
Suture line bleeding can be difficult to identify with the sutureless technique, in part because lifting the heart
to inspect the suture line may tighten the anastomosis and mask the bleeding. In addition, inadvertent entry into
the left pleural space, even if deemed trivial, can be the source of considerable hemorrhage and difficult to
control.
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FIG. 20.5 Right-sided sutureless repair. A: Through a standard left atriotomy, the stenotic ostia are identified
and the scar tissue either totally excised (dashed lines) or incisions made across the narrowed areas (dotted
lines). B: Flap of pericardium sewn to itself and right atrial wall.
COR TRIATRIATUM
Cor triatriatum is a rare defect in which the pulmonary veins drain into a common atrial chamber, usually located
behind and above the true left atrium. This chamber is separated from the left atrium by a diaphragm. The upper
chamber may or may not communicate with the right atrium through an atrial septal defect or foramen ovale.
Surgical Technique
Complete correction is usually performed on continuous cardiopulmonary bypass using bicaval cannulation. A
transatrial or transseptal incision generally provides excellent exposure. The transatrial incision is extended
across the right atrium and then across the atrial septum to the fossa ovalis (see Transatrial Oblique Approach
section in Chapter 6). Retractors are placed beneath the edge of the atrial septum to inspect the left atrium. The
entrance of
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