TOF with Absent Pulmonary Valve

Seoul National University Hospital

Department of Thoracic & Cardiovascular Surgery

TOF with Absent Pulmonary Valve

1. Definition A subset of TOF determined largely by vestigial,

severely hypoplasic, nonfunctioning pulmonary

leaflets at the junction of RV & pulmonary trunk

2. History 1) Royer & Wilson : 1st description in 1908

2) Kurtz : 2nd report in 1927

TOF with Absent Pulmonary Valve

Morphology 1. Pulmonary valve

Myxomatous nubbins of valve tissue, severely hypoplastic,

Both nonfunctioning & only minimally stenotic

2. RVOT

Often dilated and elongated

3. Pulmonary trunk

Central portion of RPA & LPA are often aneurysmally dilated

Dilation into hilar portion, then tracheobronchial compression

Beyond hilar portion, pulmonary arteries are normal in size

TOF with Absent Pulmonary Valve

PA

Pulmonary annulus

Clinical Features & Diagnosis

1. Clinical Features 1) Severe pulmonary regurgitation and somewhat increased pulmonary blood flow 2) Low pulmonary artery pressure & similar peak pressure in both ventricles due to narrowing annulus & large VSD 3) Presentation is dependent on the severity of pulmonary arterial dilatation, Qp increased and tracheobronchial compression

2. Diagnostic criteria 1) Physical examination Overactive heart, cardiomegaly, raised venous pressure 2) Chest radiography Supracardiac mediastinal widening , atelectasis or overinflation 3) Other studies include ECG, echocardiography, aortography

Natural History

1. Incidence 5% of TOF born with a large VSD + PS

2. 50% die in the 1st year of life if untreated, and most

in the few months of life, from the respiratory distress

Such patients also have heart failure with large shunt

with decreased systolic function.

3. Patients who survive infancy, generally do well for

time being, and ultimately die from intractable right

heart failure.

Operative Treatment

1. Indications 1) Urgently needed for small babies who present with

severe respiratory distress

2) If infants responds well this therapy (prone, head-up),

operation is deferred selectively to 3 -5 years electively.

2. Techniques 1) VSD closure and insertion of homograft beyond infancy

2) Reduction pulmonary angioplasty with corrective repair

is preferred in neonates and infants

3) Pulmonary arterioplasty to takes pressure off underlying

tracheobronchial tree.

Operative Procedure

• Ventriculotomy and resection of dilated portions of main & branch pulmonary arteries.• Reconstruction of the right and left pulmonary arteries & insertion of a homograft

Operative Procedure

• Placement of a homograft with a tube graft extension from the diaphragmatic surface of the right ventricle

TOF with Absent Pulmonary Valve

General management principles 1. Preoperative 1) Sternotomy 2) Prone position 3) Adequate management

2. Postoperative 1) Prone position in head-up 2) Avoid barotrauma 3) Avoid hyperinflation by air trapping 4) Short inspiratory phase (1:E>1:4)

Operative Results

1. Survival ; a high probability of hospital death after repair in young infants, currently emphasizing pulmonary arterioplasty Early death Poor preoperative conditions Severe respiratory problems Time-related survival Similar to those with TOF 2. Incremental risk factors for death Similar to those with TOF Allograft valve conduit