TOF with Absent Pulmonary Valve

1. TOF with Absent Pulmonary Valve Seoul National University Hospital Department of Thoracic & Cardiovascular Surgery

2. 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

3. 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

4. TOF with Absent Pulmonary Valve PA Pulmonary annulus

5. 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

6. 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.

7. 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.

8. 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

9. Operative Procedure • Placement of a homograft with a tube graft extension • from the diaphragmatic surface of the right ventricle

10. 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)

11. 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