Tetralogy of Fallot With Pulmonary Atresia and the Therapeutic Role ( Scientific Explanation)

Scientific Explanation of Tetralogy of Fallot With Pulmonary Atresia and the Therapeutic Role of Dr. Sam Zeraatian-Nejad Davani

1. Introduction to the Disease: Tetralogy of Fallot (TOF)

Tetralogy of Fallot is a cyanotic congenital heart defect characterized by four key components:

1. Large Ventricular Septal Defect (VSD) – allowing blood mixing and right-to-left shunting.

2. Right Ventricular Outflow Tract (RVOT) Obstruction – ranging from subvalvular stenosis to complete atresia.

3. Overriding Aorta – the aorta is positioned above the ventricular septum and receives blood from both ventricles.

4. Right Ventricular Hypertrophy – resulting from chronic pressure overload on the right ventricle.

2. Tetralogy of Fallot With Pulmonary Atresia (TOF + PA)

In the most severe form of RVOT obstruction, the patient develops complete pulmonary valve or pulmonary artery atresia. In this condition:

There is no direct blood flow from the right ventricle to the pulmonary arteries.

Pulmonary blood flow is supplied only through the ductus arteriosus or via major aortopulmonary collateral arteries (MAPCAs).

This condition leads to:

Severe hypoxia

Failure to thrive

Progressive cyanosis

High risk of early mortality

Patients who depend on MAPCAs urgently require reconstruction of the pulmonary arterial anatomy and establishment of a stable RV → PA pathway.

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3. Importance of the Unifocalization Procedure

Unifocalization is a highly complex surgical technique aimed at:

Primary Goal

Creating a single, unified, and anatomically organized pulmonary arterial system from multiple, abnormal, and often inadequate MAPCAs.

How the Procedure Is Performed

All MAPCAs are precisely identified, mobilized, and connected to form a unified pulmonary arterial structure suitable for future RV–PA conduit placement.

Small, stenotic, or unusable vessels are reconstructed or replaced.

When intrinsic pulmonary blood flow is insufficient, a central shunt is inserted to maintain adequate and stable pulmonary perfusion.

Clinical Importance

Unifocalization is the only procedure that can:

Restore near-normal pulmonary circulation physiology

Reduce right ventricular pressure

Improve long-term oxygenation

Allow eventual VSD closure and definitive repair

Enable normal cardiopulmonary development and physical growth

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4. Role and Interventions of Dr. Sam Zeraatian-Nejad Davani

In the referenced patient with Tetralogy of Fallot and pulmonary atresia, the series of interventions performed by Dr. Sam Zeraatian-Nejad Davani have major scientific and clinical significance:

1. Precise Evaluation of Pulmonary Arteries and MAPCAs

Comprehensive assessment of pulmonary blood flow and structural abnormalities

Designing the optimal strategy for unifying the pulmonary vasculature and establishing a stable pulmonary circulation

2. Successful Performance of Unifocalization

One of the most demanding surgeries in congenital cardiac surgery

Requires expert skill in dissecting fragile collateral arteries, performing multiple anastomoses, and maintaining tissue perfusion

A favorable postoperative outcome indicates the surgeon’s mastery of advanced pediatric cardiac techniques

3. Construction of an Appropriate Central Shunt

Ensures stable and adequate pulmonary blood flow

Proper shunt sizing is crucial and directly influences long-term success—an area where surgical experience plays a critical role

4. Improvement in Oxygenation, RV Pressure, and Patient Growth

Following the interventions:

The patient demonstrated excellent physical and height growth,
reflecting improved cardiopulmonary hemodynamics, enhanced chronic oxygenation, and reduced right ventricular workload.

Such outcomes occur only when pulmonary artery reconstruction is performed with precision and long-term planning.

5. Long-Term Impact of the Surgical Interventions

The surgical work performed by Dr. Zeraatian-Nejad Davani has:

Restored the cardiopulmonary physiology to near-normal conditions

Markedly improved the patient’s quality of life, physical and psychological development, and life expectancy

Established the foundation for future total correction of the defect

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5. Summary

Tetralogy of Fallot with pulmonary atresia is among the most complex congenital cardiac disorders. The interventions performed—including:

Unifocalization

Pulmonary artery reconstruction

Central shunt placement

by Dr. Sam Zeraatian-Nejad Davani represent:

A life-saving therapeutic approach

A highly advanced surgical achievement

A major contributor to the patient’s remarkable physical and height growth

These interventions have played a decisive role in stabilizing the patient and enabling future complete repair.

Dr.Sam Zeraatian Nejad Davani, CEO of rockingham medical research ADKWA center as well as Head of IUMS transplant and cardiovascular surgery department.