Premier children’s hospital in Asia:

LRH creates history

Text and Pix by Rosanne Koelmeyer ANDERSON

THE FIRST successful neonatal Arterial Switch Operation (ASO) in the Government medical history of Sri Lanka has been recorded at the Lady Ridgeway Hospital (LRH) Borella, the premier Children's Hospital in Asia.

The eight hour operation was performed by Dr. Gamini Ranasinghe, Consultant Cardiothoracic Surgeon of the LRH with Dr. Kanachana Singappuli and a team of Para medical and medical staff on 13-day-old Nipuna from Gampaha who has recovered speedily and is doing fine at Ward Number 20.

Little Nipuna will be discharged shortly. This Cardiothoracic Unit was commissioned in January this year, Dr Ranasinghe said and has been a step forward in Sri Lanka's medical advancement.

Dr. Ranasinghe in an interview said that this operation has to be performed in the neonatal stage before the child reaches the 14th day after birth. Ninety per cent of children do not survive after the 14th day, he

 said.

In Little Nipuna's case the operation was done on the 13th day as Nipuna had recorded a good weight of 4.5 kg which made the confident Dr. Ranasinghe take the plunge of performing the major surgery which was previously attempted at the National Hospital, Colombo and Sri Jayewardenepura Hospital ended in failure.

Dr. Ranasinghe said the most difficult part of this operation was the coronary transfer (where you transfer the arteries supplying blood to the heart to another position) which involves meticulous and accurate handling with every single stitch which will decide the fate of the patient.

Little Nipuna was born at Gampaha Base Hospital and within 24 hours he was detected with a serious coronary condition. His nails had turned very blue and the child had showed signs of acute illness.

He was subsequently put on a ventilator and transferred to the Lady Ridgeway Hospital. Proper cardiac facilities, assessments and confirmations were available and immediate intervention helped little Nipuna survive.

Dr Ranasinghe said he had decided to go ahead with the operation as 44-year-old G. K. Jasintha, Nipuna's mother had said little Nipuna was her only child and she was not certain if she would conceive again as she had other complications and was a diabetic too.

The operation was performed on October 1, which coincides with World Children's Day. Jasintha was bubbling with joy wanting to tell the world of this life saving surgery. Director of the LRH, Sulochana Yoganathan said she was proud of the Hospital's record of success in neonatal Arterial Switch Operation (ASO).

Explaining the ASO operation Dr. Ranasinghe said this operation was a Transposition of the Great Arteries.

Transposition of the Great Arteries or TGA is diagnosed when the two main blood vessels that carry blood away from the heart are formed in a position opposite from where they should be when the Aorta and the Pulmonary Arteries are "transposed".

The Pulmonary Artery normally arises from the Right Ventricle pumping the "blue" or deoxygenated blood to the lungs. The Aorta normally arises from the Left Ventricle and pumps the "red" blood out to the head, limbs, and body. In Transposition of the Great Arteries the opposite holds true, he explained.

What happens when Transposition of the Great Arteries occurs?

When the "Great Arteries", the Aorta and the Pulmonary Artery, are transposed it creates a situation in

 which the body receives "blue" or deoxygenated blood instead of the "red" or oxygenated blood that it needs. In this defect the "blue" blood returns to the Right Atrium, flows through the Tricuspid Valve to the Right Ventricle and back out the Aorta to the body.

The "red" blood returning to the heart from the lungs enters the Left Atrium, flows through the Mitral Valve to the Left Ventricle and back to the Lungs through the Pulmonary Artery.

Since the "red" blood is already fully saturated with oxygen its trip back to the lungs is useless. This situation is not compatible with life unless there is a place for the "red" and "blue" blood to mix (ASD, VSD, and/or PDA).

A second concern that arises with Transpostions is the de-conditioning of the Left Ventricle. In a normal heart the Right Ventricle is made up of tissue that is much less muscular than the Left Ventricle.

The Right Ventricle is made to pump against the low-pressured lungs, and the Left Ventricle is made to pump against the high-pressured circulation of the body. With infants diagnosed with Transposition of the Great Arteries the opposite is true.

The Right Ventricle must pump out the Aorta to the high-pressured circulation of the body, and the Left Ventricle pumps blood through the Pulmonary Artery to the low-pressured lungs. If the heart anatomy remains like this for any length of time complications can occur.

The Left Ventricle (the more muscular ventricle) can become de-conditioned over time. This ventricle at the time of the operation to "switch" the Great Vessels must take over its intended job of pumping blood against the high-pressured circulation of the body. If the ventricle is de-conditioned it may fail.

The Arterial Switch operation should be done within the first week of life to prevent the de-conditioning of the Left Ventricular muscle.

For these infants to survive through the first few days, hours, or sometimes minutes, some mixing of the "red" and "blue" blood must occur. Mother Nature seems to step in at some critical point during the infant's development in the womb creating one or more additional defects allowing for the mixing of "red" and "blue" blood.

With the mixing of the "red" and "blue" blood occurring, the baby may be kept alive long enough to completely repair the defect, giving the baby a chance to live a normal healthy life.

If adequate mixing does not occur it may be necessary to create a "hole" in the wall of the Atrium or enlarge the Arterial Septal Defect, if one exists, through which the "red" and the "blue" blood mix.

In this situation the infant would be taken to the catheterization lab where a procedure known as a Balloon Septostomy would be performed. During this procedure a "hole" would be created in the wall between the Right and the Left Atria if one did not already exist at birth.

If the infant already had an Arterial Septal Defect, but it was not large enough to allow for adequate mixing of the "red" and "blue" blood, the "hole" could be enlarged by pulling a catheter across it with a balloon on the tip.

The "hole" in the septum would be "ripped" larger, improving the oxygenation of the blood oxygen levels. This Arterial Defect is then closed when the surgical procedure is done.

The Arterial Switch Operation is a simple concept.

The Aorta and the Pulmonary Arteries are transected above the valves, moved to the correct position, and sewn in place. The difficulty with this operation is the Coronary Arteries. They must also be moved during this operation.

The Coronary Arteries are very small, and are critical to the perfusion and blood supply to the heart muscle itself.

The Coronary Arteries normally arise from the Aorta, branching immediately off the ascending Aorta just beyond the aortic valve.

In an infant with Transposition of the Great Vessels the Aorta arises from the Right side of the heart. When the Vessels are switched the Coronary Arteries must be freed from the Right side and moved to the Left side of the heart so that they are receiving oxygen-rich blood.

The Coronaries are very thin, measuring only about 1-2 mm in an infant. Any kinking of the arteries would compromise the heart muscle perfusion, causing damage to the heart muscle. Abnormalities in the Coronary Artery anatomy increase the difficulty of the ASO and decrease the success rate of the operation.