Our heart has four chambers, two auricles, and two ventricles. Through the pulmonary artery, the deoxygenated blood is sent to the lungs for oxygenation and return to the heart via pulmonary veins for redistribution in the body.
In some cases, especially in newborn children, a rare defect is observed where the pulmonary veins get attached into other sites in the heart instead of the correct position of the upper right heart chamber, also known as the right atrium and mixes with the oxygen-deficient blood in there or before entering the heart. This defect is congenital. The blood supply may continue through an Atrial Septal Defect, also present in the child just born.
The surgery for treating this error where the cardiac surgeon connects the pulmonary veins to the left atria and closes any hole between the two atria is known as Total anomalous pulmonary venous connection (or return) repair or TAPVC Repair, otherwise called an Arterial Switch.
Reason for doing it
The function of the pulmonary vein is to provide the heart with blood saturated with oxygen so that it can be distributed to the tissues and organs spread over the body. In the case of TAPVC, the oxygenated blood gets mixed with the de-oxygenated blood before getting spread over the body. As the level of oxygen lowers, the baby may appear blue in color, also known as a cyanotic condition.
Moreover, if the aperture between the atria is not up to size, then there may be less distribution of blood to the tissues and organs present in the body, which may cause heart failure in the patient.
To correct this condition, the pulmonary veins must be connected to the right place and the septal defect closed so that the blood flow in the body becomes alright and the affected child can get a permanent solution for this problem.
The rationale for the generation of the defect in the heart that may lead to the purpose of a TAPVC Repair procedure has no precise foundation. In most of the cases, this situation is seen in the newborn baby within a few days of its life. The few cases that have been known for the generation of Total anomalous pulmonary venous connection can be given as;
- Congenital: It has been seen that the baby born with this condition has no specific demarcating factor for this situation. In the United States, every year, almost 400 babies are born with this condition.
- Genetic: There may be some genetic predisposition of TAPVR in some families, as with all heart diseases. Although, it is not definite that if a baby in a family is born with Total anomalous pulmonary venous connection, a second baby will also surely have this condition.
- Environmental: Some drugs or other substances that the mother ingested or came in contact with during pregnancy may affect the child to have this condition.
In the majority of the cases, the circumstance occurs in the newborn children by sheer chance and has no exact reason for its occurrence.
The symptoms of this condition are more prevalent and detectable after the birth of the baby. The several symptoms that may urge a neonatal cardiologist to consider the application of a Norwood procedure can be surmised as;
- A grey-blue skin color, also known as cyanosis.
- Hurried breathing or having problems in inhaling.
- Withdrawal of rib-cage muscles.
- Less feeding than normal.
- Sluggish and strenuous heartbeat.
- Showing lethargy or extended periods of idleness.
- Heart murmur, a whooshing sound heard through a stethoscope during a physical examination.
Diagnosis of a heart defect during the gestation period is possible but may not be fruitful as the blood circulation does not need to work completely inside the womb. The TAPVC condition, if present, can be more easily identified after the baby has been delivered.
Diagnostic examination for Total anomalous pulmonary venous connection depends on the child's developmental phase, any existing medical conditions, etc. Some tests that may be suggested by the pediatrician can include the following:
- Chest X-ray: A diagnostic test that uses high-wavelength and invisible X-ray energy to produce a two-dimensional image of inner tissues, skeletons, and to recognize any structural problems in the organs, especially heart.
- Electrocardiogram: This test is used to distinguish abnormal rhythms (arrhythmias or dysrhythmias) in the heart and the presence of any incorrect conditions in the cardiac tissues.
- Echocardiogram: This technique is applied by attaching sensors that emit sound waves that can detect inconsistency in the structure and function of the heart.
- Pulse oximetry: this is a simple bedside examination that can be used to determine the amount of oxygen present in the child’s blood. Low amount of soluble oxygen may be an indication for Total anomalous pulmonary venous connection and treatment could be started as such.
Also, Magnetic Resonance Imaging, Ultrasound, and other techniques can also be used to perform a diagnosis of the health situation of the patient.
Application of the repair procedure for Total anomalous pulmonary venous connection may comprise of risks and complications as:
- Persistent issues in heart rhythms (arrhythmias or dysrhythmias).
- Obstruction in one or more pulmonary veins.
- Abnormal electrical activity in the atrium.
- Infections in the operation site.
- Presence of rapid or slow heartbeats.
- Need for additional cardiac surgery.
- The children after surgery may be admitted to the neonatal intensive care unit (NICU) for a small duration.
- An IV channel will be created to give sustenance, drugs and medicines, and other factors to the patient.
- The doctor may suggest a course of antibiotics for a short time after the operation.
- The child may be placed under bed-rest to ensure the complete healing of wounds.
Management of TAPVR with medicines is not a correct decision, as the defect of the heart is structural, and can be permanently solved using surgery only. According to the age of the patient, development of the health indicators, and the emergency of the children, the pediatric doctor may mention the subsequent guidelines for before, during and after the surgery;
Before the procedure
The surgeon may advise several tips for the hitch-free operation of your baby. Some of them can be stated as;
- Hospital caregivers may note your family history, any medicine usage by the mother, and any instances of an allergic reaction to certain drugs.
- Medicines that help in dilating the blood vessels may be given.
- If your baby has breathing trouble, he or she may be connected to a breathing machine or ventilator, which will assist in having a constant source of oxygen.
- Your baby will be given medicines and other required liquids through an intravenous channel.
- A feeding tube may be applied if your child gets tired while feeding or has difficulty in it.
- The surgeon may provide antibiotics before the operation.
- Your child may have the need for extracorporeal membrane oxygenation (ECMO) prior to surgery for correcting the instability in blood flow.
During the procedure
- Your child will be placed in the surgical table in a position where the chest faces upward.
- Your baby will probably be given general anesthesia to make him or her totally unconscious.
- He or she will be connected to a heart-lung bypass machine which will keep the flow of blood continuing during the procedure of the heart chambers.
- The surgeons will reconnect the pulmonary veins and the other blood vessels to the back of the left atrium, resulting in the correct connection of the veins to the heart.
- The pediatric cardiac surgeon will then close off any other routes of aberrant drainage from the pulmonary vein.
- In case, the child has Atrial Septal Defect also, then a balloon dilation procedure may be performed to improve the patient’s condition before the reconnection is done.
The surgery may take up to six to eight hours, depending upon the condition and health conditions of the patient.
FACTORS AFFECTING COST
The cost of surgical procedure for the treatment of Total anomalous pulmonary venous connection repair or TAPVC Repair will be more than a general open-heart surgery and will change according to the following;
- The charge of the operation theater
- The fees of the pediatric cardiac surgeon and any other consultant.
- The life-support machines (heart-lung machine, ventilator).
- The cost of the drugs given.
Yes, as it is the only procedure by which this defect in the child’s heart can be corrected.
There have been some reports that relate to the development of TAPVR to the mutation of several genes.
For the children or patients going through as elective surgery, the success rate is found to be 95%.