What is AV Canal/Septal Defect (AVCD or AVSD)?
A normal heart has four chambers- two upper chamber (Right Atrium - receives blue blood from the body, Left atrium receives oxygen rich red blood from the lungs) and two ventricles (Right Ventricle - receives blood from the right atrium and pumps it to the lungs and Left Ventricle receives blood from the left atrium and pumps it to the body).
So, blue blood from the body reaches the right atrium, goes to the right ventricle, is pumped to the lungs. Lungs will add Oxygen to the blood and blue blood turns red, this red blood returns to the left upper chamber (left atrium), goes to the left ventricle and left ventricle pumps it to the body.
Blue blood on the right side of the heart and red blood on the left side of the heart are kept separate by partitioning ‘wall’ in both upper and lower chambers- Atrial Septum is the wall between the right and left atrium and the Ventricular Septum is the wall between the two pumping chambers- Right ventricle and Left Ventricle.
AV Canal Defect (AVSD) is when the junction area between the Atria and Ventricle (upper and lower chambers of the heart) does not form- and these leads to three issues that need to be corrected by surgery-
- Hole (defect) in the wall (septum) separating the upper chambers that receive blood (Atrium- Atrial Septal defect)
- Hole (defect) in the wall (septum) separating the lower pumping chambers of the heart (the right and left ventricles- Ventricular septal defect) and
- Incompletely formed valves between the upper and lower chambers (Mitral and Tricuspid Valves) that do not work correctly and tend to leak.
Why do the surgery?
Normal blood pressure in the body is around 120 mm- this is the blood pressure that is generated by the left ventricle – so, as you can understand, blood pressure in the left ventricle is about 120 mm.
Normal blood pressure in the pulmonary artery (that takes blood from the right ventricle to the lungs) is about 30 mm- and so, the right ventricle pumps at a pressure of 30 mm which is much lower than the left side.
The Ventricular septum separates the left ventricle from the right ventricle and allows the two ventricles to pump blood at different pressures.
However, if there is a large hole in this septum (VSD), then blood from the left ventricle at a very high pressure enters the right ventricle- increases the pressure in the right ventricle and the pulmonary artery and increases blood pressure in the lungs (Pulmonary Artery Hypertension- PAH).
This leads to heart failure symptoms (Shortness of breath, Repeated chest infections, failure to gain weight, poor feeding, and perspiration with feeds etc)
The valves between the upper and lower chambers of the heart (Mitral and Tricuspid Valves) are there to maintain blood flow in the correct direction - when the pumping chambers squeeze – these valves will close, and blood will not go backwords in the upper chamber.
In children with AV Canal defect these valves are incompletely formed and often tend to leak – leading to a backward flow of blood into the upper chambers when the heart squeezes- this increases the risk of heart failure.
Repairing this defect by surgery will decrease the blood pressure on the right side of the heart, will decrease leakage in the valves and when done at the right time- will lead to an essentially normal life for the child.
Surgical procedure
Surgery is usually done when the child is about three months old- however, it can be done earlier if the child’s heart failure symptoms cannot be controlled by medications. And it is strongly recommended that surgery in babies with this heart condition should not be delayed beyond 6 months of age as after this age, a significant proportion of children will become inoperable.
The surgeon makes an incision down the front of the chest to get access to the heart. The heart is connected to a cardiopulmonary bypass machine. This machine takes over the heart’s work of pumping blood so the surgeon can enter the heart to repair it.
The ‘Holes in the heart’ (ventricular septal defect and atrial Septal Defect) are usually closed with a patch and the valves are repaired with sutures.
The surgery will take an average of five to six hours from start to finish.
Risks and benefits of the surgery
The benefit of the surgery is for the child to have a better functioning heart. This would mean that the child will not have heart failure symptoms and his/her growth and development will be better. In addition, the risk of death and heart failure are also avoided
Risks of surgery include:
- Bleeding,
- Infection,
- Stroke,
- Organ damage,
- Requirement for a temporary or permanent pacemaker,
- or Possibly death.
However, the total the risk of these occurring is 4 to 5% or less.
What to expect during the hospital stay?
The length of the hospital stay usually varies from five to 10 days, and this will depend on how quickly the heart recovers.
For a few days following surgery, we will take care of your child in the ICU. In the Intensive Care Unit, we will keep a watch on the child’s Heart Rate, Blood Pressure, Respiration and other organ functions. To avoid frequent interruptions in the care of your child, there is a restriction to visitors, however, parents can visit the child.
Going home
The hospital will supply specific discharge instructions, medicine list and dosages and operation notes. All instructions from the Artemis hospital, cardiac surgeon, and cardiologist should be strictly followed. The child should get back to his or her normal routine upon arrival at home. For the first week, the child may wish to take more frequent naps or wake up occasionally at night- and this is normal. The child should be seen by us after 3-6 days of discharge from the hospital.
Happy Patient What is AV Canal/Septal Defect (AVCD or AVSD)?
For our patients in Uganda- Treatment of AV Canal (Septal) Defect- Luganda versionn
For our patients in Uganda-Treatment of AV Canal (Septal) Defect- Kiswahili version
Translation by kind curtesy of mother and Health care provider (nurse) of our recent patient from Uganda
