...HLHS is a serious heart defect that involves several parts of the left side of the heart. In this condition, the heart's lower left pumping chamber and the large artery that carries blood to the body are too small to support normal blood flow.  In basic terms it means that the whole left side of the heart does not develop normally.

Each year, approximately 40,000 babies are born in the United States with a congenital heart defect. Children with HLHS require lifelong follow-up by a cardiologist for repeated checks of how their heart is working, and virtually all the children will require heart medicines. Nearly twice as many children die from CHD’s as from all childhood cancers combined, yet research for cancer receives five times the funding. This is due in large part to the lack of awareness most people have about congenital heart defects. 

Diagnosis methods for HLHS

The sooner that HLHS is diagnosed, the more likely that treatment will be successful. An HLHS diagnosis may be made either before or after birth. If the diagnosis is made while in-utero, a fetal echocardiogram may be used. Commonly referred to as an ultrasound, an echocardiogram allows the physician to see images of the developing fetus and its various organs and systems, including the heart and cardiovascular system. If diagnosis is made before birth, parents will likely be offered the option of a medical termination of pregnancy (MTP), also referred to as a “therapeutic abortion.” This is a difficult and personal decision. Those who choose to carry the pregnancy to term will need to make more choices regarding the treatment of their baby’s condition.

HLHS is not a survivable lesion without major open heart surgery. There are two options, one is cardiac transplantation, in which the entire heart is replaced by a donated heart, and the other is called staged palliation, which is explained below. Your doctor should advise you about the risks and benefits to each of these two options.

For HLHS, staged palliation involves three operations or the Norwood Procedure. In order, these are the Norwood operation, bidirectional Glenn operation, and the Fontan operation.

Norwood procedure for HLHS

The Norwood procedure is a series of three open-heart surgeries. Each open-heart surgery is done at a different age, ranging from infancy through the toddler years. The first two surgeries (Stages I and II) are used to temporarily relieve blood flow problems to and from the lungs. The third surgery (Stage III) is used to permanently correct the effects of the underlying congenital heart defects. The three surgeries are done at three different ages, which are as follows:

Stage I (the Norwood operation) is usually done soon after birth.


Stage II (the bi-directional Glenn procedure, partial Fontan or a staging procedure before the Fontan) is usually done at three to nine months of age.


Stage III (the Fontan procedure) is usually done between 18 months and 4 years of age.
 

The Norwood operation is done very soon after birth, and converts the right ventricle into the main, or systemic ventricle. The bidirectional Glenn operation is done next, and diverts half of the blood returning from the body to the lungs. It is typically done at about six months of age. The Fontan operation is the last stage of the staged palliation, and diverts all of the blood returning from the body to the lungs. It is typically done around 2 years of age. The timing of these operations is variable, and depends on many clinical and social factors.

Staged palliation for HLHS is one of the great achievements of congenital heart surgery in the 90's. In what used to be a uniformly fatal disease, consider the following: Survival following a Norwood operation is around 80%, following a bidirectional Glenn operation around 100%, and following a Fontan operation around 95%. Overall, survival at 5 years of age is around 70 - 75%. Most patients who get through the three stages do quite well: Very few are on medications, almost all have normal growth and development, and very few have any exercise or other kinds of limitations.
 

Watch some animated videos on HLHS Proceedures