Hypoplastic Left Heart Syndrome : Treatment, Procedure, Cost And Side Effects

Hypoplastic Left Heart Syndrome is a rare, congenital heart defect that hinders blood flow by weakening the walls of the heart. It affects a foetus during pregnancy when the left walls of the heart do not develop properly and remain weak. It is generally diagnosed before or immediately after birth. The condition can affect a number of structures on the left side of the heart. For example, the left ventricle may be underdeveloped and too small or the aortic and mitral valves may be too small, or babies with HLHS may have an atrial septal defect which is a hole between the left and right sides of the heart. The causes of a variety of heart defects in infants including Hypoplastic Left Heart Syndrome are mostly unknown. However, it is a generally accepted idea that these defects are caused due to changes in genes and chromosome structures that are caused due to a variety of genetic and other risk factors that are including but not limited to things that the mother eats or drinks during the pregnancy and environmental factors.

Unfortunately, there is no cure for hypoplastic left heart syndrome and neither has any consensus been reached as to the treatment and management of this condition in neonates. However, there are a few treatment procedures that can be attempted, supportive care, multistage surgical intervention and cardiac transplant are some of the only available options. Some of it are as follows:

1. Staged Palliation is a three-step surgical procedure. It is considered to be one of the greatest developments in congenital heart surgery in recent years. The survival rate for patients above 5 years of age is about 70% and after successful surgery, most patients live relatively normal lives. Performed shortly after birth, the Norwood Procedure is the first step, it involves making the right ventricle the main ventricle that pumps blood to the body. The Bi-directional Glenn Operation is done six months after the first surgery. Half of the blood is diverted to the lungs. The last procedure is the Fontan Operation, it is done 18 to 36 months after the second surgery. The inferior vena cava is directly connected to the pulmonary artery.
2. In cases where the reconstruction surgery fails, a heart transplant is the only possible solution. However, hearts for infants are difficult to obtain and hence survival rate for these infants is very low.

The available treatment is the reconstructive surgery known as the Staged Palliation Procedure which is as follows:

• The first part of the Staged Palliation Procedure is the Norwood Operation. The purpose of this surgery is to create an unobstructed systemic blood flow from the right ventricle to the aorta, and restricted pulmonary blood flow through a systemic to pulmonary artery shunt. The main pulmonary artery and the aorta are connected by the insertion of a shunt to supply blood to the lungs. The main pulmonary artery is cut off from its two branches that supply blood to both sides of the lungs.
• In the Glenn Surgery, the shunt is removed since the lungs no longer require a large amount of pressure from the ventricle. The right pulmonary artery is directly connected to the superior vena cava which sends a part of the deoxygenated blood directly to the lungs without passing through the ventricle.
• The Fontan Operation is the final stage of the three-step procedure. It joins the inferior vena cava, carrying deoxygenated blood from the lower body, to the pulmonary artery, that transports blood to the lungs for oxygenation, by constructing a channel through the heart or making one just outside the heart to direct the blood to the pulmonary artery.

If the reconstructive surgery fails, a heart transplant is the only option left. A heart from a donor of the same age group, blood and tissue type has to be implanted into the patient. However, not only is the procedure extremely risky, but infant donors are also very difficult to find. Furthermore, if the surgery is successful, the patient is required to remain on immunosuppressants for a long time and has to take a vigorous course of antibiotics before any surgery or dental work for the rest of his/her life.

1. The Norwood Procedure is performed shortly after birth. The requirements for the surgery include, (a) unobstructed systemic outflow from the single right ventricle to a reconstructed aorta, (b) unobstructed pulmonary venous return into the right atrium and (c) controlled pulmonary blood flow (PBF).
2. The Bi-directional Glenn Procedure is performed six months after the first surgery unless any unforeseen complications have cropped up. The Fontan Operation is performed 18 to 36 months after the second surgery and 24 to 42 months after the first procedure.
3. Heart Transplant is a viable option only in cases where a certified transplant team has declared that no other options are available. The patient is then put on a transplant waiting list until a matching donor is found. Body size, blood type and tissue type are checked when matching a donor to a recipient.

Hypoplastic Left Heart Syndrome is a rare, congenital heart defect that hinders blood flow by weakening the walls of the heart. Infants or people with who don't have this problem are ruled out of this treatment and thus are not eligible for the treatment.

All the procedures that are part of the reconstruction surgery are prone to a number of post-surgery complications. The type of post-surgery complications that a patient may suffer from depends upon a variety of genetic, environmental, immunological, physiological and idiopathic factors. Heart failure, occurring in spite of the surgery, is the most serious complication. Other complications include arrhythmia, respiration insufficiency requiring intubation, acidosis and low cardiac output. In the case of heart transplants, the most obvious and serious complication is rejection. This happens when the recipient's immune system identifies the heart as foreign and attacks it. Graft failure is another possible complication that occurs soon after the transplant when the donated heart fails and does not work properly. Both these complications can be fatal.In case any patient reports any other complexity after undergoing the treatment the patient is advised to consult the doctor immediately.

Immediately after the surgery, the patient is brought to the Intensive Care Unit (ICU). The cardiac surgical team and the anesthesiologist gives a one-over check up making sure that the surgery has gone smoothly. Heart rate, blood pressure and oxygen concentrations are constantly monitored for any changes that may point to a post-op complication. Hemodynamic assessments are regularly conducted that includes a review of current medications, heart rate and rhythm, mean arterial pressure, central venous pressure, and EKG analysis to exclude ischemia and conduction abnormalities. Heart transplant patients have a three-week hospital stay after the surgery. Immunosuppressants are to be taken to prevent rejection of the new heart. In order to ensure proper functioning of the heart over time, a low-sugar, low-fat, low-cholesterol diet should be maintained. Regular exercise is also important.

Recovery periods vary from procedure to procedure. Recovery time after the Norwood Procedure is uncertain and takes about three to four weeks. After the Glenn Surgery, patients are generally discharged after about 4 days, complete recovery may take about two to three weeks. The Fontan Operation takes about 5 hours for completion with a 2 to 3-week hospital stay. After the cardiac transplant, the hospital stay is about 3 weeks while most daily activities can be resumed in about 6 weeks. However, complete recovery from the surgery may take anywhere between 3 to six months. All numbers of recovery time are calculated assuming the absence of any major complications.

The Norwood Procedure along with its post-op care costs around INR 8.3 lakhs. The Glenn Surgery costs INR 3.5 lakhs and the post-op care costs an additional 1.8 lakhs. The Fontan Operation has a cost of INR 6.8 lakhs. A heart transplant is the more expensive of the two options, costing around INR 30 – 40 lakhs.

If the reconstructive heart surgery is successful, without any major complications then it is permanent with patients living relatively normal lives. Heart Transplant, as a procedure, has a lot more risks involved but for those patients who survive the surgery and the recovery period live extremely normal lives for the most part.

If the reconstructive surgery fails and transplantation does not seem to be a viable option, then the condition is most certainly fatal. As of today, there are no other alternatives to this treatment.