Pediatric Pulmonary Stenosis: Information on Causes, Diagnosis & Treatments

Pediatric Pulmonary Stenosis is a serious condition involving the fusing or thickening of a heart valve that cannot fully open. The stenosis is often the result of a deformity of the pulmonary valve that influences the flow of blood into the lungs from the heart. When blood flow is slowed, it can cause considerable complications including other illnesses. In most cases, the condition is a congenital heart defect, where the stenosis of the valve developed before the child was born.

Stenosis of the pulmonary valve can be mild, with no noticeable indicators or symptoms. However, some cases can become significantly worse over time and require surgery. Treating the condition typically produces a highly successful outcome where individuals who had the repair can expect to live healthy normal lives.

The pulmonary valve forms between the pulmonary artery and the right ventricle. Normal development of the valve's three leaflets provides a necessary function to allow blood flow to move forward from the heart into the pulmonary artery without regurgitation or backing up into the right ventricle.

• Who Is at Risk for Pediatric Pulmonary Stenosis?
• Common Symptoms
• Diagnosing Pediatric Pulmonary Stenosis
• Treating Pediatric Pulmonary Stenosis

The stenosis of the pulmonary valve causing significant problems that make it challenging for the leaflets to fully open. This restricts the flow of blood forward causing serious problems in children that could include:

• The valve developed thick leaflets that restrict full movement of opening and closing


• The leaflets of the valve restricted flow because that have partly fused together


• A narrowing has developed below or above pulmonary valve

Who Is at Risk for Pulmonary Stenosis?

Nearly all cases involving pulmonary stenosis occur as a congenital heart defect. This means the child was born with the condition that developed while in the mother's womb. Because its congenital, doctors have yet to determine many of the underlying risk factors. Doctors do believe that in some cases, genetics plays a key role in the development of the condition that is considered to be a rare disorder. This could include a chromosome abnormality or the mother's exposure to the environment during pregnancy.

Common Symptoms

Mild forms of pediatric pulmonary stenosis usually do not cause detectable symptoms. Generally, the doctor will diagnose a case of pediatric pulmonary stenosis by identifying a heart murmur just after the child was born. However, other common symptoms associated with the condition include:

• Poor appetite when feeding tha t leads to weight loss


• Fainting


• Chest pain


• Rapid and heavy breathing


• Cyanosis (a bluish tint to the skin, lips, and nails


• Shortness of breath


• Abdominal distention (bloated tummy)


• Swollen abdomen, ankles, feet, face, and/or eyelids


• An infant's failure to thrive because of a severe blockage


• Sudden death

Sometimes, pediatric pulmonary stenosis goes undetected because it resembles other serious heart problems or medical conditions.

Complications

In critical cases, the opening in the heart is so small that the heart muscle cannot pump sufficient quantities of blood to meet the needs of the body. Without treatment, the newborn can develop serious issues caused by right-sided heart failure.

Additionally, the child can develop subacute bacterial endocarditis (SBE), which is a serious heart infection involving bacteria in the bloodstream. Because of that, doctors will often prescribe a dose of an antibiotic before any medical procedure or dental visit, to minimize the potential risk of developing an infection.

Diagnosing Pulmonary Stenosis

Usually, the doctor will diagnose pediatric pulmonary stenosis after detecting a heart murmur when using a stethoscope. The murmur usually makes a distinct rasping, whooshing or blowing sound. To verify a diagnosis the doctor will identify clinical features, evaluate physical characteristics and order tests. These include:

• Clinical Features – Many of the symptoms associated with pediatric pulmonary stenosis will slowly develop as the child grows older. This is because the stenosis usually causes excessive narrowing of the valve and produces symptoms that include low stamina and shortness of breath upon exertion. Critical cases of the condition at birth will produce cyanosis (blueness of the skin, lips, and/or nails). There also might be signs of congenital heart failure.


• Physical Characteristics – Usually, the doctor will detect a heart murmur caused by some level of narrowing of the valve. If the murmur is loud, it typically identifies a moderate level of valve narrowing. As the child develops and grows, the valve problem may improve, stay the same, or gradually worsened causing other significant health problems.


• Medical Tests – An electrocardiogram can identify the overdevelopment of the right side of the heart due to elevated forces on the right ventricle caused by the severe case of pulmonary stenosis. However, the test can also identify mild cases of stenosis. The doctor may also choose to use a cardiac catheter to view the interior of the heart to obtain a 100 percent accurate diagnosis.

Treating Pulmonary Stenosis

Treating severe cases of pediatric pulmonary stenosis often requires balloon angioplasty or heart surgical procedures. Determining what procedure to use is generally based on the degree of narrowing of the valve and the need to prevent tissue damage to the right side of the heart muscle.

• Balloon Angioplasty – This procedure is highly successful at producing desirable outcomes in babies who suffer from pediatric pulmonary stenosis. This is usually the first treatment of choice to avoid surgical intervention. The doctor will insert a thin plastic catheter (tube) threaded into a large blood vessel in the leg. The tube is then guided into the heart where a balloon attached to the tip of the catheter is inflated across the pulmonary valve.

During the procedure, the expansion of the balloon will dilate the area that has become progressively narrow. This procedure can also be done later in life on patients who are suffering from Williams and Noonan syndromes. Though the procedure is invasive, it is performed with an IV sedation and usually does not require long hospitalization.

• Surgical Procedure – Some patients with the severe form of pediatric pulmonary stenosis will require a surgical valvotomy when the leaflets have become fused. This procedure is performed as an open-heart surgery with the doctor makes a midline sternotomy by making a long incision in the middle of the chest. The patient is then attached to a heart-lung machine to provide support for the body. During the procedure, the heart will be opened so a repair can be made to the pulmonary valve.

The surgeries use of the procedure choice in patients who suffer an extensive narrowing of the pulmonary valve. Having direct access to a stopped heart during the surgical procedure is often required to enlarge the narrowed areas and possibly add a transannular patch. While the procedure is highly invasive, complications associated with the repair are rare and the length of time required to stay in the hospital is usually no more than 3 to 4 days.

Children and adults with untreated pulmonary stenosis rarely experience a worsening of the condition. Additionally, the outcome or prognosis after a balloon dilation (angioplasty) or open heart surgical repair is good. However, there may be other congenital heart defects involved in the patient's condition that could change their prognosis over time. If the patient required a new valve, it is designed to last for decades without the need of replacement.

Sources:

http://www.chop.edu/conditions-diseases/pulmonary-stenosis

https://www.cincinnatichildrens.org/health/p/pvs

http://www.mayoclinic.org/diseases-conditions/pulmonary-valve-stenosis/basics/definition/con-20013659

https://my.clevelandclinic.org/health/articles/pulmonary-artery-stenosis