patent ductus arteriosus



OVERVIEW

Definition

Arterial Ductus Arteriosus is a congenital heart disease in which the ductus arteriosus fails to close properly after birth for a variety of reasons.

The ductus arteriosus is a “channel” that connects the pulmonary artery to the aorta during fetal life, and is necessary for a specific type of blood circulation during fetal life. After birth, the ductus arteriosus will close on its own as it becomes obsolete, and 95% of infants will have it closed by 1 year after birth.

Types

Unclosed ductus arteriosus varies in thickness, length, and morphology, and can be categorized into five types based on pathologic anatomy.

Tube type: the most common type, accounting for more than 80% of arterial ductus arteriosus, with longer ducts and more uniform diameter.

Funnel-shaped: also more common, the catheter is funnel-shaped, wider near the end of the descending aorta and narrower near the end of the pulmonary artery.

Window type: the catheter is extremely short, almost no length, the descending aorta and the pulmonary artery seem to be connected between the window-shaped, direct anastomosis.

Aneurysmal type: the middle part of the duct is enlarged in aneurysm-like fashion with a very thin wall.

Dumbbell type: the catheter is thin in the middle and thick at both ends, resembling a dumbbell.

Morbidity

The prevalence of arterial ductus arteriosus accounts for 10% to 21% of congenital heart disease, and occurs in 1 in 2500 to 5000 surviving newborns.

The prevalence of preterm infants is significantly higher than that of term infants, and the prevalence of preterm infants with a birth weight of less than 1 kg is as high as 80%.

It is more common in females, with a male to female ratio of about 1:3.

Causes

Causes

The cause of the disease is unknown and may be related to the following factors.

Genetic factors

Arterial ductus arteriosus is polygenic in nature and is often associated with other chromosomal disorders.

Environmental factors

Intrauterine environmental factors: the mother suffered from rubella, influenza, diabetes mellitus, hypercalcemia and other diseases during pregnancy, or the mother was exposed to radiation or took certain drugs during pregnancy.

Environmental factors after birth: birthplace is high altitude area such as plateau.

High risk factors

Premature babies.

Family members with congenital heart disease or other genetic diseases.

Pathogenesis

Normally, the ductus arteriosus gradually closes and degenerates into the ductus arteriosus ligament about 4 weeks after birth. If the gene itself is unstable due to inheritance of the causative gene or genetic mutation, the ductus arteriosus may be unclosed when prompted by environmental factors; or it may be affected by postnatal environmental factors, in which the contraction of the ductus arteriosus muscle cannot be prompted, causing the disease.

Symptoms

Symptoms and course of arterial ductus arteriosus are related to the thickness of the ductus and the amount of blood shunted from the aorta to the pulmonary artery (shunt volume).

A small catheter with a small shunt volume may have no obvious symptoms and may be discovered by chance during a physical examination or examination for other diseases.

If the catheter is large and the shunt volume is high, symptoms may appear soon after birth.

Main Symptoms

Weakness.

Palpitations after exertion.

Cough.

Chest tightness.

Shortness of breath.

Other symptoms

Infants and young children may have difficulty in feeding, low milk intake, sweating, crying and shortness of breath during feeding.

Infants and young children may also have no weight gain and lag behind in growth and development compared to normal, which is characterized by small stature, height and weight that are not in accordance with age.

Recurrent respiratory infections: there may be recurrent cough and sputum.

Complications

Pulmonary arterial hypertension: there may be shortness of breath after exertion, purplish-red color of skin and mucous membranes (cyanosis), which is obvious in the lower half of the body and the left upper limb; the ends of the fingers and toes are enlarged like a pestle, i.e., pestle-like fingers (toes).

Infective endocarditis: fever and skin petechiae may be present.

Heart failure: manifested by different degrees of dyspnea, shortness of breath, cough, sputum, hemoptysis, decreased physical strength, etc. In severe cases, drowsiness and coma may occur.

Ruptured arterial duct bleeding: less common and can lead to death quickly.

Consultation

Department of Medicine

Pediatric Surgery

It is recommended to consult the doctor as soon as possible when the child has rapid breathing, difficulty breathing, cyanosis, backward growth and development, or when the heart ultrasound suggests abnormalities.

Emergency Department

When your child experiences labored breathing, fainting, etc., it is recommended that you consult the Emergency Department as soon as possible.

Preparation for medical treatment

Preparing for your visit: registering, preparing information, and common problems.

Tips

Avoid strenuous exercise to avoid aggravating your child’s condition when the above symptoms occur.

Preparation Checklist

Pay particular attention to the time of onset of symptoms and special manifestations.

When did the rapid breathing start?

When did the skin turn blue?

Is there any recurrent coughing and sputum?

Is the child’s growth and development behind that of children of the same sex and age?

Is there a family history of congenital heart disease?

Test results in the last six months, which can be brought to the doctor’s office.

Laboratory tests: blood test, C-reactive protein, blood gas analysis

Imaging tests: cardiac ultrasound, chest radiograph, chest CT

Medication for the past 3 months, if available, bring along the box or packaging

Cardiotonic drugs: deacetyl furfuryl glucoside

Diuretics: spironolactone, hydrochlorothiazide

Diagnosis

Diagnosis is based on

Based on symptoms and signs, combined with echocardiography, X-rays and ECG changes, the diagnosis can be made definitively in most cases, and in a small number of cases, a combination of other tests is needed to confirm the diagnosis.

Medical history

Preterm birth.

Family members with congenital heart disease or other genetic conditions.

Maternal illness, medication, or radiation exposure during pregnancy.

Clinical manifestations

Weakness, palpitations after exertion, cough, chest tightness and shortness of breath, feeding difficulties and growth retardation in infants and children.

Auscultation may include a loud continuous machine-like murmur (characteristic change) and systolic murmur in the 2nd intercostal space at the left edge of the sternum.

Height and weight findings are not consistent with age.

There were peripheral vascular signs such as nail bed capillary pulsations, watery pulse, and gunshot sounds from the femoral artery.

Cyanosis of the lower body, pestle-like fingers (toes), etc.

Electrocardiogram

An electrocardiogram records changes in the electrical activity of the heart and can help in diagnosis based on changes in the individual waveforms.

In mild cases, there is no obvious abnormality in the ECG; in severe cases, there may be left ventricular hypertrophy, combined right and left ventricular hypertrophy, or right ventricular hypertrophy.

Imaging

Echocardiography is the main test to confirm the diagnosis of ductus arteriosus and is usually the first choice.

Echocardiography can directly detect the unclosed ductus arteriosus, measure its length and thickness, and show the direction and size of the shunt, and has the advantages of being safe, non-invasive, real-time, accurate, simple, and inexpensive.

Cardiac ultrasound requires the probe to be scanned in front of the chest, so it is necessary to wear loose, comfortable and easy to put on and take off clothes, ladies should not wear dresses.

Chest X-ray can observe the size of the heart, the distribution of blood in the lungs, and the thickening of blood vessels, helping to identify heart disease, arteriosclerosis, pneumonia and other diseases.

X-rays can sometimes reveal the characteristic changes of the “hilar chorea”.

Right heart catheterization is an interventional technique in which a special catheter is delivered to the heart and blood vessels through the peripheral blood vessels to be examined, and is commonly used in this disease.

During the examination, the catheter is passed through an unclosed arterial conduit into the aorta.

A retrograde aortogram may be performed at the same time to help identify other diseases.

Differential Diagnosis

Arterial duct failure should be differentiated from other conditions that may present with a similar heart murmur.

Aorto-pulmonary septal defect

The clinical presentation of aorto-pulmonary septal defect is very similar to that of ductus arteriosus, but the heart murmur is louder and lower; retrograde ascending aortography reveals the ascending aorta along with the common pulmonary artery, and echocardiography reveals a defect between the aorta and the pulmonary artery.

Ruptured aortic sinus aneurysm

Ruptured aortic sinus aneurysm has a lower heart murmur than this disease; there is a history of sudden onset of severe anterior cardiac pain, followed by panic attacks and chest tightness; echocardiography may show aortic sinus deformity, and aneurysm rupture and shunt are often seen.

Ventricular septal defect combined with aortic valve insufficiency.

In ventricular septal defect combined with aortic valve insufficiency, the heart murmur has no obvious continuity, echocardiography shows the continuity of the ventricular septal echo is interrupted, and cardiac catheterization fails to pass through the unclosed arterial conduit into the aorta.

Coronary artery fistula

Coronary artery fistula can have angina pectoris, dyspnea and other symptoms; echocardiography can be seen dilated coronary artery, and can be found to have a fistula; coronary angiography with coronary artery alignment and fistula can be clearly identified.

Treatment

Treatment objective: to close the arterial conduit, relieve symptoms, prevent complications such as infective endocarditis, and improve the prognosis.

Treatment principle: After diagnosis of arterial ductus arteriosus, treatment must be carried out as soon as possible, and the treatment program needs to be decided according to the severity of the disease, age and other comprehensive decisions.

General treatment

Observation and waiting: premature infants whose ductus arteriosus does not close on time can be observed for a period of time, waiting for it to close on its own. Arterial ductus arteriosus in infants and young children may also heal on its own. In the absence of obvious symptoms, you may want to wait and see if it causes any other health problems.

Rest: Avoid exertion and physical activity.

Adjust diet: Give nutritious and easily digestible food.

Adjustment of feeding: Breastfeed the baby in small amounts and several times.

Medication

When arterial ductus arteriosus occurs in preterm infants, drugs can be applied first to assist in closing the arterial duct.

Commonly used drugs are indomethacin and aspirin, and the arterial duct may close within 24 to 30 hours after application.

Adverse effects, such as bowel perforation, occasionally occur after use.

Surgery is still required for those who fail to close after treatment.

Surgical treatment

Indications

Preterm infants, infants and children with recurrent pneumonia, respiratory distress, heart failure, feeding difficulties, or failure to thrive should be operated on promptly.

For those without obvious symptoms, if accompanied by pulmonary congestion and enlarged heart shadow, elective (choose the right time) surgery is appropriate.

Contraindications

Eisenmenger syndrome.

In combination with severe pulmonary hypertension with right-to-left shunting.

Combined infective endocarditis (requires at least 3 months of treatment and 4 weeks of normalization of body temperature before surgery).

Surgical approach

It is the commonly used treatment in the past, which has the disadvantages of high trauma and slow recovery, and has been gradually replaced by interventional therapy.

It can be performed through open-heart surgery to ligate the unclosed ductus arteriosus, or to cut off the unclosed ductus arteriosus and suture it.

It is mainly applicable to those who need simultaneous treatment for congenital heart diseases such as combined aortic arch dissection, complete transposition of the great arteries, pulmonary atresia, etc.; it can also be used as a remedy for the failure of interventional therapy.

It is a method of percutaneous puncture of the femoral artery and femoral vein, and application of a blocker to close the arterial conduit under X-ray or ultrasound guidance.

It is the main means of treatment and has the advantages of small incision, light trauma and quick recovery.

For those who are older than 6 months and weigh more than 8 kg, the intervention should be taken, except for contraindications and cases that require surgery.

Postoperative complications

Complications such as hypertension, injury to the recurrent laryngeal nerve, rupture and bleeding of the arterial conduit or nearby aorta and pulmonary artery, catheter recanalization, and infective endocarditis may occur after the procedure.

Intervention may also lead to complications such as hemolysis, residual shunt and blocker migration, descending aortic stenosis, left pulmonary artery stenosis, etc., which occur and most often require the application of surgical treatment.

Postoperative precautions

Do not remove the gauze at will, and keep the surgical incision or puncture wound clean and dry to prevent infection. If the wound oozes blood, is painful, or if the gauze falls on the floor, ask the medical staff to deal with it promptly.

After surgery, you need to stay in bed for a period of time, during which you can turn over slowly with the help of your family. After that, you should start to move around moderately, and you can gradually increase the amount of activity, but you should avoid more strenuous activities for 1 month.

After the intervention, the patient should lie down for 12 hours, with pressure on the wound for 2 to 4 hours, and the punctured limb should be immobilized for 6 hours, after which the patient can gradually get out of bed.

Prognosis

Cure

In preterm infants, the ductus arteriosus can be closed after medication, and in a few cases where it cannot be closed, the ductus arteriosus can be closed surgically.

In full-term infants and adults, the ductus arteriosus can be closed after surgical treatment.

If the ductus arteriosus is closed without complications, the cardiovascular function is basically the same as that of a normal person after recovery, and there is no impact on life expectancy.

The prognosis is poorer for those who are too ill to undergo surgical treatment and for those with severe and irreversible pulmonary vascular disease.

Hazards

Some patients may have slower growth than their peers, with lower weight and height than their peers.

There may be symptoms such as chest tightness and shortness of breath, and they are prone to upper respiratory tract infections and pneumonia.

Due to frequent oxygen deprivation, the slightest physical activity may cause the patient to breathe faster, feel fatigued, and need to rest.

It may lead to complications such as pulmonary hypertension, infective endocarditis, heart failure, and even unclosed arterial duct rupture and bleeding, which can be life-threatening in severe cases.

Female patients are potentially at risk for pregnancy complications and even death when they become pregnant later.

Daily

Daily management

Rest

Minimize the amount of activity and avoid strenuous and intense exercise.

Adopt a good routine, go to bed early and get up early.

If symptoms such as palpitations, shortness of breath, coughing, fatigue and excessive sweating occur during normal activities, you should rest immediately. If symptoms do not get better after resting, or if symptoms reappear or worsen, you should go to the hospital in time.

Dietary management

Provide a reasonable dietary structure to ensure the intake of protein, potassium, iron, vitamins and trace elements.

You can eat some fruits, vegetables, eggs and fish food.

Pay attention to small meals and avoid overeating.

Avoid drinking alcohol, coffee, strong tea and other stimulating beverages.

Avoid infection

Pay attention to environmental hygiene, ventilate the room frequently, and maintain suitable temperature and humidity.

Avoid cold and flu.

During the epidemic period of influenza and other infectious diseases, go to shopping malls and other densely populated places less often.

Keep the wound clean and dry after surgical treatment to prevent wound infection.

Psychological support

Patients or family members (including parents of affected children) should actively learn disease-related knowledge and correct misperceptions.

Family members should communicate with the patient, encourage the patient, help the patient to overcome the fear of the disease and surgery, and build up the confidence to overcome the disease.

Regular follow-up

Follow the doctor’s instructions for regular follow-up.

Usually, patients should go to the hospital for a follow-up examination at 1 month, 3 months and 6 months after the surgery.

If the structure and function of the heart are normal and there is no discomfort, you can have a follow-up once a year thereafter.

If there are problems with the structure and function of the heart, shorter intervals may be needed.

If palpitations, shortness of breath, coughing, fatigue and excessive sweating occur after discharge from the hospital, or if there are any other symptoms, you should go to the hospital promptly.

Prevention

Arterial ductus arteriosus is a congenital disease, there is no good preventive method, you can reduce the probability of the disease in the offspring by strengthening the health care during pregnancy and preventing preterm delivery.

Pregnant women should try not to go to crowded places during pregnancy to avoid infection during pregnancy.

Avoid exposure to radiation, tobacco, alcohol and other harmful substances during pregnancy.

Maintain a balanced diet structure during pregnancy and take appropriate walks and other activities to prevent diabetes and hypercalcemia.

Pregnant women should have regular prenatal checkups as recommended by their doctors so that abnormalities can be detected in time for early intervention.

If abnormalities in blood glucose or calcium appear during the checkup, active treatment is needed to control the condition.