Congenital Diaphragmatic Hernia Flashcards
When does the diaphragm form during gestation?
The diaphragm forms between week 7 and 10 of gestation.
What happens to the intestines during weeks 7 to 10 of gestation?
The intestines lengthen rapidly and temporarily leave the abdominal cavity.
When do the intestines return to the abdominal cavity?
The intestines return between weeks 10 and 14 of gestation.
What structures are involved in the formation of the diaphragm?
The pleuroperitoneal folds, the embryological precursor to the diaphragm, must fuse with the mediastinum, dorsal body wall, and developing sternum.
What are the classifications of hernias
- Bochadalek
- Morgagnia
- Diaphragmatic eventration
- Haitus
What is a Bochdalek hernia?
A Bochdalek hernia is a posterolateral diaphragmatic defect (Foramen of Bochdalek) and is the most common type in neonates. It is usually left-sided (85%).
Where is a Bochdalek hernia most commonly located?
A Bochdalek hernia is most commonly located on the left side (85%).
What is a Morgagni hernia?
A Morgagni hernia is caused by improper development of the central tendon, resulting in an anterior parasternal defect, usually on the right side.
When do Morgagni hernias typically present?
Morgagni hernias typically present late, not in the neonatal period, as they do not cause significant pulmonary hypoplasia.
What is diaphragmatic eventration?
Diaphragmatic eventration is an abnormal high position of the intact diaphragm due to weakness of the central tendon, which can cause respiratory distress or frequent chest infections.
What can cause diaphragmatic eventration?
Diaphragmatic eventration can be congenital or acquired, often following a phrenic nerve injury.
What is a hiatus hernia?
A hiatus hernia is a hernia through areas where anatomical structures traverse the diaphragm, such as a para-oesophageal hiatus hernia next to the oesophagus.
What is the incidence of Bochdalek hernia?
Bochdalek hernia makes up about 90% of all cases and occurs in 1 in 2,200 to 5,000 live births.
What is the male-to-female ratio for Bochdalek hernia?
The male-to-female ratio for Bochdalek hernia is 1:1.
What is the left-to-right incidence ratio for Bochdalek hernia?
The majority of Bochdalek hernias occur on the left side (Left:Right 8:1).
What percentage of hernias are Morgagni hernias?
Morgagni hernias make up about 2% of all diaphragmatic hernias.
Which gender is more likely to have a Morgagni hernia?
Morgagni hernias are more common in girls.
What happens when abdominal contents protrude through a diaphragmatic defect?
The abdominal contents protruding through the defect press on the developing lung (around the 15th week), creating pulmonary hypoplasia.
How does a diaphragmatic defect affect lung growth?
Lack of normal diaphragmatic movements also affects lung fluid volume, impairing normal lung growth.
What are the main consequences of diaphragmatic hernias on the lungs?
The consequences include:
- Lung hypoplasia (fewer alveoli than normal)
- Mediastinal shift (heart shifted to the contralateral side)
- Thickened pulmonary arteries (more muscle in the arterioles, less surfactant)
- Pulmonary arterial hypertension, leading to a left-to-right shunt, persistent fetal circulation, hypoxia, and hypercarbia.
What signs might the pregnant mother show if the fetus has a diaphragmatic hernia?
The pregnant mother may show signs of polyhydramnios (excessive amniotic fluid).
How can fetal ultrasound help in diagnosing a diaphragmatic hernia?
Fetal ultrasound can show abdominal contents in the chest cavity, with the liver possibly displaced and the stomach bubble next to the heart.
How can the position of the liver affect the prognosis of a diaphragmatic hernia?
The position of the liver is important for prognosis. If the liver is positioned in the chest (liver up), it gives a worse prognosis.
What is the significance of the lung-to-head ratio in diagnosing diaphragmatic hernia?
The lung-to-head ratio is of significant prognostic value in assessing the severity and potential outcome of the condition.
What is the recommended delivery plan if a diaphragmatic hernia is diagnosed on antenatal ultrasound?
If a diaphragmatic hernia is diagnosed antenatally, an elective caesarean section delivery in a tertiary institution is advised.
What fetal intervention may be performed in very high-risk cases of diaphragmatic hernia?
Endotracheal balloon occlusion of the trachea may be performed in high-risk cases with poor prognostic indicators to improve lung development.
How might a baby with a Morgagni hernia present?
A baby with a Morgagni hernia may or may not show symptoms.
What factors affect the symptom complex in a baby with a diaphragmatic hernia?
The symptom complex and severity depend on the degree of pulmonary hypoplasia.
What does immediate respiratory distress in a neonate with diaphragmatic hernia suggest?
Immediate respiratory distress implies a worse prognosis.
Are babies with diaphragmatic hernia always symptomatic at birth?
No, although certain patients may be asymptomatic at birth, this is uncommon.
What are the common symptoms and signs of diaphragmatic hernia in neonates?
Symptoms and signs include:
Respiratory distress, cyanosis (to a variable degree)
Asymmetric chest development and movements
Absent breath sounds on the affected side
Heart sounds on the right
Bowel sounds in the chest
Scaphoid abdomen
What does a chest X-ray show in a case of diaphragmatic hernia?
A chest X-ray may show cystic radiolucencies in the hemithorax, with no visible hemi-diaphragm on the affected side (bowel in the chest cavity).
How do bowel loops appear on a chest X-ray in diaphragmatic hernia?
Bowel loops in the chest may appear slightly tubular due to partial obstruction from being in the chest cavity.
What does shifting of the mediastinum indicate on a chest X-ray?
Shifting of the mediastinum to the opposite side (mass effect) is seen, with the cardiac shadow displaced to the right.
How do the lungs appear on a chest X-ray in diaphragmatic hernia?
The lungs may appear hypoplastic and consolidated.
How can an erect chest X-ray help in the diagnosis?
An erect chest X-ray helps differentiate diaphragmatic hernia from cystic lung lesions
How does a lateral X-ray help in diagnosing diaphragmatic hernia?
A lateral X-ray helps differentiate between anterior (Morgagni) and posterior (Bochdalek) herniation.
What role does ultrasound & fluoroscopy play in diagnosing right-sided lesions?
Ultrasound & fluoroscopy help differentiate between a hernia (with liver in it) and a high-riding but intact diaphragm, or conditions like eventration or phrenic nerve palsy.
How can contrast studies aid in diagnosing chest lesions?
A contrast meal or enema can help identify the stomach or colon in the chest, especially in small anterior defects.
What gastrointestinal issue is commonly associated with diaphragmatic hernia?
Gastrointestinal malrotation is common because the intestines never returned to the abdomen in the normal way.
How does diaphragmatic hernia affect the development of the gastro-oesophageal junction?
Gastro-oesophageal reflux occurs because the normal angle of His and O-G junction development are compromised.
What other birth defects are associated with Bochdalek type diaphragmatic hernia?
Babies with the Bochdalek type of diaphragmatic hernia are more likely to have other birth defects. Around 20% have a congenital heart defect, and between 5 to 16% have a chromosomal abnormality.
What is one differential diagnosis for a cystic lung lesion or an abnormally raised diaphragm?
Congenital lobular emphysema is a possible differential diagnosis.
What is diaphragmatic eventration, and how does it differ from other causes of an abnormally raised diaphragm?
Diaphragmatic eventration occurs when the diaphragm is intact, but there is central tendon weakness or diaphragmatic paralysis, often due to phrenic nerve palsy.
What are some rare mass lesions of the lung that can cause cystic lung lesions or an abnormally raised diaphragm?
Rare mass lesions include:
- Congenital pulmonary airway malformation (CPAM, formerly called congenital cystic adenomatous malformation or CCAM).
- Bronchopulmonary sequestration.
- Pleuro-pulmonary blastoma (a very rare malignancy).
What determines the prognosis in patients with lung hypoplasia?
The degree of lung hypoplasia determines the prognosis. If there is insufficient functioning lung, patients cannot survive or be weaned from a ventilator.
What is the general approach to treatment for lung hypoplasia and related conditions?
The treatment approach is based on a “Trial of life,” which involves stabilizing the patient. If the neonate has sufficient lung tissue to be compatible with life, improvement is expected over the next 24 hours.
What is included in the management of patients with lung hypoplasia?
Management includes gentle ventilation to avoid damaging the lungs, and medication to reduce pulmonary hypertension. Surgery does not influence pulmonary pathology and is not urgent.
What complications may arise from aggressive ventilation in these patients?
Aggressive ventilation can lead to barotrauma, resulting in interstitial edema, possible bleeding, and tension pneumothorax.
What is the first step in emergency management of lung hypoplasia?
The first step is to keep the bowel decompressed using nasogastric tube decompression.
What is the recommended approach for intubation after birth in these patients?
Immediate intubation should be done without prior bag-valve mask ventilation after birth.
What should be done regarding feeding in the emergency management of these patients?
The patient should remain nil by mouth.
How should oxygenation be optimized in emergency management?
Oxygenation should be optimized through:
- Intubation and positive pressure ventilation.
- Use of high-frequency (oscillatory) ventilation.
- Extra-corporeal membrane oxygenation (ECMO) for about 10% of cases with severe hypoxia. ECMO has improved survival but comes with a high complication rate.
What is important to support circulation and treat pulmonary hypertension in these patients?
- Keep the baby warm (avoiding hyperthermia to prevent acidosis).
- Monitor blood gases and electrolytes.
- Sedate the baby (using fentanyl or other opiates).
- Provide emergency transfer to a specialized unit.
- Administer cardiovascular support and inotropes as needed.
When is surgery planned for infants with lung hypoplasia and diaphragmatic hernia?
Surgery is planned once the baby is stable.
What are the surgical options for repairing a diaphragmatic hernia in stable larger infants?
Surgery can be performed via laparotomy or thoracoscopy. The objective is to reduce the hernia contents into the abdomen and close the diaphragmatic defect.
How is the diaphragmatic defect typically repaired during surgery?
The diaphragmatic defect can be repaired using a primary sutured repair or by placing a synthetic patch.
What happens if the abdomen is too small to accept the hernia contents during surgery?
If the abdomen is too small, a temporary abdominal patch closure is performed, with staged reduction of the abdominal wall defect.
What is a common long-term issue in severe cases of lung hypoplasia and diaphragmatic hernia?
Chronic lung disease is common, and these babies may require oxygen for an extended period.
How is gastro-oesophageal reflux managed in infants with lung hypoplasia and diaphragmatic hernia?
Many babies will have gastro-oesophageal reflux, which can often be controlled with medications.
What complications may arise from associated malrotation in these babies?
The associated malrotation is occasionally symptomatic, though adhesions from surgery typically prevent volvulus.
What are some potential developmental challenges for infants with severe lung problems?
Some infants may experience failure to thrive (due to serious lung problems and increased caloric needs), gastro-oesophageal reflux (GORD), and developmental issues.
What long-term side effect may occur in infants who underwent ECMO treatment?
Infants who had ECMO may develop some degree of hearing loss.
