Congenital Diaphragmatic Hernia

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Congenital Diaphragmatic Hernia

• Jeff Wu
• Pediatric Surgery Clerkship, David Geffen SOM at
  UCLA
• March 8, 2006

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• ID/CC 38 4/7 week gestation newborn male NSVD to
  31 y/o mother.
• PMHx patient antenatally diagnosed with CDH at
  28 weeks.
• Infant intubated in delivery room
• Placed on conventional mechanical ventilation
• PE Right-deviated trachea diminished breath
  sounds on L abdomen scaphoid
• pH of 6.74, pCO2 of 111, pO2 of 98, bicarbonate
  14.8, oxygen
• Saturation 82, and base deficit of -22.
• High-frequency oscillator Mean airway pressure
  of 18, FiO2 100,
• Nitric oxide 20 ppm. Amplitude was 38 to 42 and
  freq 10 Hz.
• O2 Sat 48.
• Head ultrasound was obtained no evidence of
  intraventricular
• hemorrhage

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What is it?

• Failure of diaphragmatic fusion
• Foramen of Bochdalek (85-90)
• Foramen of Morgagni

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What is it?

1. Herniation of abdominal contents into thoracic
   cavity
2. Pulmonary hypoplasia

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Incidence

• 12500 live births
• 1100 cases in the U.S. annually
• 230M spent on hospitalization
• Despite advances in care, survival remains around
  65

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Diagnosis

• Antenatal
• U/S at 20 weeks gestation
• 60 of CDH patients are diagnosed antenatally
• Proposed prenatal determinants of outcome
  polyhydramnios intrathoracic stomach or liver
  abdominal circumference lung-to-head ratio
• Also search for associated malformations

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• Postnatal
• clinical signs of respiratory distress
• XR absent diaphragmatic outline, loops of bowel
  in chest, tip of NG tube in thorax

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Initial Management

• Goal oxygenate, avoid barotrauma
• Intubate conventional mechanical
  ventilation
• /- Sedate
• NGT for decompression

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Pathophysiology
1) Pulmonary hypoplasia compression theory
- modeled in fetal lambs - rationale for
early surgery to remove compressive bowels
from thorax global embryopathy - modeled
in newborn rats - rationale for new therapeutic
ideas 2) Pulmonary hypertension causes
persistent fetal circulation
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Medical Management

• Goal stabilize patient until definitive surgical
  repair
• Pulmonary vasodilators inhaled nitric oxide
• Inotropes, systemic vasoconstrictors
  dobutamine, dopamine, epinephrine
• high frequency oscillatory ventilation
• ECMO
• Surfactant
• Antenatal steroids?
• Liquid ventilation?

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ECMO
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Surgical Management

• typically a subcostal incision (thoracotomy
  rarely considered)
• gentle reduction of abdominal viscera
• identification and excision of hernia sac (found
  in 10)
• approximate diaphragmatic tissue with sutures,
  Goretex, or muscle flaps

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Developing Therapy

• Fetal surgery idea to remove herniated bowels
  early in development stemmed from Compression
  hypothesis initial findings demonstrated no
  survival benefit.
• PLUG fetal surgery is an idea which makes use of
  the observation that laryngeal atresia is
  associated with enlarged hyperplastic lungs Plug
  the Lung Until it Grows
• Growth factors injected during embryologic
  development
• - Vitamin A important in lung development, maybe
  can prevent CDH prenatal treatment of Nitrofen
  rats with Vit A showed decreased incidence of CDH
  at term.

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Take home points
Defect, herniated bowel, and pulmonary
hypoplasia Treat pulmonary hypoplasia/hypertension
medically until stabilized Timing of surgical
therapy based on optimization of patient Possible
new therapies including prevention?

• An ounce of prevention is worth more than a
  pound of cure. - Benjamin Franklin

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References

• 1 Downard CD, Wilson JM. Current therapy of
  infants with congenital diaphragmatic hernia.
  Semin Neonatol. 2003 Jun8(3)215-21.
• 2 Smith NP, Jesudason EC, Losty PD. Congenital
  diaphragmatic hernia. Paediatr Respir Rev. 2002
  Dec3(4)339-48.
• 3 Jesudason EC. Challenging embryological
  theories on congenital diaphragmatic hernia
  future therapeutic implications for paediatric
  surgery. Ann R Coll Surg Engl. 2002
  Jul84(4)252-9.
• 4 ONeill J, Grosfeld J, Fonkalsrud E. Chap 44.
  Congenital Diaphragmatic Hernia. Principles of
  pediatric surgery, 2nd Ed. Mosby 2003.