CCAM Fetal Surgery

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CCAM Fetal Surgery

• Shabina Nazir
• MS113
• 12/02/04

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Introduction

• Until recently, little could be done for unborn
  babies suffering from anatomical abnormalities
• But now, improved fetal sonographic techniques
  make therapy for the fetus an option
• With these advances, the diagnosis of many fetal
  anatomical defects has improved
• We now get a much better image of the fetus
  inside its sac and can study functional
  abnormalities

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Introduction Contd.

• These abnormalities, if left alone, would result
  in death, even after birth
• One such anatomical abnormality that has
  life-threatening prenatal pathophysiological
  consequence and that may benefit from correction
  before birth includes congenital cystic
  adenomatoid malformation (CCAM)

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Congenital Cystic Adenomatoid Malformation

• CCAM is a benign cystic lung mass
• Characterized by overgrowth of terminal
  bronchioles at the expense of alveolar spaces
• The lesion is almost always unilateral, usually
  confined to one lobe, with no preference for the
  right or left lung
• No known cause for this birth defect
• Cystic tissue involved never functions as normal
  lung tissue

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CCAM
Large left-sided CCAM in fetal chest
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CCAM

• CCAM was briefly described by Stoerk in 1897
• Described in detail, acknowledged as a separate
  entity, and introduced into English literature by
  Chin and Tang in 1949

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CCAM

• CCAM is categorized according to the size of the
  cysts
• Type I has large cysts
• Type II has multiple small cysts (less than 1.2
  cm in diameter)
• type III consists of microscopic cysts. Since the
  cysts in type III are microscopic, the ultrasound
  appearance is of a highly echogenic solid tumor
• Type III CCAM has the worst prognosis

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Type I CCAM
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TYPE III CCAM

• The normal lung tissue is compressed, and the
  heart is displaced to the left

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CCAM

• May be a coincidental finding at fetal ultrasound
  or it may be diagnosed when an ultrasound is done
  on a fetus in distress
• Most CCAMs shrink
• In rare cases, they become cancerous later in
  life
• Extra large CCAMs can result in serious and
  potentially fatal problems in fetuses

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Associated Risks

• CCAM can lead to a mediastinal shift, impaired
  cardiac function, and fetal hydrops (congenital
  heart failure)
• If the fetus develops hydrops, the mother may
  "mirror" the sick fetus, becoming sick with signs
  of preeclampsia
• Large CCAMs limit lung development, resulting in
  "pulmonary hypoplasia" or small lungs
• The CCAM also can push on the heart and the
  esophagus of the fetus, preventing the fetus from
  swallowing amniotic fluid. This can result in the
  mother suffering from polyhydramnios
• The presence of polyhydramnios and fetal hydrops
  indicate a likely poor outcome

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Ultrasound Appearance

• It appears on ultrasound as an intrathoracic lung
  tumor that may be solid or cystic
• The growth appears as a bright mass, the size of
  which varies with each fetus
• The heart may be shifted to the opposite side of
  the chest and the normal lung tissue may be
  difficult to see on the side of the mass
• Fetus may have abdominal ascites, pleural or
  pericardial effusions, skin or scalp edema,
  polyhydramnios, or a slightly thickened placenta

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CCAM
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Fetal CCAM
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Fetal CCAM
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CCAM
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Longitudinal section of thorax showing a large
cystic lesion
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CCAM at 22 Weeks Gestation

• Right-sided fetal lung mass with dominant cyst
  measuring greater than 1 cm

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Treatment

• Number of options available when considering
  fetal therapy
• If the mass is cystic in appearance, then it
  usually can be drained percutaneously
• If the fluid re- accumulates, a shunt can be
  placed to continuously drain the cyst
• If hydrops develops, the mass needs to be removed
  during open fetal surgery
• This procedure usually occurs prior to 28 weeks
  of pregnancy

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Treatment Contd.

• Fetal surgery is currently performed in a few
  select facilities, reflecting its extremely
  specialized nature.
• Fetal surgery
• Evolved alongside the development of refinements
  in fetal imaging techniques- ultrasound and
  Doppler technology
• Reserved for fetuses with conditions associated
  with an extremely poor prognosis
• Two patients are involved in fetal surgery, the
  fetus and the pregnant mother
• Pre-operative workup includes detailed fetal
  ultrasonography to diagnose and define the extent
  of the lesion
• MRI and fetal echocardiography
• amniocentesis to rule out major chromosomal
  anomaly

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History of Fetal Surgery

• UCSF (University of California, San Francisco)
  Childrens Hospital was the first in the world to
  successfully perform open fetal surgery in 1981
• In 1990, the UCSF fetal surgery team conducted
  the first successful fetal resection of
  congenital cystic adenomatoid malformation of the
  lung (CCAM)

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Fetal Surgery
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Procedure

• The mother's uterus is surgically opened, like a
  cesarean section, and the fetus' chest is opened
  and the mass is removed
• Fetal surgery begins with the administration of
  analgesics and antibiotics
• This is followed by the administration of
  anesthetic agent that provides anesthesia for
  both mother and fetus
• The uterus is exposed with a low transverse
  abdominal incision, and medications are injected
  into the fetus to lessen fetal stress and also to
  reduce the chance of pre-term labor
• Approximately 400 ml of amniotic fluid is
  aspirated through a trocar passed under
  ultrasonographic guidance. The fetus and the
  uterus are continually bathed in warm saline
  (38-40C)

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Procedure Contd.

• Fetal and placental position are determined by
  ultrasound and the hysterotomy is extended with a
  special, absorbable uterine stapler
• appropriate fetal part is exposed. "Only the part
  of the fetus that it is necessary to reach for
  surgery is exposed. The rest of the body remains
  in the uterus
• A miniature pulse oximeter on the fetal hand and
  an implanted radiotelemetric device monitor fetal
  electrocardiogram, temperature, and intrauterine
  pressure
• After the surgical repair is made, the exposed
  part of the fetus is returned to the uterus, the
  staples are removed, the amniotic fluid
  substitute (warmed saline solution and nafcillin)
  is instilled, and a water-tight, two-layer
  uterine closure is supplemented with fibrin glue
  to help seal membranes

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CCAM Fetal Surgery
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Complications

• Complications of this procedure include
• fetal loss
• premature labor
• infection
• amniotic fluid leakage from the incision

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Post Surgery

• Following surgery, mother and fetus receive
  intensive care with constant monitoring of
  maternal hemodynamics, fetal condition, and
  uterine contractions, usually for 48 hours
• After this procedure the mother will need to be
  on bedrest for the remainder of her pregnancy and
  medications to help control preterm labor
• Shortly after in utero lobectomy, the fetus'
  hydrops resolves and the squished lobe starts to
  expand to fill the chest

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PRE and POST
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CCAM

• The remaining lung tissue will continue to grow
  until the child reaches eight years of age

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References

• http//www.childrenshospital.org/cfapps/A2ZtopicDi
  splay.cfm?TopicCysticLungDisease
• http//www.ucsfhealth.org/childrens/medical_servic
  es/surgical/minimal/conditions/lung/diagnosis.html
  
• http//www.pennhealth.com/phys_forum/pto/v6n2/wh.h
  tml
• http//www.indianpediatrics.net/nov2000/nov-1269-1
  274.htm
• http//www.fetalsurgery.chop.edu/CCAMint7.shtml
• http//pediatrics.aappublications.org/cgi/content/
  abstract/30/5/759
• http//www.childrenshospital.org/cfapps/A2ZtopicDi
  splay.cfm?TopicCongenital20Cystic20Adenomatoid
  20Malformation2028CCAM29
• http//www.emedicine.com/ped/topic534.htm
• http//www.fetalsurgery.ucsf.edu/ccam.htm
• http//home.earthlink.net/vigg/Miracles.html
• http//www.ajronline.org/cgi/content/full/175/6/15
  51
• http//www.obgyn.ufl.edu/ultrasound/MedinfoVersion
  /sec14/14_5.html
• http//www.thefetus.net/page.php?id397