born closer to term. Now, let’s look at
some common abnormalities of lung development
and one of the more common among lung development
abnormalities is tracheo-oesophageal fistula
with oesophageal atresia. Now these are standard
terms which have particular meanings.
So let’s just explain what those particular terms mean.
In addition, we’ll also find tracheo-oesophageal
fistulas on their own, syndromes called VATER
or VACTERL, which are a combination of different
kinds of defects all present in one child, lung
hypoplasia where the lung is underdeveloped,
and even lung agenesis where a lung completely
fails to develop altogether. So tracheo-oesophageal
fistula with oesophageal atresia is the most
common of the lung conditions occurring in
perhaps one in 3,000 or one in 4,500 live
births. As you can see from the diagram, what
happened is that there is a connection from the
oesophagus to the atresia. This is the fistula.
In addition, the oesophagus has blind ending,
and it can either be above or below
the level of the fistula. What happens under
these circumstances is that there’ll be
an excessive amount of amniotic fluid present.
Because normally, the baby will swallow amniotic
fluid and recycle it. So the amniotic fluid
will build up in excess. Once the baby is
born, when it begins to suckle, milk was likely
to run down the oesophagus into the trachea
and what that will do, in turn, is to make
the baby choke on feeding, and perhaps
regurgitate milk. Milk will dribble from the mouth
and it’s important to note that it dribbles
rather than being expelled forcibly. This
is not projectile vomiting. I would indicate
a different condition, pyloric stenosis, which
will be covered in another lecture.
Initially, the baby will be breathing normally, but
one of the consequences of milk entering the lungs
is that pneumonia may subsequently develop.
Another sign that tracheo-oesophageal fistula
with oesophageal atresia is present is that
when the baby takes in-breath, then air
can get into the stomach, and this may expand
the stomach as a consequence. So we can see
this in the lower form of the two diagrams.
Less common is a fistula on its own.
So this is sometimes called an H-type tracheo-oesophageal
fistula. And only 4 percent of cases of tracheo-oesophageal
fistula with oesophageal atresia are tracheo-oesophageal
fistula on their own. Nonetheless, milk may
still enter the respiratory system driven
by the pressure of air. So a baby may still
show many of the same signs as we saw with
tracheo-oesophageal fistula with
oesophageal atresia. I mentioned complex syndromes
and VATER or VACTERL syndrome, maybe one of those,