TWIN SEPARATIONS: A HISTORY OF RISK
By Martin Hutchinson
BBC NEWS
7762588.stm
2008/12/03 13:53:59 GMT
The death of baby Hope following an operation to separate her from her
sister is a reminder that despite advances, the outcome of conjoined
twin surgery remains unpredictable.
Even in the modern era, these operations are among the most challenging
for doctors, with painstaking preparation involving large teams
of specialists.
Only a handful of hospitals in the world have the resources and skills
needed to attempt separation.
Yet the history of such operations stretches back more than a century.
Conjoined twins are created just a few days after they are conceived –
most likely by the incomplete splitting of the fertilised egg.
Most are stillborn, and a proportion of those who a born alive do
not survive long afterwards.
They can be joined at the hip, the back, the chest, or even the head,
perhaps sharing one or more internal organs, each adding to the
complexity of any operation to separate them, as the surgeon seeks
to provide each with enough to support life.
In past centuries, when separation was frequently not an option,
there are many references to twins who grew up still joined.
These included two pairs reputedly born in Rome in the fourth and
seventh centuries AD and Armenian twins joined at the abdomen in the
tenth century AD, alongside the so-called "Biddenden Maids" from
England, who were joined at the spine, and reportedly lived into
their 30s.
The term "Siamese twins", now discarded, refers to Chang and Eng
Bunker, who found fame as circus performers.
Early operations
While there are reports of unsuccessful attempts to separate twins in
the 1600s, what is thought to be the first successful twin separation
was carried out in 1689, on twins joined only by a ligament at
the chest.
While operations on other twins with comparatively simple anatomies
were also successful, later attempts to separate those with more
shared organs and tissues were frequently only partially successful.
One example is in 1900, with chest-joined Brazilian sisters Maria
and Rosalina separated, only for Maria to die within days.
However, by the 1950s, specialists were becoming far more practised,
with the first recorded successes in separating twins joined at
the skull.
US surgeon Dr C. Everett Koop also managed to separate two girls who
shared a bowel, urinary system and genitals – one even managed to go
on to mother her own children.
‘Preparation key’
Professor Alastair Millar, from the Red Cross War Memorial Children’s
Hospital in Capetown, heads a centre responsible for dozens of
successful operations in recent years.
He said the key to success in recent years was the ability to plan
complex operations well in advance.
"You can now create 3D models on the computer to work out just how
you are going to do these operations.
"We are just getting better at everything – the surgical team has
been able to discuss what to expect and what role each will play."
However, he said: "In the end, it might not matter how extensively
you have prepared, there can always be a surprise for the surgeon
when the operation starts, an unexpected complexity.
"And if the operation is an emergency, then the difficulties are
far greater."