I'm back here again
Like a man who has two hearts
One day they fell apart
Both of them played their part, you know
-Men At Work, "Two Hearts"
http://www.newscientist.com/article/dn17460-girl-with-two-hearts-healthy-after-loss-of-one.html
Girl with two hearts healthy after loss of one
* 10:58 14 July 2009 by Andy Coghlan
A British girl has recovered fully after spending 10 years with an
extra heart transplanted alongside her own.
Surgeons this week described in detail how they saved her life twice,
first by transplanting the heart, and then by taking it out again 10
years later.
Now 16 years old, Hannah Clark received a second heart in 1995 at the
age of two to do the work of her own heart – the muscles of which were
rapidly failing through cardiomyopathic disease.
Ten years after the operation, her own heart appeared to have fully
recovered, but the donor heart – originally taken from a 5-month-old
baby girl – was flagging.
Moreover, Hannah's life was again threatened, this time by a type of
lymph cancer caused by an otherwise dormant virus, called the
Epstein-Barr virus. The cancer struck four times altogether, mainly
because immunosuppressive drugs to stop the donated heart being
rejected prevented Hannah's immune system from keeping the virus in
check.
So in February 2006, the second heart was removed, Hannah's
immunosuppressive drugs halted, and within days her cancer
disappeared, apparently for good.
'Magical recovery'
On Monday, she appeared with her family at a press conference in
London alongside the two surgeons who had saved her life.
"The possibility of recovery of the heart is like magic," says Magdi
Yacoub, the heart surgeon at Harefield Hospital in Middlesex, UK who
performed the operations. "Now, her heart is functioning normally."
"This is the first time a second donor heart has been removed safely,"
according to Victor Tsang of Great Ormond Street Hospital in London
where the operation took place three years ago.
Tsang says that about 50 patients had received second hearts between
1974 and 1983 in a "piggyback" procedure first developed by Christiaan
Barnard, the South African heart surgeon who performed the world's
first heart transplant in 1967.
Backup plan
The principle behind using a pair of hearts was that if the
transplanted heart failed through rejection, the patient's own could
sustain life till another transplant was available. But the procedure
was superseded once powerful immunosuppressive drugs were available,
and has largely been abandoned since the mid 1980s.
Hannah, though, was an exception because of her circumstances. Giving
her a second heart when she was two was the only way to save her life.
No heart of the right size was available, ruling out a straight swap,
and resistance to blood flow from her lungs was causing her to
deteriorate, so time was running out.
So when a much smaller heart became available – from a baby half
Hannah's weight at the time – her medical team decided the only
life-saving option was to plumb the heart directly into Hannah's to
make a double heart.
For the first few months, the new heart did nearly all the work, but
this "rest" gave Hannah's own heart a chance to begin recovery. By the
time of the second heart was finally removed, Hannah's heart was doing
virtually all the work itself.
Wasted hearts
But now the viral cancer, called post-transplant lymphoproliferative
disorder (EBV-PTLD), was threatening Hannah's life, with cancerous
swellings in her windpipe obstructing her breathing to the point where
she needed to be put on a ventilator.
So Yacoub and Tsang had to weigh up the balance between retaining the
second heart to continue helping Hannah's own heart and taking it out
so that the immunosuppressive drug regime could be halted and the
cancer destroyed.
In the end, they opted to take out the heart, thankfully leading to a
full recovery.
The surgeons say that mechanical hearts are now more widely available
to act as "auxiliary pumps" in patients with cardiomyopathies until a
suitable donor comes along. However, a quarter die still while
waiting. This toll could be cut, they say, if smaller hearts were used
as in Hannah's case, to do some but not all of the work. At present,
many such hearts are discarded because they are the wrong size.
--
((Udhay Shankar N)) ((udhay @ pobox.com)) ((www.digeratus.com))
