Page 84 - The Economist Asia January 2018

The Economist January 27th 2018
68 Science and technology
2 ing”; “for soothing a baby”; “for healing ill- points higher than healing songs and 1.19 produce bile; with insulin to regulate the
ness”; “for expressing love for another”; points higherthan love songs. organ’s metabolism; and with nutrition in
“for mourning the dead”; and “for telling a Healing songs proved a bit more trou- the form ofglucose and amino acids.
story”. The first four of these were real blesome. They scored only 0.47 and 0.31 Once a liver is hooked up inside a me-
functions, as stated by the people from points higher than dance and love songs tra, its health can be tracked by monitoring
whom the song in question had been col- respectively for “to heal illness”, and were things like blood flow, bile production and
lected. The last two were made up, and statistically indistinguishable from lulla- aciditylevels. All these data permit a trans-
were included as foils. bies. The outlier, though, was love songs. plant team to see how the organ is faring.
Dr Mehr and Mr Singh found that vol- Listeners could distinguish them from Moreover, a metra not only keeps a liver
unteers’ perceptions of a song’s function healing songs, but not from lullabies or healthybutcan, in some circumstances, ac-
were generally in good agreement with its dance songs. tually improve its health. Putting a liver
actual function—with one exception. Why love songs were hard to identify is that has been cooled for storage into a me-
Dance songs were particularly easy to unclear. Because such songsinvolve show- tra can reverse damage it has sustained
identify. They rated 2.18 points higher on ingoffto the objectofone’saffections, they when cold by providing an environment
the certainty scale as being used “for danc- may require more creativity, and thus gen- in which its natural propensity to rejuve-
ing” than lullabies did; 1.38 points higher erate more variety than lullabies or dance nate can come to the fore. More remark-
than love songs; and 1.09 points higher songs. Perhaps the fact that both dancing ably, metras may even be able to recondi-
than healing songs. Similarly, lullabies and cooing are involved in romance con- tion livers that are sickly because they
were rated 1.53 points higher than dance fused listeners. This genre aside, however, contain too much fat, and are thusuntrans-
songs as being “to soothe a baby”, 1.42 Andersen was clearly onto something. 7 plantable. Once a liver has been removed
from the body that was makingit fat, it will
recover surprisingly quickly. A mere two
Medicine days in a metra “liver spa” is enough to
External organs have a palpable positive effect on the
health ofsuch an organ.
At the moment, this last benefit is of
onlytheoretical value, because regulations
mean livers for transplant can be stored in
a metra for a maximum of 24 hours. That,
though, is twice the maximum a liver
ought to be kept chilled for transplant, and
Livers fortransplantcan nowbe keptalive atbodytemperature
almostthree timesthe nine-hourlimit gen-
HEN Constantin Coussios, a bio- erally preferred—hence Dr Coussios’s in-
W medical engineeratOxford Universi- souciance at the hospital back in 2013. Re-
ty, arrived one day in 2013 at the transplant search on metras suggests that the 24-hour
centre of King’s College Hospital, in Lon- limit could safely be raised to three days,
don, with a liverfortheiruse, he triggered a and possibly longerthan that.
brief flurry of panic. Two other livers had Twenty-four hours is, though, still long
arrived at the same time. The hospital had enough to conduct tests on the quality of
only one operating theatre in which liver liversthatmightotherwise be rejected. The
transplants could be carried out—and be- existingassessmentofa liverfortransplant
cause livers intended for transplant can be is necessarily subjective, because there is
kept in cold storage for no longer than 12 no sure way to tell if a cooled organ will
hours, the situation looked serious. work normally when it is warmed up and
What saved the day, and possibly a pa- reconnected. Many surgeons therefore err
tient’s life, was that Dr Coussios was bring- on the side ofcaution, knowingthatif they
ing not a cold liver, stored on ice, but a put a defective liver into a patient, it will
warm one. Instead of having had its me- probably kill him.
tabolism slowed, it was fully functional. All this means that using metras should
This was because it was connected to a increase the availability of livers for trans-
supply ofblood and nutrients inside a spe- plant. Dr Coussios reckons that reducing
cial box known as a metra (a Greek word Now for a bit of metra-analysis the rate of rejection by surgeons could, by
meaning “womb”), invented by Dr Cous- itself, double the number which can be
siosand hiscolleague PeterFriend. The me- A metra is designed to keep the organ it used in Britain. Metras could also make it
tra even had a graphical interface to show, is nurturing supplied with the correct easier to perform the tricky operation of
moment by moment, how well its cargo amount of blood—an amount which va- splitting livers in two, which is sometimes
was faring. Dr Coussios told the surgeon to ries from one instant to the next. It detects done to create a child-sized organ while
transplant the cold-stored livers first. The the organ’s demand for blood by monitor- still leaving enough over to transplant into
one he had brought would keep. ing pressure in the arteries and veins going an adult. The use ofa metra is likely to per-
That was in the early days of metras. into and out of the liver. It then adjusts the mit these divisions to be carried out more
Now, the devices are starting to spread. So powerofits pump in response. slowly and carefully.
far 25 have been deployed around the The blood in question has been tin- The metra is being commercialised by
world and othersare aboutto be. There are kered with to make it more effective. It has OrganOx, a firm based in Oxford. DrCous-
also plans, by Dr Coussios and others, to had itswhite cellsand plateletsremoved to sios estimates that the world’s hospitals
extend the idea behind the metra to the avoid inflammation, clottingand the trans- have need for about 300 of the machines,
preservation of other vital organs. If that fer ofdisease. For the further prevention of but the firm says it will have reliable repeat
works, it would change the transplant clotting, it has had anticoagulants added. business from furnishing the metras it has
business by improving both the supply And it has been boosted with special sold with the disposable plastic connec-
and the health ofsuch organs. chemicals that the liver needs in order to tors that hook machine and organ up to- 1