Heart Valves Are For Life
What are heart Valves
Heart Valves separate the four chambers of
heart that collect and pump blood. They control the direction of originated and
unoxigenated blood flow for proper functioning of heart. Heart valves are
marvels of natural engineering as they last a life time, even for few hours
after death.
Valve
Damage
Sometimes valves get diseased and do not
work right. They might not open all the way leading to reduced flow of blood or
they might have problem closing leading to leakage of blood backwards. Due to
these problems the heart will have to work harder to pump the same amount of
blood and the blood may back up in the lungs. Therefore valve repair or replacement
is required.
Heart valves get damaged in various
diseases either because of age, infection or failure of previous heart valves
operations. Sometimes, as the problem exists by birth, the valve need
replacement even for new-borns.
Rheumatic heart Diseases (RHD) is one of
the key reasons for valve related problems. Many researches have established
that the countries with low socio economic groups like India are more
susceptible to RHD due to conditions like poor hygiene, lack of medical
facilities, poverty, illiteracy and fear of drugs.
Need
of Valve Transplantation
Every year, more than 1 lac heart valve procedures
are being done worldwide and the number is expected to go as much as 8 lakh by
2050.
If valve is to be replaced then there are
options of mechanical or biological transplants. The biological valves obtained
from human beings through cadaveric donation, called homograft, are closest to
the ideal valve as they are silent, last longer, do not require
anti-coagulation and are comparatively free of complication.
Out of the four valves in heart 95% of
valve replacements are performed for mitral or aortic valves.
Cadaveric
Valve Donation
In case of a cadaveric donor, heart valves
are tissues that can be harvested even from the patients whose complete heart
is not suitable for transplantation. Heart valves must be recovered within 15
hrs
if the body is not refrigerated of within
24 hrs if the body is refrigerated within 12 hours of death. Most important is
that even if transplant surgeons are not available at the centre where death
occurs, even a general surgeon extract the heart and sent it to the specialized
centre on required temperature and time frame. Once it reaches the specialized
centre of transplant, the experts can extract valves by careful aseptic
dissection from the donor heart. Then, valves are inspected carefully by the
expert’s medical team for the suitability of that valve for preservation and
future use in the patient.
After that valves are packaged in asepting
allograft packaging and then stored at -150c in liquid nitrogen as freezed
valve and they can be utilized in next 10 years.
Advantage
of Valve Transplant
The benefit of human heart valve is that
they are closest to natural and life saving. After transplantation, the patient
does not require blood thinners which makes is particularly beneficial for
young children, pregnant women and older age group. They provide excellent
hemodynamic performance due to a more natural function of the surrounding
structures.
However, with limited number of organ donors in our country, it is challenging to find homograft’s for the needy patients requiring valve transplant. It is indeed the need of the hour to develop homograft banks and raise awareness of valve transplant & organ donation.