Everyone knows the importance of the Lungs. It is a primary spongy organ that serves as a gas exchanger. It is very delicate and highly sensitive to damage. According to the American Lung Association, transplantation carries out only in 28% of donor lungs as it is sensitive. The reason being, while transporting, the donor lungs are kept in an icebox. This slows down the metabolic activity and thereby eliminates many of it from the criteria of transplantation. But is it possible to regenerate our damaged lungs using the blood of live pigs?
Ex Vivo Lung Perfusion (EVLP) comes into action:
So far, EVLP, a procedure to preserve and evaluate the lungs, has been used during lung transplantation. EVLP helps to restore the ventilation and circulation of the ex vivo lung. The donor’s lungs kept in a sterile plastic dome is connected to a pump, perfusate(fluid used in perfusion) and a ventilator. Also, it contains a reservoir, a thermostat (automatically regulates temperature), an oxygenator (supplies oxygen), and filters. The passage of Steen solution(perfusate) provides oxygen, nutrients, and proteins to the lungs and it also maintains the lungs at the normal body temperature(37°C). This helps in healing any lung injury and removal of excess water from the lungs. Only 6-8 hours of support can be provided which is a short time for recovery. It is a major drawback of EVLP.
Xenogenic Cross Circulation- Idea of Transformation:
The researchers from Columbia Engineering and Vanderbilt University have been trying to provide more lungs for patients for the past eight years. For this, a Xenogenic (outside the organism) cross circulation technique has been introduced for connecting the donor lung with host pig.
The researchers collected six damaged lungs from different transplant centres and then connected each lung to an anaesthetized pig’s neck. They made sure that the regular supply of air is being provided to the lungs using a ventilator. Later they added immunosuppressant drugs for preventing pig’s immune system from taking any action on this foreign tissue (donor lung). After 24 hours, these damaged, swollen lungs seemed to be healthy. A series of tests revealed the improvement in the structure of tissues, cells, capacity for delivering oxygen and respiratory function.
WBCs in the Recipient
Pig is an effective animal model for human conditions as the size and weight of a pig’s lungs are similar to those in humans. Based on this, the senior researcher Dr.Gordana Vunjak-Novakovic aims to repeat the procedure on damaged donor lungs with medical-grade pigs. From the current study, traces of pig’s white blood cells have been found in the donor lung which could activate an immune response in the recipient later. However, the complete removal of pig cells from donor lung is impossible now and through further more experiments it may be possible.
Does this research resemble a Science Fiction?
Moreover, the researchers are hoping to use a human host instead of swine. Imagine a transplant patient being hooked up to a lung (“breathing”) with a respirator outside the body. Yes, in upcoming years, researchers hope that the lung recipients can regenerate donor lung with their own blood. This technique does not guarantee to save the most severely damaged lungs. But it saves 2 out of 4 rejected lungs and thereby increases the number of lungs available for patients in the waiting list.
After all, the COVID-19 pandemic has undoubtedly increased the number of patients with damaged lungs. Hope that further development in this technique provides a “touch of compassion” for the needy and justice for donors.
That breath that you just took….that’s a gift.
-Rob Bell
Let Organ Donation be the next step to help our fellow beings.
DIVE IN DEEP
Milestones in this Research:
2017 – Demonstration of the possibility of cross circulation support for lungs outside the body
2019 – Demonstration of the effectiveness of the cross circulation through the regeneration of damaged Swine lungs.
2020 – The researchers succeeded in increasing the duration of support upto 4 days
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