5 innovations in organ transplantation

The OrganOx metra®: keeping donor livers alive outside the body

Once an organ becomes available, a series of tests and screenings need to be done to match a donor organ to your body. However, with standard static cold storage methods, the types of assessments on donor organs are limited because sub-optimal organs, such as livers, do not tolerate it well. There is no reliable way to assess true organ viability prior to transplantation surgery.¹

The metra® is a perfusion system that keeps donor livers alive outside the body before being transferred into a patient. The liver receives oxygenated blood, medications and nutrients at normal body temperature and can be preserved for 24 hours.

This critical care medical device also improves clinical understanding of liver function, leading to fewer livers being discarded. Because this normothermic perfusion system maintains the liver at the same state as it would be inside the body, surgeons can monitor a range of parameters such as perfusate lactate clearance, pH, transaminase levels and more. Consultants can make informed decisions about liver transplants which results in fewer organs being discarded.

This ground-breaking technology developed by OrganOx, with the help of Team Consulting, has already supported over 1,500 liver transplants worldwide.

Successful kidney transplants: changing blood type of donor kidney

Imagine that you’ve been suffering for a long time with kidney disease and have been on a transplant list for years. Suddenly, a kidney becomes available but it’s incompatible – the wrong blood type. What if you could change an organ’s blood type?

That’s exactly what a team of researchers at the University of Cambridge have done. If the organ donor is blood type A, it cannot be transplanted to a type B receiver and vice versa. However, researchers have successfully altered the blood type of three donor kidneys. So now, if say a donor kidney is blood type A, it can be changed to the universal blood type O.

The team used a normothermic perfusion machine to flush enzyme-infused blood through the donor kidney. This enzyme can remove blood type markers on the kidney’s blood vessels which allows the scientists to convert it to the universal O type.

This breakthrough means that more donor kidney transplants can become available and thus has the potential to reduce transplant lists.

Emptying livers of their cells

This relatively new and experimental method has been trialled on livers. The process involves ‘emptying’ the liver of its cells by a process called decellularization. This leaves a scaffold called an extracellular matrix which can later be decellularized using the receiver’s native vascular system.²

The benefit from using this method on donor organs is that it ‘removes’ the donor’s antigens and other cellular elements which have the potential to lead to an adverse immune response and ultimately, organ rejection.

OrganEx: blood substitute to revive dead organs

OrganEx was developed by researchers at the Yale University School of Medicine. The technology works by connecting the body to a pump that sends a blood substitute to organs that have been damaged by a lack of oxygen after death.

In addition to carrying oxygen, the fluid has the correct acidity and levels of electrolytes. It is made up of 13 drugs including blood thinners and anti-inflammatory compounds. Similar to the metra®, this artificial blood mixture has the potential to keep donor transplants healthy before surgery. When blood supply to major organs is cut off or reduced during organ removal for example, it is likely to result in cell death due to a lack of oxygen, an irreversible process. By perfusing organs, such as the heart for example, with this blood substitute, it has the potential to revive organs which would otherwise become unviable.

The last innovation is less akin to sci-fi movies but relates to another crucial aspect of organ transplants: logistics and infrastructure.

A real-time organ tracker

Organ transportation can be a real logistical ordeal. In the United States alone, there are over 100,000 people on the organ waiting list. So, when an organ becomes available, there are multiple challenges involved. Up to 12 transplant centres might be interested in securing the organ so procurement organisations (OPOs) have to make decisions as to which patient on the waiting list will receive the transplant. Once a decision is made, the question is: how will the organ get there?

These decisions have to be made extremely quickly as once an organ is outside a donor’s body, it’s a race against the clock before it can no longer be used for transplant. It depends on a few factors including the type of organ but, typically, a donor organ has to be transplanted within 6 to 24h.

OPOs affiliated with UNOS came up with a real-time organ tracker which can give surgeons live updates on arrival time. If surgeons know exactly where the transplant is and what time it will arrive, they know when to start prepping receiver patients for surgery, so no time is wasted. In addition to providing information on location, this new tracking system can show all the suggested travel routes when an organ becomes available such as flight options or travel time if it is going to be transported by car.

Although not directly related to organs themselves, this new platform increases organ viability and thus chances of successful transplantation.

Some of these transplant innovations are already helping thousands of patients successfully acquire a life-saving new organ. Other breakthroughs mentioned in this blog are still at the experimental stage.

I am proud to work for a medical device company that can make a real difference to patients, including in the surgical and critical care field. If you need help developing life-saving surgical devices, please get in touch.

References

1. Nasralla, D. et al., 2018. A randomized trial of normothermic preservation in liver transplantation. Nature, 557(7703), pp.50-56.

2. Fathi, I. et al., 2021. Decellularized Whole-Organ Pre-vascularization: A Novel Approach for Organogenesis. Frontiers in Bioengineering and Biotechnology, 9.