Tyson Smith woke up on Valentines Day with two hearts. A rare surgery called "piggyback" transplantation allowed two hearts to do what neither could do alone.

Klingons are no longer the only race in the galaxy that benefit from having redundant organs. Straight out of Star Trek, surgeons last month at University of California, San Diego’s Thorton Hospital performed a rare surgery to save Tyson Smith’s life. He woke up on Valentine’s Day with two hearts—literally.

The thirty-six year old Smith was suffering from congenital heart disease which made his heart grow progressively larger. A normal heart is about the size of a person’s fist––Smith’s heart is three times that size. It’s abnormal size caused it to beat irregularly, weakening its ability to pump blood. It was working at about three- to four-fifths the capacity of a healthy heart. To make matters worse, Smith has pulmonary hypertension, a type of high blood pressure in the lungs that made it even more difficult for the impaired heart to deliver blood and oxygen to the body. The reduced blood flow turns the simplest activity into a grueling endeavor. It took Smith three breaths to deliver the same amount of oxygen carried by a single breath of a healthy person. That sort of exertion is debilitating: before the surgery, he was sleeping 20 hours a day. The condition runs in the family. Smith’s father had died of congenital heart disease at the age of 28. A father of four himself, the cardiologists at UCSD deemed their patient critical. At the time of the surgery they estimated that Smith had about a month to live.

Smith’s pulmonary hypertension further complicated matters. A conventional transplant in which his heart was replaced with a healthy one wasn’t going to work. The new, donor heart wouldn’t have the pumping power required to force blood through Smith’s constricted lung arteries.

Okay, if one heart isn’t enough, try two.

Nicknamed the piggyback transplant, heterotopic heart transplants leave the patient’s heart in place to work in cooperation with the donor heart. The donor heart is situated to the right of the patient’s heart and the filling chambers of each—the left atria—are surgically connected. This allows oxygenated blood to pass from the patient’s heart to the new one where it is ejected by the new heart’s more capable left ventricle into the aorta and to the rest of the body. Together, the two hearts pump about three times as much blood as the original heart. Watch Smith’s two beating hearts in the phenomenal video below.

Piggyback surgeries are rare. Out of approximately 2,000 heart transplants performed in the U.S. each year, one or two will be piggybacks. Not surprisingly, the surgeries pose a greater technical challenge than conventional transplants. But Smith was in good hands. Dr. Jack Copeland, who performed the surgery, is himself a heart transplant pioneer. Now the director of cardiac transplantation and mechanical circulatory support at UCSD Health System, Dr. Copeland made history in 1979 when he performed Arizona’s first heart transplant. He made history again in 1985 when he became the first surgeon to implant the Jarvik 7 artificial heart into a patient, buying the patient time until he could receive a real heart. Although he has performed about 850 transplants over a 33 year long career, Smith’s surgery marked only the fifth time Dr. Copeland had performed a piggyback transplant. As an interesting side note, the piggyback surgery meant Smith needed only one surgery instead of two. This saved him a cool $400,000, as the cost of the operation was about $100,000 instead of a half million.

The "piggyback" transplant was performed by UCSD's Dr. Jack Copeland, one of the world's premier heart transplant surgeons.

The prognosis for heart disease patients is continually being improved by advances in technology and, as with Smith’s case, technique. In 1983 there were 172 transplants performed in the U.S. In 2008, that number climbed to 2,163. A consequence of the increased success of transplants is increased demand. At any given time there are about 3,000 people in the U.S. waiting for a heart with only 2,000 donor hearts available. Although I have no doubt they one day they will, today’s artificial hearts can’t yet replace real ones. But they do serve as crucial bridges to transplantation while the patient waits for his turn (artificial hearts have supported a person for up to 1,100 days). We’ve followed major advances in artificial heart technology such as those created by AbioCor and SynCardia Systems, Inc. Dr. Copeland is a co-founder of SynCardia which developed the first and only Total Artificial Heart to be approved by the FDA. We reported on Charles Okeke, the first person in the U.S. to be released from a hospital with a TAH. His release was made possible by replacing the TAH’s power supply weighing 418 lbs with a backpack unit called Freedom Driver that weighed only 13.5 lbs. By the end of 2010, two other patients with TAHs had gotten their freedom and left their hospital rooms behind.

Heart disease is the leading cause of death worldwide, claiming 7.2 million lives each year. Important risk factors include high blood cholesterol, obesity, physical inactivity and smoking. Unfortunately, it’s much easier to develop treatments for bad habits than it is to get people to change those habits. Of course genetics and age are also factors, but if we remember that before 1900 very few people died of heart disease, the fact that today it’s the number one killer means the nature vs. nurture argument becomes very easy to figure out. The Industrial Revolution transformed whole industries from human to machine, and we steadily saw less potato farmers transformed into couch potatoes. The rise in heart disease occurrence was so rapid between 1940 and 1967 that the World Health Organization declared it the world’s most serious epidemic. The impact of technology changes not only our world, but our bodies too.

Just ask Tyson Smith.

When he woke up on Valentine’s Day and heard the thump of two heartbeats in his chest, he called it a blessing. The second heart had given him a second chance. He was so impressed with the people around him, people like Dr. Copeland, that he made a promise to himself that he would do better. Currently a janitor, Smith said that he was going to go back to school and become a radiologist. I think we all would like to wish him well on his making a change for the better. And for many of us, he could very well wish us the same.

[image credit: ABC via New York Daily News, Syncardia Systems, Inc.]
[video credit: UCSD Medical Center via YouTube]

IT'S ALIVE! ...seriously though, this pig heart is still alive. Cell decay has been slowed using Somah, Harvard's new wonder preservative.

Science fiction is fraught with mad scientists who discover strange chemicals that can empower the human body or even reanimate the dead. Well, Harvard has come about as close to that scenario as anyone would want them to. Prof. Hemant Thatte has developed a cocktail of 21 chemical compounds that he calls Somah, derived from the sanskrit for “ambrosia of rejuvenation”. Using Somah, Thattle and his team have accomplished some amazing feats with pig hearts. They can keep the organ viable for transplant up to 10 days after harvest – that’s incredibly longer than the 4 hour limit seen in hospitals today. Not only that, but using low temperatures and Somah, they were able to take a pig heart that was removed post mortem and get it to beat 24 hours later in the lab. Watch that amazing video after the break.

We’ve seen amazing chemical treatments that have the potential to transform the medical industry. Mark Roth is working with hydrogen sulfide to put soldiers and other trauma victims into suspended animation on the way to hospitals. The University of Bristol uses xenon gas and low temperatures to prevent brain damage caused by oxygen deprivation. Now Somah could help preserve organs for more than a week outside the body. As researchers continue to unlock the mysteries of your body’s chemistry, they may find more ways of preserving and protecting it indefinitely. This will make it much easier to repair or replace parts of your body as they fail, letting you live longer, and healthier. Maybe indefinitely.

Thousands of patients waiting for an organ transplant die each year in the US alone. Donated organs are limited in availability by distance and time. After harvesting, a heart has just about 4 hours to reach its recipient, anything more than that and decomposition will render the heart nonviable. If we could extend that window to 10 days, almost any organ could be made available to almost anyone, anywhere. That will lead to many saved lives. It will also lower costs as there would be no need for chartered jets and other speedy transports.

Somah may also save lives by extending the number of viable heart donors. Now, most of these organs are harvested from patients who are brain dead, but with a beating heart (effectively still alive as far as the body is concerned). After death, cells begin to degrade quickly. If a donor arrives to a hospital DOA, their organs may not be available to transplant to needy recipients. Somah, however, has been shown to reverse some of this cell decay. The chemical cocktail helps transform metabolic agents into preservative agents. Thatte’s team took a pig heart harvested post mortem and let it sit in Somah for 24 hours at lower temperatures. The cell degradation was very low. They then warmed the heart up, hooked it into an artificial circulatory system and got it to beat. This clip is brief, but it shows the incredible achievement:

To better understand if and how Somah preserved a heart, Thatte and his group harvested two female pig hearts and placed them in two different containers. One was filled with Somah, the other with Celsior from Genzyme – the standard chemical bath which preserves organs in hospitals today. As described in the journal Circulation, the team took tissue samples every four hours from each heart. They found that the Somah heart had a much lower rate of cell decay, including important cardiomyocyte and endothelial cells which are necessary for the heart to work in a new host. Based on this research they concluded that hearts preserved in Somah should be viable for up to 10 days. Celsior can store the organ for 4 hours. That’s an epic difference.

And one that investors are hoping to bank on. A new startup, Hibergenica, is looking to commercialize Somah for use in humans. The company is still in its very early stages. Likewise, Somah still has a ways to go. Transplants from pigs to other pigs (using Somah) will have to be performed before human clinical trials can begin. We’re talking years of research before the FDA would possibly approve Somah for use in the US.

Other companies are relatively closer to augmenting the time hearts stay fresh outside the body. We’ve already seen how TransMedics can keep a heart beating for 12 hours inside a machine, and they are moving forward with tens of millions in funding. Somah, however, could potentially keep hearts viable for 20 times longer, and probably with fewer electrical and mechanical requirements. It will be interesting to see how these technologies ramp up in comparison to stem cell projects aimed at creating entirely new organs from a patient’s own cells. Simpler forms of that concept (for windpipes) have had a series of successes recently with human patients. No matter which of these technologies is the first to achieve widespread use, the future seems ready to provide us with the means to get a new heart when we need it.

[image credit: Harvard]
[video credit: Thatte, Harvard]
[source: Technology Review, Tech Transfer (Harvard), Circulation]

The Abiocor artificial heart

The artificial heart has come a long way since its first clinical use in the 1960’s.  Wireless technology and an internal microprocessor make the AbioCor better than its predecessors.  The entire system is implanted during a procedure where the diseased heart is cut out and the arteries are clamped onto the thoracic unit.  Wires are laid in the body down to the abdomen, where the controller and battery are implanted.  Wires then connect the controller to a receiver planted in the chest called the TET, or Transcutaneous Energy Transfer.  Wearing a similar device on the outside of the skin allows for an external battery to power the system without having wires breaking through the patients skin.

The internal battery allows the patient more mobility, as the external power source can disconnected for up to 45 minutes as the patient bathes or conducts other activities of that nature.  Being hooked up to the power isn’t that bad either, as a fanny-pack portable battery system can provide up to four hours of continuous juice before needing to be recharged.  Despite all these seemingly beneficial quality of life improvements, there are still some drawbacks.

Battery life may seem to be a problem, but that may be easily overcome as battery technology evolves.  The main issue with the AbioCor system is its size.  Weighing in at around two pounds and taking up the space of about two hearts, the system is too big to fit in many people’s chest cavities.  Researchers have duly noted this problem and are currently working on a smaller version that will fit into more people and even some children.

An even bigger challenge to researchers is the longevity of the system.  The longest time a patient has survived on the AbioCor system is about 17 months from the time of implantation (not a very appetizing prospect for potential recipients), and in that time the system operated perfectly.  Doctors, however, are worried that the system can only last about 2 to 5 years before the plastic and metal components wear out and require additional surgery to replace them.

Barney Clark endured 112 days on the Jarvik-7

Comparing such a nearly sublime quality of life given by the AbioCor system to the artificial heart technology of even a decade ago would make any human cringe.  The most famous artificial heart, the Jarvik-7, was first used in 1982 and did not boast any sort of internal battery system.  Instead, two tubes were permanently implanted in the patient that allowed hydraulic fluid to pass in and out of the body to an external pump.  This meant that the patient had nearly no mobility.  Even worse was the constant pulsing of hydraulic fluid that was known to cause patients to be physically jolted every time the heart pumped.

So today’s artificial hearts are much better than they were before, right?  Right.  But all the anal-retentive scientists and doctors out there (House M.D. not included) know that the system can still be so much better.  There are still a lot of complications that can occur with the system that cause limited post-implant life span such as infections and strokes.  Researchers are working on these potentially deadly problems to help increase the life expectancy of patients with the AbioCor system but, even if longevity is increased, patients still have to look forward to another surgery to replace the mechanically compromised artificial heart after 2 to 5 years.  Yes, life expectancy must be increased before the artificial heart replaces the donated heart in most patients faced with the option, but the mechanical integrity of the device must also be increased so that it is capable of lasting longer than the patient ever could.  Only then will artificial hearts beat the donated hearts.  Until then, our money is on motorcyclists and skateboarders.

Insert heart here

You’ve heard a bit about heart transplants and they’re no piece of cake, but now there’s a company out there trying to make it a little bit easier.  It’s not an off-color SNL skit, but it is a heart in a box.  TransMedics Incorporated has designed a system that allows doctors to transplant still-beating hearts up to 12 hours after they are removed from the donor (compared to the standard 4 to 6 allowed by current technology where they freeze the heart).  Yup.  Scientists have invented a box that keeps the heart beating outside of the body.  Holy crap!

This Massachusetts based company has raised $27.6 million in series B funding.  Their proprietary machine pumps warm, nutrient-rich oxygenated blood through the donor heart until it is ready for transplant.  The heart is kept in a sterile compartment that simulates the conditions within the human body, allowing it to function normally while outside the body.  Along with the life-support systems, the TransMedics machine also has the capabilities for performing the necessary diagnostics that doctors require before the heart is transplanted through the use of a wireless monitor.  Take a look at the video and prepare to… woah.

Doctors are impressed by the machine because, well, it works.  There is no swelling of the organ or damage over the 12 hour residence time in the machine.  The extended timeframe for transplant means that more suitable organs will be able to make it to their patients before time runs out and the organ dies.  This could turn relatively unsuitable donors into prime candidates and reduce the number of patients on waiting lists across the country.

The TransMedics machine has already been cleared for widespread marketing in the European Union, but is still enduring clinical trials here in the United States.  So expect to see this technology in the operating room relatively soon.  Of course, we here at the Hub would never wish you the unfortunate circumstance to have a few pounds of flesh cut out of the center of your chest cavity, but if it just so happens to be the way life deals the cards and they wheel in one of these bad boys, know that you’re in safe hands.  Well, unless your surgeon has narcolepsy.  But that’s a relatively rare disease.  You’ll be fine.

Where can it go from here?  Humanity has certainly not reached the peak of heart transplant technology.  Is 12 hours really enough time to get from donor to prepped patient?  Probably not.  It’s a sure step up from the 4-6 hours offered by current technologies, but it would certainly be a better situation to have a raft of waiting organs rather than a list of waiting patients.  Perhaps one day the technology will exist to keep hearts beating and healthy outside of the body indefinitely, making for the immediate availability of donated organs when they are needed.

We have featured a few stories here on Singularity Hub about growing organs in the laboratory and perhaps this new way of keeping organs alive could be mated to these lab-grown organs.  No, we’re not talking about a dystopian future where every family will have an organ room in their house with spare parts hooked up to these TransMedics machines just in case somebody has an organ failure.  It could be a world where when an organ is needed, it is grown from the patient’s own cells and placed in one of these devices for safe, reliable and healthy transport from lab to patient.  Though such a time is just over the horizon, we must now make due with harvesting our organs from dead people.  At least we have a cool way of keeping those organs alive.  Kali Ma!!!!

Insert heart here

You’ve heard a bit about heart transplants and they’re no piece of cake, but now there’s a company out there trying to make it a little bit easier. It’s not an off-color SNL skit, but it is a heart in a box. TransMedics Incorporated has designed a system that allows doctors to transplant still-beating hearts up to 12 hours after they are removed from the donor (compared to the standard 4 to 6 allowed by current technology where they freeze the heart). Yup. Scientists have invented a box that keeps the heart beating outside of the body. Holy crap!

This Massachusetts based company has raised $27.6 million in series B funding. Their proprietary machine pumps warm, nutrient-rich oxygenated blood through the donor heart until it is ready for transplant. The heart is kept in a sterile compartment that simulates the conditions within the human body, allowing it to function normally while outside the body. Along with the life-support systems, the TransMedics machine also has the capabilities for performing the necessary diagnostics that doctors require before the heart is transplanted through the use of a wireless monitor. Take a look at the video and prepare to… woah.

Doctors are impressed by the machine because, well, it works. There is no swelling of the organ or damage over the 12 hour residence time in the machine. The extended timeframe for transplant means that more suitable organs will be able to make it to their patients before time runs out and the organ dies. This could turn relatively unsuitable donors into prime candidates and reduce the number of patients on waiting lists across the country.

The TransMedics machine has already been cleared for widespread marketing in the European Union, but is still enduring clinical trials here in the United States. So expect to see this technology in the operating room relatively soon. Of course, we here at the Hub would never wish you the unfortunate circumstance to have a few pounds of flesh cut out of the center of your chest cavity, but if it just so happens to be the way life deals the cards and they wheel in one of these bad boys, know that you’re in safe hands. Well, unless your surgeon has narcolepsy. But that’s a relatively rare disease. You’ll be fine.

Where can it go from here? Humanity has certainly not reached the peak of heart transplant technology. Is 12 hours really enough time to get from donor to prepped patient? Probably not. It’s a sure step up from the 4-6 hours offered by current technologies, but it would certainly be a better situation to have a raft of waiting organs rather than a list of waiting patients. Perhaps one day the technology will exist to keep hearts beating and healthy outside of the body indefinitely, making for the immediate availability of donated organs when they are needed.

We have featured a few stories here on Singularity Hub about growing organs in the laboratory and perhaps this new way of keeping organs alive could be mated to these lab-grown organs. No, we’re not talking about a dystopian future where every family will have an organ room in their house with spare parts hooked up to these TransMedics machines just in case somebody has an organ failure. It could be a world where when an organ is needed, it is grown from the patient’s own cells and placed in one of these devices for safe, reliable and healthy transport from lab to patient. Though such a time is just over the horizon, we must now make due with harvesting our organs from dead people. At least we have a cool way of keeping those organs alive. Kali Ma!!!!

An average day for heart transplant specialists

Modern day heart transplants are normally conducted by donations from recently deceased or brain-dead donors.  The heart is taken out of the donor and given a potassium chloride injection to stop the heart from beating.  It is capable of surviving outside of the body for about 4-6 hours.  In this last year in the United States, there were about 2300 successful heart transplants (3500 worldwide) while 800 U.S. patients died while waiting for a suitable donor.  More than half of U.S. heart transplant patients are between 50 and 70 years old.

The road to successful heart transplants was a bit of a rocky one.  The first heart transplant was conducted in 1964 when a monkey heart was placed in the chest of a dying man.  This, of course, raised a great number of ethical considerations.  Unfortunately, the man’s life was only prolonged for about 90 minutes, but the procedure set the stage for future operations between humans.  The first intra-human operation was performed in 1967 with a heart from a brain-dead donor.  The patient lived only 18 days before succumbing to pneumonia.

The procedure for a heart transplant is tricky at best.  The body is opened with a cut through the sternum and the heart is exposed.  A heart/lung machine is attached to the blood vessels leading in and out of the heart, which acts to pump and oxygenate the blood during the operation.  After the patient is weaned off of the defective heart, it is literally cut out of the body, leaving only a little bit of the original heart behind.  The part left behind contains the pulmonary veins and some heart tissue.  The donor heart is trimmed to fit to the remaining tissue and is then sewed in place.  The heart is restarted (and defibrillated if necessary) and the patient is removed from the heart/lung machine.  At this point, the patient is surviving solely by their new heart.  The patient is closed up with plenty of sutures and some metal wire to reconnect the sternum.  NOVA Online has a very informative and slightly eerie interactive game that describes exactly how the procedure is conducted.  Be sure to check it out if you never wish to forget how to replace a heart.

Ready For Heart Transplant!

Overall, the transplant process is about 7 hours long and costs roughly $150,000.  The patient is generally sent home as quickly as possible (about 1 to 2 weeks after the operation) to avoid contracting any diseases.  Anti-rejection medication must be taken for the rest of the patient’s life or else they risk the body rejecting the new tissue and causing heart failure.  Survival rates from the procedure are about 86% after the first year but drop to about 70% after five years among US citizens.

So, where can it go from here?  Though any patient would prefer a 99% survival rate, the odds don’t seem all that bad for somebody who doesn’t have long to live otherwise.  The majority of problems occur in the body rejecting the new tissue and attacking it.  Current medication reduces the body’s ability to fight off the new tissue, but also makes the patient more vulnerable towards other infections.  It is in these complications that much of the focus should be placed.

The end goal is to make the rejection issue a moot point by growing organs in the laboratory that are autologous.  If the patient is given their own cells, then the body will not react negatively towards the transplant.  Lifelong suppressant medication would not be necessary and the immune system would be able to fend off many of the diseases that can cause complications among heart transplant patients.  Unfortunately, such an advancement is a long way off and the rejection problem is the issue to focus on in the near term.

It’s amazing to look back and see how far modern medicine has gone with the heart transplant.  For over forty years, the procedure has progressed and transformed into what it is today.  Ideally, it will continue to become more reliable and more accessible, but what modern medicine has created in the heart transplant is already astounding.