Innovative flushing therapy Haermonics saves thousands of people per year

9 August 2021 16:09

Each year, almost 1.5 million people undergo open heart surgery across the world. Approximately 17% of patients suffer complications after these operations, caused by residual blood and clots around the heart. 250 patients die each day as a result of these post-operative complications. The medical startup Haermonics has come up with a solution. "Our goal is to save 10,000 lives by 2030."


Haermonics has developed an innovative flushing therapy that ensures residual blood and clots no longer cause complications after surgery. The startup has built a machine that drains and flushes out wound fluid and blood during and after surgery without causing blockages. CEO Wouter Markus explains: "Extreme blood loss and blocked drains during and after surgery cause complications. The complications can be so bad that a second emergency operation is required. But that comes too late for around 250 people each day."

Searching for a solution

The solution to this problem was conceived 11 years ago by heart surgeon and co-founder of Haermonics, David Koolbergen. Markus: "From newborn babies with congenital heart defects to elderly people needing a bypass, David is a master surgeon who carries out between 150 and 200 open heart operations each year, often saving people’s lives. After these tough operations, he was often back in the operating theatre with the same patient a few hours later, removing a blockage that had formed due to a build-up of clots. Throughout his career, he saw this as an unnecessary problem that began to bother him more and more. That motivated him to search for a solution."

And that solution has now been found. After surgery, the Haermonics medical device washes the area around the heart until the bleeding stops. Markus: "What makes our innovation so special is that we first demonstrated that it works in the clinic, and only now are we building the device. It’s usually the other way round."


Trials were held over many years so that the device could be tested. "Hundreds of people have now been helped thanks to our device, and the results are better than we had dared to hope. During the two trials, we showed that in a younger patient group with congenital heart defects, we managed to reduce blood loss by 155ml, which is a 41% reduction. In a patient group undergoing bypass surgery, there was a reduction of 385ml, which is equivalent to 76%. But more significant is that over the two studies combined, there were no tamponades or (unnecessary) second operations in the flushed group, while there were eight in the control group. This shows that the principle really works."

Collaboration in the Brainport region

The company, which originated in Amsterdam, is now established in Eindhoven. Markus says this was a conscious decision. "Being established in the Brainport region allows us to collaborate with local technical partners who can help us further develop our device."

Rabo Innovation Loan

Although Haermonics has been in existence for five years now, it has not earned a single euro. This is the fate of many MedTech startups. "That’s why we’re dependent on investors and subsidy providers. Generally speaking, it’s not even worth turning to a bank as they consider investing in startups too risky. But Rabobank makes an exception to this. Thanks to the Rabo Innovation Loan, we have been able to make substantial progress. Without that money, we would never have been able to introduce our system to the market and save thousands of lives."

Account manager John Paul van Heel: "In order to maintain the best level of healthcare in the Netherlands, we need to support startups such as Haermonics from an early stage. It’s great that Rabobank can contribute to that. I have confidence in Wouter Markus and his team."