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A tiny pump that can keep blood flowing after a heart attack

A TINY PUMP THAT CAN KEEP BLOOD FLOWING AFTER A HEART ATTACK

Lewis Packwood
August 2018

A team of engineers and cardiologists from Jena, Germany, has developed and successfully tested the first pulsatile, catheter-based, electrocardiogram-controlled heart pump in the world. This device can be inserted within 15 minutes in emergency cases, such as right heart failure or cardiogenic shock, and can provide circulation support of more than 3 litres per minute1.

Pressure relief

Right ventricular failure (RVF) can result from various problems, such as a heart attack (myocardial infarction) or blockage of an artery in the lungs (pulmonary embolism). The veins become overloaded and eventually congested, which can lead to organ damage, and the central venous pressure shoots up to above 10 mmHg.

Prof Markus Ferrari, now Chief Physician of the Department of Internal Medicine I at the Helios Dr Horst Schmidt Clinics in Wiesbaden, Germany, was looking for a way to bring down this pressure and keep blood flowing through the veins. “I had the initial idea for PERKAT when using an IABP [intra-aortic balloon pump] in a cardiogenic shock patient suffering from a posterior myocardial infarction more than 12 years ago,” he says. The IABP device was developed in the 1960s: this tiny balloon on a wire is threaded up through the femoral artery on the patient’s leg until it reaches the aorta, where the balloon is rapidly inflated and deflated with helium to force blood through constricted arteries. But an IABP cannot be used in cases of acute right heart failure. “I was wondering whether an IABP would also work in the venous circulation,” Prof Ferrari recalls. “I wrote the first patent during my winter holiday after initial experiments.”

The percutaneous catheter pump (PERKAT RV) that Prof. Ferrari designed consists of an expanding metal cage that is covered by a very thin membrane peppered with more than 100 foil valves2,3. Inside the PERKAT cage is an IABP connected to a standard IABP console: when the console deflates the IABP, the foil valves open, and when it is inflated with helium, the blood is directed into the pulmonary artery. And all of this is packed into an 18-French sheath just 6 millimetres across, which can be threaded through the patient’s veins to reach the heart, without the need for surgery. The standard IABP technique provides a maximum circulation of 0.7 litres per minute, whereas the PERKAT system can provide more than four times that amount.

“In our animal studies in a sheep model with acute pulmonary embolism,” notes Prof. Ferrari, “we observed an increase of cardiac output by more than 40% under PERKAT support.”4

Developing the idea

Prof. Ferrari and his colleagues developed PERKAT with support from a network of medtech suppliers, the Fraunhofer Institute and a team from the Cardiology Department of the University Clinic in Jena. Research, product development, and in vitro and in vivo testing were financed via “private money, a grant from the German Ministry of Research, and financial support from two venture capitalists,” says Prof. Ferrari, while production of the device was undertaken by an external manufacturer under strict European healthcare regulations. 

PERKAT is not the only device that has been developed to treat acute right heart failure: the TandemHeart and Impella RP are just two of the devices that can effectively support the circulation in acute situations. But PERKAT has the advantages of simplicity, size and cost: it requires a much smaller cannula than other devices, has no rotating parts, works like the natural human heart and only needs to be inserted into one rather than multiple veins. Prof. Ferrari explains that the insertion procedure, the Seldinger technique, is relatively straightforward: “Anaesthesiologists, surgeons, intensive care physicians and cardiologists perform this standard procedure every day.”

The real challenge, he notes, was in finding “the optimal technical solution for easy insertion and removal of the device”. This came down to the design of the metal cage – a specially designed stent made of nitinol (nickel titanium) – and of the tiny patented foil valves that are placed around the stent. “It was somewhat challenging bringing all the specialists for the different parts together – specialists for the sheath, nitinol stent, outflow tubing, foil valves, balloon pump, and several other medtech specialists,” Prof Ferrari recalls. “In addition, we had support from numerous external technicians, physicians and regulatory partners.”

Looking ahead

Today, the core PERKAT development team consists of six people: three medtech engineers, one regulatory affairs specialist and two physicians. “Dr Daniel Kretzschmar at University Hospital Jena and I are responsible for the animal studies and the design of the first-in-human study,” says Prof Ferrari. The PERKAT RV, targeting the right ventricle, has already shown success in sheep, and the team expects to conduct first-in-human trials in 2019. Prof Ferrari anticipates that the device will reach the market in 2020.

PERKAT has come a long way from that initial inspiration 12 years ago. But when it came to making PERKAT a reality, Prof Ferrari thinks it was the specialist help he received that mattered far more than the money. “The value of technical support from external experts and partners has a higher value for start-up companies than any financial support.”

 


in a sheep model ..we observed an increase of cardiac output by more than 40% under PERKAT support.


References

1

Interview with Prof Markus Ferrari, July 2018.

2

Kretzschmar D, Lauten A, Ferrari MW. In vitro evaluation of a novel pulsatile right heart assist device – the PERKAT system. Int J Artif Organs. 2015;38(10):537–541.

3

Kretzschmar D, Schulze PC, Ferrari MW. Hemodynamic performance of a novel right ventricular assist device (PERKAT). ASAIO J. 2017;63(2):123–127.

4

Kretzschmar D, Lauten A, Schubert H, Bischoff S, Schulze C, Ferrari MW. PERKAT RV: first in vivo data of a novel right heart assist device. EuroIntervention 2018;13(18):e2116–e2121.