Stent Tek Ltd. – Improving outcomes for hemodialysis patients

Stent Tek Ltd. – Improving outcomes for hemodialysis patients

  • Current ePATH Design
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    Current ePATH Design
  • First MVP ePATH Design
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    First MVP ePATH Design
  • Electronic circuit housed in handle
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    Electronic circuit housed in handle
  • First 3D printed electrical prototype
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    First 3D printed electrical prototype
  • Handle concept sketches
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    Handle concept sketches
ePATH procedure for minimally invasively creating an access site for dialysis
What It Does

Our minimally invasive medical device aims to make it safer, easier and cheaper for the 2.5 million patients world wide with kidney failure to receive dialysis by eliminating the need to undergo surgery, reducing the $45 billion yearly cost of treatment.

The Inspiration

The current gold standard for how patients connect to a dialysis machine involves surgery and has very poor outcomes, 25% fail immediately and a further 50% fail in the first year. This puts a patient's life at risk and requires costly surgical or interventional revisions. During my Masters at Imperial College London I developed a minimally invasive catheter system that can connect two independent vessels, achieving the same result as the surgical approach but with potentially better outcomes.

How It Works

Dialysis patients currently need to undergo a surgical procedure to prepare their vessels by forming a connection between an artery and a vein in their arm; called a fistula or vascular access site. This allows the dialysis machine to connect to the patient and filter their blood.

Our Electronic Percutaneous Anastomosis Technology for Haemodialysis (ePATH) system consists of two catheters, one that goes in a patient's artery and the other in the vein. The catheter alignment system utilizes a robust and novel electromagnetic method in which an asymmetric electric field is generated by one catheter and measured by the other. This provides feedback to the clinician allowing them properly align the catheters and cross between the two vessels with a needle. Once the needle is deployed, the two vessels can be permanently connected with a small plastic tube called a stent graft.

Stages of Development

The core mechanical concept and design of a needle crossing system is based on an off patent design which was never commercially available. With our first pre-clinical fully functional prototype we made several improvements on the design which allowed for a smaller catheter profile as well as a unique handle system that allows 360 degree continuous rotation.

The core design innovation lies in the electronic alignment technology which minimises the need for x-ray imaging. The electronic alignment was first tested using computer simulation. The simulations allowed for a more detailed design of the electrode size and distribution to be established, which results in the most accurate signal. The electrical system was then integrated into a series of catheter mockups and tested in lab based in-vitro models. The current functional pre-clinical prototypes have been successfully tested in cadaver and in-vivo models. We have worked closely with our manufacturers to achieve the smallest profile possible so as to be clinically suitable. The design of the electronic control circuit has also undergone 5 main iterations from breadboard, to a miniaturised PCB MVP, and currently a confidential desktop development and testing system suitable for clinical trials.

Novelty

This year the first two devices for creating a minimally invasive dialysis access site came on the market in the EU from TVA Medical and Avenu Medical. Their systems function in a different part of the anatomy, leaving only the Stent Tek ePATH procedure to create access sites at the wrist level, a site which is preferred clinically.

Other existing technologies for catheter alignment use ultrasound and are more complicated and costly to manufacture and more sensitive to variation in tissue. Furthermore, ultrasound systems cannot be miniaturised enough to fit within the device handle therefore requiring costly stand-alone user interface.

Stent Tek has filed patents in the UK and US covering the alignment technology and the overall clinical procedure.

Future Plans

The next steps involve a further iteration on the mechanical design in order to produce clinical prototypes ready for a first in man trial. These prototypes will undergo another in-vivo validation and then further testing necessary for regulatory approval.

Stent Tek aims to receive approval in the US and EU by late 2018 at which point it would be able to enter a market estimated at $1.9 billion per year. Furthermore, the core alignment technology has the potential to be applied to several other clinical procedures in which a clinician needs to bypass a blockage in a vessel, allowing us to develop into a true platform technology.

Awards

We have raised £1.2m in grant funding and £300k in private capital since starting in Oct 2014 including:

NIHR i4i Grant
Innovate UK SMART Grant
RAEng ERA Foundation Entrepreneurs Award
RAEng Launchpad Competition, National finalist
IPEM Innovation and Research Award
ICL, Breakthrough Innovation Award, Runner up