A new technology studied at the Texas A&M School of Veterinary Medicine and Biomedical Sciences (VMBS) Veterinary Medical Park is making giving dialysis to patients with end-stage renal disease (ESRD)—or complete kidney failure—easier while also prolonging their ability to continue receiving treatment.

The device, called the Ark, creates a permanent port in a patient’s arm allowing access to a high-flow vein that can handle repeated punctures with large dialysis needles. The Ark is being used successfully in human trials outside the United States and will undergo a US Food and Drug Administration-approved pivotal trial in the US this fall.

Living with end-stage kidney disease

According to the Centers for Disease Control and Prevention, chronic kidney disease (CKD) affects about 15% of adults in the United States. It occurs when the kidneys, which perform essential functions like removing waste from blood and producing urine, are no longer functioning correctly. Approximately 750,000 patients in the US have progressed to complete kidney failure.

“In end-stage renal disease, the patient’s kidneys have failed, and they require dialysis in order to live,” said Dr. Alan Glowczwski, the founder and chief medical officer of Voyager Biomedical and an adjunct professor in the Texas A&M Department of Large Animal Clinical Sciences who invented the technology.

“Dialysis is a process where a technician inserts two large needles into a blood vessel—called cannulation—to allow the dialysis machine to pull the patient’s blood out of their body, clean it and put it back into the vessel downstream,” Glowczwski explained.

“The dialysis flow rate is 400 milliliters per minute and requires a high flow vein in the arm, which is created by attaching an artery to the vein to support blood flow through the dialysis filter. The process takes about four hours and must be done at at least three days per week. This calculates to 312 needle punctures per year if each stick is on target.”

Patients with ESRD are dependent on dialysis for survival, but the current method of blood vessel access is only viable as long as the patient’s veins can undergo repetitive successful cannulation. Dialysis uses 15-gauge needles, which are about five times larger than the needles used to draw blood.

“The process requires a very high-flowing conduit and use of large needles, and patients with end-stage renal disease have very delicate veins. The veins can easily compress, making it easy to miss with the needle and damage the vein to the point. that it can no longer be used for dialysis,” said Dr. Jennifer Fridley, a clinical assistant professor in the VMBS’s Department of Large Animal Clinical Sciences who oversaw veterinary medical care for the study. “Dialysis itself also wears out veins, and the patient can lose their ability to receive dialysis.”

“Using the current dialysis method, it’s only a matter of time before a patient runs out of veins to use in each arm,” Glowczwski said. “With the Ark, a patient’s ability to receive treatment can be maintained for years without having to find another vessel, which can be very difficult and would limit the patient’s access to dialysis treatment.”

The science behind the Ark

Due to economic factors and job stress in the US, dialysis clinics all over the world are experiencing a high rate of turnovermeaning there are fewer dialysis technicians who are experienced in manipulating the large needles used in catheterization.

“The goal in creating the Ark was to make dialysis catheterization simpler so there are fewer attempts to place each needle, because each one can ruin veins for future dialysis use. The goal is one stick, no miss,” Glowczwski said. “When I first started making the implant, it looked a little bit like a boat, so I decided to call it an Ark, after the life-saving biblical ark.”

The tube-shaped device is 3D printed using titanium alloy—similar to orthopedic implants—and is composed of two parts that fit around the vein. There is an opening on the top half to guide the dialysis needle into the vessel while the back is solid metal preventing back wall puncture and infiltration. The unique design of the Ark also allows the device to integrate into the patient’s tissues like a scaffold.

“The Ark implant keeps the blood vessel from collapsing and has a metal wall on the bottom so that the needle can’t accidentally go through the other side. The patient can then receive all of their dialysis treatments using that one vein,” Fridley said. .

From animal to human trials

As one of the final stages in the development process, Glowczwski and Fridley collaborated on a study to see if the Ark device could be implanted around a surgically created vein-artery circuit in goats and maintained for 15 months.

“The study was very successful,” Fridley said. “Not only were we able to implant the devices, but we were also able to remove them to show that the entire process is reversible, which is important for getting approval from the FDA for human trials. Once we were finished with the study and the implants were removed, we were able to adopt out the goats to new homes.”

After the goat study, Glowczwski has been able to start human trials in Panama, where 11 patients underwent Ark implantations. At six months after surgery, all 11 patients are continuing to use their Ark devices for blood vessel access.

“We expect to get approval from the FDA soon so we can start working on a US trial this fall,” he said. “That will probably take about two years, and then we can start making the device available for commercial use.”