Ark allows patients to maintain their ability to receive dialysis treatment for years without having to find another blood vessel.
Image courtesy of Dr. Alan Growsky
A new technology researched at the Texas A&M School of Veterinary and Biomedical Sciences (VMBS) Veterinary Medical Park facilitates dialysis and extends the ability to continue dialysis for patients with end-stage renal disease (ESRD) or complete renal failure. Ta. undergoing treatment.
The device, called the “Arc,” creates a permanent port in a patient's arm, allowing access to a high-flow vein that can withstand repeated punctures with a large dialysis needle. Ark has been successfully used in human trials outside the United States and is scheduled to undergo a pivotal U.S. Food and Drug Administration-approved trial in the U.S. this fall.
Living with end-stage renal disease
According to the Centers for Disease Control and Prevention, approximately 15% of adults in the United States have chronic kidney disease (CKD). This occurs when the kidneys, which perform important functions such as removing waste from the blood and producing urine, stop working properly. Approximately 750,000 patients in the United States progress to complete kidney failure.
“In end-stage renal disease, a patient's kidneys fail and they require dialysis to survive,” said Voyager Biomedical's founder and chief medical officer and adjunct professor at Texas A&M University. said Dr. Alan Growsky. The technology was invented by an animal clinical scientist.
“Dialysis is a process in which a technician inserts two large needles into a blood vessel, called cannulation, which allows the dialysis machine to draw the patient's blood out of the body, clean it, and return it to downstream blood vessels. “We can do that,” Groczewski explained. “Dialysis has a flow rate of 400 milliliters per minute and requires a high-flow vein in the arm. This vein is created by connecting an artery to a vein to support blood flow through the dialysis filter.” The process takes about four hours and must be performed at least three days a week, which equates to 312 needle sticks per year if each needle hits the target.
The titanium alloy Ark implant prevents blood vessel collapse and has a metal wall at the bottom so the needle can't accidentally pass through the other side.
Photo courtesy of Dr. Alan Growsky
ESRD patients rely on dialysis for survival, but current vascular access methods are only viable if the patient's veins cannulated successfully repeatedly. Dialysis uses 15-gauge needles, which are about five times larger than the needles used to draw blood.
“This process requires the use of very high-flow conduits and large needles, and the veins of patients with end-stage renal disease are very delicate. Veins are susceptible to compression, which makes it easy for needles to dislodge and prevent them from being used for dialysis. You can damage the vein to the point where it runs out,” said Dr. Jennifer Fridley, clinical assistant professor in the VMBS Large Animal Clinical Department. Scientist who supervised veterinary care for the study. “Dialysis itself can also deplete the veins and patients may no longer be able to receive dialysis.”
“With current dialysis methods, it's only a matter of time before a patient runs out of veins in each arm,” Groczewski says. “Using the vape preserves a patient's ability to receive treatment for years without having to find another container, which is extremely difficult and can limit a patient's access to dialysis treatment. there is.”
The science behind the ark
Economic factors and work stress in the United States are causing dialysis clinics around the world to: high turnover rateThis means that there are fewer dialysis technicians who have experience working with the large needles used in catheter treatments.
“Our goal in creating Ark was to make dialysis catheter insertion easier and reduce the number of times each needle must be inserted, as each needle can damage a vein in preparation for future dialysis. .The goal is one stick, no mistakes,” Growszowski said. “When we first started making the implant, it looked a bit like a boat, so we decided to call it the Ark, after the life-saving Biblical Ark.”
The tubular device is 3D printed using a titanium alloy similar to orthopedic implants and consists of two parts that fit around a vein. The top half has an opening to guide the dialysis needle into the blood vessel, and the back is solid metal to prevent puncture and invasion of the back wall. Ark's unique design also allows the device to be integrated into the patient's tissue like a scaffold.
“The Ark implant has a metal wall on the bottom to prevent blood vessels from collapsing and to prevent needles from accidentally sticking into the other side. Patients can then use that one vein for all their dialysis treatments. “You can receive it,” Fridley said.
From animal experiments to human experiments
As one of the final steps in the development process, Glowczwski and Fridley collaborated on a National Institutes of Health-funded study to implant the Ark device around a surgically created veno-arterial circuit in goats and maintain it for 15 months. I checked to see if it could be done.
“The study was very successful,” Fridley said. “Not only were we able to implant the device, but we were also able to remove it to demonstrate that the entire process was reversible, which is important in order to gain approval for human trials from the FDA.” Once the research was completed and the implants were removed, the goats were placed in new homes.
After the goat study, Glowczwski was able to begin human trials in Panama, where 11 patients received Ark implants. Six months after surgery, all 11 patients continue to use the Ark device for vascular access.
“We expect to receive FDA approval soon and be able to begin clinical trials in the U.S. this fall,” he said. “It will probably take him about two years. Then he will be able to start using the device commercially.”
