Tiny titanium implant makes dialysis easier and less painful

October 14, 2016

The kidneys are the natural filters of the human body. Their function is to eliminate waste and excess water from the blood to avoid any harmful effects to the body. But people with failing or damaged kidneys are not able to carry out this function on their own so they undergo dialysis. It is a life-support treatment that uses a special man-made machine to filter harmful wastes, salt and excess fluid from the blood.

The lifeline of a hemodialysis patient is the vascular access, which makes the filtering process possible. It connects the patient’s blood flow to the filter outside the body. A vascular access lets large amounts of blood flow continuously during hemodialysis treatments to filter as much blood as possible per treatment.

The access is a surgically created vein that is used to remove and return blood during the treatment. The blood flows through the needle and then travels through a tube that takes it to the filter, called a dialyzer. Inside the dialyzer, the blood flows through thin fibers that filter out wastes and extra fluid. The machine returns the filtered blood to the body through a different tube.

One type of a vascular access is called the arteriovenous fistula (AV fistula). Made by a vascular surgeon, an AV fistula is a connection of an artery to a vein. To avoid damaging this special vein, kidney dialysis patients endure needle jabs at different spots on their arms.

A Singaporean firm, Advent Access, is offering a solution for this. They have created a tiny titanium implant that sits under the skin, helping nurses to slip in a needle exactly the same way each time. The result is a single clean slit, almost like an ear piercing, which leaves the rest of the vein as intact as possible.

“Kidney dialysis has been around for 70 years, but even up to today, the Achilles heel of dialysis is still vascular access,” saidPehRuey Feng, the company’s founder.

When people have regular dialysis, needles are inserted at different points along the arm each time to reduce damage to the specially modified vein underneath, Peh explained. Dialysis treatments can last a lifetime and over time, the vein can weaken from these repeated puncture wounds, eventually becoming unfit for use.

Apart from reducing stress on the AV fistula, the titanium implant also makes inserting a needle so simple that they hope people will eventually be able to carry out dialysis on their own.

“Right now, the most difficult technical hurdle (for patients) is to perform vascular access,” said Peh, adding that doctors have told him that educated patients nowadays are capable of operating dialysis machines on their own.

In 2014, there were nearly 6,000 dialysis patients in Singapore, with the number continuously growing each year.These patients spend 12 hours a week at dialysis centers, but the new implant could mean a step towards greater independence.

Dr. Akira Wu, a renal specialist at Mount Elizabeth Hospital, said the device, called the av-Guardian, could be especially useful for larger people or those with smaller veins. Finding the fistula in people whose veins are a bit smaller can be a real challenge, said Dr. Wu.

Advent Access – a spin-off from the Agency for Science, Technology and Research – is working with National University Hospital, Singapore General Hospital and National Kidney Foundation on a pilot trial.

One patient on the trial said that he felt a difference, noting that using the implant was less painful because now a blunt needle was used instead of the sharp needles used before.

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