The 21st Century and the continuous advancements in medical technology are opening more doors for people with certain medical conditions. According to Healthline, researchers at the University of California, San Francisco (UCSF) are devising an implantable artificial kidney that can mimic the functions of real human kidneys. If the research becomes successful, the scientists’ results could help eliminate the need for dialysis.
What is Dialysis?
Dialysis is a form of treatment that replicates some of the essential functions of healthy kidneys. The treatment process involves expelling excess water, solutes, and toxins from the blood in patients whose kidneys can no longer perform these roles naturally. According to the National Kidney Foundation, “You need dialysis when you develop end stage kidney failure — usually by the time you lose about 85 to 90 percent of your kidney function and have a GFR of <15.”
The average life expectancy for patients undergoing dialysis is five to 10 years, although some have lived for many more decades. However, dialysis — which removes some (but not all) toxins from the bloodstream that the kidneys would typically discard — must be performed everyday if done at home through peritoneal dialysis. It otherwise requires three visits to a clinic each week, if performed via hemodialysis.
Dialysis vs. Kidney Transplant
Kidney transplantation is often the treatment of choice for several people with chronic kidney disease, which can significantly impact survival (life expectancy) and quality of life. In many cases, a kidney transplant is considered better than dialysis.
Kidney Transplant Success Rates
Kidney transplants for men and women with end-stage renal disease (ESRD) have a relatively high rate of success. About 93 percent of transplanted kidneys continue working after a year, and about 83 percent are still functioning after three years.
In hindsight, it is crucial to note the shortage of kidneys available for donation. While over 25,000 kidney transplants occur each year, as of early 2016, a little more than 100,000 people were on the organ transplant waiting list in the United States. Patients without direct donors commonly wait up to 5 or 10 years for a perfect match or suitable organ to become available.
Implantable Kidneys and the Future of Dialysis
“The implantable bioartificial kidney is an alternative to dialysis and other externally wearable devices that would tether patients or limit their mobility,” says Shuvo Roy, a professor in the UCSF Department of Bioengineering and Therapeutic Sciences and co-inventor of the device, told Healthline. “A live kidney transplant from a matching donor is still considered one of the best treatment options for ESRD, but unfortunately, there is a shortage of organ donors that prevents transplants from being available to the vast majority of ESRD patients. Unlike transplants, our device will not require that patients be on immunosuppressive drugs to prevent rejection.”
Human Trials of the Device in the Works
Professor Roy asserts that the bioartificial kidney could be the ultimate solution to the vast majority of patients now on dialysis and the organ transplant list. “This is a long-term solution, and any case where a kidney transplant is needed, our device will be a viable option,” he said.
How the Device Works
Roy is pioneering the Kidney Project, a national research initiative concentrated on the development and experimentation of a surgically fixed, freestanding bioartificial kidney that does “the vast majority of the filtration, balancing, and other biological functions of the natural kidney.”
With the body’s blood pressure powering the bioartificial kidney, the device does not need the external tubes or tethers required for wearable artificial kidneys, such as the ones Victor Gura of Cedars-Sinai invented in Medical Center in Los Angeles. That particular device was tested on seven patients undergoing dialysis at the University of Washington Medical Center in Seattle in 2015.
The two-part artificial kidney by Roy and his team involves recent developments in silicon nanotechnology, making it feasible to mass-produce reliable, sturdy, and compact filtering membranes. The advanced technology likewise has external molecular layers that guard the silicon membranes and allow them to become blood-compatible.
“A hemofilter module processes incoming blood to create a watery ultrafiltrate that contains dissolved toxins as well as sugars and salts,” taught Roy. “Second, a bioreactor of kidney cells processes the ultrafiltrate and sends the sugars and salts back into the blood. In the process, water is also reabsorbed back into the body, concentrating the ultrafiltrate into ‘urine,’ which will be directed to the bladder for excretion.”
The Need for Hormonal Supplements
Patients with the implantable kidney may still be expected to take hormonal supplements, as they do on dialysis, said Roy.
The development of safe alternatives to existing treatments for kidney disorders is “very important, since the outcome of premature mortality and poor quality of life are common for the dialysis population, particularly for in-center hemodialysis,” explains Dr. Joseph Vassalotti, chief medical officer for the National Kidney Foundation.
What Lies Ahead
The scientists behind the Kidney Project will test for a working prototype of the bioartificial kidney in 2020. “The long-term challenges center around keeping the device operating trouble-free after implantation beyond a few months,” remarked Roy. “Some problems won’t become clear until we do clinical trials.”
In addition to $6 million in government grants, the project has received substantial donations from private individuals. “Their support is a testament to the acute need for a revolution in ESRD treatment, and the donations we have received are invaluable in allowing our research to progress,” said Roy.
In the distant but nearing future, scientists may even be able to grow artificial kidneys:
- In 2013, Melissa Little of the University of Queensland’s Institute for Molecular Bioscience and her team of researchers were able to build a primitive kidney from human stem cells.
- In 2016, scientific researchers from the Salk Institute in California stated to have been able to grow nephron progenitor cells, which can morph into kidney tissue in the lab.
Similar research continues in the search to alleviate kidney problems around the world, but the reality of growing replacement organs remains a more distant dream than the possibility of devising an implantable artificial kidney.