We’ve discussed the new wearable kidney and the new home dialysis device. Today, we’ll discuss an implantable device- one that replaces the dialysis device, but not the kidneys. Which will have to do until there is a stem-cell kidney replacement.
This new kidney project involves the UCSF (UC San Francisco) and Vanderbilt University (Tennessee) working in tandem. The project was granted $ 6 million by the National Institute of Biomedical Imaging and the Bioengineering Quantum Program. The goal- using Dr. Shuvo Roy’s (UCSF) device (I first reported on its development some 5 years ago here) , as improved by Dr. William Fissell (Vandebilt)- is to evaluate this device’s functionality and efficacy in several patients.
At the ASN (American Society for Nephrology) meeting in November, three papers described the device in question. Drs. S. Kim, W. Moses, J. Park, C. Chow, C. Blaha, Z. Iqbal, R. Kant, B. Chui, K. Goldman, W. Fissell, and S. Roy (paper FR-P0365) demonstrated that this nanofilter was capable of 3X the diffusive clearance of toxins of that found in conventional extracorporeal circuits. Moreover, the functionality was examined under pulsatile blood flow conditions- the flow that exists in the body. (Dialysis is normally effected via blood pumps,with steady flow conditions.)
Drs. A. Buck, J. Groszek, C. Kensinger, D. Colvin, S. Roy, and W. Fissell (paper FR-P0363) developed a model for the system, from which they discerned potential regions where thrombosis may occur, due to the pulsatile flow that normally obtains in blood vessels. Given this information, they proposed changes in the device design to minimize the chances for thrombogenesis.
The final paper (FR-P0373, authored by Drs. J Groszek, J Cheng, C Blaha, R Kant, J Park, B Chui, K Goldman, S. Roy, and W Fissell) described the ability of the silicon nanofilter with uniform slits to remove more of the higher molecular weight toxins (these are termed middle molecules) than could conventional dialysis membranes.
This coffee cup sized device, which was conceived and developed by Dr. Roy, is based upon silicone which filters out the toxins that accumulate when one’s kidneys have failed. As stated above, the silicone nanofilter uses the body’s own blood pressure with no external pump or pressure device to effect the desired purification. When implanted in the body, it is connected to the bladder and to its blood supply, contiguous to the patient’s own kidneys. This is not a transplant; as such, the kidneys are left in the body and not removed.
