Septermber 2014 | ASN Kidney News | 11

In 1972, when the Medicare Act provided people in the United States with coverage for renal replace-

ment therapy, 40 percent of patients were doing home hemodialysis (HHD). In 2003, only 0.7 percent of the dialysis population in this country were doing HHD. The Aksys Company was founded in January 1991 to develop an HHD machine that would be patient friendly; reduce the labor of setting up, putting on, and tearing down; provide ultrapure water; and reuse the dialyzer and blood tubing to reduce cost. Since then, the following advances in HHD devices have continued to evolve.

The Baxter VIVIA hemodialysis system is designed to deliver high-dose hemodialysis in the home. The machine provides reuse of the dialyzer and blood lines by means of heat disinfection and automatic prime and rinseback; an integrated access disconnect sys-tem; an animated, patient-friendly, graphic user inter-face; wireless connectivity to the clinic; an integrated heparin pump; an integrated water treatment source; and online dialysate generation. The device provides all types of hemodialysis. It is not portable and does not have an integrated blood pressure monitor sys-tem. The device received approval from the European Community in December 2013, initially to be used in

selected European clinics in 2014, with the ultimate goal of coming to North America in 2015 or 2016.

The 2008K@Home machine, developed from the Fresenius Medical Care 2008 in-center series, was in-troduced as the Baby K@Home in 2004, withdrawn from the market in 2008, and reintroduced in 2010 with approval from the U.S. Food and Drug Admin-istration (FDA) for home therapy. This machine, which provides all types of hemodialysis, has a stand-ard platform as used in a center, is reliable and easy to maintain, provides ultrapure water, and uses stand-ard supplies. It has automated prime and rinseback, and a blood pressure monitor and a heparin pump are integrated in the device. The dialysate concentration can be adjusted in a manner similar to that used by in-center machines. A patient interface assists patients with setup and interacts with alarms. Remote real-time monitoring is provided by iCare connectivity. WetAlert, a wireless wetness monitor at the needle site, will stop the blood pump if the alarm is activated. The machine is not portable and requires an external water treatment source and significant home remodeling.

NxStage Medical, Inc., was founded in December 1998. The NxStage System One was approved for he-modialysis in July 2003 and for HHD in June 2005.

NxStage System One is being used by more than 6000 patients in the United States (i.e., 95 percent of HHD patients in this country) and has performed more than 6 million short daily treatments with low-dialysate-flow hemodialysis at home.

The machine is a cycler (similar to the peritoneal dialysis cycler platform) and has a disposable drop-in cartridge with blood and dialysate lines and dialyzer attached. There is no blood or dialysate interface with the device; thus, disinfection involves removing the disposable cartridge and wiping down the machine. Ultrapure dialysate is provided in sterile 5-L bags, by the Pure Flow system, or by both. The Pure Flow, ap-proved by the FDA in 2008, is a compact, self-con-tained, disposable deionization water filtration system with a simple faucet or an under-sink connection with a standard electric outlet; thus, it requires no signifi-cant home remodeling. The Pure Flow makes a 60-L sack of lactate base dialysate in 7 hours that can be used for as long as 96 hours from the time of prepa-ration. Maintenance of the cycler and Pure Flow is provided through FedEx exchange by the patient of the cycler and Pure Flow components. The device pro-vides short daily low-dialysate-flow hemodialysis five

Technical Advances in Home HemodialysisBy Robert S. Lockridge, Jr.

Baxter VIVIA Hemodialysis System

PAK Sorbent Hemodialysis System

Fresenius Medical Care 2008K@Home machine

NxStage System One

Physidia S3 Quanta SelfCare+ Wearable Artificial Kidney (WAK)

Continued on page 12

Home Dialysis

or more times per week. The maximum dialysate flow rate is 200 mL/min. The cycler is portable, weighing 72 pounds. The patient can travel only with sterile bags. There is no integrated heparin pump or auto-mated blood pressure monitor.

The NxStage System One S, approved by the FDA in November 2013, increased the maximum dialysate flow to 300 mL/min, allowing more flexibility in the dialysis prescription. The Nx2me Connected Health, approved by the FDA in October 2013, created a wireless connectivity to the clinic that uses an iPad app for patient entry and transfer of secure patient and treatment data. NxStage is working with the FDA to receive approval for nocturnal HHD.

The PAK Sorbent Hemodialysis System makes use of old technology to provide a portable HHD de-vice that requires only 9 L of tap water per treatment; sorbent technology is used to regenerate the spent di-alysate. The REDY (Recirculating Dialysis System) was developed in 1975 and has been used for more than 6 million treatments. This sorbent technology was pur-chased by Renal Solutions, which developed the Allient machine and had it approved for hemodialysis in June 2005. Renal Solutions was purchased by Fresenius in November 2007, and the intellectual rights of Xcorpo-real were purchased by Fresenius in 2009 to facilitate the development of the PAK.

The PAK Sorbent system is designed for tradi-tional, every-other-day and short daily HHD. The machine is separated into two sections, making it portable, and requires no home remodeling. It has

a cartridge setup, automated prime and rinseback, touch-screen patient interface, wireless connectivity to the clinic for transmission of treatment and patient data, and a WetAlert similar to the device in the K@Home system, which detects moisture at the needle site. It has no integrated heparin pump or automated blood pressure monitor. The goal is to have the device to market in the United States in 2015 or 2016.

Professor Jules Traeger, MD, developed the con-cept of the four-cylinder balance chamber technology to push sterile dialysate through the dialyzer, elimi-nating the proportionate pumps and thus reducing the size of the device to make it portable. This tech-nology was validated with VALEMONT in animal and human trials in 2004 and 2005.

The Physidia S³ device was created from Profes-sor Traeger’s proven concept. The machine is designed for short daily and every-other-day low-dialysate-flow HHD. The balance chamber technology is able to provide hemodiafiltration. The device has a cartridge setup, automated prime, touch-screen patient inter-face, and the ability to store and transmit treatment data to the clinic in real time or after the treatment. The device is portable and weighs 44 pounds. All di-alysate is made in sterile bags and delivered to the pa-tient. It has an integrated automated blood pressure monitor but no integrated heparin pump. Clinical trials continue, and the goal is to have it to market in France in 2015 or 2016.

The Tablo System from Silicon Valley–based HDPlus was designed with smart technology and consumer product simplicity, to significantly improve the patient’s experience and increase the efficiencies of providing dialysis care. This new HHD system was designed with input from dialysis nurses, physicians, and patients currently using HHD. It has single-pass

dialysate, a touch-screen patient interface to shorten putting it on and taking it off, alarm interaction, and wireless automatic treatment data transfer. Ultrapure water is produced in real time with Microfluidic Heat Exchange flash pasteurization of incoming tap water and wide-ranging rates of blood and dialysate flow for treatment flexibility. The device is portable and has an integrated water source. Its projected time to market in the United States is unknown.

Quanta SelfCare+ is being developed by Quanta, a company based in Warwickshire, England. Its dis-posable pumping system, unique to this device, al-lows it to provide a high-performance hemodialysis system that weighs 64 pounds and is portable. The machine is designed for HHD and in-center self-care, with cartridge setup, automated prime and rinseback, and touch-screen patient interface. It can store and transmit treatment data to the clinic in real time or after the treatment. Standard supplies are used for this machine. The patient can travel only with sterile bags. The machine must have a separate water treatment source for home setup. It has no integrated heparin pump or automated blood pressure monitor. The goal is to market it first in the United Kingdom in 2015 or 2016.

The wearable artificial kidney, whether using blood access or peritoneal access, has unique problems. In February 2014, the FDA approved the start of the first human clinical trials in the United States for the wearable artificial kidney, designed by Blood Purifica-tion Technologies, Inc., based in Beverly Hills, Cali-fornia. The results of this trial will be critical in the advancement of this device in the United States.

Robert S. Lockridge, Jr., MD, is a retired clinical neph-rologist in Lynchburg, Virginia.

Technical AdvancesContinued from page 11

By Allen R. Nissenson

Impact of the Prospective Payment System (PPS) on Home Hemodialysis

The vast majority of patients with end stage renal disease (ESRD) undergoing dialysis receive this care through

a Medicare entitlement enacted in 1972. Up until 2011, payment for dialysis treatments included one payment for the basic treatment itself, including all of the associated costs, and a separate payment for injectable medications (primarily erythropoietin, vitamin D, and iron) and some laboratory tests. In January 2011 the Prospective Payment System (PPS)—sometimes called “the bundle”—approach to payment was initiated, so-called because the basic pay-ment plus the payment for injectable medications (and some laboratory tests) were bundled together into a single

payment. In addition, the provisions of the PPS included withholding 2 percent of the bundled payment, which could be earned back if dialysis facilities met certain qual-ity outcomes. The PPS applied to patients independent of dialysis modality or site of care, so included home hemodi-alysis (HHD) patients, although the quality metric related to dialysis adequacy was not included for such patients who were receiving more than three treatments per week.

When the PPS was implemented there was a measur-able increase in the number of patients selecting peritoneal dialysis (PD) as a dialytic modality. While there are many factors that led to this occurrence, it was clear that total costs of care for PD patients were lower than for in-center hemodialysis (ICHD) patients, and the PPS further incen-tivized PD since the weekly payment was the same for PD and ICHD, but the costs for PD were lower. A similar in-crease in growth of HHD has not been seen, however, and the PPS does not favorably reward placement of patients on this form of therapy. It should be noted that the current PPS payment level is not sufficient to pay for the costs of dialysis, thus necessitating cost shifting from patients with other forms of insurance in order to maintain viability of dialysis facilities.

There is currently a lack of granular data on the costs of HHD training, including retraining and “futile” training

for patients who switch out of the therapy in the first 3 to 6 months. In addition, the lack of a payment policy by Medi-care to cover the costs of more frequent dialysis makes it chal-lenging to provide more than three treatments, even at home. If the clinical value of more frequent dialysis can be convinc-ingly demonstrated, and patients live longer, are healthier and remain out of the hospital, have an enhanced experience of their treatments, and a better quality of life, the imperative will be on the kidney care community to convince Medicare to: 1) reimburse for the additional treatments under the cur-rent fee-for-service system, or 2) move more rapidly to the value-based fully bundled or capitated system where the up-front costs of providing more treatments are more than offset by savings in keeping patients healthier.

Allen R. Nissenson, MD, FACP, FASN, is the Chief Medi-cal Officer for DaVita HealthCare Partners and is Emeritus Professor of Medicine at the David Geffen School of Medicine at UCLA.

Reference

1. Tennankore KK, et al. Survival and hospitalization for intensive home hemodialysis compared with kid-ney transplantation. J Am Soc Nephrol. doi:10.1681/ASN.2013111180.rlagshandlung, 1861, pp 398–400.