Ambulatory Hemodialysis Could Improve Prospects of ESRD Patients, but Hurdles Remain

By Will Boggs MD

November 22, 2019

NEW YORK (Reuters Health) - Ambulatory hemodialysis could give greater freedom to patients with end-stage renal disease (ESRD), but several technical hurdles remain, according to a new review.

"Ambulatory devices for hemodialysis can provide the benefits of frequent and prolonged treatments, especially in the home setting," Dr. Shuvo Roy of the University of California, San Francisco, told Reuters Health by email. "These devices address one of the key patient desires: ability to travel."

Nearly two-thirds of the more than 725,000 Americans with "ESRD are treated with hemodialysis, but only 2% of the dialysis patients in the U.S. have chosen home hemodialysis, Dr. Roy and his colleagues note in the Clinical Journal of the American Society of Nephrology, online November 14.

The equipment is generally bulky, complex and requires operation by trained clinical staff, and some patients are apprehensive about dealing with blood and needlesticks.

In their report, Dr. Roy and colleagues explain the motivation for ambulatory hemodialysis and an overview of the necessary features of key technologies that will be the basis for new wearable and implantable devices.

These devices must satisfy at least three key requirements: they must be of manageable size and weight for the patient; they must be able to deliver sufficient clearance of uremic toxins; and they must meet important technical requirements for dialysis membrane characteristics, dialysate regeneration, vascular access and patient monitoring.

One current ambulatory-hemodialysis device, the belt-like Wearable Artificial Kidney, weighs about 5 kg and connects to vasculature via catheters. In three separate clinical studies, patients remained hemodynamically stable and there were no serious adverse events, but the most recent trial was stopped after the seventh of 10 hemodialysis patients experienced device-related technical problems, including excessive carbon dioxide bubbles in the dialysate circuit and variable blood and dialysate flows.

The authors are working on a two-stage Implantable Artificial Kidney that combines a high-efficiency membrane for hemofiltration with a bioreactor of kidney tubule cells for electrolyte balance. Some of its components are being evaluated in a series of preclinical studies.

Preliminary work has also demonstrated the feasibility of another implantable silicon nanopore membrane-based hemodialyzer.

"Questions around implantation technique, device lifetime, ultrafiltration control, and periodic maintenance will require further consideration," the authors note. "For both wearable and implantable devices, the potential need for administration of continuous or intermittent anticoagulation therapy without compromising safety will need to be addressed. Future work will need to continue to focus on the technology improvements to facilitate ambulatory implementation and clinical evaluation."

"On the 'science' side, reliability of the vascular access connecting the wearable hemodialysis machine as well as overall weight will determine success," Dr. Roy said. "For the implantable device, long-term performance of the membranes will determine time between potential surgical interventions. On the non-technical side, the principal hurdle is likely funding to finalize prototypes and conduct clinical trials."

"The recent Executive Order (on Advancing American Kidney Health) from the White House is aimed to encourage home therapies for kidney failure patients," he said. "Ambulatory hemodialysis devices can help achieve that goal."

Two of the three authors of this article have patents related to the technology they discussed.


Clin J Am Soc Nephrol 2019.