I thought I would resurrect this thread to talk about the Aksys home dialysis machine in context - the company folded in 2007. I was the first person to use it post FDA approval, I switched to Aksys from a standard machine in September of 2002. The primary problem with the technology was that it kept breaking. You know you have problems when your Windows based computer is more reliable than your dialysis machine. Believe me it is not fun to have the 'my dialysis machine broke' conversation with your Mom every week or two.
My machine was actually one of the more reliable ones - the comment I heard was that mine was hand built by the guys who came up with the system - I cannot imagine having to deal with a less reliable machine, and some were lemons from the start. So for me the biggest difference between the Aksys and the NxStage is reliability. The NxStage just keeps on ticking, I've taken the cycler down the Rogue River, it is not a delicate contraption like the Aksys. And the NxStage has a business plan
that works that may some day work.
Aksys required their own technician to come out when the machine went down ... that guy was busy. It would have had to have been orders of magnitude more reliable for that model to work. NxStage I think learned from this and came to the market with their swap out model, which seems to work well from what I've experienced and heard. All that said, the Aksys gave great dialysis.
It was the first device that offered ultra pure dialysate. It used high end materials for the blood circuit, silicon instead of pvc. The backflush process increased UFR by 800ml/hour which, when coupled with the treatment UFR, increased the UFR to > 1000ml/hr which is when convective diffusion comes into play. Convective clearance increases the movement across the membrane of protein bound solutes - like β2 microglobulins. In general the Aksys was designed to minimize 'compartment activation' - which is the term for the chronic inflammation that comes with exposing the blood to synthetic surfaces - such as the artificial kidney and blood tubing - and from less than ultra pure dialysate.
The Aksys was the first hemodialysis machine to address the compartment activation issue directly in a comprehensive way but this aspect of the device: its ability to manufacture ultra pure dialysate and disinfect its own blood circuit was also the machine's downfall. Including those features made it clinically ideal but it also made it three different machines crammed into one very complicated device. So when I think of an ideal home dialysis machine it has all the features of the Aksys, with the reliability and transportability of the NxStage but I also want a device that has a viable business model. That last one is a real kicker because the US dialysis market is a tough one to compete in considering it is a duopoly with one of the dominate providers being a vertically integrated manufacturer/provider and the other an entity that will take full advantage of their market position and squeeze your margins to the bone. And at this point one has to question the potential size of the market.
Thus, when I imagine what machine I'll be using in 2014, I think it will be an update on the current NxStage cycler. I've long said that
the cycler could be lighter very easily. That would be a great improvement. Display technology gets cheaper by the day so one hopes that its LED snapshot display would evolve into a conversational touchscreen. The big thing would be if there was a innovation in dialysate technology so that a future PureFlow could deliver ultra pure dialysate on demand, up to 500 or 800ml/min, for an extended period. Then future NxStage could use traditional dialysate flow rates.
Not sure if compartment activation gets comprehensively addressed again any time soon.