Why does kidney dialysis only work for a certain time?

Duration of dialysis: The limits of kidney dialysis are due to dialysis access issues, inflammation from artificial membrane exposure, exposure to toxic medications to control the metabolic effects of kidney disease, and the complications of kidney failure that dialysis cannot totallyprevent, like cardiovascular disease, calcium, phosphorus vitamin d and PTH abnormalities, and peripheral or autonomic nerve damage.

It's not...: It's not that it only works for a "certain period of time". It is that the only time the machine can function as your kidneys is when it is hooked up to you. Thus, unless you are on the machine constantly, you will have periods when the substances filtered by your kidneys are just collecting in your blood..