How long can someone live on ECMO?

I'm curious to know, how long can a patient typically survive while on ECMO, also known as extracorporeal membrane oxygenation? I understand it's a life-saving technology that provides both cardiac and respiratory support to critically ill individuals, but I'm interested in understanding the duration of this support and what factors might influence its longevity. Is there a typical range of survival time, or does it vary greatly from case to case?