Membrane lined insulated gutters are designed to last for many years. However, as with all insulated gutters, regular inspections and maintenance will be required.
Insulated gutters, and in fact any gutter, should be inspected on a yearly basis and after any adverse weather. The insulated gutters and connecting downpipes etc… should be checked for damage and debris that may block the system. The best way to do this is by using non-metallic tools such as soft bristled brushes and PVC shovels to ensure the membrane is not damaged.
Usually, manufacturers of galvanised insulated gutters will detail the expected maintenance needed.
Also, as a side-note, gutter maintenance is often an insurance consideration too. Failing to maintain membrane lined insulated gutters could lead to further damage beyond the gutter itself.