Maple tree issues

[Wazzu]

I just trimmed up a bunch of branches from my maple trees. A lot of the branches have this brown center. Some are a even hollow. Anyone got recommendations?

 

[ATH]

The tree was damaged at some point. Bark is really good at keeping rot out. However, once it gets in, it can spread through existing wood.

That is a lot of branches off of one tree. Was it topped? Was it previously topped (would explain widespread rot)?

 

[Wazzu]

No, it hasn’t been topped.