US Patent 10045769 Circular surgical staplers with foldable anvil assemblies

Circular stapling instruments and anvil assemblies. The anvil assemblies may have collapsible anvil support members that may be inserted through an opening in a patient and then expanded to be attached to an anvil plate assembly that has a staple-forming surface thereon. The anvil support member is attachable to the anvil plate assembly in such a way that when the anvil assembly is coupled to the stapling head of a circular stapler, the staple-forming surface is in substantial registry with the staples supported in the stapling head. A variety of different anvil support members and anvil plate assemblies are disclosed.