My husband has a very large splenic infarction caused when they had to embolize his splenic artery. Does his spleen need to be removed?

Not necessarily. Is he having a lot of pain? Is the original issue that required arterial embolization still active? How much of the vascular arcade was embolized? It is in your husband's best interest to keep in touch with the doc who performed the procedure.
Not usually. This is what the purpose of embolizing the splenic artery, or a for sure and expected consequence. Usually with time the spleen sloly shrinks nd the body takes care of it, but it can be painful a nd prolonged. If the pt can not bear the pain and discomfort thus every may be an option.