I agree with my neurosurgeon colleague. If the stroke is large enough, then there is swelling of the brain immediately after stroke. Just like your ankle gets swollen after sprain. In brain, due rigid skull all around,This rapid rise in swelling and blood clot needs to be evacuated as soon as possible. If allowed to persist, this swelling can cause death or new areas of stroke due to rise in brain pressure. As after sometime an ankle swelling goes down after a sprain, even brain swelling comes down. Rapidity of surgery is critical to save life and to control brain pressure.

If the clot is large enough to increase the pressure inside the skull cavity, it might be necessary to open the skull ( Craniotomy and hematoma evacuation). Sometimes, we may have to take out part of the skull bone and keep it in the abdominal wall of the patient till his brain swelling comes down ( Decompressive craniectomy).

It all depends upon what is the cause of blood clot, mri report need to seen. If big area of brain is affected by clot then swelling will be big, for reduction of swelling sometimes surgery is required.