Which procedure involves removing a portion of the skull that is then replaced?

The procedure in question is a craniotomy. This surgical technique involves creating an opening in the skull to access the brain. During a craniotomy, a section of the skull is temporarily removed, allowing the surgeon to perform necessary interventions on the brain, such as removing tumors, alleviating pressure, or repairing damaged areas. Once the procedure is completed, the section of bone is typically replaced and secured with plates or screws to allow for proper healing.

In contrast, a craniectomy involves the permanent removal of a portion of the skull without replacement, usually done to relieve pressure in cases of severe brain swelling. Neuroplasty refers to procedures aimed at restoring or repairing nerves, and hemostasis pertains to the process of stopping bleeding during surgery, but does not involve skull surgery. Thus, craniotomy is the correct answer as it specifically includes the removal and replacement of a section of the skull.