CPT® Code 61543

The procedure described by CPT® Code 61543 involves a craniotomy with elevation of a bone flap for a partial or subtotal (functional) hemispherectomy. This surgical intervention is performed on the brain, which is anatomically divided into two cerebral hemispheres: the right and left. Each hemisphere consists of an outer layer known as the cerebral cortex, which is primarily composed of grey matter, and an inner layer of white matter. The two hemispheres are interconnected by a structure called the corpus callosum, which facilitates communication between them. In a functional hemispherectomy, a portion of the affected hemisphere is surgically removed, and the remaining nerve fibers, including those of the corpus callosum, are transected. This procedure is typically indicated for patients with severe epilepsy or other neurological conditions that affect one hemisphere of the brain. The deeper structures of the brain, such as the basal ganglia, thalamus, and brain stem, remain intact during this operation. The surgical approach involves making a long incision in the scalp, creating a scalp flap, and drilling burr holes to access the skull. The bone flap is then elevated to allow for the necessary surgical manipulation of the brain tissue. This complex procedure requires careful dissection and the use of specialized instruments to ensure the precise removal of the affected brain tissue while preserving critical structures.