CPT® Code 61524

The procedure described by CPT® Code 61524 refers to a craniectomy performed in the infratentorial or posterior fossa region of the brain, specifically for the excision or fenestration of a cyst. The infratentorial area is located beneath the tentorium cerebelli and encompasses critical structures such as the cerebellum and brainstem. A craniectomy involves the surgical removal of a portion of the skull to access the brain. This is achieved by first creating scalp flaps, followed by the drilling of burr holes in the skull. The intervening bone between these burr holes is then meticulously cut using a surgical saw or craniotome, allowing for the elevation and removal of a bone flap, which may be done temporarily or permanently. In this context, the term 'fenestration' refers to the creation of an opening in the cyst, allowing it to drain into the cerebrospinal fluid pathway, while 'excision' involves the complete removal of the cyst without compromising its wall. The procedure concludes with the repair of the dura mater, the tough outer membrane covering the brain, followed by the placement of the bone flap over the dura, secured with steel sutures. In some cases, the skull defect may be filled with materials such as bone wax or silicone. Finally, the scalp flap is reapproximated, and the skin incision is closed, ensuring proper healing and recovery.