CPT® Code 61535

Craniotomy with elevation of bone flap; for removal of epidural or subdural electrode array, without excision of cerebral tissue (separate procedure)

The CPT® Code 61535 refers to a specific surgical procedure known as a craniotomy with elevation of the bone flap, which is performed for the removal of an epidural or subdural electrode array. This procedure is classified as a separate procedure and is characterized by the fact that it does not involve the excision of any cerebral tissue. The context for this procedure typically arises following a previous surgery where an electrode array was implanted to help identify an epileptogenic focus, which is a region of the brain responsible for generating epileptic seizures. During the craniotomy, the surgeon reopens the site of the previous incision, allowing access to the underlying structures. A skin incision is made along the original incision lines, and scalp flaps are raised to expose the skull. The bone flap is then elevated to gain access to the dura mater, the protective covering of the brain. Depending on the type of electrode array present, either an epidural or subdural, the appropriate removal technique is employed. For an epidural electrode array, the array is removed from the surface of the dura, while for a subdural electrode array, the dura is opened to facilitate its removal. This procedure is critical for patients who have undergone prior evaluations for epilepsy and require the removal of these electrodes without any additional brain tissue being excised.