CPT® Code 61698

The procedure described by CPT® Code 61698 involves the surgical intervention for a complex intracranial aneurysm located within the vertebrobasilar circulation, utilizing an intracranial approach. A complex intracranial aneurysm is characterized by specific features that complicate its treatment, including a size greater than 15 mm, the presence of calcification at the neck of the aneurysm, and the involvement of normal blood vessels within the aneurysm neck. These factors contribute to the complexity of the surgical procedure. In cases where the surgical approach necessitates temporary occlusion of blood vessels, trapping of the aneurysm, or the use of cardiopulmonary bypass, the aneurysm is classified as complex, indicating a higher level of surgical difficulty and risk. The surgical approach is tailored to the precise location of the aneurysm, which may involve accessing the aneurysm through the interhemispheric fissure or the pterion. The procedure begins with an incision through the skin and subcutaneous tissue, followed by the removal of the overlying bone through a craniectomy. Once the dura mater is opened, the arachnoid membrane is carefully nicked, and cerebrospinal fluid may be drained to enhance visibility and access to the internal carotid or vertebrobasilar artery. The surgeon then identifies and isolates the artery from the surrounding arachnoid membrane, allowing for direct exposure of the aneurysm. Treatment options for the aneurysm include clipping and resecting the mass lesion, followed by vessel reconstruction through direct repair or bypass grafting. Alternatively, if there is sufficient collateral circulation, the aneurysm may be trapped, with clips applied above and below the lesion to achieve complete occlusion.