Please help. When coding Skull Base Procedures, can you code 61595, 61615, and 62147 (for a crainioplasty when the tumor has invadied the bone). Can you mix 62147 with Skull Base Procedure codes. Also can you charge Skull Base Codes with 61458 (Craniectomy, suboccipital; for exploration or decompression of cranial nerves.)? Please reference your answer with realible documentation.