The CUSA Clarity Bone Tip Study

Inclusion Criteria: * Subject is at least 18 years of age * Subject requires a cranial skull base procedure involving removal of bone with ultrasonic aspirator * Subject is an appropriate candidate to receive use of the CUSA Clarity Bone Tip product during cranial skull base bone removal surgery, per the study surgeon * Subject signed the IRB/EC-approved informed consent form demonstrating that the subject is willing and able to participate in this clinical study and to comply with all study procedures Exclusion Criteria: * Subject is currently pregnant or plans to become pregnant prior to the study index surgery * Subject has any significant medical condition that in the opinion of the investigator will interfere with protocol evaluation and participation * Subject's surgical plan includes utilizing CUSA Clarity Bone Tip for bone removal anywhere besides the cranial skull base in an open craniotomy (e.g. transsphenoidal approach or spinal procedures). * Subject is a prisoner or member of a different vulnerable population that should not be included in the study per the investigator or ethics committee. Intra-operative exclusion criteria : * Surgeon does not utilize CUSA Clarity Bone Tip for cranial skull base bone removal during surgery or utilizes CUSA Clarity Bone Tip anywhere else besides the cranial skull base