Success of Paravertebral Blocks in Analgesia for Interventional Hepatic Procedures

Inclusion Criteria: * Male or non-pregnant female subjects, between the ages of 18 and 80 at the time of enrollment. Subjects referred for liver/biliary interventions to the angiography department. Written informed consent to participate in the study. Ability to comply with the requirements of the study procedures Exclusion Criteria: * Subjects who participated in an active stage of any drug, intervention or treatment trial within 30 days of enrollment. Subjects with preexisting conditions, which, in the opinion of the investigator, interfere with the conduct of the study. Patients will only be excluded on this basis following discussion with another interventional radiologist. Subjects who are uncooperative or cannot follow instructions. Mental state that may preclude completion of the study procedure or ability to obtain informed consent. Pregnant or nursing female subjects. Patient who are to undergo liver biopsy or routine biliary tube exchange. Patients with neurological/spinal conditions, or a BMI over 40, that would prevent safe/effective or well-targeted paravertebral blockade. Patient unable to tolerate the paravertebral block procedure, for example due to inability to lie prone