Institutional Ethics Board concern regarding sham procedure, requiring modifications that are not feasible within the man-power limitations of our institution.

This study is aimed at assessing whether performing a paravertebral block (a type of regional pain relief) can reduce the pain and anxiety patients experience during radiological procedures on the liver.

Percutaneous procedures of the liver can be very painful and range from bliliary drain insertions to tumor ablation procedures. The study will randomize patients in two groups, one receiving a paravertebral nerve block prior to the procedure and one receiving a sham procedure in which saline will be injected in the paravertebral space. Pain scores and use of IV sedation will be monitored post procedure and both groups will be compared to assess whether paravetebral nerve blocks are effective at reducing pain in patients receiving such 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