Efficacy of EUS-guided Celiac Plexus Blockade in Chronic Pancreatitis

There are few effective options for the treatment of abdominal pain in chronic pancreatitis. For the past 20 years, percutaneous injection of anesthetic agents into the celiac plexus (celiac plexus blockade or CPB) has been performed by pain anesthesiologists to diagnose the origin of pancreatic pain (visceral vs. non-visceral). Anesthetic blocks provide very short-term and variable pain relief. More recently, endoscopic ultrasound has been used to provide a transgastric approach to the celiac plexus (EUS-CPB).

Corticosteroids may lengthen the effect of CPB to provide longer-lasting pain relief ("therapeutic block"). Case-series report that about 50% of patients experience partial or complete relief lasting an average of 1-2 months. Combined corticosteroid (triamcinolone) and anesthetic (bupivicaine) has now become standard practice for EUS-CPB. However, there have been no randomized controlled trials to prove that corticosteroid blocks are truly therapeutic (i.e. that they lengthen the effect of the typical "diagnostic" CPB with anesthetics). Randomized controlled trials are needed to demonstrate the therapeutic efficacy of CPB with corticosteroids.

This is a triple-blind, parallel group, randomized controlled trial to assess the benefit of triamcinolone injection as a therapeutic measure for control of chronic pancreatitis pain. The treatment group will undergo EUS-CPB with bupivicaine plus triamcinolone ("therapeutic block"). There control group will undergo EUS-CPB with bupivicaine alone ("diagnostic block").

Eligible patients with abdominal pain undergoing EUS for the diagnosis of chronic pancreatitis or EUS-CPB for pancreatic pain will be recruited. Patients will complete a 2-week run-in period to establish baseline pain scores and opioid consumption. Following the run-in, EUS will be performed. If EUS reveals CP (>4 criteria), patients will be randomized to one of the two treatment groups. 74 patients will be randomized and followed for 2 months after the EUS-CPB. The primary endpoint is an improvement in the pain disability index (PDI) of greater than 10 points at 1 month. Secondary endpoints include opioid consumption, duration of pain relief, and quality of life (SF-12).

If this trial shows that the addition of triamcinolone produces a long-lasting (1-month) benefit, then EUS-CPB can be more strongly advocated as a therapeutic option to patients with chronic pancreatitis. If triamcinolone does not produce a benefit over a diagnostic block, then EUS-CPB should be considered a primarily diagnostic measure for differentiation of visceral from non-visceral pain.

Inclusion criteria

include:

• Age >18 yrs
• Ability for informed consent
• Chronic pancreatic-type abdominal pain (type B) (11).

Exclusion criteria

include:

• Pregnancy
• Malignancy
• Recent acute pancreatitis (within 2 months)
• Elevated INR (>1.5) or low platelet count (<75 cells/mm3)
• Allergy to eggs or "caine" anesthetics or corticosteroids; AND
• Becks depression score>20.