Prospective Randomized Trial of EUS Guided Celiac Plexus Block for Chronic Pancreatitis

1.0 Background and Hypothesis: Chronic pancreatitis is an inflammatory disease of the pancreas characterized by painful scarring and loss of glandular function.The prevalence of chronic pancreatitis in the United States is estimated to be 0.2 to 5% and results in 86,000 hospitalizations. The majority of patients with chronic pancreatitis will develop significant abdominal pain which is debilitating and results in a significant burden on the health care system.

Multiple approaches, including pancreatic enzymes, narcotic analgesia, celiac plexus block and surgical ganglionectomy have been used to treat pancreatic pain with variable success. Injection of local anesthesia agents and steroids into the celiac plexus for pain control has been used for many years via both surgical and percutaneous approaches. Topical therapy theoretically prevents the conduction of painful stimuli from the pancreas and addresses inflammatory changes in the afferent nerves themselves. Splanchnic nerves pass from the pancreas to the thoracic root ganglia via the celiac ganglia which are the target for intervention. Nerve changes in chronic pancreatitis including perineural inflammation, altered diameter, and upregulation of pain neuropeptides (including Substance P) are associated with increased sensitivity to stimuli from the pancreas (distension and inflammation) as well as pain independent of stimuli (neuropathic). Endoscopic ultrasound allows for close proximity, high resolution assessment of the gastrointestinal tract wall and adjacent anatomic structures. Physicians are able to perform EUS-guided celiac plexus injections in the outpatient setting under conscious sedation. The EUS guided approach offers better visualization of the celiac region and direct access to the celiac plexus. EUS guided celiac plexus block is a core part of the routine care of patients at Los Angeles County Hospital with chronic pancreatitis. Celiac plexus block is a recommendation for refractory chronic pancreatitis pain by the European Society of Gastrointestinal Endoscopy (ESGE).

Several studies have shown that EUS-guided CPB has a beneficial role in treating pain caused by chronic pancreatitis. A randomized trial by Gress et al looked at the efficacy of EUS-guided versus CT-guided celiac plexus block for controlling abdominal pain of chronic pancreatitis in 18 patients. They found significant improvement in pain symptoms in patients randomized to EUS-guided celiac plexus block over a mean time period of 10 weeks. A study by the same group showed an improvement in overall pain score in 55% at 4 and 8 weeks of follow-up in 90 patients. Adverse events including diarrhea and infection occurred in 3%. A comprehensive review by Kaufman et al in 2010 evaluated the efficacy of EUS-guided celiac plexus block and celiac plexus neurolysis in alleviating chronic abdominal pain due to chronic pancreatitis and pancreatic cancer respectively. A total of 6 studies were included in their analysis, comprising 221 patients, and found that EUS-guided celiac plexus block was effective in 51.46% of patients with chronic pancreatitis. EUS-guided celiac plexus neurolysis (with alcohol) was effective in 72.54% of those with pancreas cancer.

These modest improvement for celiac block for chronic pancreatitis (especially in comparison to celiac plexus neurolysis in pancreas cancer) have led some investigators to question whether EUS guided celiac plexus block is an effective treatment for chronic pancreatitis pain despite its routine use. Prospective randomized controlled studies examining the efficacy of endoscopic ultrasound guided celiac plexus block are lacking.

2.0 Objectives and Purpose Our aim is to perform a pilot randomized trial to gauge the degree to which celiac plexus block performed under endoscopic ultrasound guidance will benefit patients with chronic pancreatitis. We will assess whether celiac plexus block significantly decreases pain scores, hospitalization, and pain medication requirements and increases the ability to return to normal activities.