This is the standard technique. In this approach, the needle is passed through the body of the stomach adjacent the celiac artery into the retroperitoneal space in 1 or 2 passes. The injectate (bupivacaine or alcohol) is injected and spreads through the retroperitoneal space, effectively "bathing" all the ganglia.

This is a more recent technique which has been often used. In this procedure, the needle is inserted under EUS guidance directly into as many ganglia as possible. For celiac ganglia <1cm in diameter, the solution is injected into the central point; for those ≥1 cm, a needle is advanced to the deepest point into the ganglia and solution is injected as the needle is slowly withdrawn. Injections are continued until an echogenic pattern is produced over the entire celiac ganglia.

The intervention technique of EUS-CGB is the realization of EUS-guided celiac block with injection of bupivacaine directly into the ganglia for patients with chronic pancreatitis.

The primary endpoint will be pain relief at 1 week after the block, defined as a decrease of 3 or more points in the VAS scale measuring "average pain over past week".

Decrease in pain to 1 or 0.

Duration of pain relief will be assessed during a 2-month follow-up.