**7. Endosonography-guided celiac plexus block (CPB)**

Once medical treatment options fail, persistent severe pancreatic pain can be treated endoscopically or surgically. The CPB can be used in patients with significant abdominal pain who have a poor general condition and have not responded to endoscopic treatment. In this technique, a combination of glucocorticoids and a longacting local anesthetic (generally bupivacaine) can be administered using CT or EUS. EUS guidance is safer, more effective, and longer-lasting than CT. Bilateral injection (bupivacaine 0.25% [4 ml each side], followed by triamcinolone 80 mg [40 mg each]) and, central or unilateral injection (bupivacaine 0.25% [8 ml], followed by triamcinolone 80 mg) could be used. Bilateral injection seems to be an optimized distribution; however, supporting data are lacking.

It is unclear which patients derive the benefits of CPB. A long duration of pain may negatively affect the outcome because of permanent neuroplastic changes. Narcotic dependence is another factor that makes the treatment challenging. It is difficult to determine whether it is a hyperalgesia-related opioid or ineffective treatment, which also predicts a poor outcome. In a meta-analysis, it has been reported that EUS-guided CPB can relieve pain in 51–59% of patients [53]. However, it is reportedly inferior to surgical management. In a cohort study of 248 patients with CP, CPB was associated with pain relief in 177 patients (76%), with a median duration of 10 weeks [54]. The effect of CPB generally lasts for 3 months, after which the pain may worsen. It could be repeated for 3 or 6 months if it is beneficial in the initial celiac intervention. Nerve destruction may cause an increase in pain, hypotension, hemorrhage, infection, and neurological complications.

Celiac plexus neurolysis and absolute alcohol injection are used in pancreatic malignancies. However, it is not recommended for CP because of its potentially severe side effects. Due to the desmoplastic reaction, the possible future pancreatic surgery

may get complicated. There is no routine recommendation or consensus for CPB or neurolysis for managing CP in the current guidelines.
