Pain in chronic pancreatitis: Managing beyond the pancreatic duct

Abstract

Chronic pancreatitis (CP) continues to be a clinical challenge. Persistent or recurrent abdominal pain is the most compelling symptom that drives patients to seek medical care. Unfortunately, in spite of using several treatment approaches in the clinical setting, there is no single specific treatment modality that can be earmarked as a cure for this disease. Traditionally, ductal hypertension has been associated with causation of pain in CP; and patients are often subjected to endotherapy and surgery with a goal to decompress the pancreatic duct. Recent studies on humans (clinical and laboratory based) and experimental models have put forward several mechanisms, including neuroimmune alterations, which could be responsible for pain. This might explain the partial or no response to single modality treatment in a significant proportion of patients. The current review discusses the recent concepts of pain generation in CP and evidence based therapeutic approaches (other than ductal decompression) to handle persistent or recurrent pain. We focus primarily on parenchymal and neural components; and discuss the role of antioxidants and the existing controversies, drugs that interfere with neural transmission, pancreatic enzyme supplementation, celiac neurolysis, and pancreatic resection procedures. The review concludes with the treatment approach that we follow at our institute.

Keywords: Pain, Chronic pancreatitis, Nociception, Neuroplasticity, Antioxidant micronutrients, Pregabalin, Pancreatic enzymes

Core tip: Pain in chronic pancreatitis (CP) has multiple but simultaneously occurring mechanisms. Recent data have shown expression of nociceptors and neurotrophic factors in different neural locations. The expression of these and other neural chemokines (fractalkine) have positive correlation with pain. Pain also results from global sensitization. Among the therapeutic modalities, beneficial effects have been demonstrated with methionine containing antioxidant micronutrients supplements and pregabalin. Of the pancreatic enzymes, only non-enteric coated preparations might benefit a subgroup of patients. The threshold for performing celiac neurolysis should be high in view of variable response across clinical trials.