Chronic pancreatitis is a progressive inflammatory disease of the pancreas characterized by destruction of pancreatic parenchyma and subsequent fibrosis. The prevalence of chronic pancreatitis has been found to be very high in southern India (114-200/100 000 population). Alcohol is the most common etiology worldwide, while idiopathic pancreatitis is the most common type in India and China, accounting for approximately 70% of all cases of chronic pancreatitis. It is a cause of considerable morbidity in the form of pain, steatorrhea and diabetes mellitus. Natural history of chronic pancreatitis is characterized by variable course stretching over decades with recurrent acute pancreatitis in the early stage and steatorrhea, diabetes and pancreatic calcification in the later stages. Pain is a prominent clinical feature of chronic pancreatitis and the most troublesome symptom for which medical attention is often sought. Unfortunately, despite much work, the pathophysiology of pain in CP remains poorly understood. Multiple factors have been suspected, which include inflammation, encasement of sensory nerves by the fibrotic process and neuropathy, and duct obstruction, which can lead to high back pressure and parenchymal ischemia. Increased pressure in the main pancreatic duct is likely to be an important cause of pain, particularly in patients with duct dilatation. This explanation forms the conceptual basis for both endoscopic and surgical drainage procedures. Approximately one half of patients with pain owing to chronic pancreatitis come to an intervention aimed principally at pain relief, along with relief of bile duct, duodenal, and major venous obstruction. Patients with chronic pancreatitis can be treated with medical management, endoscopic therapy and surgical treatment. For patients with dilated ducts, ductal decompression is advocated. The pros and cons of endoscopic versus surgical therapy are debated.

The modified Puestow or lateral pancreaticojejunostomy is the most commonly employed surgical procedure. Lateral pancreaticojejunostomy relieves chronic abdominal pain in 65%-93% of patients. Morbidity and mortality rates are generally low, averaging 20% and 2%, respectively. Long-term follow-up of patients after lateral pancreaticojejunostomy reveals that up to 50% of patients develop recurrent symptoms and 10%-35% fail to obtain pain relief.

Overall more than 60% of patients undergoing pancreatic endotherapy are pain free 1 year after the procedure. There are only two randomized controlled trials comparing endoscopic treatment with the surgical therapy.

Dite et al. reported the first trial. Surgery consisted of resection (80 %) and drainage (20 %) procedures, while endotherapy included sphincterotomy and stenting (52 %) and/or stone removal (23 %). In the entire group, the initial success rates were similar for both groups, but at the 5-year follow-up, complete absence of pain was more frequent after surgery (37 % vs. 14 %), with the rate of partial relief being similar (49 % vs. 51 %). In the randomized subgroup, results were similar (pain absence 34 % after surgery vs. 15 % after endotherapy, relief 52 % after surgery vs. 46 % after endotherapy). The increase in body weight was also greater by 20 - 25 % in the surgical group, while new-onset diabetes developed with similar frequency in both groups (34 - 43 %), again with no differences between the results for the whole group and the randomized subgroup. The authors concluded that surgery is superior to endotherapy for long-term pain reduction in patients with painful obstructive chronic pancreatitis.

Cahen et al. reported the second trial. All symptomatic patients with chronic pancreatitis and a distal obstruction of the pancreatic duct but without an inflammatory mass were eligible for the study. Thirty-nine patients underwent randomization: 19 to endoscopic treatment (16 of whom underwent lithotripsy) and 20 to operative pancreaticojejunostomy. During the 24 months of follow-up, patients who underwent surgery, as compared with those who were treated endoscopically, had lower Izbicki pain scores (25 vs. 51, P\<0.001) and better physical health summary scores on the Medical Outcomes Study 36-Item Short-Form General Health Survey questionnaire (P=0.003). At the end of follow-up, complete or partial pain relief was achieved in 32% of patients assigned to endoscopic drainage as compared with 75% of patients assigned to surgical drainage (P=0.007). Rates of complications, length of hospital stay, and changes in pancreatic function were similar in the two treatment groups, but patients receiving endoscopic treatment required more procedures than did patients in the surgery group (a median of eight vs. three, P\<0.001). Authors concluded that surgical drainage of the pancreatic duct was more effective than endoscopic treatment in patients with obstruction of the pancreatic duct due to chronic pancreatitis.

Both these trials had a small sample size. The population studied was also different. ESWL was not included in protocol in one of the trials. In one of the trials only pancreatic duct drainage was chosen as the surgical therapy. The proposed study will compare surgery with endoscopic therapy in Indian population with chronic pancreatitis. The outcomes compared would include pain relief, quality of life, morbidity, mortality, length of hospital stay and changes in pancreatic endocrine and exocrine function.