Management

After a negative initial evaluation in patients younger than 40 years of age with only one mild episode of unexplained acute pancreatitis, expectant approach and no further testing is an acceptable management strategy, because the medium-term recurrence rate is believed to be low and the incidence of malignant neoplasm is low in patients with no family history of pancreatic cancer and no use of tobacco.^28,29

However, in patients older than 40 years of age, with more than one attack of acute pancreatitis or when the initial attack is severe, a systematic identification and/or elimination of correctable inciting factors is required (see Figure 3).⁴ Occult biliary stones can be demonstrated using repeated U/S (for the gallbladder) or EUS (for the common bile duct) and treated using endoscopic biliary sphincterotomy (EBS) and laparoscopic cholecystectomy if the gallbladder is in situ.

Early ERCP and EBS are safe and beneficial, particularly in severe biliary pancreatitis and when there is evidence of bile duct obstruction or cholangitis (see Figure 4).³⁰

Empiric administration of a low-fat diet and oral therapy with ursodeoxycholic acid (UDCA) have been proposed for patients with suspected biliary microlithiasis or sludge before proceeding to more technically demanding investigations in high-risk patients or patients already cholecystectomised or unfit for cholecystectomy^.6,8

At present, bile analysis and sphincter of Oddi manometry are less often performed, because these tests are invasive, insensitive and only available at tertiary institutions.^11,24 Available data suggest that, in suspected pancreatic SOD (on the basis of either a basal dilation of the main pancreatic duct or an abnormal dynamic response of the pancreatic duct at S-MRCP), a dual endoscopic biliary and pancreatic sphincterotomy, whether at single or separate sessions, yields significantly better response than EBS alone.^8,11

However, the risk of post-sphincterotomy pancreatitis is five times higher for this indication than for other indications.³¹ Placement of a transient pancreatic stent might reduce this risk when the accessory duct is not patent.³² This stent usually migrates spontaneously, but in case migration does not occur, it should be removed for 10 to 14 days following dual endoscopic sphincterotomy.

The selection of patients for treatment of ARP associated with PD is difficult, because there is currently no diagnostic modality that identifies patients who may benefit from dorsal pancreatic duct decompression.¹³

S-MRCP could be indicative of true or relative stenosis of the minor papilla if prolonged dilation of the main pancreatic duct is observed after secretin administration.¹⁵

Endoscopic therapy for patients with ARP associated with PD consists of minor papilla sphincterotomy, stent insertion or a combination of both.³³ The majority of therapeutic trials are small retrospective case series with only one randomised controlled trial on 19 patients showing a clinical benefit after dorsal duct stenting at a mean follow- up of 24 months.³⁴ Prolonged stenting of the dorsal main pancreatic duct should be avoided because of the risk of inducing pancreatic damage, mainly when the ductal morphology is initially normal.³⁵ Therefore, it is recommended that a stent is placed after minor papilla sphincterotomy to prevent early obstruction secondary to oedema and early restenosis, but that the stent is removed in two to four weeks if it has not migrated spontaneously into the duodenal lumen^.355

In conclusion, ARP should be evaluated in specialist referral centres as diagnosis is time-consuming, usually expensive and may expose the patient to a substantial morbidity. Future prospective clinical trials should define which patients with idiopathic ARP (whether or not it is associated with anatomical variants) are most likely to benefit from endoscopic intervention. These studies should allow appropriate patient selection and the development of novel, effective, preventive and therapeutic strategies to improve the clinical condition of these patients.