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Sphincter of Oddi Dysfunction

Obstruction has been described as a cause for acute pancreatitis. Gallstones are  a good example. I am going to talk about why I think pancreas divisum and sphincter of Oddi dysfunction has been incorrectly attributed as a cause of acute pancreatitis. I am going to present data refuting or supporting pancreas divisum as a cause of pancreatitis. I am going to do the same for sphincter of Oddi dysfunction.

Now, obstruction has been described for many years as a pathogenic factor in pancreatic disease. Gallstones, microlithiasis are a good example. Tumors, pancreatic cancer or other tumors enters into acute pancreatitis and presumably obstruction plays a role. I think ERCP is disruptive rather than obstructive pancreatitis after ERCP.

The calcifications and duct plugging are a consequence, not a cause, of the disease but some people believe that is true. Pancreas divisum and sphincter of Oddi dysfunction are thought to be examples of obstructive diseases which cause acute pancreatitis. There have been numbers of diseases which have been attributed to sphincter of Oddi dysfunction and pancreas divisum. Not only idiopathic acute pancreatitis but also chronic pancreatitis, which I really don't have time to discuss, and pancreatic pain syndromes - which I think is really stretching the envelope very very thin - to say that people with normal pancreatic testing.

There are limitations in the studies of idiopathic acute pancreatitis, in terms of both sphincter of Oddi dysfunction and in terms of pancreas divisum. They are nearly all retrospective. Many of them are abstracts. They have variable inclusion criteria, variable diagnostic algorithms, and very variable criteria for therapeutic outcomes. Now, if you look at the literature in patients with acute pancreatitis, the incidence of the etiology identified in nine series is detailed here. You can see they used ERCP, bile microscopy, sphincter of Oddi dysfunction and endoscopic ultrasound, just to make the point that there is a tremendous variability in the literature - depending on who you read and how they investigated patients - in the incidence of gallstones, sphincter of Oddi dysfunction, pancreas divisum, etc. The incidence of pancreatic duct strictures, choledochoceles and Santoriniceles.

Now, here is the incidence of gallstones and microlithiasis in idiopathic acute pancreatitis using ERCP alone. You recall that I indicated the ERCP is not a good way to make a diagnosis of gallstones. Recall also that in idiopathic pancreatitis in the series I just presented, about two-thirds of the patients with idiopathic pancreatitis subsequently had microlithiasis.

Now, what is the sensitivity of bile microscopy in patients with proven gallstones and gallbladder crystals? Again, this is rehash of information Iíve already presented to you. This is a duodenal bile collection, around about 70%. If you take the bile at ERCP, itís a little bit higher. I think the point is that even if itís a little bit higher at ERCP there is roughly a two-thirds to perhaps a little bit more ability of biliary microscopy to make the diagnosis of gallstones or microlithiasis when it is present. So thatís pretty much the same data that I showed you previously. What about the coexistence of microlithiasis and sphincter of Oddi dysfunction in acute pancreatitis? Here are three studies. Paul Paserika and De Francesco, and I think you can see - and without showing you a lot of numbers - that you had sphincter of Oddi dysfunction and biliary crystals in one-third of patients to nearly two-thirds of patients, making you wonder if the sphincter of Oddi dysfunction is totally unrelated to the cause of the pancreatitis on the first hand, and secondly perhaps its sphincter of Oddi dysfunction is a consequence of passing small stones through the papilla, developing papillitis and abnormalities in the pressures.

The incidence of chronic pancreatitis in patients initially classified as idiopathic acute pancreatitis depends on the test that you use. This is just another way of showing you that you have to be very careful of peopleís technologies.