the Cranky Panky

                   Spreading Awareness for Pancreas Research

Which Came First?  The Chicken or the Egg?

Or in this case, the diseased gallbladder or the SOD?

First, let's understand the sphincter of oddi.  This sphincter is a muscular valve that controls the flow of digestive juices (bile and pancreatic juice) through ducts from the liver and pancreas into the first part of the small intestine (duodenum). There are two types of dysfunctions that can occur with this opening:

Sphincter of Oddi stenosis – a physical abnormality associated with the narrowing of the sphincter of Oddi . It can be caused by inflammation or scarring (from pancreatitis, from gallstones, trauma, infection, etc.) Sphincter of Oddi stenosis is associated with abnormal sphincter motility and elevated basal pressure.

Sphincter of Oddi dyskinesia – a functional disturbance of the sphincter of Oddi, which leads to intermittent biliary obstruction. The cause is not well understood. Spasm and relaxation of the sphincter can often be induced with medications known to affect smooth muscle function (such as nitroglycerin) if dyskinesia is present.

Both forms of SOD have generally been associated with two medical problems: 
biliary pain and pancreatitis. The prevalence is difficult to estimate because of several potential sources of bias among studies evaluating SOD in these settings.  SOD usually involves invasive testing; therefore, does not include an adequate control group.  In the case of biliary pain, patients are suspected to have SOD if no other apparent cause is seen.  It is harder to determine the cause of pancreatitis in many cases involving SOD. 

Ironically (or maybe not!) most of these patients have undergone a Cholecystectomy (removal of the Gallbladder).  The reasons are still not well understood.  

It is believed that the dysfunction of the sphincter can be related to “unmasking” a previous SOD condition that had been present before the removal of the gallbladder.  The gallbladder may have served as a reservoir that accommodated the increased pressure of biliary juices, and once removed, the pressure increased significantly.  

Another explanation could be that the sphincter is altered when the nerve fibers are severed between the gallbladder and the sphincter.  

With each of these arguments, it must also be stated that SOD sometimes occurs in patients whose gallbladders are in-tact. 

So, the actual reasoning why most SOD patients have had the gallbladder removed is still unknown, and can be multi-factorial.  Maybe each of these stated theories plays a role in different patients and in different circumstances.  Or maybe, SOD actually leads to problems with the gallbladder itself.  Either way, SOD is still an uncommon occurrence following a Cholecystectomy, estimated to be less than 1 percent; but for those who suffer, much is yet to be understood and treatments are still often by trial and error.  The difficulty in poor diagnostic testing, and the invasive treatments that patients are left with, cause many to suffer without a known end or cause.

One "treatment" for pain from SOD is a procedure called an ERCP.  It is used to measure the pressure of the sphincter of Oddi, and often used to cut the muscle to attempt to allow a better flow of bile juices through the opening.  This technique is still invasive and can cause additional problems for the patients as well, including severe pancreatitis.  

Help to find a cure for SOD and biliary pain or pancreatitis by supporting pancreatic research.  New ways of testing are constantly being discovered, but researchers must first have the funds to do so.  See what role you can play in creating a cure today.