The Sphincter of Oddi

The other day I was reading a report on an ERCP.  An ERCP, or endoscopic retrograde cholangiopancreatography, is a procedure where they stick a flexible endoscope in your mouth, advance it down into the duodenum, and look for the ampulla of Vater.  Then dye is squirted into the ampulla, and imaging aids visualization of the pancreatic duct and common bile duct in order to look for a number of abnormalities (stones, cancer, inflammation, strictures, etc.) which could be causing another large number of patient symptoms (jaundice, elevated liver/pancreas enzymes, abdominal pain, etc.).  The pathologist comes in because the gastroenterologist, who performs this procedure, will often take a tiny brush and get some cells to submit for us to look at.  

The ampulla of Vater, while it looks tough to miss on this large picture, is actually rough to find - at least at autopsy.  I have made many false probe-holes in the duodenum in my past, frustratedly searching for the common bile duct and pancreatic duct in order to attempt to please the GI princess Dr. Styles.  I imagine that there is a trick for finding it easily in a live individual, or there would be a lot of bowel perforations, which are much more detrimental to a live human being than a cadaver.  But I wouldn't know -- I'm just the pathologist.

Anyway, while I was reading the ERCP, I read it's purpose, which sent me all over the internet searching for explanation.  "Intervention or manipulation of the sphincter of Oddi for pneumobilia."  I of course remembered the sphincter of Oddi, who could forget a sphincter with a name like that?  Despite my uncertainty of its pronunciation (ode-eye?  odd-ee? or another variation), I still like the name better than the more common sphincter located caudally. 

Pneumobilia is gas filling the biliary tree, leading to abdominal pain, which can be caused by dysfunction of the sphincter of Oddi.  A real problem for a select few (around 4% etiology of abdominal pain, I read somewhere).  It is called sphincter of Oddi dysfunction, or SOD for short.  Who knew the sphincter of Oddi could be dysfunctional?  Not me, until this week.  I guess I shouldn't be so surprised - after all, in existing on this planet, whether animate or inanimate, everyone or thing has the potential for dysfunction.  Dysfunctional is not just an adjective reserved for "families" or "uterine bleeding," although it is used most commonly in these arenas.  Even the sphincter of Oddi can become dysfunctional. 

And it made me laugh out loud, because I automatically thought of Ignatius J. Reilly in Toole's A Confederacy of Dunces, which I read last winter.  He was forever manipulating his pyloric valve, a valve that plagued him by snapping shut "indiscriminately," filling his stomach with "trapped gas, gas which had character and being and resented its confinement.  He wondered whether his pyloric valve might be trying, Cassandralike, to tell him something . . ."

I remember thinking if his gas was Cassandralike, wouldn't the warnings be falling on deaf ears?  And Ignatius' ears appeared hyper-acute to me, especially when it came to the issue of his pyloric valve.  I was both amused and filled with admiration by his ability to be so in tune with his inner workings.  I never even knew I was in labor.  And I think I shocked the pediatrician, who tried to hand me pieces of paper with narcotic prescriptions before I left the hospital, by tearing them up in front of him and throwing them in the trash.  I was a nursing mother, for goodness sake!  And who needs narcotics (someday I will, and I will retract these words, I am sure, but I've yet to need them).

So what do you do if your sphincter of Oddi is dysfunctional?  Call a gastroenterologist.  There are medical therapies.  If your sphincter is so tight that it causes a certain high level of measurable pressure (by manometry), the definitive cure for the blockage of the normal happy flow of bile and pancreatic juices is sphincterotomy, where it is surgically cut to release the pressure.  Or you can lie upstairs in the bedroom of your mother's house and perform your own manipulations.  Call Ignatius for help.  You'll probably find him somewhere with that Minkoff chick.