Sphincter of Oddi Dysfunction

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Sphincter of Oddi Dysfunction

Question:

For the past three months, I have been experiencing pain in the upper right quadrant of my abdomen. My gallbladder was removed four years ago. My doctor thinks I have something wrong with my "sphincter of Oddi." He prescribed Hyoscyamine and Omeprazole. Can you tell me if this is an appropriate treatment and if there are other options for relieving the pain?

Answer:

The sphincter of Oddi is a muscular bundle wrapped around the very end of the bile duct where the duct enters the intestine. Its job is to release bile into the intestine. (Imagine your hand wrapped around a straw. You can loosen your grip to let liquid out of the straw or tighten your grip to keep liquid from getting out.)

Sphincter of Oddi dysfunction refers to excessive spasm or scarring of the sphincter. This causes increased pressure in the bile duct, which produces pain in the right upper abdomen.

Diagnosing this is tricky. Blood tests such as liver enzymes and bilirubin levels may or may not be abnormal. Doctors can be more certain if they can see the bile duct dilating on an ultrasound or other imaging study.

Drugs are often prescribed stop the pain. Nifedipine, a calcium channel blocker, is used because it reduces spasms and thereby helps relieve pain. However, only a lucky patient will get a major benefit from nifedipine, which can also cause unwanted side effects. Doctors sometimes prescribe Actigall (ursodeoxycholic acid). This drug dissolves gallstones. This assumes tiny cholesterol crystals have settled in the sphincter and are blocking bile flow. Again, this may help a few patients, but most will be disappointed.

A more direct approach to treating sphincter of Oddi dysfunction is to disrupt the sphincter itself. There are two methods:

In the most common procedure, the doctor first administers a sedative and then places an endoscope in the mouth. The scope is advance down the esophagus, through the stomach and into the intestine. The doctor locates the opening of the bile duct surrounded by the sphincter of Oddi. Using an electrocautery, he or she makes a small cut through the sphincter. Because of the intricacy and risks of this technique, only a doctor highly skilled with an endoscope should do it. And even with this skill, this procedure is successful no more than half the time.

Less often, a patient may have regular surgery. A larger incision is made to allow the surgeon to cut through the sphincter. The success rate of this method is not much better than that of the less invasive procedure above in relieving the symptoms of sphincter of Oddi dysfunction.

Stephen Goldfinger, M.D., is a professor of medicine at Harvard Medical School. He is a graduate of Columbia College of Physicians and Surgeons, and his clinical base is at the Massachusetts General Hospital.

Last updated:	July 20, 2009