While members of the Thoracic-Foregut Group at USC University Hospital are actively involved with the diagnosis and treatment of esophageal disease, as academically-based surgeons they are also interested in the "why" of esophageal problems. For example, the focus of investigation for Peter F. Crookes, M.D., assistant professor of Surgery, is esophageal physiology-specifically, why the lower esophageal sphincter fails. "Normally," explains Dr. Crookes, "the sphincter remains closed all day except when we swallow or burp. While some believe the primary problem is failure of the sphincter to regulate its opening, we see in other patients that the sphincter is permanently hypotonic (defective in muscle tone). The question, then, is how does the muscle reach this hypotonic stage."

To investigate this question, Dr. Crookes has actually performed some experiments on himself, placing a motility probe down through his own esophagus and subsequently consuming a fast-food double hamburger, French fries and two cans of cola -all in an effort to determine what effect the typical American diet has on the lower esophageal sphincter. Interestingly, after this kind of meal, the sphincter almost disappears, relaxing to the point that it is incapable of doing its job. Other components of the American diet-such as peppermint, chocolate, coffee, alcohol, cigarettes, fat, onions, and garlic -all have a similar effect on the sphincter. "Yet a mystery remains," says Dr. Crookes. "There must be something new in the last 20 to 30 years that has led to the incredible escalation of reflux we are seeing in America." An alarming fact is that there now are over-the-counter remedies specifically for children who suffer from heartburn.

Dr. Crookes says one factor that became apparent during the last few years was that, like any other muscle which is paralyzed, the lower esophageal sphincter cannot repair itself. "Once it's gone, it's gone. While the lining of the esophagus, the mucosa, changes every day or two-much like the skin-once the lower esophageal sphincter is damaged, it does not seem to improve, which is why the Nissen fundoplication plays such a key role." The next step was to determine whether the Nissen could restore the function of the sphincter.

In the spring of 1996, Dr. Crookes and his colleagues presented at the Society of American Gastrointestinal Endoscopic Surgeons conference a paper which demonstrated the Nissen fundoplication's effect on the ability of the sphincter to relax. The study found that in most patients, sphincter relaxation was within the normal range. "There is no point in creating a valve tight enough to stop the acid if it can't relax enough to let the food through," says Dr. Crookes. Consequently, reconstructive surgery such as this requires experience like that available at USC so that the new valve stops reflux yet allows effortless, normal eating.