How often do really good surgeons misdiagnose appendicitis and operate on a patient with a normal appendix who actually doesn't have this common disease?
Talk about obvious questions. The answer is almost never, right? Not quite.
Ever since the first operation for appendicitis in 1889, diagnosing an inflamed appendix has been one of the toughest calls in medicine.
About two dozen other diseases can cause abdominal pain similar to appendicitis. They include food poisoning, painful menstruation, kidney infections, stomach ulcers, cancer, pelvic infections in women, and gall bladder disease.
No X-ray, computerized scan, or lab test is 100 percent accurate in pinning down the diagnosis of appendicitis.
Doctors still must diagnose appendicitis mainly with decades-old techniques. They involve analyzing the patient's medical history, poking and prodding the belly with a hand, and ruling out other causes of abdominal pain.
For the last 112 years, doctors have juggled two big risks in deciding whether to operate immediately or wait until the symptoms come into sharper focus.
Operate right away, and the appendix may be normal - the pain is caused by some other disease. Chalk up an unnecessary operation, with all its pain, risk, and expense.
Wait too long and the inflamed appendix may rupture, spilling intestinal contents inside the abdomen and causing a life-threatening infection. Chalk up a seriously ill patient and a long hospital stay with sky-high hospital bills.
That balancing act led to a time-honored rule of thumb in the surgery community: A really competent surgeon probably will find a healthy appendix in 15 out of every 100 operations overall.
Misdiagnosis of appendicitis is a major problem because the disease is so common. Almost one in 10 people will develop appendicitis.
Suspected appendicitis is the No. 1 reason for emergency abdominal surgery. About 500,000 operations are performed each year for appendicitis.
Doctors hoped that tests like ultrasound scans and computerized tomography (CT) imaging would have a big impact in reducing misdiagnosis of appendicitis. A few small research studies done in university medical centers hinted that these advanced technologies had solved the problem.
A major new study, however, has found no change in misdiagnosis and unnecessary appendectomies between 1987 and 1998. It covered the period when new diagnosis technologies were used more and more on patients with suspected appendicitis.
Headed by Dr. David R. Flum of the University of Washington in Seattle, the study checked on misdiagnoses of appendicitis among 85,790 patients. It included virtually every patient who underwent appendectomy in Washington State during that 12-year period.
There was no decline in the percentage of unnecessary operations done during the period. On average, surgeons found a normal appendix in 15.5 percent of operations annually.
Likewise, new test technology had no overall effect in keeping surgeons from waiting too long to operate.
Estimates indicate that 50,000 unnecessary appendectomies were performed in the United States each year during the 1990s. Thousands of other patients don't get surgery until their appendix had ruptured.
The 21st century has arrived. High-technology medicine works its wonders and marvels. But thousands of people suffer for want of a test that can tell whether a three-inch pouch of intestinal tissue is inflamed.
Michael Woods is the Blade's science editor. His column on health appears each Monday. Email him at email@example.com.