Antibiotic therapy can prevent or delay the need for an appendectomy, but ultimately nearly half of the patients will eventually require the surgery, according to the largest, long-term comparison of immediate surgery versus antibiotic treatment.

Although 20 percent of 702 patients still needed an appendectomy within 30 days after beginning a 10-day antibiotic regimen, the odds had grown to 40 percent after 1 year and 46 percent after 2 years.

The risk was even higher if appendicolith was present — 31 percent at 30 days, 52 percent at 1 year and 54 percent at 2 years.

Without appendicolith, the rates were 16 percent, 36 percent and 43 percent respectively.
The risks tended to plateau after 2 years, but the number of patients who were studied for that long was small.

The final results of the randomized CODA trial, which involved 1,552 participants at 25 U.S. medical centers, were released Monday at this year’s American College of Surgeons Clinical Congress and online by The New England Journal of Medicine.

“Although some clinicians and patients may determine that these longer-term rates of appendectomy make antibiotics a less desirable treatment than early appendectomy, substantial numbers of patients report a preference for antibiotics, even if appendectomy may ultimately be necessary,” the researchers wrote in the Journal.

The CODA team has developed a website, http://www.appyornot.org/, to help patients decide whether they prefer to opt for surgery or antibiotic therapy.

More than one in 20 Americans will develop appendicitis at some point in their lives, according to the National Institute of Diabetes and Digestive and Kidney Diseases. About 11.6 million cases occur worldwide each year, with about 50,000 deaths.

The results also suggest that antibiotic therapy can be used again if appendicitis recurs. At the two-year mark, 14 percent of the patients had received additional antibiotics and 66 percent subsequently underwent an appendectomy.

A year ago, the team released preliminary results showing that antibiotic treatment was a viable option, although when antibiotics were given, 29 percent of the patients ended up receiving surgery within 90 days anyway.

“But many of our patients were quick to point out there’s a 7 in 10 chance of avoiding surgery,” coauthor Dr. David Flum of the University of Washington School of Medicine in Seattle, told Reuters Health at the time. “Some are going to say, get it over with, I don’t want to have the risk. But a lot of others have to worry about copays, travel, work schedule or caregiver burdens” and will prefer the antibiotic option.