TUESDAY, June 16, 2015 (HealthDay News) -- Although surgical removal of the appendix has long been a standard treatment, a new study found that almost three-quarters of people treated with antibiotics could be spared the invasive procedure known as appendectomy.

"For more than a century, appendectomy has been the standard treatment," said the study's lead author Dr. Paulina Salminen, of Turku University Hospital in Finland.

But about 80 percent of patients with an inflamed appendix, commonly called appendicitis, don't need to have their appendix surgically removed, and those who ultimately do need the surgery aren't hurt by waiting, according to Salminen.

She thinks that this and other studies will change how appendicitis is treated. "Now we know that only a small proportion of appendicitis patients need an emergency operation," Salminen said.

However, there are two types of appendicitis -- one that always requires surgery and a milder form that can be treated with antibiotics, Salminen explained. "The majority of appendicitis is the milder form, making up almost 80 percent of the cases of appendicitis," she said.

The more serious type of appendicitis can cause the appendix to rupture. Treating this type of appendicitis requires that the appendix be removed, she said.

A CT scan can accurately detect which type of appendicitis someone has, Salminen added.

The study's findings were published June 16 in the Journal of the American Medical Association.

For the study, Salminen and colleagues randomly assigned 530 patients with acute appendicitis to appendectomy or a 10-day course of antibiotics.

The researchers found that appendectomies were 99.6 percent successful. Among patients treated with antibiotics and followed for a year, 73 percent did not need surgery. However, 27 percent of the patients treated with antibiotics had to have their appendix removed within a year after treatment.

But there were no major complications associated with delaying surgery, the researchers said.

Dr. Edward Livingston, deputy editor of JAMA and coauthor of an accompanying editorial, said, "It's kind of lost to history why people started doing appendectomies, but it has become so routine that when someone comes in with appendicitis they get whisked into the operating room."