Most Appendicitis Patients See Good Long-Term Outcomes With Conservative Tx

— Decades after antibiotic treatment, 60% of patients had avoided appendectomy

A computer rendering of a transparent body with the appendix highlighted and a close up of bacteria.

Data on long-term outcomes with antibiotics for appendicitis show that most patients will not experience a recurrence, reported researchers who followed up on patients from the first two randomized trials of nonoperative treatment for acute appendicitis.

In total, 82 of the 137 patients (60%) randomized to antibiotics across both trials, conducted in Sweden in the 1990s, did not experience appendicitis recurrence at the end of follow-up, and 71% who were discharged without appendectomy successfully avoided surgery, reported Simon Eaton, PhD, of UCL Great Ormond Street Institute of Child Health in London, and colleagues.

In total, 21 individuals in the antibiotic groups underwent appendectomy due to failure of nonoperative treatment at initial hospital admission, and 34 underwent a subsequent appendectomy due to recurrence, they noted in a research letter published in JAMA Surgery.

"This study is the first to our knowledge to report truly long-term results of nonoperative treatment of acute appendicitis, by a registry study of patients included in 2 RCTs [randomized clinical trials]," Eaton and team wrote.

"[M]ore than half of the patients treated nonoperatively did not experience recurrence and avoided surgery over approximately 2 decades," they added. "There is no evidence for long-term risks of nonoperative management other than that of recurrence of appendicitis. The present data will further be beneficial to clinicians as well as patients with acute appendicitis in making a treatment decision."

Of note, the study did show that a significantly higher proportion of antibiotic-treated patients went to a surgical outpatient clinic for abdominal pain during follow-up compared with those who underwent appendectomy (9.5% vs 0.01%, P<0.002), though no patient from either group underwent surgery for bowel obstruction.

A larger, more recent, clinical trial reported similar results in the New England Journal of Medicine. In this trial, known as CODA, 1,552 patients were randomized to antibiotics or appendectomy. In the antibiotic group, 29% had to have an appendectomy within 90 days. The rate of serious adverse events was 4.0 per 100 participants in the antibiotic group and 3.0 per 100 in the appendectomy group (rate ratio 1.29, 95% CI 0.67-2.50).

A co-author of the CODA study, David Flum, MD, MPH, of the University of Washington in Seattle, said the results reported by Eaton's group were comparable to CODA. "This study reinforces the findings from the much larger CODA trial ... that the risk of early appendectomy (we defined that as 90 days) after starting antibiotics is ~1 in 3, and that there is a small but real risk of recurrence," he told MedPage Today.

The results of both studies suggest that approximately 40% of patients who receive antibiotic therapy will ultimately need an appendectomy, Flum noted. "The findings of low long-term risk of the antibiotic treatment should further inform decision making. We encourage people deciding about antibiotic treatment to use a decision aid that describes the competing risk/benefit of both approaches."

For the current cohort study, Eaton and colleagues used data from the Swedish National Patient Registry on 292 participants in two randomized trials of appendectomy versus antibiotics for acute appendicitis (diagnosed clinically in 252, with ultrasound in 40). The first was a small pilot trial of 40 patients (13 female) randomized from May 1992 to March 1994. The second was a larger multicenter trial of 252 male patients randomized from March 1996 to June 1999.

Of the total 292 patients, 122 were treated with appendectomy and 137 were treated with antibiotics. The 1-year recurrence rates were 36.8% in the first trial and 14.4% in the second trial among those whose treatment had been initially successfully managed nonoperatively.

Important limitations to the study included the fact that most patients were male, and the patients were not followed prospectively, Eaton's group noted.

"In addition, we were looking at results of standards of diagnostics as they were when the initial studies were performed," they added. "This renders it difficult to extrapolate to current diagnostic standards, which involve much higher rates of imaging and consequently lower rates of both negative appendectomy and missed perforation."

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    Jeff Minerd is a freelance medical and science writer based in Rochester, NY.


The study was supported by the Swedish Research Council.

Eaton was supported by the NIHR Biomedical Research Centre at Great Ormond Street Hospital. A co-author reported receiving grants from the Lovisa Foundation.

Primary Source

JAMA Surgery

Source Reference: Pátková B, et al "Long-term outcome of nonoperative treatment of appendicitis" JAMA Surg 2023; DOI: 10.1001/jamasurg.2023.2756.