Until recently the management of acute appendicitis has lay squarely in the hands of the surgeon. But there is a growing body of evidence examining the use of antibiotics alone in uncomplicated appendicitis. Most of the data exploring this question has found that the majority of patients treated with antibiotics alone will avoid surgery in the short term, with only about a quarter of patients requiring an appendectomy within one year of initial presentation. But what is still unknown are the consequences such a non-invasive strategy will have over the long term. How many of these patients will require an appendectomy downstream, and more importantly do these delays lead to any complications?
In JAMA, Salminen et al published the 5 year follow-up results to the APPAC trial, a large RCT examining an antibiotic strategy for patients with acute uncomplicated appendicitis1. The 1-year results were discussed in a previous post, but in brief the authors randomized 530 patients presenting with CT-confirmed acute uncomplicated appendicitis to undergo an open appendectomy or 3-days of IV ertapenem sodium (1 g/d), followed by 7 days of oral levofloxacin (500 mg once daily) and metronidazole (500 mg 3 times/d). Seventy patients (27.3%; 95% CI, 22.0% to 33.2%) in the antibiotic group underwent surgical intervention within 1 year of initial presentation for appendicitis2. 15 of these patients experienced failure of medical therapy during their initial presentation and required an appendectomy.
At 5-years the need for appendectomy in the antibiotic group increased to 39.1% (95% CI, 33.1%-45.3%). The bulk of these surgeries occurred in the first few years following their initial bout of appendicitis, 35.2% occurring at 2-years and the remaining 3.9% occurring over the following 3-years.
There are two ways to examine these results. The first is that the failure rate of antibiotic therapy was close to 40%. Meaning almost half the patients treated with this strategy will eventually require an appendectomy. Most therapeutic strategies with such a high failure rate are abandoned for clinical futility.
But when viewed from a different perspective, antibiotic therapy for acute appendicitis, prevented the need for surgery in 60% of the population. From this perspective while 40% of the antibiotic therapy group eventually required an appendectomy, 99.6% of the surgical group underwent the very same procedure. To argue that early appendectomy is superior, one has to demonstrate that the delay to surgery caused the patients harm. This does not seem to be the case. There was no difference in the number of patients with perforated appendices between the groups (2 vs 5), and in fact, the surgical group experienced a much higher rate of complications than was observed in the antibiotics alone group (the overall complication rate of 24.4% in the appendectomy vs 6.5% in antibiotic group).
Certainly more data is required before we embrace an antibiotic alone strategy for all patients with acute appendicitis. Are there specific markers that predict patients who will go on to fail medical management? What is the ideal antibiotic regimen for these patients? Is an inpatient admission required at all? Despite these continued uncertainties, the long-term follow-up data continues to support the viability of a medical approach to acute appendicitis.