What is the evidence behind intravenous (IV) antibiotics versus surgical removal of the appendix for acute appendicitis?

From the Guidelines

For uncomplicated appendicitis, surgical removal (appendectomy) is the preferred treatment, while antibiotic therapy can be considered for patients with significant surgical risks or those strongly preferring to avoid surgery, according to the 2020 update of the WSES Jerusalem guidelines 1. The evidence suggests that antibiotics can successfully treat approximately 70-80% of uncomplicated appendicitis cases without surgery, but about 30% of antibiotic-treated patients experience recurrence within one year 1.

Key Considerations

• Surgical management typically involves laparoscopic appendectomy, which offers definitive treatment with low complication rates (1-3%) 1.
• For antibiotic therapy, regimens often include intravenous options like piperacillin-tazobactam (3.375g every 6 hours), ertapenem (1g daily), or ceftriaxone (1-2g daily) plus metronidazole (500mg every 8 hours) for 1-3 days, followed by oral antibiotics (amoxicillin-clavulanate 875/125mg twice daily or ciprofloxacin 500mg plus metronidazole 500mg three times daily) to complete a 7-10 day course 1.
• Surgery is strongly preferred for complicated appendicitis (perforation, abscess), in immunocompromised patients, during pregnancy, or when diagnosis is uncertain 1.
• The antibiotic approach may be suitable for patients with significant surgical risks or those strongly preferring to avoid surgery, but patients should understand the risk of recurrence and potential need for eventual surgery 1.

Recommendations

• Laparoscopic appendectomy is recommended as the preferred approach over open appendectomy for both uncomplicated and complicated acute appendicitis, where laparoscopic equipment and expertise are available 1.
• A single preoperative dose of broad-spectrum antibiotics is recommended in patients with acute appendicitis undergoing appendectomy, and postoperative antibiotics are suggested for patients with complicated acute appendicitis 1.

From the Research

Comparison of IV Antibiotics and Surgical Removal of Appendix for Appendicitis

• The use of IV antibiotics as an alternative to surgical removal of the appendix for appendicitis has been studied in several research papers 2, 3, 4, 5, 6.
• According to a study published in 2018, approximately 90% of patients treated with antibiotics are able to avoid surgery during the initial admission, while the other 10% require a rescue appendectomy 2.
• Another study published in 2014 found that antibiotic therapy was associated with fewer immediate complications than surgery, but more subsequent failures 3.
• A systematic review and meta-analysis published in 2011 found that complications were considerably less likely to occur with antibiotic treatment than with appendectomy 4.
• A population-based study published in 2012 found that primary antibiotic treatment had fewer complications compared to primary surgery 5.
• A meta-analysis published in 2019 found that appendectomy is more effective than antibiotic therapy for definitive cure of acute uncomplicated appendicitis, but antibiotic therapy might be a reasonable alternative for selected patients 6.

Effectiveness of Antibiotic Therapy

• The effectiveness of antibiotic therapy for appendicitis varies depending on the study, with success rates ranging from 62.6% to 77% 2, 5, 6.
• A study published in 2014 found that 78% of patients in the antibiotic group had no symptoms of appendicitis after one month, and 63% were asymptomatic and had no complications or recurrences after one year 3.
• Another study published in 2011 found that 6.9% of patients treated with antibiotics alone failed to respond and required appendectomy, and acute appendicitis recurred in 14.2% of patients 4.

Complications and Risks

• The risk of complications and recurrence varies depending on the treatment approach, with antibiotic therapy associated with a higher risk of recurrence and appendectomy associated with a higher risk of surgical complications 2, 3, 4, 5, 6.
• A study published in 2019 found that the incidence of complications did not differ significantly between antibiotic therapy and appendectomy 6.
• Another study published in 2012 found that primary antibiotic treatment had fewer complications compared to primary surgery, but the risk of long-term relapse was unknown 5.