Patients with an appendicolith are twice more likely to require appendectomy within 30 days of starting antibiotic treatment for acute appendicitis, suggests a study published in JAMA Surgery.¹

In this multicenter study conducted in the US, researchers set out to examine the risk factors that influenced the need to undergo appendectomy within a month of starting conservative treatment with antibiotics for acute appendicitis. For this, data was obtained from the Comparison of Outcomes of Antibiotic Drugs and Appendectomy (CODA) randomized clinical trial. A total of 1552 participants with acute appendicitis were enrolled between May 2016 and February 2020. Of these, 776 participants were administered antibiotics and 776 underwent appendectomy. The average age of the study population was 38 years; 63% of the participants were men.

Among the 776 patients managed with antibiotics, 735 had 30-day outcome data; 154 (21%) patients in this group underwent appendectomy within 30 days. Overall, 27% patients had an appendicolith and in 42% of those who had an appendectomy within a month. The reason for surgery was reportedly increasing severity of appendicitis in majority (77%) of the patients. Other reasons cited were worry about recurrence, family influence in deciding to undergo the surgery.

Female patients were more likely to undergo appendectomy with odds ratio (OR) of 1.53. Other factors that increased the probability of surgery within 30 days were identified as wider appendiceal diameter (OR per 1-mm increase, 1.09) on radiography and the presence of appendicolith (OR 1.99). Surprisingly, clinical factors such as fever and TLC were not associated with increasing the odds for surgery within 30 days with ORs of 1.28 and 1.03 per 1,000 cells/μL increase, respectively. The OR was 1.14 for abscess, perforation or fat stranding. Likewise older age and presence of comorbidities also did not increase the possibility of surgery within 30 days. When a sensitivity analysis was done just for surgeries performed for clinical indications, the association with appendicolith was not only persistent but also became more robust with OR of 2.41.

It cannot be known with certainty as to which patients with acute appendicitis would favorably respond to antibiotics. The findings of this secondary data analysis of the CODA study show that while clinical factors were not associated with 30-days risk of appendectomy, an appendicolith was the major factor that correlated with the likelihood of undergoing appendicectomy within 30 days of starting treatment with antibiotics. Evaluating such patients for the presence of appendicolith with CT scan may help determine a more individualized line of management and informed decision making. The authors conclude by stating “Beyond these factors, site characteristics, potentially including physician decision-making and unmeasured processes of care and structural barriers, may also be involved in determining which patients get an appendectomy”.

Reference

1. Monsell SE, et al. Patient factors associated with appendectomy within 30 days of initiating antibiotic treatment for appendicitis. JAMA Surg. 2022 Mar 1;157(3):e216900. doi: 10.1001/jamasurg.2021.6900.