Incidence of appendicitis during COVID-19 lockdown: A nationwide population-based study.

AIM: To investigate how a nationwide lockdown influences the incidence of appendicitis. BACKGROUND: Communitive infectious diseases may play a role in the pathogenesis of appendicitis as indicated by a seasonal variation in the incidence rate. The spread of communitive infectious diseases has decreased during the COVID-19 pandemic lockdown; thus, we have an opportunity to study the incidence rate of appendicitis in an environment with less impact from common community infections. METHODS: The study is a nationwide register-based cohort study of the entire Danish population of 5.8 million. The difference in the incidence of appendicitis in a population subjugated to a controlled lockdown with social distancing (study group) was compared to a population not subjugated to a controlled lockdown and social distancing (reference group). RESULTS: The relative risk of appendicitis during the lockdown was 0.92 (95% confidence interval (CI): 0.82-1.03, p = 0.131). The relative risk of complicated appendicitis during the lockdown was 0.68 (95% CI: 0.49-0.93, p = 0.02). The incidence of uncomplicated appendicitis was not significantly different during the national lockdown. CONCLUSIONS: During the national lockdown of Denmark due to the COVID-19 pandemic the incidence of complicated appendicitis was reduced significantly compared to previous years, indicating that infectious disease might be a factor in the pathogenesis of appendicitis with complications. TRIAL REGISTRATION: The study was registered on ClinicalTrials.gov (NCT04407117).

Readmission and reoperation rates following negative diagnostic laparoscopy for clinically suspected appendicitis: The "normal" appendix should not be removed - A retrospective cohort study.

BACKGROUND: In cases with clinically suspected appendicitis, there is controversy regarding the decision to remove a macroscopically normal appearing appendix during laparoscopy when no other intra-abdominal pathology is found. The aim of this study was to examine the rate of appendicitis, along with readmission and reoperation rates following diagnostic laparoscopy of clinically suspected appendicitis in patients where the appendix was not removed. METHODS: We performed a retrospective cohort analysis of patients who underwent a diagnostic laparoscopy due to clinical suspicion of appendicitis where no other pathology was found and the appendix was not removed. The study period was from 2008 to 2013 and involved patients from two university hospitals in the Copenhagen area. RESULTS: Of the 271 patients included (81.6% women, median age 27), 56 (20.7%) were readmitted with right iliac fossa pain after a median time of 10 months (range 1-84). Twenty-two patients (8.1%) underwent a new laparoscopic procedure. Appendix was removed in 18 patients, of which only one showed histological signs of inflammation. The median follow-up time was 5.6 years (range 1-109 months). CONCLUSION: There was a low rate of appendicitis after a previous negative diagnostic laparoscopy. Therefore, based on results from the current study, we do not consider that it is necessary to remove a macroscopic normal appendix during laparoscopy for clinically suspected appendicitis. The high readmission rate warrants the need for further investigation or follow-up.