Search

Background During the COVID-19 pandemic, a decrease in the number of patients presenting with acute appendicitis was observed. It is unclear whether this caused a shift towards more complicated cases of acute appendicitis. We compared a cohort of patients diagnosed with acute appendicitis during the 2020 COVID-19 pandemic with a 2019 control cohort. Methods We retrospectively included consecutive adult patients in 21 hospitals presenting with acute appendicitis in a COVID-19 pandemic cohort (March 15 – April 30, 2020) and a control cohort (March 15 – April 30, 2019). Primary outcome was the proportion of complicated appendicitis. Secondary outcomes included prehospital delay, appendicitis severity, and postoperative complication rates. Results The COVID-19 pandemic cohort comprised 607 patients vs. 642 patients in the control cohort. During the COVID-19 pandemic, a higher proportion of complicated appendicitis was seen (46.9% vs. 38.5%; p = 0.003). More patients had symptoms exceeding 24 h (61.1% vs. 56.2%, respectively, p = 0.048). After correction for prehospital delay, presentation during the first wave of the COVID-19 pandemic was still associated with a higher rate of complicated appendicitis. Patients presenting > 24 h after onset of symptoms during the COVID-19 pandemic were older (median 45 vs. 37 years; p = 0.001) and had more postoperative complications (15.3% vs. 6.7%; p = 0.002). Conclusions Although the incidence of acute appendicitis was slightly lower during the first wave of the 2020 COVID-19 pandemic, more patients presented with a delay and with complicated appendicitis than in a corresponding period in 2019. Spontaneous resolution of mild appendicitis may have contributed to the increased proportion of patients with complicated appendicitis. Late presenting patients were older and experienced more postoperative complications compared to the control cohort.

Radiologic imaging can accurately diagnose acute appendicitis, but little is known about its discriminatory capacity between complicated and uncomplicated appendicitis.This study aims to investigate the accuracy of imaging in discriminating complicated from uncomplicated appendicitis.Data was used from the prospective, nationwide, observational SNAPSHOT appendicitis database, including patients with suspected acute appendicitis who were planned for an appendectomy. Usage of ultrasound (US), CT, MRI or a combination was recorded. Radiological reports were used to group for complicated or uncomplicated appendicitis. The reference standard was based on operative and pathological findings. Primary outcomes were sensitivity and specificity in discriminating complicated from uncomplicated appendicitis. Secondary outcomes were diagnostic accuracy results per imaging modality and for the subgroups age, BMI, and sex.Preoperative imaging was performed in 1964 patients. In 1434 patients (73%), only US was used; in 109 (6%) patients, only CT was used; and 421 (21%) patients underwent US followed by CT or MRI. Overall, imaging workup as practiced, following the national guideline, had a poor sensitivity for complicated appendicitis of only 35%, although specificity was as high as 93%. For US, accuracy for complicated appendicitis was higher in children than in adults; sensitivity 41.2% vs. 26.4% and specificity 94.6% vs. 93.4%, respectively, p = 0.003. For relevant subgroups such as age, sex and BMI, no other differences in the discriminatory performance were found.A diagnostic workup with stepwise imaging, using a conditional CT or MRI strategy, poorly discriminates between complicated and uncomplicated appendicitis in daily practice.

IntroductionGrowing evidence is showing that complicated and uncomplicated appendicitis are two different entities that may be treated differently. A correct diagnosis of the type of appendicitis is therefore essential. The Scoring system of Appendicitis Severity (SAS) combines clinical, laboratory and imaging findings. The SAS rules out complicated appendicitis in 95% (negative predictive value, NPV) and detects 95% (sensitivity) of patients with complicated appendicitis in adults suspected of acute appendicitis. However, this scoring system has not yet been validated externally. In this study, we aim to provide a prospective external validation of the SAS in a new cohort of patients with clinical suspicion of appendicitis. We will optimise the score when necessary.Methods and analysisThe SAS will be validated in 795 consecutive adult patients diagnosed with acute appendicitis confirmed by imaging. Data will be collected prospectively in multiple centres. The predicted diagnosis based on the SAS score will be compared with the combined surgical and histological diagnosis. Diagnostic accuracy for ruling out complicated appendicitis will be calculated. If the SAS does not reach a sensitivity and NPV of 95% in its present form, the score will be optimised. After optimisation, a second external validation will be performed in a new group of 328 patients. Furthermore, the diagnostic accuracy of the clinical perspective of the treating physician for differentiation between uncomplicated and complicated appendicitis and the patient’s preferences for different treatment options will be assessed.Ethics and disseminationEthical approval was granted by the Amsterdam UMC Medical Ethics Committee (reference W19_416 # 19.483). Because of the observational nature of this study, the study does not fall under the scope of the Medical Research Involving Human Subjects Act. Results will be presented in peer-reviewed journals. This protocol is submitted for publication before analysis of the results.