A lower number of acute appendicitis cases were identified during the pandemic period, this might be due to an increase in the number of self-treated mild conditions. These mild conditions used to get hospitalized, however, in the pandemic era, the fear of contracting the virus might have made patients reluctant to seek care. This finding was published previously by several studies[8–11] including Tankel et al.[11], who emphasized the need for further investigation and research on these patients[11]. Indeed, identifying these patients could spare surgical interventions and unnecessary cost burdens for patients and hospitals.
Another hypothesis could be related to the pathophysiological mechanisms of the diseases. It is believed that acute appendicitis begins as a result of an obstruction at the appendiceal orifice; this obstruction could be due to fecalith, tumor, or lymphoid hyperplasia (infection/inflammation)[12]. This obstruction compromises the blood and lymphatic flow to the appendix leading to ischemia, inflammation, and necrosis[12]. As such, it is reasonable to hypothesize that the decrease in the number of acute appendicitis cases in the COVID-19 pandemic could be due to decreased social contact and eventually decreased microbial exposure.
It is important to note that the cases of AA are circannual in nature with increased cases during the summer months and decreased cases during the winter months[13, 14]. However, collecting the data from the same time-period from 2019 to 2021 ruled out seasonal variations as a potential cause for this decrease. Finally, further research is needed to rule out the possibility of annual variations. For instance, in the United States, the incidence of acute appendicitis and appendectomies has been decreasing in the last couple of years[15]. Conversely, the incidence of AA is increasing in newly industrialized countries such as Turkey[15].To rule out this cause, similar epidemiological studies should be conducted in Lebanon.
The duration of pre-treatment (or symptoms period) directly correlates with the severity of many surgical and infectious diseases [16]. In our study, the duration of symptoms was not significantly different between the two cohorts. This finding confirms data in published the literature[9, 11, 17]. For instance, both cohorts in the study by Finkelstein et al. had a mean duration of symptoms of 2 days (p = 0.5)[9]. Conversely, some studies have shown an increase in the duration of symptoms in the COVID-19 cohort compared to control[10, 18–22]. For example, a study by Delgado-Miguel et al. reported longer symptoms progression time (p = 0.046) in a pediatric population during the COVID-19 pandemic compared to control. This null comparison in the duration of symptoms in our study could be attributed to several reasons. Namely, decrease in the magnitude of fear created by the pandemic in our population, also, the fact that the American University of Beirut Medical Center (AUBMC) did not decrease its emergency medical/surgical services during the pandemic period.
It is evident that the management of AA did not change in the study cohort. Most of the patients underwent surgery in the pre-pandemic and pandemic cohorts (87.1% and 91.5% respectively) with no significant difference in both cohorts. Additionally, most of the surgical operations were laparoscopic surgeries (76.1% and 78% respectively, p = 0.43). This approach to management has been consistent in several studies[9, 11, 17, 22]. In these studies, the number of surgeries in AA patients was not statistically different in the pre-pandemic and pandemic periods, and laparoscopic surgeries were the predominant surgery type. For example, a study of 378 patients, of which 237 had AA pre-pandemic and 141 during the pandemic showed non-statistical differences in conservative and surgical managements of AA[11]. Furthermore, Rudnicki et al. showed no change in the percentage of laparoscopic appendectomies, open appendectomies, abdominal drain and antibiotics, and antibiotics only management strategies[22]. The reason why the management strategy of AA did not drastically change in these studies was the preservation of traditional care for these patients by the hospitals to decrease the disease burden of AA.
On the other hand, two studies have shown a significant difference in surgical and conservative treatment of AA between the pre-pandemic and pandemic cohort[10, 23]. Scheijmans et al. included adult patients with AA from 21 hospitals and showed that conservative management increased between the 2019 and 2020 cohort from 6.4–10.4% (p = 0.011). An unsettled debate has been ensued during the pandemic on whether conservative management should be adapted instead of surgeries. Surgery has been shown on several occasions to be more efficacious, a meta-analysis of four RCTs showed significantly higher efficacy for surgery, however complication rates were higher[24]. Non-surgical approach in AA are not considered viable alternatives to surgery during normal times[24]. However, some would argue that non-surgical approaches would be better off adapted during pandemics to decrease the risk of transmission. Particularly, a meta-analysis of fourteen studies showed that the failure rate of non-operative management (NOM) in AA was 16.4%, and the complication rate after NOM was 4.5%[25]. The authors argue that NOM could be a safe alternative in times of hardships as it has an acceptably low failure and complication rates[25]. Our study serves as an example of intact surgical management in times of pandemic with no delay in pre-treatment presentation. However, further studies are needed to identify the best management strategy for such patients in abnormal situations.
In addition, the imaging modalities adapted in both periods were similar. Most of the patients were diagnosed by CT (86.6% and 88.7% in the pre- pandemic and pandemic cohorts respectively), followed by ultrasound. Diagnostic imaging was also largely unchanged in the study by Hayatghaibi et al. which comprised pediatrics patients from the Pediatric Health Information System[8].
The non-delayed emergency department presentation coupled with the predominant surgical management of AA patients during the pandemic lead to normal complication rates during this period. Particularly, similar percentages of peri-appendicular abscess, perforation, peri-appendicular fluid, appendicolith, and thickened appendix wall were seen in both cohorts. Similar percentages were seen on CT and Ultrasound. Additionally, no significant increase in abscess, perforation, and gangrene were noticed as part of surgical findings. This particular finding was uncommon, as most of the studies published reported increased complications during the COVID-19 pandemic[9, 10, 17, 22].
Further, surgical, and post-surgical complications did not differ between both cohorts. The number of drains placed admission complications, re-operations, and post-op abscesses were similar between the cohorts. Additionally, approximately equal numbers of readmissions were seen in the different periods. In short, no extra surgical or post-surgical complications were seen during the pandemic period.
The main limitation of our study is that it is a single-institution, retrospective analysis. The records of the patients were retrieved using their medical record numbers (MRNs) and data was collected, it is possible that some patients or some data were missed during the process. Additionally, we did not assess the patient’s fear of acquiring COVID-19 nor did we assess the severity of their symptoms. Another limitation to keep in mind is the relatively low sample size and narrow timeframe of data collection. Further investigation is needed with a larger sample size and broader timeframe. Finally, the literature lacks prospective studies of that sort and thus such studies are needed to get a holistic picture of this subject.