Management of acute appendicitis during COVID-19 pandemic. Single center data from a tertiary care hospital in Germany

Introduction

After the outbreak of pneumonia of unknown etiology in December of 2019 in Wuhan City, Hubei Province in China, the World Health Organization (WHO) identified the novel Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) as causal and named the new disease COVID-19 [1]. In following COVID-19 reached pandemic status and caused an international health crisis [1]. Due to acute need for hospitalization and intensive care of rising number of COVID-19 patients, many medical disciplines, including surgery, were strongly affected. Numerous elective surgeries have been postponed or even cancelled [2], [3], [4].

The lack of clinical experiences and scientific data set a dilemma, if patients infected with SARS-CoV-2 would meet an impaired postoperative course, considering higher morbidity and mortality after a surgery. Additionally, it was unclear if admission of infected patients would endanger already hospitalized uninfected surgical patients and medical staff [3, 5, 6].

Therefore, several recommendations for clinical management during the COVID-19 pandemic have been published by surgical societies [7, 8]. The European Society of Trauma and Emergency Surgery (ESTES) recommended postponing of all elective surgeries during COVID-19 pandemics [9]. The treatment of emergencies such as acute appendicitis became also challenging, especially due to non-operative concepts with antibiotics being introduced in last years [10, 11]. Diverse studies showed success of non-operative management for uncomplicated acute appendicitis in over 90 % of cases for initial treatment course, 80 % after 3 months and 73–80 % after one year [11], [12], [13], [14], [15]. The recurrence of acute appendicitis is still being an issue possibly reaching a 5-year rate of 39 % according to APPAC-Study [16]. Although some risk factors for failure of non-operative treatment of appendicitis have been identified such as complicated appendicitis, faecolith, diabetes etc., the forecast of disease recurrence is still not reliable [10, 17, 18]. However, patients who needed an appendicectomy after experiencing failure of conservative treatment did not show higher morbidity than primarily operated patients [12, 14, 17]. The first line therapy with antibiotics obviously becomes an alternative to emergent appendectomy for uncomplicated appendicitis [10].

Now, in the pandemic situation the treatment concepts for acute appendicitis have been challenged for medical, epidemiological and organizational reasons. Therefore, the first line therapy with antibiotics for uncomplicated acute appendicitis in the COVID-19 pandemic has been recommended in UK and USA [8, 19, 20]. At the same time, laparoscopic appendicectomy remained the recommended standard for acute appendicitis in Germany - even during COVID-19 pandemic [21].

The first national lockdown in Germany with extensive contact restrictions was declared on March 22, 2020 [22]. In our center, elective surgery capacity during the COVID-19 period had to be reduced to 75 %, whereas only oncological indications and highly symptomatic benign diseases were allowed to be scheduled. On the other hand, the emergency program has been continuously performed. Therefore, in the case of justified suspicion on acute appendicitis, an indication for laparoscopic appendectomy was unquestionably accepted by anesthesia. Still, in selected cases conservative treatment for suspected uncomplicated appendicitis was initiated after informed consent.

The aim of this study was to investigate the impact of the COVID-19 pandemic on treatment routine and outcomes of acute appendicitis at a tertiary care hospital in Germany. For this purpose, we investigated adult patients with appendicitis between March 22 2020 and December 31, 2021 (649 days). The comparison group was defined as “Non-COVID-19” and consisted of patients treated during the same time period (649 days) before COVID-19 pandemic.

Patients and methods

Results

Frequency of appendicitis cases

Regarding the frequency of appendicitis cases, we observed continuous reduction of average case number throughout investigated period from June 12, 2018 to December 31, 2021, as presented in Figure 1. With beginning of COVID-19 period there has been an obvious reduction of presented cases, followed by high peak during third quarter of the year 2020. This observation was not significant (p=0.142).

Figure 1:

Presentation of appendicitis case frequency related to year quarters (Q3 2018–Q4 2021).

Discussion

The treatment of acute appendicitis was intensively investigated in the last years [23, 24]. To apply tailored approach, a stricter differentiation of inflammation grade of appendicitis with the new classification by EAES has been proposed [23]. A paradigm shift towards conservative treatment of uncomplicated appendicitis as an alternative to emergent appendicectomy was reported internationally [24]. The unexpected global overload of the health system during COVID-19 pandemic has forced changes in routine treatment of acute appendicitis worldwide [20].

Regarding to the frequency of appendicitis cases referring to our hospital, we observed continuous reduction of average case number through the study period (June 12, 2018 to December 31, 2021), however without significance (p=0.142). As presented in the results (Figure 1), there was an abrupt reduction of appendicitis cases at the beginning of COVID-19 period, which overlaps with overall rising number of COVID-19 cases from April to June 2020 in Germany [25]. Furthermore, we observed a peak of appendicitis cases during third quartal of the year 2020. This finding might be the result of increase of the incidence according to the disease seasonality [26].

In the present study similar baseline characteristics of the appendicitis patients during COVID-19 and Non-COVID-19 period have been shown. However, more patients showed relevantly elevated inflammatory signs, as far as CrP is concerned, with values over 50 mg/L in the surgical group during the pandemic period (p=0.042), indicating a complicated appendicitis [24, 27, 28].

Indeed, more CT scans have been performed during the pandemic than before (22.7 % vs. 30.2 %, p=0.092) also in comparison to other centers in Germany before COVID-19 pandemic (19.9 % in 2017 according to Schildberg et al.) [29], but the rate of 70 % as reported in the UK during COVID-19 lockdown was never reached [11, 30].

The internationally reported increase of complicated appendicitis rates during the pandemic period [31] was intraoperatively confirmed in our institution (59.6–68.6 %). However, probably due to relatively small case series, this observation was not statistically relevant (p=0.085).

A possible explanation for this phenomenon could be the patient’s hesitation to consult their doctor, out of fear of SARS-CoV-2 infection, as already discussed in other studies [3, 32]. These concerns were repeatedly communicated by patients in the present collective throughout anamnesis. However, this hypothesis is not supported by the available results, which shown no difference in symptom duration before approaching the emergency room between two examined periods, in contrast to data reported by Willms et al. [32].

According to our previous data, the laparoscopic approach for appendicectomy was evolving to standard at our institution with proportion of 33.1 % in years 1996/97 to 85.8 % in years 2008/09 [33], finally reaching 99.3 % in present study during the COVID-19 period, significantly more than during the interval before COVID-19 (93.4 %, p=0.013). This fact jointed with tendentially less intraoperative morbidity such as bleeding, small intestine lesions etc. and higher use of antibiotics during pandemic (p=0.002), could be an explanation for significantly less postoperative complications during the pandemic then in the reference period (p=0.015; p=0.013). The above-mentioned study also recorded less complications (p>0.001) related to increase of laparoscopic approach for appendicectomy [33]. Although increasing numbers of open appendicectomies during COVID-19 pandemic are reported from other German centers [34], we did not share the same experience. The higher rate of antibiotics administered during the COVID-19 period could be a result of successive implementation of the current recommendation to introduce antibiotics immediately after the diagnosis of acute appendicitis [24] and to continue the antibiotics in the postoperative setting in case of complicated appendicitis [24].

Furthermore, we observed a relative increase of cases with non-operative management from 9.9 % to 15.9 % during COVID-19 period (p=0.074). These numbers are similar to the results of the recent German meta-analysis (13–16 %), convincingly less than 54 % published in a multicenter cohort study from UK [11, 34]. Consequently, a more often and longer use of antibiotics was necessary for conservative treatment compared to surgical cohort (p<0.001; p=0.02), but it led to shorter overall length of stay and less complications when compared to surgery (p<0.001; p=0.016). The failure of conservative treatment after at least 24 h of treatment is documented in 10.9 % (6 of 55 cases), which matches to reported rates in the literature [12]. Also, the rate of readmissions within first 3 months of follow up was relevantly higher after conservative treatment than after surgery (6.1 % vs. 0.6 %, p=0.001), possibly indicating that a part of surgical patients with low grade complications were treated by family doctors. However, the case series (5 patients) is too low for definitive statement about readmission rate depending on treatment modality.

Lower morbidity and following shorter overall length of stay with shorter antibiotic therapy (p=0.005; p=0.052; p<0.001) related to the entire study collective, implicate better short-term outcome of appendicitis therapy during COVID-19 period in comparison to the collective of non-COVID-19 period in our institution.

The COVID-19 pandemic has changed our daily routine relevantly. The regulations during the first national lock down in Germany following restricted virus transmission policy have been applied in our institution [22]. In contrast to UK reports to SARS-CoV-2 Test rate of 32 % at the beginning of pandemic [11], in our center we required obligatory swab test before admission or entering the operating theatre. This enabled good triage with safe processing of patients, followed by lowering the infection risk for medical stuff and other patients.

There were no COVID-19-positive patients with appendicitis in our investigated collective (only 3 children, that were excluded), whereas only 0.3 % of suspected SARS-CoV-2 infections among appendicitis patients were tested positive according to other available data [32].

Regarding the time spent in the emergency room, we interestingly recorded shorter waiting times during COVID-19 period than before pandemic for over 2 h per admission. A remarkable decrease in emergency room cases during the COVID-19 pandemic was reported in some recent studies, as eventual explanation for this observation [35]. On the other hand, a strict organization and patient triage might have leaded to faster transfer to corresponding ward or discharge.

According to our analysis the overall number of appendicitis cases among adults in our institution has decreased during the COVID-19-pandemic by 10.35 % and the number of appendectomies by 16.4 %. The latest meta-analysis from Germany reported a decrease in overall appendicitis case number of 20 % and reduction of appendectomies of 12.9 %, similar to our findings [34]. However, when compared to this data reported, during the pandemic there was a lower reduction of appendicitis cases overall, but a higher reduction of appendectomies. The last one indicates a relevant increase in conservative treatment.

Limitations

The present study is a retrospective single-center study, with limited case number and inclusion of only adult patients. We are aware, that the present study includes low number of cases with conservative treatment for adequate comparison with outcomes of operative treatment and a short-term follow up. Furthermore, there was no randomization in terms of treatment choice.

Conclusions

The COVID-19 pandemic had a relevant impact on management of acute appendicitis at our institution, leading to reduction of appendectomy rate. The present study demonstrates that by maintaining the system of emergency treatment and performing a good case triage, the quality of treatment and outcome can be kept at a very good level, even under pandemic circumstances. Additionally, the implementation of a sufficient screening system before admission is essential to avoid SARS-CoV-2 infections under patients or hospital-staff. Furthermore, the increase of laparoscopic approach for appendicectomy and selective, but critical use of antibiotics leads to lower postoperative morbidity. The pandemic also highlighted the potential of conservative treatment for well selected cases, ensuring shorter length of stay and morbidity than after surgery in short term outcome.

Laparoscopic appendicectomy remains the standard procedure for treatment of acute appendicitis in Germany with potential for improvement of outcomes even throughout pandemic conditions. Non-operative management shows excellent short-term outcome and can be safely applied for uncomplicated appendicitis as an alternative to surgery during potential new waves of COVID-19 pandemic or any other conditions, where surgical treatment cannot be immediately provided. Of course, further evidence in terms of RCT in patients with uncomplicated appendicitis is needed, in order to consider conservative treatment as a standard procedure in this patients’ collective.