Where have all the appendicectomies gone?

Abstract

Introduction

The COVID-19 pandemic stimulated a national lockdown in the UK. The public were advised to avoid unnecessary hospital attendances and health professionals were advised to avoid aerosol-generating procedures wherever possible. The authors hypothesised that these measures would result in a reduction in the number of patients presenting to hospital with acute appendicitis and alter treatment choices.

Methods

A multicentred, prospective observational study was undertaken during April 2020 to identify adults treated for acute appendicitis. Searches of operative and radiological records were performed to identify patients treated during April 2018 and April 2019 for comparison.

Results

A total of 190 patients were treated for acute appendicitis pre-lockdown compared with 64 patients treated during lockdown. Patients treated during the pandemic were more likely to have a higher American Society of Anesthesiology (ASA) score (p = 0.049) and to have delayed their presentation to hospital (2 versus 3 days, p = 0.03). During the lockdown, the use of computed tomography (CT) increased from 36.3% to 85.9% (p < 0.001), the use of an antibiotic-only approach increased from 6.2% to 40.6% (p < 0.001) and the rate of laparoscopic appendicectomy reduced from 85.3% to 17.2% (p < 0.001). The negative appendicectomy rate decreased from 21.7% to 7.1% during lockdown (p < 0.001).

Conclusions

The COVID-19 lockdown was associated with a decreased incidence of acute appendicitis and a significant shift in the management approach. The increased use of CT allows the identification of simple appendicitis for conservative treatment and decreases the negative appendicectomy rate.

Introduction

The United Kingdom began a nationwide lockdown on 23 March 2020 to slow the transmission of the novel coronavirus (SARS-CoV2) causing COVID-19.¹ The World Health Organization (WHO) declared COVID-19 a pandemic and by 30 April 2020 some 26,711 people in the UK had died as a result of COVID-19.^2,3 The well-publicised lockdown restricted all non-essential travel, imposed social distancing and encouraged the general public to ‘protect the NHS’.¹

Although this message appears to have been successful in reducing transmission of the virus, there are concerns that the simplified message unintentionally deterred patients from seeking medical attention for other, treatable pathologies. Initial reports suggested the numbers of emergency department attendances with acute coronary syndromes, gastrointestinal problems or pneumonia had been half normal levels.⁴

In preparation for the anticipated demand on hospital services, and to minimise potential exposure of patients and staff to COVID-19, surgeons were advised to treat early appendicitis with antibiotics and favour open surgery over laparoscopy.⁵

The authors hypothesised that the COVID-19 lockdown would lead to a decreased, or delayed, presentation of acute appendicitis to hospital and a decrease in the number of appendicectomies. The aim of this study was to identify the effect of the lockdown on the observed incidence of acute appendicitis in secondary care and to identify any change of practice in the management of acute appendicitis.

Methods

A prospective audit was carried out across four hospitals in South Wales, UK, from 1 to 30 April 2020. These sites were: The Royal Gwent Hospital (RGH) and Nevill Hall Hospital (NHH), who combined their surgical admissions to RGH in 2020, University Hospital of Wales (UHW) and Morriston Hospital (MOR). Patients with suspected, or confirmed, acute appendicitis were identified from the surgical admission units. Patient demographic data was collected along with details of their symptoms, presentation, radiological imaging, surgical procedure, hospital discharge and readmission.

To enable comparisons of patients treated prior to COVID-19, electronic theatre records were scrutinised for all appendicectomies, and diagnostic laparoscopies, performed in April 2018 and April 2019. To validate this data set and identify cases of acute appendicitis managed non-operatively, an electronic search of all abdominal computed tomography (CT) and magnetic resonance imaging (MRI) reports, performed within the study dates, was also undertaken.

Patients were included if they were over 18 years old and had radiological confirmation of acute appendicitis or had undergone a surgical procedure for suspected appendicitis. Cases of acute appendicitis caused by a caecal malignancy were excluded from the study.

The appendix was graded (radiologically or during surgery) as normal, simple or complex. An injected, inflamed or thickened appendix in the absence of ‘complex features’ indicated simple appendicitis. Complex appendicitis features included evidence of free fluid, perforation, pus or necrosis.

A negative appendicectomy was defined as a normal appendix at operation or on histological examination. Electronic hospital records were utilised to follow-up patients, for reattendance or subsequent operations, within 30 days of diagnosis.

Statistical analysis

Data analysis was undertaken using SPSS version 26 (IBM Corp., Armonk, NY, USA). Statistical calculations suitable for non-parametric data (Pearson’s chi-square test) were used to compare groups. A p-value less than 0.05 was considered statistically significant.

Results

A total of 254 patients received treatment for suspected acute appendicitis during the study periods, April 2018 (95 patients), April 2019 (95 patients) and April 2020 (64 patients). UHW treated 94 patients, with MOR, RGH and NHH treating 73, 65 and 22 patients, respectively. There was no statistical difference between the initial treatments given in each hospital pre-COVID-19 lockdown (2018 and 2019, p = 0.922) or during the lockdown (2020, p = 0.525). Table 1 indicates the patient demographics according to pre-COVID-19 lockdown (2018 and 2019) and during lockdown (2020) status. Patients treated for appendicitis during the pandemic were less likely to have an American Society of Anesthesiology (ASA) score of 1 (p = 0.049) and more likely to be over 35 years old, although this trend did not reach statistical significance (p = 0.192).

Table 1 .

Comparison of all patients treated for appendicitis pre-COVID-19 lockdown and during lockdown (including patients undergoing diagnostic laparoscopy)

	Pre-lockdown (n = 190)	During lockdown (n = 64)	p-value (chi-squared)
Gender
Male	98 (51.6)	29 (45.3)	0.386
Female	92 (48.4)	35 (54.7)
ASAa
1	118 (62.1)	28(47.5)	0.049
2	53 (27.9)	29 (49.1)
3	9 (4.7)	2 (3.4)
4	2 (1.1)	0 (0)
Age, years
<35	104 (54.7)	29 (45.3)	0.192
≥35	86 (45.2)	35 (54.7)
Duration of symptoms, median days (IQR)	2 (1,4)	3 (1,6)	0.030
Length of stay, median days (IQR)	3 (2,4)	2 (1,3)	0.323
CT/MRI imaging
No	121 (63.7)	9 (14.1)	<0.001
Yes	69 (36.3)	55 (85.9)
Appendicitis grade (all patients)b
Normal	28 (14.7)	2 (3.1)	0.342
Simple	95 (50.0)	32 (50.0)
Complex	67 (35.3)	30 (46.9)
Appendicitis grade (non-operative)
Simple	0 (0.0)	14 (21.9)	0.006
Complex	6(3.7)	8 (12.5)
Initial management
Surgery	184 (96.8)	38 (59.4)	<0.001
Antibiotics	6 (3.2)	26 (40.6)
Re-attendance
No	160 (84.2)	41(64.0)	0.001
Yes	30 (15.8)	23 (36.0)
Complications
CV <3	33 (17.4)	10 (15.6)	0.098
CV >3	1 (0.5)	2 (3.1)
Histology
Malignant	6 (3.2)	2 (3.1)	0.876
Benign	5 (2.6)	2 (3.1)

ASA = American Society of Anesthesiology; CT = computed tomography; MRI = magnetic resonance imaging; IQR = interquartile range; CV = Clavien–Dindo complication classification grade

Unless stated otherwise, values in parentheses are percentages

Values given in bold are statistically significant

^aASA data was missing on 13 patients

^bBased on radiological and operative findings

Overall, 124 patients (48.8%) received cross-sectional imaging. One patient underwent an MRI scan rather than CT as they were pregnant and was included within the CT group for the analysis. There was a significant increase in the proportion of patients receiving a CT/MRI scan in the lockdown cohort (36.3% versus 85.9%, p < 0.001). The median age of patients who underwent CT/MRI fell significantly from 53 (IQR 35,64) to 40 (30,58), p = 0.018, in the lockdown cohort.

Surgery was the predominant treatment option in both patient cohorts, however there was a higher proportion of patients commenced on antibiotic-only treatment during lockdown than in the pre-lockdown group (6.2% versus 40.6%). No patients failed conservative treatment prior to lockdown. However, at the time of writing, four patients in the lockdown cohort that were initially treated conservatively had received an appendicectomy. Three of these patients had a planned review after 48h of treatment (two as an outpatient) and subsequently had surgery for ongoing pain. The fourth patient to fail conservative treatment in the lockdown group had an unplanned readmission with recurrent abdominal pain and sepsis two weeks after their initial diagnosis. At operation, this patient had a gangrenous appendix, requiring conversion to an open procedure, and subsequently had a prolonged hospital stay.

Across all patients with appendicitis, most were categorised as having simple disease. Prior to COVID-19 lockdown, all patients managed without surgery had complex appendicitis, however during lockdown, 14 of 22 patients (63.6%) had simple disease.

There was variation in the treatments that patients ultimately received, as displayed in Figure 1. Aside from an increase in the number of patients treated conservatively during lockdown, the laparoscopic appendicectomy rate decreased (85.3% versus 17.2%, p < 0.001).

Figure 1 .

Definitive management of patients treated for acute appendicitis according to year treated (p < 0.001)

Histopathology results identified three cases of neuroendocrine tumours, two cases of goblet cell carcinoid tumours and two cases of adenocarcinoma. Appendicitis was caused by threadworms in two patients and a third case of intestinal worms was identified within a histologically normal appendix. Other benign causes included: an appendix diverticulum, two fibrotic appendixes and three chronically inflamed appendixes. When operative findings were combined with histological findings, the actual negative appendicectomy rate was 21.7% pre-lockdown compared with 4.7% during lockdown (p < 0.001).

Discussion

As hypothesised, this study identified a significant reduction in the numbers of patients being treated for appendicitis after the nationwide lockdown compared with the two preceding years. This pattern has been noted elsewhere with other conditions such as acute cardiac events.⁶ In England, 76% fewer GP referrals were made in April 2020 in comparison with April 2019, with non-elective hospital admissions down by 38.5%.⁷

The reduced incidence of appendicitis could be explained by patients delaying their presentation to hospital and a proportion resolving spontaneously, as suggested elsewhere in the literature.⁸ Our study detected patients presenting to hospital a day later than in previous years, however patients did not appear to have more complex disease as one might expect. The current study was not necessarily powered to identify a difference in this outcome and therefore this could be considered in future studies.

Another explanation for a decrease in the number of patients with acute appendicitis seen in hospital could be related to the increased use of antibiotics by GPs during the COVID-19 pandemic. It is possible that some cases were, either purposely or inadvertently, treated in the community.^9,10

An important finding was the reduction in negative appendicectomy rate. This is almost certainly due to the increased use of cross-sectional imaging and represents a significant change in the management of suspected appendicitis. Other countries have previously incorporated CT into their treatment pathways, but the risks of ionising radiation have led to a reluctance in the UK. Our study suggests that the desire to avoid unnecessary admissions or surgery now outweighs the concerns of CT.^11–13 An alternative to the ionising radiation of CT is a diagnostic laparoscopy but this is not without its own risks, as well as an increased length of stay and higher overall cost.^14,15 The reduction in the negative laparoscopy rate by two-thirds is difficult to overlook and provides a strong argument for continuing the current pathways beyond lockdown.

Prior to COVID-19, appendicectomy was the recommended treatment for acute appendicitis despite a growing body of evidence confirming an antibiotic-only approach was safe.^16–18 When interpreting our findings of patients manged non-operatively, one should consider the change in patient selection during lockdown. Historically, only complex disease was treated conservatively, however during lockdown, most patients treated with antibiotics had simple appendicitis. It is this type of variation from normal practice that requires an informed patient consent process. This could explain why there was not a higher uptake of a conservative approach among patients.

One systematic review found that the effectiveness of non-operative management of appendicitis varied between 41% and 85% at one year.¹⁹ The included studies had heterogeneous inclusion criteria and contained <14% from randomised controlled studies and as such, question its validity for everyday practice.

Conservative management is thought to have several drawbacks, most notably the failure of treatment and subsequent surgery. In the current study, only 4 of the 26 patients required an appendicectomy after a conservative approach. Our findings are limited by a short follow-up period and one should consider that if the appendix remains in situ there is a risk of recurrence. Previous publications have estimated a recurrence rate between 20% and 30%, specifically the NOTA study has shown an 83% success rate at two years.^18,20

A final consideration in non-operative management of suspected appendicitis is the potential for missed pathologies such as malignancy.²⁰ While this was not common in this case series, none of the preoperative imaging suggested an underlying tumour. The literature suggests approximately 1% of specimens contain an appendiceal tumour and therefore should surgeons discuss this when consenting for the antibiotic only approach?²¹

Study limitations

The authors recognise that there are limitations of a reasonably small observational study but believe that these findings represent an important change in practice. A robust process for case identification was utilised, but there remains a possibility that a patient treated conservatively prior to 2020, without radiological imaging, could have been missed. The probability of this event is low given that appendicectomy was the gold standard treatment option and, as we have shown, the non-operative approach was historically used on more complex disease.¹⁷

Unfortunately, the COVID-19 pandemic is not over. COVID HAREM is a large, nationwide, multicentre study that is currently recruiting and seeks to further map the changing management strategies.²² Their initial results indicate an even higher rate of conservative management, nationally, of 54%.

Conclusion

During the COVID-19 lockdown, fewer patients were treated for appendicitis compared with previous years. More patients underwent cross-sectional imaging and were treated with antibiotics alone resulting in fewer operations for appendicitis. The majority who were managed non-operatively were treated successfully.