Key questions in the diagnosis and management of appendicitis

James Ashcroft (@JamesAshcroftMD) Academic Clinical Fellow, Department of Surgery, Cambridge, UK;

Salomone Di Saverio (@salo75) Consultant General and Colorectal Surgeon, Professor of Surgery, University of Insubria, Regione Lombardia, Italy;

Justin Davies (@jdcamcolorectal) Consultant General and Colorectal Surgeon and Deputy Medical Director, Addenbrooke’s Hospital, Cambridge, UK.

Key questions in the diagnosis and management of appendicitis

Throughout my surgical training, decision making and risk prediction in patients with a clinical suspicion of appendicitis has been a prominent challenge. The accurate diagnosis of appendicitis should lead to improved healthcare provision to the patient, however there is still debate amongst the use of tools and imaging to assist this. The appropriate use of antibiotics to manage appendicitis, and the use of operative techniques to remove the appendix, have recently become a global debate.

Diagnosis of appendicitis

I have personally found the diagnosis of appendicitis to be challenging, with presenting history and examination of patients with right iliac fossa pain variable and often confounded. Clinical risk scores have recently been investigated through prospective international collaborative studies.¹ The Alvarado score was one of the earliest scores demonstrating efficacy in appendicitis diagnosis when confirmed to histopathological diagnosis leading to its widespread uptake.² However, this been superseded by the Appendicitis Inflammatory Response score (AIRS) in males and Adult Appendicitis Score (AAS) in females which have demonstrated improved performance in a pragmatic clinical setting.¹

I have often been taught that appendicitis is a diagnosis made on clinical judgement alone and I feel this has become one of the most prominent dogmas present in surgical practice. The use of AIRS and AAS have been recognised to decrease negative appendicectomy rates in low-risk groups and reduce the need for imaging.^1,3 I believe that the use of risk scoring should be taught to all surgical trainees routinely as a standard work up for the assessment of right iliac fossa pain.

Recent news reports have disseminated to the public that “Thousands of young women have their appendix removed unnecessarily”⁴ and although this may represent the appropriate conservative approach to imaging in females, it emphasises that we cannot justify ignoring the diagnostic tools at our disposal. Point of care ultrasound is recommended by the World Society of Emergency Surgery for decision making as a first point of call in both adults and children, however operator variability is noted.³

In my experience, and as per the general consensus of the departments I have worked in, ultrasound imaging is often useful in female patients to identify any ovarian cause of right iliac fossa pain and inconclusive for appendicitis. However, I can envision the use of ultrasound as part of clinical-radiological scores to enhance the sensitivity of diagnosis and could assist in avoiding radiation exposure through CT scan, which remains a pertinent research question.

Non-operative and operative management of appendicitis

Mirroring teachings in the diagnosis of appendicitis, in my experience it is taught that there is only one definitive management plan for simple appendicitis – an emergency appendicectomy. When considering modern sources of evidence, my belief is that the UK national normal appendicectomy rate (NAR) of around 20% is too high, when compared to countries such as Switzerland where the NAR has been found to be around 6%.⁵ The high NAR in the UK was again picked up by British media outlets who published headlines such as ‘Unnecessary appendix surgery performed on thousands in UK’.⁴

Antibiotic-first strategy has been found to be safe and effective in selected patients with uncomplicated acute appendicitis however, the risk of recurrence has been suggested to be up to 39% after 5 years.³ A 2019 meta-analytical review of 20 studies (7 prospective RCTs, 8 prospective cohort studies, 4 retrospective cohort studies and 1 quasirandomised study) investigated outcomes in non-operative management with antibiotics in appendicitis with an overall moderate quality of evidence when regarding complications and treatment efficacy.⁶ Overall antibiotic therapy achieved a significantly lower post-intervention complication rate including postoperative abscesses, surgical site infections, incisional hernias, obstructive symptoms, and other general operative complications at 5 years compared to index event surgery.⁶ However, there was a lower complication free treatment success rate and a non-significantly higher rate of complicated appendicitis with delayed surgery in patients receiving initial antibiotic therapy.⁶

I feel that the stratifying of patients by risk and utilisation of outpatient surgical ambulatory units with repeated history taking, observations, and blood tests could be effective in reducing the NAR in the UK with or without imaging. Accurate diagnostic imaging in the form of a CT scan could reduce the UK’s NAR further, improving patient outcomes, surgical planning, and healthcare service provision at an organisational level. This may outweigh the impact of radiation exposure of a CT abdomen scan which has been well described by Aneel Bhangu the lead director of the RIFT/West Midlands Collaborative as giving “the same radiation as flying to New York”.⁴ T

his is a risk which I believe many would not be concerned about when travelling. This view is in opposition to that of the recently updated World Society of Emergency Surgery guidelines which suggest that CT imaging may be avoided prior to laparoscopic operation, but it should be noted that there was debate regarding this within the writing committee.³

I believe that more care must be taken in patients with suspected appendicitis to undertake a discussion around imaging use, operative management, and non-operative management which is unbiased and evidence based. Those opting for conservative management should be warned of the possibility of failure and misdiagnosis of complicated appendicitis. In my training so far, conservative management has been discussed in those judged to be low-risk however this does not come without the risk of the on call surgeon’s bias seeping into conversation. Further research should be undertaken to identify precisely which cohort of patients are optimal for non-operative outpatient management.

Appendicitis and COVID-19

Recent research into risk scoring in appendicitis has demonstrated a clear benefit in stratifying patients into risk categories to guide management plans.^1,3 As highlighted I believe that all patients presenting with right iliac fossa pain should undergo scoring, by either AIRS or AAS. It has been suggested that due to local population characteristics and health systems, risk scores should be validated locally prior to routine adoption.⁷ It has further been emphasised that risk score models should not replace clinical judgement and should be used as an adjunct to enhance decision making.⁸

In the current COVID-19 pandemic the use of non-operative management has been suggested to be increased for acute surgical conditions such as appendicitis⁹ and this has been the experience of my department. The evidence at present suggests that this is safe and feasible, and therefore the COVID-19 pandemic presents a unique period for investigation.¹⁰ It could be a valuable endeavour for all centres to perform local analyses of the impact of conservative management on patients presenting with right iliac fossa pain in the COVID-19 period.

This is also being undertaken on a national level in the COVID- HAREM Study: Had Appendicitis and Resolved/Recurred Emergency Morbidity/Mortality. Locally, one year clinical outcomes could be measured for those diagnosed with appendicitis pre-COVID and during the COVID period. Finally, with the restoration of normal patient pathways post-COVID, risk scoring could be introduced to local departments with a pre-COVID / post-COVID comparison to allow for the clear demonstration of any benefit to the patient.