Appendicitis: a rare adverse event in colonoscopy
- 1 Department of Medicine, Gastroenterology and hepatology unit, Sahlgrenska University Hospital, Gothenburg, Sweden
- 2 Department of Radiology, Sahlgrenska University Hospital, Gothenburg, Sweden
- 3 Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Correspondence to Dr Samer Al-Dury; samer.al-dury@gu.se
Abstract
We present a case of a 41-year-old woman who visited the emergency department (ED) with acute abdomen. She was diagnosed with perforated appendicitis and abscess formation on CT. She was treated conservatively with antibiotics and discharged. On control CT 3 months later, the appendix had healed, but signs of thickening of the terminal ileum were noticed and colonoscopy was performed, which was uneventful and showed no signs of inflammation. Twelve hours later, she developed pain in the right lower quadrant, followed by fever, and visited the ED. Physical examination and blood work showed signs consistent with acute appendicitis, and appendectomy was performed laparoscopically 6 hours later. The patient recovered remarkably shortly afterwards. Whether colonoscopy resulted in de novo appendicitis or exacerbated an already existing inflammation remains unknown. However, endoscopists should be aware of this rare, yet serious complication and consider it in the workup of post-colonoscopy abdominal pain.
Background
Colonoscopy is a widely used endoscopic modality to perform both diagnosis and therapy. Given the large volume of procedures performed daily, it is inevitable that some complications might occur. Good training and modern endoscopic techniques may limit the rate of complication. Nevertheless, the rate of post-procedure bleeding and colonic perforation still stands at around 1%.1 The complication rate generally increases with older age and patients with underlying pathology in the colon, such as inflammatory bowel disease (IBD) and diverticular disease.
Post-colonoscopy appendicitis is a rare complication, which may arise within several hours up to several days after a routine colonoscopy.2 This condition may start as a non-alarming post-colonoscopy bloating with pain and progress into acute abdomen, peritonitis and sepsis.
In this case report, we discuss a patient with a history of conservatively treated appendicitis who presented with fever and abdominal pain to the emergency department (ED) after a diagnostic colonoscopy. Her workup led to the diagnosis of perforated appendicitis, which was subsequently managed with a laparoscopic appendectomy. We highlight the possible cause–effect relationship between colonoscopy and appendicitis and present some core tips for endoscopists and clinicians on how to diagnose, manage and potentially avoid this condition.
Case presentation
A 41-year-old woman with a history of irritable bowel syndrome with mixed bowel habits presented to the ED with a 3-day anamnesis of abdominal pain in the umbilical region and right lower quadrant, fever and signs of acute inflammation with C reactive protein (CRP) of 210 mg/L and leucocyte count of 9.0×109/L. She underwent a CT of the abdomen showing appendicitis with perforation and an abscess measuring 4×1.5 cm (figure 1). The localisation of the abscess was not ideal for drainage. Due to the lack of resources at the time of presentation and the complicated nature of this case, the patient was admitted to the surgical ward and was treated conservatively with intravenous piperacillin-tazobactam. Her inflammation markers gradually decreased to CRP of 79 mg/L and leucocyte count of 4.8×109/L. Her symptoms resolved within 24 hours, and the risk of acute surgery was deemed to outweigh the benefit at this point. After 3 days of intravenous antibiotics, she was successfully discharged with oral metronidazole and ciprofloxacin for 10 days and was scheduled for follow-up at the surgical outpatient clinic 3 months after discharge.
CT of the abdomen with intravenous contrast demonstrates appendicitis with localised perforation and abscess formation in the right lower quadrant. (A) The selected coronal image shows a distended appendix with an enhancing wall (red arrow), surrounded by extensive stranding periappendiceal fat. (B) The coronal image shows periappendiceal fluid collection with an enhancing rim, in keeping with an appendicular abscess (yellow arrow). (C) The axial image shows the same finding with an inflamed appendix (red arrow) with an appendicular abscess (yellow arrow).
At follow-up, she underwent a CT of the abdomen to assess abscess resolution. No residual abscess was detected and the appendix was without signs of inflammation (figure 2). However, the wall of the terminal ileum was assessed as somewhat thick. Therefore, she was then referred to the department of gastroenterology for investigation of possible IBD. After a review of the patient’s history, symptoms and risk factors, the index of suspicion for IBD was considered low. Blood work, represented by CRP, sedimentation rate and leucocyte count, was unremarkable. There were no signs of anaemia or other malabsorption findings. Faecal calprotectin was also below the detection rate. After discussion with our radiologists, it was suggested that ileal wall thickening could be a residual finding after her perforated appendicitis. Nevertheless, the patient was referred for a colonoscopy to exclude IBD per the national guidelines for IBD screening.
A 3-month follow-up CT of the abdomen with intravenous and oral contrast reveals a normal appendix with no enhancement (arrows), and complete regression of previously detected appendicular abscess.
Bowel prep with macrogol was unremarkable and the patient was feeling fine before, during and after the colonoscopy. A standard diameter colonoscope from Fuji Film was used. The patient was premedicated with alfentanil 0.5 mg and midazolam 2 mg, as per routine. The bowel was clean enough for proper visualisation of the entire colonic mucosa (Boston Bowel Preparation Scale of 2+2+2). The endoscope was carefully advanced to the caecum, and the ileocaecal valve was identified. Then, the terminal ileum was intubated and the scope was advanced approximately 25 cm. The procedure was technically uncomplicated and looping was minimal in the sigmoid area and was swiftly resolved before advancing further into the left colon. Manual abdominal pressure to facilitate scope advancement was not necessary. The patient was asked to change her position from the standard left to supine during insertion and then to the right, supine and left position during withdrawal to achieve ideal visualisation of the mucosa. Macroscopic findings were normal, and no signs of inflammation, stricture or aphthous ulcers were identified. Biopsies were taken from the terminal ileum. The scope was then pulled back to the caecum and the appendiceal orifice was examined closely without any signs of irritation. Biopsies were taken from the right, transverse and left colon before the procedure was terminated. Insertion time was 14 min and withdrawal time was 19 min. The patient was observed uneventfully for 45 min after the procedure. Histopathological analysis of the biopsies showed normal mucosa with no signs of IBD or other structural abnormalities.
Twelve hours later, the patient presented to the ED with central abdominal pain, nausea, vomiting and fever (38.3°C). On physical examination, she was tender on abdominal palpation over Mcburney’s point, psoas sign was negative, and there was involuntary guarding in the right fossa and normal abdominal sounds. Her lab showed CRP of 17 mg/L, leucocyte count of 13.3×109/L, with an over-representation of neutrophils. Her Appendicitis Inflammatory Response score was 10, and the patient was admitted to the surgical ward and planned for a laparoscopic procedure within 6 hours.
Perioperatively, free fluid was identified in the pouch of Douglas without signs of irritation of gynaecological organs. The caecal area was then inspected where the appendiceal base was without signs of inflammation, but the appendix itself continued retrocaecally where it was clearly inflamed with signs of microabscesses (figures 3 and 4). The appendix was removed, the patient was returned to the surgical ward, where she received antibiotics intravenously for 1 day, and she recovered remarkably well postoperatively and was discharged the following day without any complications.
Explanted tissue shows no signs of inflammation in the appendix base (red arrow), while the appendix itself is severely inflamed with local signs of necrosis (yellow arrow).
Microscopic image showing a heavy infiltration of neutrophilic granulocytes into the appendix wall. The histological picture is typical of phlegmonous appendicitis.
Discussion
Colonoscopy is a common diagnostic and therapeutic procedure, and due to the advances in endoscopic equipment and technique, the risk of peri-procedural and post-procedural complications is very low. The overall incidence of colonic perforation during colonoscopy has been estimated to range from 0.03% to 0.7%.3 4 In a recent study, the risk of colonic perforation during colonoscopy was mostly associated with age >75 years and therapeutic endoscopy.5 Appendicitis following colonoscopy is a very unusual complication and so far less than 30 cases of pericolonoscopy appendicitis have been reported.2 Those cases have been more frequently diagnosed in males above 50 years of age, but this association could be confounded by the higher incidence of appendicitis in males compared with females in a ratio of 1.4:1. Moreover, a higher number of males undergo diagnostic and therapeutic colonoscopy.6 7
Given the condition’s rare occurrence, it has been difficult to study in detail and a few insights on its pathophysiology have been gained. Several theories describing the chain of events leading to post-colonoscopy appendicitis have been proposed.8 9 The most common cause is direct trauma during colonoscopy due to unintentional intubation of the appendiceal lumen. Overinsufflation of the right colon with air or carbon dioxide is another cause. Additionally, the impaction of faecal matter into the appendix in inadequate bowel preparation may initiate a proinflammatory response. Finally, the presence of subclinical appendicitis even before colonoscopy might be aggravated by the examination or develop coincidentally afterwards. Most reported cases presented within 24 hours after the procedure.
Colonoscopy may diagnose appendicitis in situations with atypical presentation or when radiology is inconclusive. In those cases, signs of oedema and/or erythema at the appendiceal orifice can contribute to the diagnosis. In our case report, the appendiceal orifice was without any signs of acute inflammation during colonoscopy and the colonic wall was free of faecal residue. At subsequent laparoscopy, the appendiceal base was free of oedema and other signs of inflammation, which makes it difficult to determine whether low-grade appendicitis was indeed present before colonoscopy. Since the reason for performing the colonoscopy was to exclude IBD, namely, Crohn’s disease, adequate colonic insufflation with carbon dioxide was applied in the caecum and the terminal ileum to inspect the area for signs of macroscopic inflammation. Biopsies were indeed taken from the terminal ileum and caecal area. However, the risk of perforation caused by biopsy forceps is very low. Several biopsies accompanied by insufflation of the area might have resulted in a combination of physical and pneumatic pressure to the mucosa, thus inflaming an already fragile appendix, which then prompted a visit to the ED, resulting in laparoscopic acute appendectomy. In previous reports, colleagues have hypothesised similarly and discussed whether post-colonoscopy appendicitis is a coincidence or a consequence of colonoscopy. Imaging, preferably with CT of the abdomen, has been recommended to facilitate diagnosis and treatment.10 Finally, it is worth mentioning that a less traumatic diagnostic modality, such as capsule endoscopy, could be considered in cases with recent appendicitis, if this technique is available at the unit.
Post-colonoscopy abdominal pain is common and self-limiting and may last up to 2 weeks. It is usually caused by retained gas, colonic spasm or post-polypectomy syndrome. However, if abdominal pain is accompanied by other symptoms, such as fever and leucocytosis, other differential diagnoses should be considered. We, therefore, suggest that appendicitis diagnosed within 48 hours after a colonoscopy showing a normal appendiceal orifice should be suspected for a post-colonoscopy appendicitis.
In conclusion, post-colonoscopy appendicitis is rare but still a potential consequence of a generally safe diagnostic procedure. The pathophysiology of this condition remains unclear. Nevertheless, endoscopists should be vigilant and avoid overinsufflation and unnecessary biopsies of the appendiceal area, especially in patients with a history of conservatively treated appendicitis. In a patient presenting with early post-procedural abdominal pain, post-colonoscopy appendicitis should always be included in the differential diagnosis to avoid delayed diagnosis and treatment.
Learning points
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Post-colonoscopy appendicitis is rare but still a potential consequence of diagnostic and therapeutic colonoscopy.
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Care should be taken while manoeuvering the scope in the appendiceal area to avoid air overinsufflation or faecal impaction into the appendix.
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In a patient with conservatively treated appendicitis or perforation, the diagnostic procedure of choice should be viewed carefully and alternative methods, such as capsule endoscopy, should be considered.
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Post-colonoscopy appendicitis should be considered in the diagnostic workup of post-colonoscopy abdominal pain.
Ethics statements
Acknowledgments
We thank the patient for agreeing to allow us to publish this interesting case report. We thank the department of radiology for providing the CT images. We thank Dr Lyubomira Dimitrova from the department of pathology for providing microscopic images of the inflamed appendix.
Footnotes
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Contributors SA-D was responsible for the patient’s case, performed the endoscopy and the outpatient clinic visit, reviewed the literature and wrote the draft of the manuscript. MK provided and interpreted the radiological images. RS helped in the assessment of the endoscopic findings and contributed to manuscript revision. PH reviewed the literature and contributed to manuscript drafting and final revision. All authors issued final approval for the version to be submitted.
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Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
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Competing interests None declared.
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Provenance and peer review Not commissioned; externally peer reviewed.
- © BMJ Publishing Group Limited 2021. No commercial re-use. See rights and permissions. Published by BMJ.
References
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