Title : Appendiceal Intussusception with Appendiceal - Caecal Fistula in Adult Caused by Acute Appendicitis: case report and literature review
Intussusception is the telescoping of the proximal segment of bowel into the adjacent distal segment, primarily seen in children but rare in adults. Although it only accounts for up to 5% of bowel obstructions in adults, 90% of cases are due to underlying intestinal pathology ranging from polyps to neoplasms. Unlike infants, adults exhibit non-specific symptoms including colicky pain, nausea, bowel changes and gastrointestinal bleeding[2,3]. Surgical resection remains the mainstay treatment in most cases of adult intussusception due to high risk of malignancy. We present a case of appendiceal intussusception with appendiceal – caecal fistula caused by an acute appendicitis treated with laparoscopic-assisted limited ileocolic resection.
A 50-year-old female presented with colicky right lower quadrant abdominal pain that she reported began 3 days prior associated with nausea but otherwise denied vomiting or abdominal distension. She had no significant past medical history other than three previous Caesarean sections.
She was afebrile and her other vital signs were normal. Abdominal examination revealed a focal tenderness over the right iliac fossa with no other signs of peritonism. Laboratory testing was largely unremarkable except for an elevated C-reactive protein of 60 mg/L. Computed tomography (CT) of the abdomen with intravenous contrast revealed findings suspicious for an appendiceal intussusception (Figure 1,2). A thickened dilated appendix up to 12mm was seen arising from the cecal junction forming the lead point.
The laparoscopic exploration confirmed appendiceal intussusception with an inflamed appendiceal tip (Figure 3).A careful attempt was made to reduce the intussusception without causing perforation but this was unsuccessful. Hence, a laparoscopic assisted limited ileocolic resection with side-to-side stapled anastomosis was performed.
The patient developed post-operative ileus on day three which resolved with conservative management and subsequently discharged on day five post-operatively. Histopathology revealed appendicitis with intussusception of base of appendix into the caecum and internal perforation causing appendiceal-caecal fistula.
Appendiceal intussusception is rare with an incidence of 0.01% in a prospective study of 71000 cases. It has been hypothesized that appendiceal intussusception results from irritation within the intestinal lumen that alters peristalsis and leads to invagination of the appendix into an adjacent segment. As both acute appendicitis and appendiceal intussusception are present, the question of “cause and effect” remains to be answered, as the literature on this subject is still scarce. Although ultrasound studies can be highly specific and sensitive in children, CT imaging is superior, with a 78% diagnostic yield amongst adults.
Based on the literature, up to 30% of small bowel and over 60% of large bowel intussusceptions result from malignant lesions. Given the risk of perforation and subsequent spillage, surgical resection is the preferred procedure over surgical reduction. In the majority of cases, a radical approach involving ileocolic resection or right hemicolectomy is undertaken to prevent recurrence and the risk of reoperation. A partial caecectomy may be an option if the caecum is involved and clear resection margins cannot be achieved with just an appendectomy, however there is a risk of ileocecal valve narrowing in which a more prudent approach of performing ileocolic resection in the first instance is advisable as seen in the case report of Park et al.
Adult intussusception due to appendicitis is rare and remains a diagnostic and treatment challenge to surgeons. Since there are no clear management guidelines and malignancy being commonly associated amongst adults, surgical resection remains a safe and reliable treatment with favourable outcomes.