58 y/o male with no significant past medical history has a 3 day history of intermittent cramping abdominal pain, vomiting, and diarrhea.
Intussusception • The Invagination or telescoping of a proximal segment of bowel (intussusceptum) into the lumen of a distal segment (intussuscipiens)
Pathophysiology • The invaginated segment is carried distally by peristalsis. • Mesnetery and vessels become involved with the intraluminal loop and are squeezed within the engulfing segment causing venous congestion. • Types: enteroenteric, enterocolic, and colocolic.
Epidemiology (Children) • Most common in infants and children • Accounts for 95% of all cases of intussusception • Ranks 2nd to appendicitis as a cause of acute abdomen • 90% of the cases in children are idiopathic • Most common in children of 6 months to 2 years in age
Epidemiology (Adults) • Rare in adults: accounts for 0.003% to 0.02% of all hospital admissions • Accounts for 1% of all bowel obstructions in adults • 80-90% of cases have and underlying cause • 65% are due to neoplasm
Epidemiology • Location • Adults: ileoileal > ileocolic > colocolic • Children: ileocolic > ileoileal > colocolic
Etiology • Idiopathic (most common in children) • Neoplasm • Benign (more common in small bowel) • Polyp, Leiomyoma, Lipoma, Lymphoma, Adenoma of appendix, Appendiceal stump granuloma • Malignant • Primary (more common in colon) • Metastatic (more common in small bowel)
Etiology • Postoperative (more common in small bowel) • Meckel’s diverticulum • Colitis • Many cases thought to be related to viral gastroenteritis in children
History and Physical • Children: • Well nourished infant • Cramping abdominal pain • Poor feeding / Vomiting • Diarrhea (often currant-jelly stools) • A palpable, tender, sausage shaped mass in the abdomen • Hx of abdominal surgery
History and Physical • Adults • Intermittent pain • Nausea and vomiting • Often red blood per rectum • Often nonspecific complaints
Abdominal Studies • Abdominal films often show signs of small bowel obstruction
Abdominal Studies • Erect films often show fluid levels in the small bowel
Barium Studies • Show a classic “coiled spring” appearance due to trapping of contrast between layers of bowel.
Ultrasound • Ultrasound: transverse scan shows a target sign
CT (see-tee) • Target sign is also seen in CT. • Can also see a sausage shaped mass
Imaging • CT is the most accurate detecting 78% of the cases. • Ultrasound is often used in children • Barium studies are also very useful
Treatment (children) • Air reduction is the treatment of choice for children and is successful 75-90% of the time • Contrast reduction was more frequently used a decade ago
Treatment (Adults) • Adults require surgical exploration and resection of the intussuscepted bowel loops • Reduction is not recommended in adults due to the risk of spreading/seeding malignant cells, potential perforation of the intussuscepted bowel, and venous embolization at the ulcerated mucosa area
References Alfred Chahine, MDIntussusception Emedicine: http://www.emedicine.com/ped/topic1208.htm Edwin C. Ouyang, Ileocolonic Intussusception Medscape: http://www.medscape.com/viewarticle/510397_1