Ultrasound Case 109

Video 1 & 2: Longitudinal and transverse views taken at the left lower quadrant, at the site of tenderness.

A small bowel intussusception is seen. The bowel remains active; the length of the intussusception is short (2cm), and the diameter small (2cm); there is no echogenic core, and no obvious pathological lead point is seen.

This is typical of a small bowel intussusception (small bowel into small bowel). These are commonly benign, and resolve spontaneously without need for intervention. Conservative management with observation in the first instance if the patient is relatively well is reasonable.

Asymptomatic short segments of intussusception have been reported as incidental findings in imaging studies done for other indications.

Intussusception

This is a short segment of small bowel intussusception with active peristalsis seen.

Intussusception involving the ileo-caecal valve (terminal ileum into caecum) or a pathologic lead point is a surgical emergency. Transient small bowel intussusception (small bowel into small bowel) is a relatively common US finding and tends to be self resolving if there are no concerning features present.

These are the features we look for that predict the need for intervention:

• Infant (< 12 months) or adults
• Total lesion diameter > 2.5 cm
• Intussusceptum length > 3 cm (the inside bit)
• A thick fatty core (a high core:wall ratio >1:1)
• Absence or blood flow or active peristalsis
• Involvement of the ileo-caecal valve
• A pathological lead point such as a lymph node, Henoch-Schönlein purpura polyp, duplication cyst, or Meckel’s diverticulum

FOAM

• Parker C. Intussusception: the Good, the Bad and the Ugly. Broomedocs 2021

Literature

• Guo JZ, Ma XY, Zhou QH. Results of air pressure enema reduction of intussusception: 6,396 cases in 13 years. J Pediatr Surg. 1986 Dec;21(12):1201-3
• Kornecki A, Daneman A, Navarro O, Connolly B, Manson D, Alton DJ. Spontaneous reduction of intussusception: clinical spectrum, management and outcome. Pediatr Radiol. 2000 Jan;30(1):58-63. 
• Grosfeld JL. Intussusception then and now: a historical vignette. J Am Coll Surg. 2005 Dec;201(6):830-3
• Wang Q, Luo M, Xie X, Wu Y, Xiang B. Can intussusceptions of small bowel and colon be transient? A prospective study. Eur J Pediatr. 2019 Oct;178(10):1537-1544
• Park BL, Rabiner JE, Tsung JW. Point-of-care ultrasound diagnosis of small bowel-small bowel vs ileocolic intussusception. Am J Emerg Med. 2019 Sep;37(9):1746-1750.
• Goel I, Anand R, Choudhury SR, Agarwal S. Evolving Concepts in Ultrasonography of Pediatric Intussusceptions: Unequivocal Differentiation of Ileocolic, Obstructive and Transient Small-Bowel Intussusceptions. Ultrasound Med Biol. 2020 Mar;46(3):589-597. 
• Lin-Martore M, Kornblith AE, Kohn MA, Gottlieb M. Diagnostic Accuracy of Point-of-Care Ultrasound for Intussusception in Children Presenting to the Emergency Department: A Systematic Review and Meta-analysis. West J Emerg Med. 2020 Jul 2;21(4):1008-1016.
• Li XZ, Wang H, Song J, Liu Y, Lin YQ, Sun ZX. Ultrasonographic Diagnosis of Intussusception in Children: A Systematic Review and Meta-Analysis. J Ultrasound Med. 2021 Jun;40(6):1077-1084
• Zhang M, Zhou X, Hu Q, Jin L. Accurately distinguishing pediatric ileocolic intussusception from small-bowel intussusception using ultrasonography. J Pediatr Surg. 2021 Apr;56(4):721-726