Intussusception

Ultrasound diagnostics and specific signs

Ultrasound is the main tool for confirming the diagnosis, searching for potential secondary lead points (secondary lead points), and ruling out concomitant abdominal pathology.

During the examination, physicians evaluate the following characteristic sonographic signs:

• Transverse plane (axial section): the classical "target sign" (target sign) or "doughnut sign" (doughnut sign) is visualized.
• Longitudinal plane: the "sandwich appearance" (sandwich appearance) is determined, which represents layers of the intestinal wall and mesenteric fat.
• "Crescent-in-doughnut" sign: a hyperechoic crescentic inclusion caused by the pulling of mesenteric fat into the intussusceptum (intussusceptum). This sign helps differentiate the pathology from conventional wall thickening or fecal masses.

It should be noted that the presence of lymph nodes or fluid inside the intussusceptum is sometimes associated with a lower success rate of hydrostatic reduction. At the same time, free fluid in the abdomen is an unreliable indirect sign of ischemia, and bowel necrosis is difficult to assess even with power Doppler.

Treatment and indications for reduction

The choice of treatment tactics depends on the patient's stability and the form of the pathology.

• Conservative reduction: performed under imaging guidance (pneumatic or contrast enema under fluoroscopic or ultrasound guidance). In the UK, the pneumatic method is prioritized.
• Small bowel intussusception: in the presence of symptoms of obstruction (ileus) or an edematous wall, surgical treatment is required, as conservative enemas are not used here.

In stable and well-hydrated children, there are only two absolute contraindications to conservative reduction:

1. Presence of free gas in the abdominal cavity (pneumoperitoneum).
2. Clear clinical signs of peritonitis.

Important: any sonographic findings, including secondary lead points, cannot serve as a reason to refuse an attempt at conservative treatment.

Features in comorbid conditions

Intussusception can develop against the background of other pathologies, for example, in Henoch-Schönlein purpura (hemorrhagic vasculitis in children).

• Ileo-ileal intussusception: occurs most frequently in vasculitis, often reduces spontaneously, and is not subject to pneumatic or hydrostatic reduction.
• Ileocolic intussusception: occurs less frequently, but requires treatment according to standard protocols for the idiopathic form.

In addition, congenital structures such as Meckel's diverticulum or enteric duplication cysts, which are frequently localized in the ileum and require surgical intervention, can act as a trigger (lead point).

Class and exam questions

What else to study on this topic

• Ultrasound criteria for differentiating small bowel and ileocecal intussusception
• Features of colocolic intussusception and atypical clinical manifestations
• Stages of performing guided hydrostatic and pneumatic reduction
• Manifestations of intussusception in Henoch-Schönlein purpura and management tactics
• The role of enteric duplication cysts as lead points

Other Topics in "Pediatric Diagnostic Radiology"

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