Intussusception reduction is a procedure performed in paediatric patients who have an ileocolic intussusception.
There are several ways that reduction can be achieved radiologically:
- air-reduction under fluoroscopic guidance
- water-reduction under fluoroscopic guidance
- physical reduction under US guidance
In air-reduction and water-reduction methods, a catheter is inserted into the rectum of the child, and under fluoroscopic guidance, air or water is instilled into the large bowel.
Assessment with ultrasound prior to the reduction allows stratified risk assessment. Intussusception with reduced vascularity or interloop fluid is usually more challenging to reduce. Most facilities that perform this procedure require IV access, staff, and equipment for fluid resuscitation with the backup of a paediatric surgeon.
With air-reduction, pressures in the region of 60-100 mmHg are used which may reduce the intussusception back to the ileocaecal valve. There are a variety of protocols that have been suggested with some advocating 3 attempts lasting 3 minutes. Success is achieved when there is reduction of the 'mass' and air or contrast refluxes into the terminal ileum.
The main risk of reduction is a perforation, but since without radiological reduction, an operation is required, this risk is worth taking. The most likely portion of the bowel to perforate is the rectum, so it is important to monitor the diameter of the rectum during the procedure rather than just concentrating on the position of the intussusception.
In up to 10%, recurrence may occur (often within 3 days) and in these cases, repeat imaging-guided reduction is advised but should not be attempted more than 3 times.
Reduction is less likely to be successful if:
- there is associated small bowel obstruction
- over 24 hours of symptoms
- signs of peritonitis
- 1. Lane F. Donnelly. Pediatric Imaging. ISBN: 9781416059073