Predicting Bowel Necrosis in Pediatric Intussusception: The Role of Ultrasound Roundness and Blood Flow

Intussusception, the invagination of a segment of the intestine into an adjacent lumen, is a common cause of bowel obstruction in infants and young children, with the majority of cases occurring in children under two years of age. While air enema reduction remains the primary treatment, surgical intervention is required when reduction fails or complications, such as bowel necrosis, occur. Early recognition of necrosis is challenging, as standard laboratory tests and imaging often lack sensitivity, and clinical symptoms may be nonspecific.

Ultrasound plays a central role in diagnosing intussusception, commonly revealing a “concentric ring” or “target sign.” Recent research has explored whether ultrasonographic parameters, including the circularity or “roundness” of the intussuscepted segment and blood flow assessed by color Doppler, can help predict bowel necrosis. Roundness, a metric ranging from 0 to 100%, quantifies how closely the cross-sectional shape of the intussusception resembles a circle, potentially reflecting intraluminal tension and mesenteric vascular compromise.

A retrospective study conducted at the Children’s Hospital of Jiangnan University included 23 children with surgically confirmed bowel necrosis and 64 controls successfully treated with air enema.1 Detailed clinical, biochemical, and ultrasonographic data were analyzed, including segment length, concentric ring thickness, head-to-neck diameter ratio, bowel wall thickness, peritoneal effusion, and color Doppler blood flow grading. Roundness was calculated from the maximal transverse area of the intussusception.

The study found that children in the necrosis group were more likely to be younger than 12 months and presented with longer intussuscepted segments, thicker bowel walls, higher concentric ring thickness, greater roundness, and reduced Doppler blood flow. Multivariate analysis identified roundness and low-grade blood flow as independent predictors of bowel necrosis. Receiver operating characteristic analysis showed that roundness alone had an AUC of 0.742, blood flow grading had an AUC of 0.771, and the combination of both parameters improved predictive accuracy to an AUC of 0.857.

These findings suggest that higher roundness and reduced blood flow on Doppler ultrasound indicate increased intraluminal tension and compromised mesenteric circulation, serving as reliable indicators of bowel necrosis risk. Incorporating these ultrasonographic markers into clinical assessment may facilitate timely surgical intervention and reduce complications.

References:

1. Xu XX, Cai YJ, Liu J, et al. Predicting bowel necrosis in pediatric acute intussusception using roundness and other related factors. BMC Pediatr. 2025;25:843.

Link: https://bmcpediatr.biomedcentral.com/articles/10.1186/s12887-025-06172-9