The Physics of Intussusception Reduction

Abstract

Ramendra Shukla*, Sudhir B Chandna, Rasna Tiwari

Aim: To understand the scientific basis of intussusception reduction and to determine the effectiveness and success rate of pneumatic reduction and also to identify factors that predict an unsuccessful outcome.

Materials and Methods: This retrospective study was carried out in 50 patients of intussusception aged 2 months to 11 years from January 2020 to December 2024. Pneumatic reduction of intussusception was carried out in the standard manner, when a pressure of approximately 100 mm of Hg was applied. Applying Pascal’s principle and Laplace’s law, the pressure could be raised to 120 mm of Hg if the lower pressure was not working. Presenting signs and symptoms, results of radiological investigations, the outcome of attempted reduction, complications and any subsequent surgical interventions were examined.

Results: Successful pneumatic reduction was achieved in 33 (66%) cases during the study period. The mean age at presentation was 1 year (range: 2 months to 12 years). The only significant predictor of failure was long duration of symptoms (p<0.05). Among the 17 cases of failed reduction, surgery was performed and the findings were colo-colic intussusception (n=2), ileo-ileo-colic intussusception (n=1) and ileocolic intussusception (n=14). Resection anasmotosis (n=8), manual reduction+ appendicectomy (n=7) and Meckel’s Diverticulectomy (n=2) was done. No deaths occurred during the study period.

Conclusion: Fluoroscopy-guided pneumatic reduction of intussusception offers a high success rate (66%) without any complications. As the gas molecules are loosely packed, it is possible to apply a little higher pressure (120 mm of Hg) vis-a-vis liquids, which have densely packed molecules. The most important predictor of outcome in this study was the long duration of symptoms.