Low prevalence of hollow viscus injury on CT in patients with abdominal seat belt sign: JAMA

USA: In a new article published in the Journal of American Medical Association - Surgery, it was seen that the frequency of hollow viscus injury (HVI) in patients with abdominal seat belt sign (SBS) and negative computed tomography (CT) results was exceedingly low.

The findings indicate that patients with an abdominal seat belt sign can be safely discharged in the setting of a high-quality, negative CT scan when in agreement with good clinical judgment.

Due to the sheer diagnostic constraints of computed tomography imaging and the high incidence of hollow viscus injury, the abdominal seat belt sign has traditionally required admission and observation. Recent single-institution observational studies have called into question the efficacy of this method. As a result, Patrick T. Delaplain and colleagues conducted this study to see if a negative CT scan can accurately predict the lack of HVI in the setting of an abdominal SBS.

This observational, prospective cohort study comprised adult trauma patients with abdominal SBS and was completed in 9 level I trauma centers between August 2020 and October 2021. In order to be included in the trial, abdomen CT was required as part of the initial trauma evaluation and before any surgical intervention, if performed. The following CT scan findings were regarded as positive: abdominal wall soft tissue contusion, bowel wall thickening, free fluid, mesenteric stranding, bowel dilation, mesenteric hematoma, pneumatosis, or pneumoperitoneum. The existence of HVI at the time of operational intervention was the primary outcome.

The key findings of this study were as follows:

1. HVI was found in 9.2% (n = 69) of 754 individuals with abdominal SBS, with only 1 patient with HVI (0.1%) having a negative CT.

2. There were significant relationships between each of the specific CT scan abnormalities and the existence of HVI in a bivariate study comparing patients with and without HVI.

3. The presence of free fluid was shown to have the highest connection, with a more than 40-fold increase in the chance of HVI.

4. In the presence of HVI, the presence of free fluid acted as the most efficient binary classifier.

5. There was also a link between a negative CT scan and the lack of HVI.

In conclusion, when a high-quality CT scan is negative, the practice of admitting and observing all patients with abdominal SBS should be reviewed, which could result in significant resource and expense savings.

Reference: 

Delaplain, P. T., Tay-Lasso, E., Biffl, W. L., Schaffer, K. B., Sundel, M., Behdin, S., Ghneim, M., Costantini, T. W., Santorelli, J. E., Switzer, E., Schellenberg, M., … Nahmias, J. (2022). Excluding Hollow Viscus Injury for Abdominal Seat Belt Sign Using Computed Tomography. In JAMA Surgery. American Medical Association (AMA). https://doi.org/10.1001/jamasurg.2022.2770