Excluding Hollow Viscus Injury for Abdominal Seat Belt Sign Using Computed Tomography

Abstract

Abdominal seat belt sign (SBS) has historically entailed admission and observation because of the diagnostic limitations of computed tomography (CT) imaging and high rates of hollow viscus injury (HVI). Recent single-institution, observational studies have questioned the utility of this practice.OBJECTIVE To evaluate whether a negative CT scan can safely predict the absence of HVI in the setting of an abdominal SBS. DESIGN, SETTING, AND PARTICIPANTSThis prospective, observational cohort study was conducted in 9 level I trauma centers between August 2020 and October 2021 and included adult trauma patients with abdominal SBS.EXPOSURES Inclusion in the study required abdominal CT as part of the initial trauma evaluation and before any surgical intervention, if performed. Results of CT scans were considered positive if they revealed any of the following: abdominal wall soft tissue contusion, free fluid, bowel wall thickening, mesenteric stranding, mesenteric hematoma, bowel dilation, pneumatosis, or pneumoperitoneum. MAIN OUTCOMES AND MEASURES Presence of HVI diagnosed at the time of operative intervention.RESULTS A total of 754 patients with abdominal SBS had an HVI prevalence of 9.2% (n = 69), with only 1 patient with HVI (0.1%) having a negative CT (ie, none of the 8 a priori CT findings). On bivariate analysis comparing patients with and without HVI, there were significant associations between each of the individual CT scan findings and the presence of HVI. The strongest association was found with the presence of free fluid, with a more than 40-fold increase in the likelihood of HVI (odds ratio [OR], 42.68; 95% CI, 20.48-88.94; P < .001). The presence of free fluid also served as the most effective binary classifier for presence of HVI (area under the receiver operator characteristic curve [AUC], 0.87; 95% CI, 0.83-0.91). There was also an association between a negative CT scan and the absence of HVI (OR, 41.09; 95% CI, 9.01-727.69; P < .001; AUC, 0.68; 95% CI, 0.66-0.70). CONCLUSIONS AND RELEVANCEThe prevalence of HVI among patients with an abdominal SBS and negative findings on CT is extremely low, if not zero. The practice of admitting and observing all patients with abdominal SBS should be reconsidered when a high-quality CT scan is negative, which may lead to significant resource and cost savings.

Improved Computed Tomography Performance in Blunt Abdominal Trauma—Has Our Care Kept Pace?

“…Importantly, this study is not about whether imaging is superior to the physical examination. It is about how to use a valuable tool to its maximum capacity.…”

“…In this issue of JAMA Surgery , Delaplain and colleagues deserve high praise for their efforts to improve trauma care by incorporating current imaging technology. Three single-center studies from the last 5 years found minimal, if any, association between SBS and hollow viscus injury in patients with blunt trauma if the CT scan on admission to the emergency department is negative.…”

“…Just as research needs to catch up with improved imaging performance, so does our ability to learn to trust the findings of these scans in the appropriate settings. Delaplain et al have provided us with some of the necessary up-to-date data; now it is up to us to put it to use.…”

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“…In this prospective observational study, 754 patients from nine US trauma centres with blunt abdominal injury and an abdominal seat belt sign (ASBS) underwent high resolution and multislice CT 3. The primary outcome was hollow viscus injury at operative intervention, which was found in in 9.2% of patients.…”