The diagnostic dilemma of shotgun injuries

Shotgun wounds pose diagnostic challenges due to variable fragment penetration and degradation of CT images. This study compared epidemiology and outcomes between shotgun wounds and gunshot wounds (GSWs), and defined the diagnostic capabilities of CT scan after shotgun wounds.

All patients presenting to our Level I trauma center after ballistic injury (01/2008-03/2017) were included. Study groups were defined by shotgun vs GSW. Demographics, clinical data, and outcomes were compared using univariate analysis. The diagnostic yield of CT scan after shotgun wounds was calculated.

Of 3177 patients, 3126 (98%) were injured by GSWs and 51 (2%) by shotguns. Of the shotgun-injured patients, 5 (10%) had superficial wounds, 8 (16%) underwent emergency surgery, and 38 (74%) underwent CT scan [10 (26%) were then brought to OR and 28 (74%) were managed nonoperatively]. The sensitivity, specificity, PPV, and NPV of CT scan after shotgun wounds were 0.93, 0.96, 0.93, and 0.97. There was one false-negative CT scan, which missed a hollow viscus injury. There was one false-positive CT scan, which suggested a hollow viscus injury, although none was found on exploratory laparotomy. Patients injured by shotgun required fewer cavitary explorations (25% vs 59%, p = 0.006) but more soft tissue (21% vs 8%, p = 0.013) and extremity vascular surgeries (86% vs 9%, p < 0.001) than GSW-injured patients.

Shotgun injuries are far less frequent than GSWs but generally follow the same diagnostic and therapeutic considerations. Clinicians must be aware of the pitfalls of CT scanning after shotgun injuries, which can be falsely positive or falsely negative. A high index of suspicion for injury and a period of observation after negative CT scan may, therefore, be prudent.