The evolution of the diagnostic work-up for stab wounds to the back and flank

Stab wounds to the back and flank infrequently cause injuries requiring operative treatment. Triple-contrast CT scan (3CT) has essentially replaced diagnostic peritoneal lavage (DPL) as the primary means of identifying patients who require operative intervention. This study aims to review the evolution of the diagnostic work-up for stab wounds to the back and flank.

We performed a retrospective review of haemodynamically stable patients with stab wound to the back or flank treated at a single Level 1 trauma centre over a 10-year period. Diagnostic accuracy of DPL and 3CT screening tests were evaluated against the patient's subsequent clinical course. The elapsed time between emergency department (ED) presentation and test results was recorded and compared.

A total of 177 patients were identified. 76 patients had stab wounds isolated to the back, 90 had stab wounds isolated to the flank and 11 had wounds in both locations. CT ultimately became the predominant initial diagnostic test during the study period. Although less frequently used over time, DPL retained good sensitivity and specificity for injuries requiring operative intervention (92% and 83%, respectively). 3CT identified all injuries requiring laparotomy (100% sensitivity) and had a specificity of 96%. 3CT was a more time-consuming process, with results available at a median of 3:31h after arrival to the ED, as compared to 1:03h for DPL (p<0.01).

3CT diagnosed all injuries requiring operative intervention, and its use was associated with a lower rate of non-therapeutic laparotomies. However, average time to diagnosis by 3CT was prolonged compared to DPL. Although 3CT has become the predominant diagnostic test when evaluating patients with stab wounds to the back and flank at our institution, efforts to further expedite the diagnostic work-up are necessary.