Outcomes of selective nonoperative management of civilian abdominal gunshot wounds: a systematic review and meta-analysis

Background: Although mandatory laparotomy has been standard of care for patients with abdominal gunshot wounds (GSWs) for decades, this approach is associated with non-therapeutic operations, morbidity, and long hospital stays. This systematic review and meta-analysis sought to summarize outcomes of selective nonoperative management (SNOM) of civilian abdominal GSWs. Methods: We searched electronic databases (March 1966-April 1, 2017) and reference lists of articles included in the systematic review for studies reporting outcomes of SNOM of civilian abdominal GSWs. We meta-analyzed the associated risks of SNOM-related failure (defined as laparotomy during hospital admission), mortality, and morbidity across included studies using DerSimonian and Laird random-effects models. Between-study heterogeneity was assessed by calculating I-2 statistics and conducting tests of homogeneity. Results: Of 7155 citations identified, we included 41 studies [n=22,847 patients with abdominal GSWs, of whom 6777 (29.7%) underwent SNOM]. The pooled risk of failure of SNOM in hemodynamically stable patients without a reduced level of consciousness or signs of peritonitis was 7.0% [95% confidence interval (CI)=3.9-10.1%; I-2=92.6%, homogeneity p<0.001] while the pooled mortality associated with use of SNOM in this patient population was 0.4% (95% CI=0.2-0.6%; I-2=0%, homogeneity p>0.99). In patients who failed SNOM, the pooled estimate of the risk of therapeutic laparotomy was 68.0% (95% CI=58.3-77.7%; I-2=91.5%; homogeneity p<0.001). Risks of failure of SNOM were lowest in studies that evaluated patients with right thoracoabdomen (3.4%; 95% CI=0-7.0%; I-2=0%; homogeneity p=0.45), flank (7.0%; 95% CI=3.9-10.1%), and back (3.1%; 95% CI=0-6.5%) GSWs and highest in those that evaluated patients with anterior abdomen (13.2%; 95% CI=6.3-20.1%) GSWs. In patients who underwent mandatory abdominopelvic computed tomography (CT), the pooled risk of failure was 4.1% versus 8.3% in those who underwent selective CT (p=0.08). The overall sample-size-weighted mean hospital length of stay among patients who underwent SNOM was 6 days versus 10 days if they failed SNOM or developed an in-hospital complication. Conclusions: SNOM of abdominal GSWs is safe when conducted in hemodynamically stable patients without a reduced level of consciousness or signs of peritonitis. Failure of SNOM may be lower in patients with GSWs to the back, flank, or right thoracoabdomen and be decreased by mandatory use of abdominopelvic CT scans.