Synergistic Effect of Combined Hollow Viscus Injuries on Intra-Abdominal Abscess Formation

The strong association between penetrating colon injuries and intra-abdominal abscess (IAA) formation is well established and attributed to high colon bacterial counts. Since trauma patients are rarely fasting at injury, stomach and small bowel colony counts are also elevated. We hypothesized that there is a synergistic effect of increased IAA formation with concomitant stomach and/or colon injuries when compared to small bowel injuries alone. Consecutive patients at a level one trauma center with penetrating small bowel (SB), stomach (S), and/or colon (C) injuries from 1996 to 2012 were reviewed. Logistic regression determined associations with IAA, adjusting for age, gender, Injury Severity Score (ISS), admission Glasgow Coma Score, transfusions, and concurrent pancreas or liver injury. A total of 1518 patients (91% male, ISS = 15.9 ± 8.4) were identified: 496 (33%) SB, 231 (15%) S, 288 (19%) C, 40 (3%) S + SB, 69 (5%) S + C, 338 (22%) C + SB, and 56 (4%) S + C + SB. 148 (10%) patients developed IAA: 4 per cent SB, 9 per cent S, 10 per cent C, 5 per cent S + SB, 22 per cent S + C, 13 per cent C + SB, and 25 per cent S + C + SB. Multiple logistic regression demonstrated that ISS, 24 hour blood transfusions, and concomitant pancreatic or liver injuries were associated with IAA. Compared with reference SB, S or S + SB injuries were no more likely to develop IAA. However, S + C, SB + C, and S + C + SB injuries were significantly more likely to have IAA. In conclusion, combined stomach + colon, small bowel + colon, and stomach, colon, + small bowel injuries have a synergistic effect leading to increased IAA formation after penetrating injuries. Heightened clinical suspicion for IAA formation is necessary in these combined hollow viscus injury patients.