Systematic surgical exploration or observation and selective exploration of suspected traumatic mesenteric and bowel injuries: A meta-analysis

Context: Mesenteric and bowel injuries (MBI) are rare and dangerous presentations of blunt abdominal trauma and often cause clinical uncertainty since their diagnosis is difficult and operative treatments are often delayed. No clear guidelines exist regarding this topic, and due to the rarity of the injury, few and highly low-quality data are available. This study aimed to compare early surgical exploration, delayed surgical exploration, and non-operative management in patients with proven and suspected blunt MBI.   Evidence Acquisition: Detailed research was performed on Medline, Embase, PubMed, Cochrane Central Register of Controlled Trials, and Cochrane Database of Systematic Reviews databases until 29th November 2019. The studies that were considered eligible to be included in this systematic review and consequent meta-analysis were those focusing on patients with proven MBI or computed tomography (CT) signs suspected for them and comparing early surgical exploration (EOR) with delayed one (DOR) or with selective surgical exploration (SOR) after clinical observation. The eligible studies were sub-grouped into those using a delay cut-off (to distinguish “early” and “deferred” surgical intervention) higher than 12 h and those using a cut-off lower than 12 h, as well as those focusing on patients with high-risk CT signs (pneumoperitoneum and active mesenteric bleeding) and those focusing on patients with low-risk ones.   Results: Finally, 16 studies fulfilled the inclusion criteria and were included in the meta-analysis with a total of 2,702 patients. All studies, although not randomized, were considered to be at the acceptable risk of bias in the important domains. It was found that in patients with proven MBI, in the subgroup of studies with a delay cut-off for surgical intervention lower than 12 h, the complication rate was significantly lower in EOR, compared to DOR (risk ratio [RR]=0.47, 95% CI=0.29-0.79, P=0.004). In patients with suspected MBI with low-risk CT signs, the complication rate was significantly lower in SOR, compared to EOR (RR=1.79, 95% CI=1.27-2.53, P=0.001). It was also revealed that in patients with high-risk CT signs, the complication rate and the length of stay (LOS) were significantly lower in EOR, compared to DOR (complication: RR=0.38, 95% CI=0.17-0.84, P=0.02; LOS: mean difference=-12.00, 95% CI=-21.44-2.56, P=0.01).   Conclusions: The present meta-analysis confirmed that in patients with proven blunt MBI a delay of surgical intervention higher than 12 h would lead to a higher complication rate and a longer LOS. Based on the results, in blunt trauma patients with pneumoperitoneum or active mesenteric bleeding at the admission CT scan, complications and LOS could be reduced by performing an early surgical exploration. On the other hand, in blunt trauma patients with low-risk CT signs of suspected MBI, a clinical observation with selective surgical exploration in case of clinical or radiological worsening could reduce the complication rate without increasing mortality and LOS.