Emergent Care of the Victim of Colorectal Trauma

Imaging

While nonspecific, plain radiographs may reveal pneumoperitoneum, pelvic fractures, foreign bodies, or wound trajectories that may prompt additional studies or operation. Peritoneal fluid found by Focused Assessment with Sonography for Trauma (FAST) in an injured, unstable patient also may trigger immediate operation. Diagnostic peritoneal lavage has largely been supplanted by sonography and computed tomography (CT), but remains useful in patients with a suspicion of abdominal pathology who are too unstable for CT and who cannot be conclusively imaged sonographically, or to analyze suspicious abdominal fluid on CT in the face of equivocal findings.

Multidetector CT is the predominant, if not indispensable, device for the evaluation of abdominal injuries in stable or stabilizing patients, without indication for immediate operative intervention. Radiographic identification of isolated injury to the large intestine is difficult because of nonspecific and often subtle findings. Frequently, it is not direct radiographic findings of bowel perforation (e.g., pneumoperitoneum, extravasation of enteric contrast, intramural gas, or colon wall defects), but the presence of indirect findings (e.g., bowel wall thickening or enhancement, stranding of adjacent mesentery or mesocolon, or free intraperitoneal fluid) that prompts operation. Active extravasation in the mesentery generally signals a need for operation, and may also be associated with direct injury to the colon or ischemia. Peritoneal free fluid may be from normal female physiology, preexisting ascites, transudate secondary to resuscitation, or blood from solid visceral or mesenteric injury, as well as from enteric spillage. The lack of free peritoneal fluid, however, has a high negative predictive value for bowel injury. Although not uniformly present in hollow viscus rupture, pneumoperitoneum has 95% specificity, despite 25% sensitivity. Retroperitoneal air may be present as a result of perforation from the extraperitoneal colon or duodenum and may track down from or up into the chest. As determining wound trajectory and depth on physical exam is difficult, one should consider CT, which can identify significant intraabdominal injuries with sensitivity and specificity greater than 90%, and may identify patients suitable for observation or selective nonoperative management, and decrease nontherapeutic laparotomies. Triple-contrast imaging has been advocated to better visualize the colon, given its false-negative rate for GI injury of 1.8% and false-positive rate of 7%. Rectal-contrast-enhanced CT can be quite useful, but the absence of extravasation does not exclude injury, and the enema apparatus may interfere with subtleties in the distal rectum.

Damage Control Laparotomy (DCL)

The patient with a colon injury may arrive hemodynamically unstable and with physiologic stores that are taxed or nonexistent. Recognition of the need to break the “trauma triad of death”—the downward spiral of coagulopathy, hypothermia, and acidosis contributing to deteriorating physiology —changed the conventional operative approach of attempting definitive repair in favor of abbreviated laparotomy. Christened damage control by Rotondo et al., it references the naval term for keeping a damaged ship afloat and functional in hostile waters by any means necessary to allow survival and definitive repair under later, more favorable conditions. This paradigm shift to prioritize physiology over anatomy is the standard of care for trauma and myriad emergency surgical situations. The willingness to perform staged anastomosis and repair following stabilization has changed outcomes but also presents challenges that were unusual in the pre-DCL era.

The goals of DCL are to rapidly control bleeding and then limit contamination in severely injured patients. This necessitates expeditious entry into the abdomen with wide exposure. Hemorrhage is quickly cleared and controlled to allow brisk intraperitoneal exploration. Obvious vascular injuries that cannot be ligated or swiftly repaired may be temporarily shunted. Once bleeding is controlled and while intravascular volume is being restored, attention is turned to contamination. Coloenteric spillage should be attended to rapidly with initial clamping, temporary suture, ligation with umbilical tapes, or stapling devices. Depending on the physiologic status of the patient, definitive suture control or resection is undertaken as deemed prudent. In the unstable patient, there should be no attempt at definitive anastomosis. Instead, with the colon in discontinuity and after removing as much contamination as possible, a temporary abdominal closure is accomplished with attention to protection of the underlying bowel and resuscitation is continued in the ICU with the abdomen open. The return for definitive operation generally occurs between 24 and 48 hours and hopefully finds the patient in a clinical and metabolic state permitting reconstruction. Restoring enteric continuity with delayed anastomosis, diversion, or additional resection can then be performed in less-hurried circumstances. In the event that physiology still precludes complete resolution, the abdominal closure is again temporized with the same plan: return once stable.

Given the complexity of decision making in these patients, transfer to a higher level of care after initial lifesaving DCL should be considered.