Traumatic transection of small bowel

A 59-year-old female patient was admitted following a single-car road traffic accident. She was found to have a fluctuating GCS (Glasgow Coma Scale), a large scalp laceration and was intubated and ventilated at the scene of the accident. On examination the patient was tender in the abdomen and pelvis. There was a clinical question of post-traumatic haemorrhage, fracture or visceral injury, with particular concern for neurological and abdominal organ insult.

Non contrast CT Head. CT Dual bolus Neck/Chest/Abdomen/Pelvis was performed as part of a trauma CT protocol with an additional delayed phase acquisition. There was complete transection of the mid jejunum with surrounding free fluid and blood. The transected ends were seen folding back over the adjacent segments of small bowel.  The small bowel segments immediately adjacent to the defect demonstrated significant oedema and hyperenhancement. There was no pneumoperitoneum. Free fluid was present in the pelvis, paracolic gutters and adjacent to the liver capsule. In addition to the intense small bowel enhancement, there were further features of hypoperfusion complex, including adrenal and pancreatic hyperenhancement. The delayed phase acquisition showed no evidence of a bladder leak. 

Background: One in twenty patients with blunt abdominal trauma experience bowel injury [1]. Following the spleen and liver, the small bowel is the most frequently injured abdominal organ [2]. Three types of injury, each with their own mechanism is seen in traumatic bowel injury. Crush injuries from direct force between an object (such as a steering wheel/seatbelt) and the spine. Shearing injuries from rapid deceleration, usually at the ileocecal junction, sigmoid colon and ligament of Treitz are considered natural fixation points. Burst injuries from sudden increase in intraluminal pressure. Seatbelts are thought to result in burst injuries by creating a closed-loop following a sudden increase in pressure [3].

Clinical perspective: Patients may present with peritoneal irritation following blunt trauma however this finding is non-specific and may not be present at initial presentation. Such patients often have concomitant head injuries further complicating accurate clinical assessment, with negative laparotomy results as high as 40% following clinical assessment alone [1].

Imaging perspective: Significant injuries involve either all layers of the bowel wall or all layers excluding the mucosa. Bowel wall discontinuity is only seen in 7% of patients with traumatic bowel injury and while highly specific, extraluminal air is only seen in 20% of such injuries and is therefore low in sensitivity. 55% of patients demonstrate bowel wall thickening, which when diffuse is thought to be secondary to shock bowel (hypoperfusion) or systemic volume overload [4]. Likewise hyperenhancement may be seen due to increased vascular permeability which accompanies hypoperfusion [5].

Outcome: The patient was taken to theatre and found to have complete transection of the jejunum about 20 cm distal to the DJ (duodenojejunal) junction. There was mesenteric injury around the transected ends with a mesenteric window about 10 cm from the distal transected end, as well as compromised bowel perfusion along the same length. Both ends of the transected jejunum were stapled and a 10 cm segment of the distal end was excised. Anastomosis was not performed at the initial operation due to the patient’s shocked state. Two days later a jejunal side-to-side anastomosis was performed.