Discussion
Colon injuries generally occur after penetrating abdominal trauma, whereas they are rarely encountered after blunt abdominal trauma. In a retrospective study, the incidence of colon injuries due to blunt abdominal trauma has been reported to be 1.1% [
1]. Motor vehicle accidents are the most common reason of colon injuries due to blunt abdominal trauma [
2]. Other common causes include impacts to the abdomen (a direct blow, occupational accidents) and falls [
3]. The retrospective study conducted by Carrillo
et al. on 27 patients showed that 20 patients (74%) presented due to intra-vehicular accident, five patients (18.5%) presented due to extra-vehicular accident, one patient (3.7%) presented due to assault, and one patient (3.7%) presented due to boating accident [
4]. In a retrospective study conducted by Zheng
et al. on 82 patients, 57 patients (69.5%) presented due to an out-of-vehicle traffic accident, 18 patients (21.9%) presented due to an occupational accident, six patients (7.3%) presented due to an assault, and one patient (1.2%) presented due to an explosion [
5]. The retrospective study conducted by Öztürk
et al. on 64 patients revealed that 32 patients (50%) presented due to motor vehicle accident, 13 patients (20.3%) presented due to fall from height, 12 patients (18.7%) presented due to car crashing, and seven patients (10.9%) presented due to assault [
6]. Barden
et al. reported bull butting in one patient [
7], whereas Ceci
et al. reported intra-vehicular accident in one patient [
8]. In the present case our patient had injured her abdominal region in the bathroom due to a fall.
Several mechanisms have been described for colon injuries occurring after blunt abdominal trauma. Crushing of the colonic segment between two objects (between the seat belt and vertebra or pelvis posteriorly) is the most widely accepted mechanism [
9]. This results in local lacerations of the bowel wall, mural and mesenteric hematomas, transection of the bowel, localized devascularization and full-thickness contusions. Devitalization of the areas of contusion may subsequently result in late perforation. Rapid deceleration is the second mechanism. This creates shearing forces between the natural fixed points, which are the Treitz ligament, both ends of the sigmoid colon, and ileocecal junction, and the mobile portions of the colon. The third mechanism is a burst injury, which occurs by the closure of the colonic segments during trauma. The bowel ruptures or bursts when the intra-luminal pressure exceeds the tensile strength of the bowel wall [
9]. The transverse colon is the most vulnerable colonic segment to blunt trauma due to its unprotected location [
2]. The sigmoid colon is relatively less vulnerable and is generally exposed to closed-loop perforations [
2]. Carrillo
et al. reported sigmoid colon injury in 12 patients (44.4%), right colon and caecum injury in eight patients (29.6%), transverse colon injury in five patients (18.5%), and rectum injury in two patients (7.4%) [
4]. In the study conducted by Zheng
et al., transverse colon injury was seen in 32 patients (39%), right colon injury was seen in 21 patients (25.6%), descending colon injury was seen in 16 patients (19.5%), sigmoid colon injury was seen in 13 patients (15.8%), and rectum injury was seen in five patients (6%) [
5]. A total of 30 patients (46.8%) had left colon injury, 17 patients (26.6%) had right colon injury, and 17 patients (26.6%) had transverse colon injury in the study conducted by Öztürk
et al.[
6]. In their studies, Barden
et al. reported transverse colon injury [
7] and Ceci
et al. reported sigmoid colon injury [
8]. In the present case our patient had a sigmoid colon injury.
Isolated colon injury following blunt abdominal trauma is a rarely encountered condition. Colon injury is usually accompanied by other intra-abdominal organ injuries, with the small intestine, spleen, liver and pancreas being the leading areas. Isolated colon injury was detected in two patients, whereas colon injury was accompanied by liver injury in 16, spleen injury in 13, and small intestine injury in 12 patients, in the study conducted by Carrillo
et al.[
4]. Zheng
et al. detected isolated colon injury in 20 patients and reported that accompanying injuries were in turn localized to the small intestine, spleen, liver, and kidney [
5]. Isolated colon injury was detected in seven patients in the study conducted by Öztürk
et al., in which colon injuries were most commonly accompanied by small intestine, spleen, liver, and pancreas injuries [
6]. Barden
et al. detected transverse colon injury [
7], whereas Ceci
et al. detected sigmoid colon injury [
8]. We found no accompanying further intra-abdominal organ injury in our patient’s case.
In a patient thought to have a colon injury caused by blunt abdominal trauma, the time between emergency department admission and surgery is of particular importance. A shorter duration minimizes the morbidity and mortality that would be encountered in the post-operative period. The rate of complications associated with colon injury is significantly higher if the duration is longer than 24 h after the injury [
10].
At present, there is no single method to accurately diagnose colon injuries caused by blunt abdominal trauma. There are some studies suggesting the efficacy of repetitive physical examination and observation in diagnosing colon injury caused by blunt abdominal trauma in the first six hours, during which the signs of peritoneal irritation appear [
11]. Tenderness, guarding, distension and abdominal wall contusion are valuable findings on physical examination. However, the absence of these findings does not rule out intra-abdominal pathology. The presence of leukocytosis becomes significant when interpreted together with the findings from physical examinations and the results of other diagnostic methods [
12]. Plain radiographs are not reliable in detecting the presence of a significant injury; the results appear normal in most cases [
13]. Ultrasonography has been widely used to evaluate blunt abdominal trauma [
14]. Ultrasonographic findings of free fluid in the abdomen, particularly between the intestinal loops without the presence of solid organ injury, may indicate a bowel injury. Computed tomography is the most appropriate diagnostic tool to document abdominal injury; however, its diagnostic value for patients with colon injury remains controversial. On computed tomography, presence of free air in the abdomen and extravasation of the contrast agent are significant findings [
15].
Treatment options include primary closure (colorrhaphy), resection with anastomosis, and colostomy. Primary closure (colorrhaphy) is performed for injuries involving less than 50% of the colonic wall, whereas resection with anastomosis is performed when the tissue loss is more than 50% or when there is extensive mesenteric injury impairing the blood supply [
16]. Colostomy should be performed when there are more than two abdominal organ injuries, when the amount of intra-abdominal bleeding is above 1000mL, when there is gross fecal contamination within the abdomen, and when the time between the injury and treatment exceeds eight hours [
17‐
20]. Carrillo
et al. performed resection plus ostomy in 12 patients (44.4%), resection plus anastomosis in 11 patients (40.7%), and primary repair in four patients (14.8%) [
4]. Zheng
et al. performed primary repair in 67 patients (81.7%), and ostomy in 15 patients (18.2%) [
5]. Öztürk
et al. performed primary repair in 40 patients (62.5), resection plus anastomosis in 13 patients (20.3%), and ostomy in 11 patients (17.1%) [
6]. Primary repair was performed in the study conducted by Barden
et al.[
7], whereas resection plus anastomosis were performed in the study conducted by Ceci
et al.[
8]. In the present study, we performed a sigmoid loop colostomy in our patient. Primary closure and resection with anastomosis have been the choice of treatment within the last two decades as they are associated with reduced morbidity, mortality and cost.
Morbidity and mortality rates following blunt abdominal traumas are increased in colon injuries depending on the difficulties in diagnosis and treatment. Morbidity was observed in 12 (44.4%) and mortality was observed in 10 (37%) patients in the study conducted by Carrillo
et al.[
4]. Zheng
et al. reported morbidity in 17 (20.7%) and mortality in five (6.1%) patients [
5]. Again, Öztürk
et al. reported morbidity in 17 (26.5%) patients, whereas mortality was observed in seven (10.9%) patients [
6]. The most common post-operative complications were wound site infection, intra-abdominal abscess, intra-abdominal sepsis, and post-operative bleeding. No morbidity or mortality was observed after the surgery in our patient’s case.
Competing interests
The authors declare that they have no competing interests.
Authors’ contributions
GE, MC and FE operated on our patient. GE, MS and TT analyzed and interpreted the data from our patient regarding the blunt abdominal trauma and colonic injury. GE was a major contributor in writing the manuscript. All authors read and approved the final manuscript.