Blunt abdominal trauma with transanal small bowel evisceration.

Small bowel evisceration through the anus can occur spontaneously or post traumatically. Traumatic transanal small bowel evisceration results from iatrogenic injuries, suction injuries, and blunt abdominal trauma (BAT). We report a 48-year-old female who presented with evisceration of small intestinal loops through the anus following BAT and discuss the etiologies and mechanisms of injury of this rare presentation.

INTRODUCTION

Most of the blunt abdominal injuries result from road traffic accidents, and majority of the patients have multisystem injuries. The incidence of major intestinal injuries among patients sustaining blunt abdominal trauma (BAT) ranges from 5-15% in various series. Transanal small bowel evisceration (TSBE) following BAT results from associated rectal or rectosigmoid perforation and requires special mention due to its extraordinary presentation. Early recognition of bowel injuries can be difficult and a high grade of suspicion is mandatory.

CASE REPORT

A 48-year-old female presented to the emergency department with complaints of severe abdominal pain and protrusion of bowel loops through the anus. She gave a history of assault with a direct kick over the lower abdomen 8 hours before presentation. On presentation, she was conscious with a pulse rate of 98/minute and blood pressure of 100/60 mmHg. The abdomen was tender with mild guarding. Loops of congested small intestine were seen protruding through the anus [Figure 1]. There were no other associated injuries or hematuria. The patient was resuscitated and transferred for urgent laparotomy. During laparotomy, a longitudinal rent was seen at the antimesenteric border of rectosigmoid region [Figure 2] with ileal loops entering the large bowel lumen. There was no hemoperitoneum or fecal contamination of peritoneal cavity. No other solid organ injury was detected. Small bowel loops were gently reduced in the abdominal cavity; warm moist packs applied and viability ascertained. Primary closure of sigmoid done in two layers and abdomen closed after thorough peritoneal lavage. The patient was under intensive care for 48 hours and discharged on the seventh postoperative day. The patient is healthy on two months follow-up.

Figure 1

Congested small bowel loops eviscerated transanally

Figure 2

Intraoperative image showing perforation of rectosigmoid region with clean peritoneal cavity

DISCUSSION

Rectosigmoid perforation with TSBE is rare and occurs spontaneously or post traumatically. The first case of small bowel evisceration through the anus was reported by Brodie in 1827.[1] Of the nearly 70 cases reported till date, majority occurred spontaneously in elderly patients. Spontaneous perforation of rectum is more commonly reported in elderly females and majority had associated rectal prolapse.[2] Straining with defecation, chronic constipation, enteroptosis and rectal ulcerations were the predisposing factors with spontaneous perforation. Traumatic rectosigmoid perforation has been reported from BAT, suction injuries, and iatrogenic injuries following reduction of rectal prolapse.[3-5]

Though intestine is the third most commonly injured organ in BAT, colonic injuries account for only 3-5% and occur less frequently than that of the small bowel.[6] The proposed mechanisms of intestinal injury in BAT include compression forces and deceleration forces. Compression forces result from direct blow or impingement between the vertebrae and anterior abdominal wall, which result in sudden increase in the intraluminal pressure of the intestine and rupture. Increased intraabdominal pressure can also increase the intraluminal pressure and pressures more than 150-260 mmHg can rupture the intestinal loops. Deceleration forces result in tangential tears at the relatively fixed points of the bowel such as the duodenum, right colon, and left colon.[67]

The type of injury varies from intramural hematoma to perforation and partially correlates with the mechanism of injury. Intramural hematomas affect duodenum more commonly than colon and are recently diagnosed more frequently with the introduction of computed tomography imaging. Serosal tears occur frequently in the transverse colon due to its vulnerable location in proximity to spine and impingement of the colon between the anterior abdominal wall and the lumbar spine. Acute perforations are more common in the sigmoid colon, probably due to the redundancy, which makes it susceptible to closed-loop formation. Proximal jejunum and distal ileum are more prone to perforation in the small intestine.[67]

Clinical features are vague at initial presentation and become obvious only at repeated abdominal examination in the observation room. Duodenal and jejunal hematomas present with obstructive features. Colonic hematomas present with rectal bleeding or shock due to retroperitoneal evacuation of the hematoma and colonic perforation presents with features of peritonitis. Fecal contamination of the peritoneal cavity in colonic perforation with TSBE will be minimal in most cases due to plugging of the rectal rent by the prolapsed small bowel loops.[4] This may result in minimal symptoms and a delayed presentation, as in our case where the patient seeked medical attention only after noticing bowel loops through the anus. Management consists of immediate exploratory laparotomy with careful reduction of small bowel loops in the abdominal cavity. Rectosigmoid tear is usually longitudinal at the antimesenteric border.[45] Gangrenous small bowel segments should be resected and defect in the rectosigmoid repaired primarily. Proximal diverting colostomy should be selectively performed on the basis of the degree of peritoneal contamination and severity of injury. Successful laparoscopic repair of rectosigmoid rupture with TSBE has also been reported.[8] We performed a primary repair as there was a longitudinal defect at the rectosigmoid with minimal peritoneal contamination.

CONCLUSION

An overlooked bowel injury following BAT results in increased morbidity and mortality because of the tremendous infectious potential. Early recognition and timely surgical intervention offers the best prognosis.