| disease | Colon Injury |
| alias | Injury of Colon |
Colon injury (Injury of Colon) is a relatively common hollow organ injury caused by blunt abdominal trauma and penetrating trauma, and can also result from iatrogenic injuries such as barium enema or colonoscopy resection of intestinal tumors leading to colon perforation. Due to the high bacterial content in the colon, peritonitis is severe, and systemic toxic symptoms are pronounced, often posing a life-threatening risk. A portion of the colon is located outside the peritoneum, and when injured, peritonitis may not be obvious, making diagnosis difficult. Abdominal injuries often involve multiple organs and segments of the intestine, with obvious peritonitis, which can easily mask colon injuries, leading to misdiagnosis or delayed diagnosis. This should be noted.
bubble_chart Etiology
Colon injury can be categorized into three main causes:
1. Penetrating injury
This is the most common type, occurring frequently both in peacetime and wartime. Examples include stab wounds from knives, scissors, or sharp objects, as well as abdominal open injuries caused by explosions or gunshot wounds, which can lead to varying degrees of colon injury.
2. Blunt injury
Abdominal closed injuries resulting from traffic accidents, earthquakes, or building collapses can exert direct force on the spine, potentially causing transverse colon rupture. Other mechanisms include rupture due to the thin colon wall, high tension, or compression of the intestinal tract. Additionally, injuries affecting the blood vessels of the mesentery may lead to colon necrosis.
3. Iatrogenic injury
During procedures such as sigmoidoscopy or fiber colonoscopy, improper operation may result in colon perforation or rupture. Similarly, electrocautery of polyps can cause perforation. Barium enema or double-contrast barium and air pressure imaging for intussusception reduction may also lead to colon rupture or perforation. Surgical injuries to the intestinal wall or mesentery can similarly cause colon injury.
Colon injuries account for 10–20% of abdominal injuries in peacetime, with even higher rates during wartime. Postoperative complications from colon injuries are frequent, and the mortality rate is correspondingly high.bubble_chart Pathological Changes
In cases of colon injury, there may be rupture of the seromuscular layer, rupture of the serosa and muscular layers, or complete rupture of the intestinal wall, even leading to transection; colon wall contusion can present as subserosal hematoma or intramural hematoma; if the mesentery is injured, there may be arterial or venous rupture, or vascular thrombosis leading to delayed intestinal necrosis.
When the colon wall is completely ruptured or necrotic perforation occurs, colonic contents (feces) spill into the abdominal cavity, causing diffuse peritonitis. If adhesions form, localized peritonitis may develop. Occasionally, small perforations may heal due to blockage by fecal debris. Colonic contents are neutral and cause less irritation to the peritoneum, so early-stage peritonitis may be subtle and easily misdiagnosed. In the late stage [third stage], local contamination becomes severe (feces contain the highest bacterial load), compounded by the "closed" nature of the colon due to the ileocecal valve and anal sphincter at both ends, which increases intraluminal pressure. This leads to massive spillage of intestinal contents, resulting in severe abdominal infection and systemic toxic symptoms, which can even be fatal. The colon wall is thin and has poor blood circulation, so healing after suturing a colon rupture is also poor, making intestinal fistula a common complication of this condition.
bubble_chart Clinical Manifestations
The most prominent sign is tenderness, rebound tenderness, and muscle rigidity throughout the abdomen, most pronounced at the affected site. The severity of peritoneal irritation signs may vary depending on the size of the colonic rupture or the amount of spillage during transection, the type of bacteria, and the time of medical consultation. Shifting dullness may be positive, and borborygmus sounds may disappear.
bubble_chart Auxiliary Examination
1. X-ray examination
Plain abdominal radiography or fluoroscopy may reveal free gas under the diaphragm or gas accumulation behind the peritoneal membrane, along with generalized intestinal distension or air-fluid levels, to determine the presence of hollow organ injury. The location can help identify potential colon rupture injuries. Plain abdominal films can also detect fractures and metallic foreign bodies, among other findings.
2. Diagnostic peritoneal aspiration (commonly referred to as abdominal paracentesis)
The nature of the aspirated fluid can aid in diagnosis: fecal-like material suggests intestinal injury, while non-coagulating blood may indicate solid organ injury. Diagnostic peritoneal lavage: A trocar is used for abdominal puncture, the stylet is removed, and a catheter is inserted to aspirate fluid for analysis. If no fluid is obtained, lactated Ringer's solution or isotonic saline (10–20 ml/kg) is instilled into the peritoneal cavity. The lavage fluid is then recovered and evaluated. The following findings are considered positive: ① visible blood, bile, gastrointestinal contents, or urine in the lavage fluid; ② microscopic red blood cell count exceeding 0.12×1012
The false-positive rate for diagnostic peritoneal aspiration or lavage is approximately 2–3%, often due to: ① pelvic or spinal fractures, where sharp bone fragments puncture the peritoneal membrane, allowing blood to enter the peritoneal cavity; ② large retroperitoneal hematomas in the lower abdomen, leading to accidental puncture into the hematoma and aspiration of non-coagulating bloody fluid. Relative contraindications include: ① Grade III abdominal distension or ileus; ② a history of extensive intestinal adhesions or multiple abdominal surgeries; ③ patients in the middle or late stages of pregnancy (third trimester).
3. Laparoscopy
In recent years, fiber-optic laparoscopy has become increasingly widespread, significantly improving the early diagnostic accuracy of abdominal injuries.
4. CT and B-mode ultrasonography
These imaging modalities have a high diagnostic yield for solid organ injuries and can provide supplementary information for hollow organ injuries. They are particularly accurate in diagnosing complications such as intraperitoneal fluid accumulation and abscesses.
Based on the presence of abdominal pain, nausea, vomiting, and signs of peritonitis after abdominal trauma, along with radiographic evidence of pneumoperitoneum and diagnostic aspiration of fecal-like fluid, a colon injury can be confirmed.
bubble_chart Treatment Measures
After diagnosing a colon injury, surgery is the fundamental principle of treatment. However, the surgical method should be determined based on the local injury conditions. Since the surgery is performed on the colon, which has poor blood circulation and abundant bacterial growth, and due to the high intraluminal pressure of the colon, repair or anastomosis is highly prone to complications such as colon fistula or residual intra-abdominal infections. Therefore, surgical skills should be enhanced, and large doses of antibiotics should be administered. The specific management methods are as follows:
1. Management of colon wall contusion
When a patient undergoes exploratory laparotomy due to abdominal injury and localized seromuscular layer injury of the colon is found, transverse suturing and repair can be performed. For intestinal wall hematomas or mesenteric hematomas, the hematoma can be incised and evacuated, followed by hemostasis. If there is no impairment of intestinal wall blood supply, repair can then be performed. For extensive seromuscular layer injuries involving a segment of the intestinal wall or multiple adjacent segments, or mesenteric hematomas or vascular injuries that compromise the blood supply of the corresponding intestinal segment, resection and anastomosis of the affected segment should be performed. If the patient is critically ill or the local contamination is severe, proximal colostomy with distal closure or double-barrel colostomy can be performed.
2. Colon rupture and transection injury
1. Primary (first-stage) suture repair For cases with mild contamination or even severe contamination but thorough irrigation within 12 hours of colon rupture, along with potent antibiotics and continuously improving surgical techniques, we advocate performing primary (first-stage) suture repair or intestinal resection and anastomosis whenever possible. During the surgery, the abdominal cavity should be thoroughly irrigated with saline, and necessary abdominal drainage should be performed.
2. Ileostomy or colostomy with delayed closure For patients with multiple organ injuries, unstable recovery from shock, poor general condition, or severe local contamination exceeding 12 hours, double-barrel colostomy can be performed. Alternatively, local intestinal repair or resection and anastomosis can be done, with proximal colostomy and distal closure, followed by delayed closure of the stoma after 3 months.
The prognosis depends on the location, severity, extent of the colon injury, and the degree of abdominal contamination, and is closely related to the timeliness of rescue and the appropriateness of treatment. Initial-stage [first-stage] repair or anastomosis often leads to complications such as intestinal fistula and residual intra-abdominal infections.
Determine whether the injury is to a hollow organ or a solid organ based on the presence of pneumoperitoneum and signs of bleeding after abdominal trauma in the patient. Then, identify whether the injury involves the intestine based on the nature of the peritoneal fluid. Of course, ileum injury can sometimes be difficult to distinguish from colon injury, requiring exploratory laparotomy to resolve the issue. During exploration, attention should be paid to injuries in the extraperitoneal portion of the colon to prevent fistula formation.
