Overview
Definition:
Colon injury refers to damage to the large intestine, which can occur due to blunt or penetrating trauma, iatrogenic causes (e.g., during surgery), or non-traumatic conditions like diverticulitis or malignancy leading to perforation
Management strategies hinge on the extent of injury, contamination level, patient's hemodynamic status, and the surgeon's judgment, primarily involving either primary repair of the colon or diversion of fecal flow.
Epidemiology:
The incidence of colon injury varies with trauma mechanisms
Penetrating injuries (gunshot and stab wounds) account for a significant proportion
Iatrogenic injuries occur in approximately 0.01-3% of all intra-abdominal surgeries
The colon is involved in roughly 10-20% of all penetrating abdominal injuries
Delayed diagnosis and inadequate management lead to high morbidity and mortality.
Clinical Significance:
Colon injuries are associated with a high risk of anastomotic leak, intra-abdominal sepsis, peritonitis, and multi-organ dysfunction
Prompt and appropriate surgical management is critical to reduce these risks, minimize patient morbidity, and improve outcomes
Understanding the nuances between primary repair and diversion is paramount for surgical trainees preparing for DNB and NEET SS examinations.
Clinical Presentation
Symptoms:
Abdominal pain, often severe and diffuse
Nausea and vomiting
Fever
Signs of hypovolemic shock: tachycardia, hypotension, pallor
Distended abdomen
Absence or decreased bowel sounds
Hematochezia or melena (less common with pure colon injury unless proximal involvement or significant bleeding).
Signs:
Tenderness to palpation, guarding, and rebound tenderness
Signs of peritonitis
Absent bowel sounds
Hemodynamic instability
Palpable abdominal distension
Rectal examination may reveal blood or gross contamination.
Diagnostic Criteria:
Diagnosis is primarily clinical, supported by imaging and operative findings
Established criteria for management decisions are based on injury severity scores (e.g., Abbreviated Injury Scale - AIS), extent of contamination (grade I-IV), presence of hemodynamic instability, and the patient's comorbidities
The American Association for the Surgery of Trauma (AAST) organ injury scale for the colon is widely used for grading severity.
Diagnostic Approach
History Taking:
Detailed mechanism of injury (penetrating vs
blunt, weapon type, number of wounds)
Time elapsed since injury
Pre-hospital management and fluid resuscitation
Previous abdominal surgeries
Comorbidities (e.g., diabetes, immunosuppression, inflammatory bowel disease) that may affect healing
Medications (e.g., steroids, anticoagulants).
Physical Examination:
Thorough abdominal examination assessing for tenderness, guarding, rebound, and rigidity
Assess for signs of peritonitis
Vital signs are crucial to gauge hemodynamic stability
Assess for other associated injuries, particularly in polytrauma patients.
Investigations:
Laboratory tests: Complete blood count (CBC) for anemia and leukocytosis
Serum electrolytes, BUN, creatinine for renal function
Liver function tests (LFTs)
Coagulation profile (PT/INR, aPTT)
Arterial blood gas (ABG) for acid-base status and oxygenation
Imaging: Focused Assessment with Sonography for Trauma (FAST) scan for free fluid
CT abdomen and pelvis with intravenous and oral contrast is the gold standard for identifying bowel injury, extravasation of contrast, and free air/fluid
Plain radiographs can show free air but are less sensitive.
Differential Diagnosis:
Other intra-abdominal injuries (liver, spleen, solid organ injuries)
Mesenteric vascular injury
Intra-abdominal hemorrhage from other sources
Non-traumatic causes of acute abdomen (e.g., perforated ulcer, appendicitis, diverticulitis, bowel obstruction).
Management
Initial Management:
Immediate resuscitation is paramount
Secure airway, breathing, and circulation (ABC)
Establish intravenous access and administer crystalloids and blood products as needed to achieve hemodynamic stability
Broad-spectrum intravenous antibiotics covering aerobic and anaerobic gut flora (e.g., cefoxitin or piperacillin-tazobactam)
Nasogastric tube decompression
Foley catheter insertion.
Surgical Management:
Decision between primary repair and diversion is complex and depends on multiple factors: \n1
Injury Severity (AAST Grade): Grade I-II injuries are generally amenable to primary repair
Grade III-IV injuries may require more aggressive management
Grade V injuries often necessitate diversion.\n2
Contamination Level: Minimal contamination (Grade I) may allow primary repair
Gross contamination (Grade IV) strongly favors diversion.\n3
Hemodynamic Stability: Unstable patients with extensive injuries often benefit from initial damage control surgery, which may include resection and ostomy creation, with planned re-exploration.\n4
Location of Injury: Injuries in the splenic flexure or sigmoid colon can be challenging for primary repair due to poor vascularity and higher tension
\n5
Patient Factors: Immunocompromised status, severe comorbidities, and malnutrition increase the risk of anastomotic leak, favoring diversion.\n\n**Primary Repair Options:** \n* **Simple Suture Repair:** For small, clean-edged lacerations in well-vascularized segments
\n* **Resection and Primary Anastomosis:** For larger injuries or segmental damage, with tension-free anastomosis
Consider with or without proximal diverting loop ileostomy or colostomy, especially if any doubt exists about leak
\n\n**Diversion Options:** \n* **Proximal Ostomy (Colostomy or Ileostomy):** The most common form of diversion
A colostomy (e.g., end colostomy) diverts fecal stream away from the injured segment
An ileostomy is typically used for more proximal colonic injuries or if distal contamination is extensive
\n* **Hartmann's Procedure:** Resection of the injured segment with end colostomy and stapled rectal stump
The rectal stump can be reconnected at a later stage (reversal of Hartmann's)
This is a robust option for severely contaminated or complex injuries where immediate anastomosis is deemed too risky.\n\n**Damage Control Surgery (DCS):** In hemodynamically unstable patients with massive contamination, DCS involves abbreviated surgery to control hemorrhage and contamination, followed by temporary abdominal closure and planned re-exploration to complete the repair or create diversion.
Supportive Care:
Aggressive fluid resuscitation and blood transfusion
Mechanical ventilation if indicated
Monitoring of urine output, central venous pressure, and arterial blood pressure
Nutritional support: Early enteral feeding is preferred once bowel function returns and contamination is controlled
Pain management
Strict fluid and electrolyte balance
Wound care and monitoring for infection.
Complications
Early Complications:
Anastomotic leak (most feared, 5-20% risk, significantly higher with poor technique or comorbidities)
Intra-abdominal abscess
Sepsis and septic shock
Wound infection
Retained bowel segment injury
Hemorrhage
Ileus.
Late Complications:
Adhesions and bowel obstruction
Incisional hernia
Stoma-related complications (e.g., retraction, stenosis, prolapse, skin irritation)
Stricture at the anastomosis site
Recurrence of hernia or incisional complications
Psychological impact of stoma.
Prevention Strategies:
Meticulous surgical technique
Adequate bowel preparation and prophylactic antibiotics
Careful selection of patients for primary repair versus diversion
Use of appropriate stapling devices for tension-free anastomosis
Judicious use of diverting ostomies for high-risk anastomoses
Early re-exploration for suspected leaks
Adequate drainage of the peritoneal cavity
Strict wound care and infection control.
Prognosis
Factors Affecting Prognosis:
Severity of colon injury (AAST grade)
Degree of contamination
Hemodynamic stability at presentation
Presence of associated injuries
Patient's comorbidities
Timeliness and appropriateness of surgical intervention
Development of complications such as anastomotic leak or sepsis.
Outcomes:
With prompt and appropriate management, outcomes can be good
Mortality rates for colon injuries range from <5% for minor injuries to >30% for severe, contaminated injuries with shock
Morbidity remains significant, primarily due to anastomotic leaks and sepsis.
Follow Up:
Close postoperative monitoring for signs of leak or sepsis
If primary anastomosis is performed, follow-up imaging (e.g., contrast enema) may be considered to assess for leaks, though clinical assessment is usually sufficient
Patients with diverting ostomies require stoma care education and planning for eventual stoma reversal
Long-term follow-up may be needed for incisional hernias or adhesions.
Key Points
Exam Focus:
DNB/NEET SS candidates must understand the factors guiding the decision between primary repair and diversion
Key factors include injury severity (AAST grade), contamination, hemodynamic status, and patient comorbidities
Know the indications for Hartmann's procedure and damage control surgery
Understand the risks and management of anastomotic leaks.
Clinical Pearls:
In cases of doubt about anastomotic integrity or in the presence of significant contamination and hemodynamic instability, a diverting ostomy (loop ileostomy or colostomy) or a Hartmann's procedure is safer than a risky primary anastomosis
Resuscitation is always the priority in trauma
When in doubt about contamination, err on the side of caution and opt for diversion.
Common Mistakes:
Performing primary anastomosis in a grossly contaminated field or in an unstable patient
Inadequate antibiotic coverage
Failure to recognize or manage anastomotic leaks promptly
Overly aggressive repair in the splenic flexure or sigmoid colon without adequate vascular assessment
Delaying definitive management in favor of prolonged resuscitation without surgical intervention.