Endoscopy: Transanal (Lower) Endoscopy – Complications

Hemorrhage

Basics

  • Risk: 1-2% – The Most Common Complication of Polypectomy
  • May See Delayed Bleeding After 5-7 Days Due to Eschar Sloughing or Extension of the Zone of Thermal Necrosis

Risk Factors

  • Right-Sided Polyp
  • Sessile Polyps
  • Large (> 2 cm)
  • Elderly
  • Anticoagulation or Coagulopathy

Treatment

  • May Consider Expectant Management if Bleeding is Small & Stable
  • Initial: Endoscopic Therapy
    • Dilute Epinephrine Injection
    • Electrocautery – Adds Risk for Perforation
    • Endoscopic Hemoclips
  • If Refractory:
    • Angiographic Embolization
      • Risk for Ischemia Requiring Colectomy (11%)
    • Surgical Resection
      • On-Table Colonoscopy May Help to Identify Site
      • May Require Subtotal Colectomy if Site Unknown

Perforation

Risk

  • Screening Colonoscopy: 0.01-0.1%
  • Stricture Dilation (Anastomotic): 0-6%
  • Stricture Dilation (Crohn’s Disease): 0-18%
  • Stent Placement: 4%
  • Colonic Decompression Tube Placement: 2%
  • Endoscopic Mucosal Resection (EMR): 0-5%

Causes

  • Therapeutic Procedures (Polypectomy, Electrocautery)
    • Hot Snare in Coagulation Mode is the Most Common Cause of Delayed Perforation
  • Excessive Force at Tip – Most Common Cause with Diagnostic Colonoscopy
  • Excessive Force from Scope Looping
  • Aggressive Resolution of the Sigmoid
  • “Slide-By Technique” Blindly Advancing by Repetitive Pushes
  • Barotrauma from Over-Insufflation

Risk Factors

  • Right-Sided Polyp
  • Sessile Polyps
  • Large (> 2 cm)
  • Central Depression
  • Unable to Saline Lift
  • Immobility (Adhesions, Diverticula, Infection or Malignancy)
  • “Low-Volume” Colonoscopist – Three Times Higher Risk After Polypectomy than “High-Volume”

Most Common Sites

  • Most Common Site of Perforation: Sigmoid Colon
  • Most Common Site of Barotrauma: Cecum
    • Barotrauma Due to Law of LaPlace: ΔP = γ/r
      • Change in Pressure = Surface Tension / Radius
      • *Largest Radius will Have Highest Surface Tension

Diagnosis

  • Initial Test: Upright X-Ray (Evaluate for Free Air)
  • If Negative but Still High Suspicion: CT

Treatment

  • Benign Pneumoperitoneum: Conservative Management (NPO & Antibiotics)
    • Pneumoperitoneum Alone is Not an Indication for Surgery
    • Intraabdominal Free Air without Perforation Can Come from Transmural Passage or Microperforation
  • Localized Peritonitis: Conservative Management with Low Threshold for Surgery
    • *Also Consider Postpolypectomy Syndrome
  • Unstable or Generalized Peritonitis: Surgery
    • Primary Repair vs Segmental Resection
    • Consider Colonic Diversion for Significant Fecal Soiling, Instability or Major Comorbidities

Postpolypectomy Coagulation Syndrome (Postpolypectomy Syndrome)

Basics

  • Definition: Localized Peritonitis Without Perforation that Develops After Polypectomy with Electrocoagulation
  • Caused by Transmural Burn & Peritoneal Inflammation from Electrical Current
  • Risk: 0-2%

Presentation

  • Abdominal Pain
  • Fever
  • Leukocytosis

Treatment

  • Primary Treatment: Conservative Management (NPO & Antibiotics)
    • Low Threshold for Surgery if Fails

Other Complications

Retained Air

  • Use of Carbon Dioxide (Readily Absorbed) Instead of Air Decreases Risk
  • Presentation: Abdominal Pain & Distention but Stable
  • Treatment: Observation

Other Complications

  • Infection/Bacteremia
    • Rarely Hepatitis B & Hepatitis C Have Been Seen Due to Breaches in Disinfection Protocol
  • Gas Explosion
    • Ignition of Hydrogen or Methane Gas in the Colon Lumen from the Use of Electrosurgical Energy
    • Gas Results from Poor/Inadequate Preparation
  • Diastatic Serosal Tear
  • Vasovagal Reflux
  • Splenic Trauma
  • Missed Disease