Adverse events related to endoscopic retrograde cholangiopancreatography (ERCP) in adults

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Executive Summary

Endoscopic retrograde cholangiopancreatography (ERCP) is a complex, specialized procedure utilized for the management of pancreaticobiliary disorders. While generally regarded as safe, it carries a significantly higher risk of serious adverse events compared to standard endoscopic procedures such as colonoscopy or upper endoscopy.

Key findings include:

  • Incidence: Overall adverse event rates range from 5% to 12%, with a mortality rate between 0.1% and 1.4%.

  • Primary Risks: The most frequent serious complications are pancreatitis, bleeding, infection, and perforation.

  • Risk Factors: Complications are influenced by patient-related factors (e.g., altered anatomy, cirrhosis), procedure-related factors (e.g., difficult cannulation), and provider-related factors (e.g., low annual case volume).

  • Critical Emergencies: Although rare, gas embolism and extraluminal injuries (such as splenic or liver lacerations) represent life-threatening emergencies requiring immediate recognition and intervention.

  • Prevention: Mitigation strategies include the use of carbon dioxide (CO2) for insufflation, pre-procedure evaluation for cardiac devices, and specific premedication for contrast allergies.

Incidence and Mortality Trends

ERCP has evolved from a diagnostic tool into a primarily therapeutic intervention, which contributes to its stable mortality rate despite technological advancements.

  • Comparative Risk: A systematic review of over 16,000 patients identified a 7% overall complication rate, with 2% classified as serious.

  • Mortality Windows:

    • 30-Day Mortality: Approximately 5%.

    • 90-Day Mortality: Approximately 12%.

    • Note: The majority of deaths occurring beyond the 30-day window (75%) are attributable to the patient's underlying disease, such as cancer, rather than the procedure itself.

Risk Factor Classification

Adverse events are categorized based on their timing (early vs. late), location (focal vs. systemic), and severity. Risk factors are broadly divided into three categories:

1. Patient-Related Factors

  • Surgically altered anatomy (e.g., Roux-en-Y).

  • Sphincter of Oddi dysfunction.

  • Periampullary diverticulum.

  • Comorbidities including older age and cirrhosis.

2. Procedure-Related Factors

  • Difficult cannulation or the need for precut (access) sphincterotomy.

  • The nature of the intervention (therapeutic procedures carry higher risk than diagnostic ones).

3. Provider and Hospital-Related Factors

  • Volume Correlation: Higher endoscopist procedure volume (ranging from 25 to 156+ ERCPs annually) is associated with a lower risk of adverse events (OR 0.65).

  • Timing: The timing of the procedure for specific conditions, such as acute cholangitis, impacts outcomes.

Common Adverse Events

Four primary complications dominate the clinical landscape of post-ERCP care:

  • Pancreatitis: Resulting from mechanical injury, hydrostatic injury from contrast, or guidewire manipulation.

  • Bleeding: Often related to biliary or pancreatic sphincterotomy.

  • Infection: Usually caused by incomplete drainage of infected systems, contaminated equipment, or obstructed ducts.

  • Perforation: Can occur in the esophagus, stomach, duodenum, or the bilio-pancreatic area.

Accessory-Related Issues

The instruments used during ERCP can themselves cause specific complications:

Stone Retrieval Basket Impaction

Baskets may become trapped, typically at the ampulla.

  • Risk Factors: Large stones (>1 cm), multiple stones (>3), barrel-shaped stones, or a small sphincterotomy size.

  • Management: May include mechanical lithotripsy to fragment the stone, extending the sphincterotomy, or, if endoscopic methods fail, surgical common bile duct exploration.

Guidewire Complications

  • Inadvertent Cannulation: The wire may enter the liver, pancreatic parenchyma, or adjacent vessels, leading to hematomas or bile leaks.

  • Fracture: While rare, fractured wire fragments can often be removed endoscopically.

Anesthesia and Contrast Considerations

Anesthesia-Related Events

Sedation-related events (hypotension, hypoxemia) occur in approximately 25% of cases but are generally transient and rarely necessitate procedure termination.

Contrast Allergy

Adverse reactions are very rare because contrast is not injected intravenously.

  • Premedication: Reserved for patients with a history of anaphylaxis or severe reactions.

  • Regimens: Typically involve glucocorticoids and H1 antihistamines.

Rare and Catastrophic Events

Gas Embolism

A rare (0.57 per 100,000 endoscopies) but lethal complication (15% mortality rate).

  • Mechanism: Gas enters the circulation through compromised mucosal barriers or bilio-venous fistulas.

  • Prevention: Routine use of CO2 instead of ambient air is recommended as CO2 is more rapidly absorbed and eliminated.

  • Immediate Management: Terminate procedure, administer 100% oxygen, and place the patient in the left lateral decubitus, head-down position.

Extraluminal Injuries

  • Splenic and Hepatic Injury: Caused by endoscope looping or manipulation. Symptoms include left upper quadrant pain, often delayed by more than 24 hours.

  • Biliary Varices: Bleeding may occur in patients with cirrhosis and portal vein cavernous transformation.

  • Cardiac Device Dysfunction: Electromagnetic interference (EMI) from monopolar electrosurgery can cause inappropriate shocks or pacing inhibition. Pre-procedure evaluation of battery life and programmed values is essential.

Pneumothorax

Reported rarely, often linked to duodenal perforation or altered anatomy. 45% of reported cases involved bilateral pneumothorax. Diagnosis should be suspected in cases of acute dyspnea and pleuritic chest pain post-procedure.