What is the incidence of portal thrombosis after Endoscopic Retrograde Cholangiopancreatography (ERCP)?

Incidence of Portal Thrombosis Post ERCP

Portal vein thrombosis is an extremely rare complication of ERCP with only isolated case reports in the medical literature, suggesting an incidence well below 0.1%.

Understanding Portal Vein Complications in ERCP

Portal vein complications following ERCP can manifest in two distinct ways:

1. Portal vein cannulation: Inadvertent entry into the portal venous system during guidewire manipulation or stent placement
2. Portal vein thrombosis: Formation of blood clots in the portal vein following the procedure

Reported Cases

The medical literature contains only isolated case reports of portal vein complications after ERCP:

• Case reports describe rare instances of portal vein cannulation during ERCP 1, 2
• These events typically occur after sphincterotomy or in the presence of portobiliary fistulas 2
• One case report described placement of a biliary stent into the portal vein during ERCP, resulting in portal vein thrombosis 1

Risk Factors for Vascular Complications

While portal thrombosis specifically is extremely rare, other vascular complications during ERCP occur at higher rates. Risk factors include:

• Anticoagulant intake
• Platelet count <50 x10^9/L
• Intraprocedural bleeding
• Low endoscopist experience 3
• Decompensated cirrhosis (odds ratio of 2.05 for post-sphincterotomy bleeding) 3

Bleeding Complications of ERCP

The most common vascular complication of ERCP is bleeding, not portal thrombosis:

• Post-ERCP hemorrhage occurs most frequently after endoscopic biliary sphincterotomy 3
• Bleeding rates after sphincterotomy range from 0.1-2% according to European guidelines 4
• A National NIS survey confirmed a statistically significant difference in bleeding episodes after ERCP between patients with and without cirrhosis (2.3% vs. 1%; p<0.0001) 3

Prevention of Vascular Complications

To minimize the risk of vascular complications during ERCP:

• Use blended current rather than pure-cutting current for sphincterotomy 4
• Consider balloon dilation (EPBD) as an alternative to sphincterotomy in high-risk patients, as it has lower hemorrhage rates 3
• Maintain balloon inflation ≥1 minute following waist disappearance if performing EPBD 3
• Consider stent placement without sphincterotomy when possible, as this reduces bleeding risk 3

Management of Suspected Portal Vein Complications

If portal vein cannulation or thrombosis is suspected:

• Immediately discontinue the procedure when portal vein opacification is recognized 5
• Obtain imaging (CT or Doppler ultrasound) to confirm the diagnosis
• Consider anticoagulation for confirmed portal vein thrombosis 6
• Monitor for signs of portal hypertension or intestinal ischemia

Conclusion

Portal vein thrombosis following ERCP is an extremely rare complication with only isolated case reports in the literature. While the exact incidence cannot be precisely determined due to its rarity, it appears to be well below 0.1% based on available evidence. Clinicians should be aware of this potential complication, particularly in high-risk patients, but recognize that other vascular complications such as post-sphincterotomy bleeding are much more common.