How long should a patient discontinue aspirin (acetylsalicylic acid) 325mg before undergoing a colonoscopy with snare polypectomy?

Management of Aspirin 325 mg Before Colonoscopy with Snare Polypectomy

For patients taking aspirin 325 mg, aspirin should be continued without interruption before colonoscopy with snare polypectomy, as the risk of thrombotic events from discontinuation outweighs the bleeding risk. 1

Risk Assessment Framework

Procedure Risk Classification

• Snare polypectomy is classified as a high-risk endoscopic procedure 1
• The risk of post-polypectomy bleeding is generally <0.5% 2

Evidence for Aspirin Continuation

The 2021 British Society of Gastroenterology (BSG) and European Society of Gastrointestinal Endoscopy (ESGE) guidelines provide a strong recommendation to continue aspirin for all endoscopic procedures, including polypectomy 1. This recommendation is based on:

• Multiple studies showing no significant increase in post-polypectomy bleeding with continued aspirin use
• Recognition that the thrombotic risk from aspirin discontinuation outweighs bleeding risk
• A large retrospective study of veterans showing no significant difference in post-polypectomy bleeding rates between aspirin users and non-users (3.2% vs 3.0%) 3

Special Considerations

1. Polyp Size:

   • For polyps <1 cm: Very low risk of bleeding with continued aspirin
   • For polyps >1 cm: Consider individual risk assessment, but aspirin continuation is still recommended 1

2. Polypectomy Technique:

   • Cold snare polypectomy has lower bleeding risk (0-5.7%) than hot snare (14-23%) 4
   • Recent evidence shows cold snare resection is safe even in patients on dual antiplatelet therapy 5

3. Risk Mitigation:

   • Consider prophylactic clip placement after removing large polyps (>1 cm) in patients on aspirin 1, 4

Post-Procedure Management

After polypectomy, continue aspirin without interruption 1. If aspirin was discontinued for any reason (against current guidelines), it should be resumed up to 2-3 days after the procedure depending on the perceived bleeding risk 1.

Important Caveats

• Despite strong guideline recommendations for aspirin continuation, approximately 32.5% of endoscopy units in the US still recommend stopping aspirin before colonoscopy 6
• The primary reason cited for discontinuation is concern about bleeding after polypectomy (62%), despite evidence showing minimal risk 6
• The number of polyps removed per patient is a more significant risk factor for post-polypectomy bleeding than aspirin use 3

Algorithm for Decision-Making

1. Assess thrombotic risk:

   • Secondary prevention (previous cardiac/cerebrovascular event): High risk - continue aspirin
   • Primary prevention only: Lower risk - continue aspirin (benefit still outweighs risk)

2. Assess bleeding risk factors:

   • Polyp size >2 cm: Consider prophylactic clip placement
   • Multiple polyps: Higher bleeding risk, but still continue aspirin
   • Renal disease: Higher bleeding risk, but still continue aspirin

3. Implement risk mitigation:

   • Use cold snare technique when appropriate
   • Consider prophylactic clip placement for large polyps
   • Ensure adequate endoscopic expertise for complex polypectomies

In conclusion, the current standard of care based on high-quality guidelines is to continue aspirin 325 mg without interruption before colonoscopy with snare polypectomy.