Colonoscopic Polypectomy

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Colonoscopic Polypectomy

• Is it safer to cease or continue anticoagulation ?

• Prince of Wales Journal Club
• October 9th 2006
• Christopher Reitz
• Mentor Dr. A. Matthews

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COLONOSCOPIC POLYPECTOMY

• Pioneered by Wolff and Shinya in 1973
• Replaced surgical removal
• Safer than surgery (In 70s assoc. with 14
  morb.and 5 mort.)
• Frequency of clin. evident bleeding in CP
  0.2-1.0
• Waye J. Colonoscopy. CA Cancer J Clin
• 199242350-65

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PROBLEMS

• Increasing use of colonoscopy
• (screening for neoplasms in elderly patients with
  multiple comorbidities)
• Some require Tx with Aspirin, Warfarin, or
  NSAIDs ? Effect on platelet function or on
  clotting factors
• 1.? increase risk of post-polypectomy bleeding
• 2.? Probability of thromboembolic complication
  following reversal or discontinuation of
  anitcoag.(Depends on preexisting condition)

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PROBABILITY OF THROMBOEMBOLIC COMPLICATIONS I

• Mechanical heart valves
• Risk Mitral gtAortic
• No therapy 4 per 100 patients per year
• On Antiplatelet 2.2 per 100 patients per year
• On Warfarin 1 per 100 patients per year
• Cannegieter SC, Rosendaal FR, Briet E.
  Thromboembolic and bleeding complications in
  patients with mechanical heart valve prosthesis.
  Circulation 199489635-41.

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PROBABILITY OF THROMBOEMBOLIC COMPLICATIONS II

• Artrial fibrillation
• No therapy 5 per 100 patients per year
• Increased Risk with assoc. Cardiomyopathy,
  Valvular heart disease, or recent thromboembolic
  event.
• Laupacis A. et al.Antithrombotic therapy in
  atrial fibrillation Chest 1992102426s-33s

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PROBABILITY OF THROMBOEMBOLIC COMPLICATIONS III

• DVT
• Early cessation of anticoagulation for a short
  time does not increase the risk of PE
• Better delay procedure gt 6 month
• Research Committee of the British Thoracic
  Society. Optimum duration of anticoagulation for
  deep-vein thrombosis and pulmonary embolism.
  Lancet 1992340873-6.

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WHAT IS THE RISK OF BLEEDING UNDER
ANTICOAGULATION IN COLONOSCOPIC POLYPECTOMY?

• Search in Medline 1966-present
• Keywords
• Anticoagulants, Colonoscopy, Haemorrhage
• 21 Results in between 1993-2006
• 9 Papers about ColonoscopyPolypectomy

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Risk of colonoscopic polypectomy bleeding with
anticoagulants and antiplatelet agents analysis
of 1657 cases
Aric J. Hui, MD, et al. Dept. of Medicine and
Therapeutics and Dept. of Surgery, Prince of
Wales Hospital, Shatin, Hong Kong,
China. in Gastrointestinal Endoscopy 20045944-8.
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WHY THIS PAPER?

• Most recent study
• High caseload

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AIM OF STUDY

• To investigate the risk of post-polypectomy
  bleeding in patients taking anticoagulant and
  antiplatelet agents.

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METHOD

• Retrospective Audit
• Colonoscopies 01/2000 to 12/2001 5593
• _at_ Tertiary referral endoscopy center in HK
• Polypectomy1657 patients
• TechniqueElectrosurgical polypectomy

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DEFINITION OF BLEEDING

• Immediate haemorrhage bleeding from polypectomy
  site of sufficient severity to require endoscopic
  intervention as judged by the endoscopist.
• Delayed haemorrhage PR bleeding within 30 days
  of colonoscopic polypectomy of sufficient
  severity to require hospitalization for further
  management.

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12 Cotton P, Williams C. Practical
gastrointestinal endoscopy. 4th ed. Oxford Alden
Press 1996. p. 168.(Post-sphincterotomy
bleeding grading)
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Statistical analysis

• SPSS, version 10.0
• Multivariate logistic regression analysis
  effect of potential risk factors for bleeding,
  adjusted for the effects of each of the other
  potential factors
• Potential risk factors that were analyzed
• age
• size of polyp
• location of polyps
• method of polypectomy (snare or hot biopsy)
• use of antiplatelet agents (aspirin, ticlopidine,
  clopidogrel), NSAIDs, or Warfarin
• skill of the endoscopist (trainee or instructor)
• presence of underlying renal impairment.

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RESULTS I

• Total of 1657 colonoscopic polypectomies
• Post-polypectomy bleeding 37 cases (2.2)
• (32 immediate, 5 delayed)
• Bleeding or no bleeding no difference in
  gender, size of the largest polyp, location of
  polyps
• Freq. of bleeding in instructors vs. trainees
  similar
• Patients with underlying renal diseases similar
• Patients with bleeding were significantly older !

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RESULTS II

• Immediate post-polypectomy bleeds
• Mild 31
• Moderate 1 (Hb ?gt4 g/dL)
• All 32 patients Tx by endoscopic methods (no
  need for angiography or surgery)

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RESULTS III

• Haemostasis achieved through
• Epinephrine injection (27),
• Thermocoagulation (6),
• Haemoclip application (3),
• Endoloop placement (1).
• 5 cases more than one modality was used

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RESULTS IV

• Delayed bleeding 5
• Mild 1
• Moderate 2
• Severe 2

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RESULTS V

• In 4 bleeding at polypectomy site (Tx was
  endoscopically)
• 1 Patient needed 3 colonoscopies and emergency
  angiography before site of bleeding identified
• All 5 patients required PC (up to 13 U)
• No patient required surgery and no mortality

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RESULTS VI

• Aspirin and/or NSAID
• 6/37 (16) bleeding group on antipl.agents
• 213/1620 (13.21) in non-bleeding group.
• No increase in risk of bleeding associated with
  Aspirin and/or NSAID (p 0.62)

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RESULTS VII

• Warfarin
• 4/37 (10.8) in bleeding group were taking
  Warfarin,
• Only 13/1620 (0.8) in non bleeding group
• (p lt 0.001). significantly higher risk for
  bleeding in patients who received Warfarin before
  colonoscopy
• INR in bleeding group not significantly different
  from non bleeders
• median INR 1.41range 1.09-1.86 vs. med. INR
  1.38range 1.08-1.84
• (The power was 91.1 to detect differences in
  bleeding related to the use of Warfarin.)

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Critique
?

• Retrospective Audit
• Non standardized preparation of patients
• Non standardized identification and management
  of bleeding
• No structured follow-up
• Mild haematochezia who did not require re-adm.
  not recorded
• Patients who presented to private hospital with
  bleeding missed
• INR in both groups subtherapeutic
• (median INR 1.41range 1.09-1.86 vs. med. INR
  1.38range 1.08-1.84

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Main findings

• 1. Use of antiplatelet agents and NSAIDs not
  associated with an increased frequency of
  postcolonoscopic polypectomy bleeding.
• 2. Warfarin should be stopped and the INR
  normalized before performing an elective
  colonoscopy anticipated with therapeutic
  maneuvers.
• The findings concur with the current ASGE
  guidelines on the use of antiplatelet and
  anticoagulant drugs during endoscopic procedures.

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Recommendations of ASGEAmerican Society for
Gastrointestinal Endoscopy
Guideline on the management of anticoagulation
and antiplatelet therapy for endoscopic
procedures Gastrointestinal Endoscopy
200255775-9.
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Recommendations of ASGE II

• Outlines in
• Procedure risks
• High (Bleeding risk 1-6)
• Low (Bleeding risklt1)
• Condition risks
• High
• Low ? Risk when anticoag. is interrupted 4-7 days
  estimated at 1 to 2 per 1000 patients (DVT, AF,
  Biovalves and mech.AVR)

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ASGE and Clopidogrel
Only limited Data regarding the safety
Clopidogrel ?For elective high-risk procedures
temporary discontinuation of these medications
particularly if the patient is on concomitant
aspirin is desirable.
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Vielen Dank !