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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. COLONOSCOPIC POLYPECTOMY. Pioneered by Wolff and Shinya in 1973 Replaced surgical removal
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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
COLONOSCOPIC POLYPECTOMY • Pioneered by Wolff and Shinya in 1973 • Replaced surgical removal • Safer than surgery (In 70‘s 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 1992;42:350-65
PROBLEMS • Increasing use of colonoscopy (screening for neoplasms in elderly patients with multiple comorbidities) • Some require Tx with Aspirin, Warfarin, or NSAID‘s 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)
PROBABILITY OF THROMBOEMBOLIC COMPLICATIONS I Mechanical heart valves • Risk Mitral >Aortic • 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 1994;89:635-41.
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 1992;102:426s-33s
PROBABILITY OF THROMBOEMBOLIC COMPLICATIONS III DVT • Early cessation of anticoagulation for a short time does not increase the risk of PE • Better delay procedure > 6 month Research Committee of the British Thoracic Society. Optimum duration of anticoagulation for deep-vein thrombosis and pulmonary embolism. Lancet 1992;340:873-6.
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 Colonoscopy+Polypectomy
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 2004;59:44-8.
WHY THIS PAPER? • Most recent study • High caseload
AIM OF STUDY To investigate the risk of post-polypectomy bleeding in patients taking anticoagulant and antiplatelet agents.
METHOD • Retrospective Audit • Colonoscopies 01/2000 to 12/2001 = 5593 • @ Tertiary referral endoscopy center in HK • Polypectomy=1657 patients • Technique=Electrosurgical polypectomy
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.
12: Cotton P, Williams C. Practical gastrointestinal endoscopy. 4th ed. Oxford: Alden Press; 1996. p. 168.(Post-sphincterotomy bleeding grading)
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.
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 !
RESULTS II • Immediate post-polypectomy bleeds • Mild = 31 • Moderate = 1 (Hb >4 g/dL) All 32 patients Tx by endoscopic methods (no need for angiography or surgery)
RESULTS III • Haemostasis achieved through: • Epinephrine injection (27), • Thermocoagulation (6), • Haemoclip application (3), • Endoloop placement (1). • 5 cases = more than one modality was used
RESULTS IV • Delayed bleeding = 5 • Mild = 1 • Moderate = 2 • Severe = 2
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
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)
RESULTS VII Warfarin • 4/37 (10.8%) in bleeding group were taking Warfarin, • Only 13/1620 (0.8%) in non bleeding group • (p < 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 1.41[range 1.09-1.86] vs. med. INR 1.38[range 1.08-1.84] (The power was 91.1% to detect differences in bleeding related to the use of Warfarin.)
? 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 1.41[range 1.09-1.86] vs. med. INR 1.38[range 1.08-1.84]
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.
Recommendations of ASGEAmerican Society for Gastrointestinal Endoscopy Guideline on the management of anticoagulation and antiplatelet therapy for endoscopic procedures Gastrointestinal Endoscopy 2002;55:775-9.
Recommendations of ASGE II Outlines in • Procedure risks • High (Bleeding risk 1-6%) • Low (Bleeding risk<1%) • 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)
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.