Feb. 14, 2020
Multiple studies have demonstrated that several factors are associated with an elevated risk of post-polypectomy bleeding (PPB). These factors include polyp size, type of electrocautery used during the procedure, patient age, polyp morphology and use of antithrombotic agents.
Patients with coronary artery disease are at increased risk of developing colonic polyps and colon cancer. Because many of these individuals are prescribed antithrombotic agents, managing their care in the periendoscopic setting and preventing post-polypectomy adverse events present challenges. Although PPB, either immediate or delayed, rarely leads to the need for surgery or death, this complication can require transfusions, hospitalization, repeat endoscopy for hemostasis and angiography with embolization.
In an article published in the February 2020 issue of Gastrointestinal Endoscopy, Neena S. Abraham, M.D., M.S., a gastroenterologist and medical director of the Cardio-Gastroenterology Clinic at Mayo Clinic's campus in Scottsdale, Arizona, highlights current best practices related to PPB. In this state-of-the-science review, Dr. Abraham articulates strategies for temporary discontinuation of antithrombotic agents, polypectomy techniques and prophylactic placement of hemostatic clips, and assesses the impact these approaches have on reducing PPB events.
Use of anti-platelet agents
According to Dr. Abraham, discontinuation of cardioprotective acetylsalicylic acids (ASAs) before endoscopic procedures is not required, and endoscopic procedures can be performed safely in patients taking ASAs. Deferring elective polypectomy is appropriate for patients taking thienopyridine anti-platelet drugs who have recently undergone bare-metal stent placement (within two months) or drug-eluting stent placement (within six to 12 months), or those who have recently experienced an acute coronary event (within the last 90 days).
When temporarily discontinuing the use of thienopyridine anti-platelet agents, Dr. Abraham emphasizes that the duration of the interruption depends on the half-life of the specific drug. Once immediate hemostasis is achieved post-polypectomy, all antiplatelet agents should be resumed. "Ideally, anti-platelet agents should be resumed within 24 hours," explains Dr. Abraham, to minimize risk associated with prolonged temporary interruption of anti-platelet therapy.
Dr. Abraham points out that the uninterrupted use of clopidogrel before polypectomy is associated with an increased risk of immediate and delayed PPB, and that properly performed temporary interruption of this drug and other non-ASA anti-platelet agents in appropriate patients is not associated with severe cardiovascular sequelae.
Use of anticoagulants
When considering the use of direct oral anticoagulant agents (DOACs), Dr. Abraham notes that decisions about timing for temporary interruption of these medications depend on the agent prescribed and the patient's creatinine clearance. In general, patients with a higher degree of kidney function impairment (and a lower creatinine clearance) will experience a more significant residual anticoagulant effect and thus require a more prolonged interruption. Once immediate hemostasis is achieved, DOACs should be restarted.
"The short half-life of these drugs makes it imprudent to prolong post-procedural DOAC interruption," says Dr. Abraham. In her expert review of studies analyzing DOAC dosing before and after interruption for polypectomy, Dr. Abraham shares the following recommendations:
- Rivaroxaban and edoxaban can be resumed at the full dose the day after polypectomy.
- Apixaban can be restarted with the evening dose after immediate hemostasis is confirmed and then with the regular dose the next day.
- Dabigatran can be restarted at 75 mg in the evening post-procedure, resuming the prescribed dose the day after the procedure.
- In patients with significant mucosal defects (related to endoscopic mucosal resection or endoscopic submucosal dissection), consider waiting 48 to 72 hours before resuming DOACs.
Heparin bridge therapy has been shown to elevate the risk of PPB, with an incidence as high as 20% in patients who are bridged, compared with 1.4% in those who are not. Dr. Abraham notes that patients receiving properly dosed DOACs should not require anticoagulant bridging. However, individuals with mechanical valves, rheumatic valvular disease, or history of venous thromboembolism, cerebrovascular accident or transient ischemic attack within the last three months will require a bridge with unfractionated heparin or low molecular weight heparin.
Takeaways related to antithrombotic use
Dr. Abraham emphasizes that the available published evidence shows that the overall incidence of PPB associated with temporary interruption and prompt resumption of antithrombotic agents is 1.8% to 7%. Without temporary interruption, the rates of immediate and delayed PPB are as high as 11%.
"At this time, a strategy of temporary interruption preendoscopy with prompt resumption of the antithrombotic agent is associated with a 30-day thromboembolic risk of less than 1% to 3%," explains Dr. Abraham. "This is the safest strategy for most patients, taking into consideration the cardiac risk and GI procedural benefit."
Polypectomy technique: Cold- versus hot-snare polypectomy
According to Dr. Abraham, it is unclear whether polypectomy technique affects the risk of PPB because the few available published studies lack standardized methods and a focus on individuals taking antithrombotic agents. "Until there is sufficient high-quality evidence testing these techniques in this unique population, we cannot unequivocally endorse cold-snare polypectomy as a technique to reduce PPB," says Dr. Abraham.
Prophylactic hemostatic clip use
Dr. Abraham states that published data related to prophylactic clipping of large lesions (>1 cm) to reduce PPB have shown varying degrees of efficacy. Cost-effectiveness data show that prophylactic clipping may be advisable if the PPB rate is ≥3.4% (due to anticoagulant bleeding risk) or ≥2.5% (due to anti-platelet bleeding risk). Recently published randomized controlled trial data suggest that clip closure of large, proximal EMR defects (>2 cm, using four clips per defect) may decrease delayed PPB.
However, Dr. Abraham advises that future research must randomize patients to balance antithrombotic drug use between control and clip groups to eliminate unmeasured confounding variables and provide a more accurate assessment of clip efficacy.
Overall, Dr. Abraham emphasizes that this a quickly evolving field with insufficient high-quality evidence to fully inform polypectomy strategy: "There is a need for future rigorous studies focused specifically on the antithrombotic population to fill knowledge gaps regarding polypectomy technique (hot versus cold polypectomy), adjunctive therapies (mechanical clipping), and optimized interruption and antithrombotic resumption schedules, using clinically relevant and clearly defined outcomes."
For more information
Abraham NS. Antiplatelets, anticoagulants, and colonoscopic polypectomy. Gastrointestinal Endoscopy. 2020;91:257.