Anticoagulant therapy: consideration of modification in conjunction with minor surgery

To the Editor:—I am writing to JOMS regarding the topic of oral surgery procedures in patients who are taking oral anticoagulant therapy for a variety of conditions. This topic has been debated considerably in the literature for quite some time. Traditionally, many oral surgeons have consulted with the medical community and reduced the dose of anticoagulation prior to a procedure and then resumed therapy. My experience over the past 8 years is that this approach works quite well except for patients with prosthetic valve replacement. It seems, however, that recently, many in the medical community have concluded that withdrawal of anticoagulant therapy is not indicated for oral surgery due to the risk of thromboembolic events in these patients and the low risk of bleeding events for these patients. While I agree that this is true in many patients, I do not think it can be so uniformly applied that no consideration be given to the individual patient, the reason for anticoagulation (atrial fibrillation vs deep vein thrombosis vs prosthetic valve) and the nature of the procedure. A variety of procedures are required for our patients and the bleeding, while not frequently life threatening, can be quite disconcerting and require repeated local measures and occasionally require further modification of the anticoagulation therapy that was initially not desired.

The consensus of opinion on this topic seems to originate from an article by Michael Wahl.1 This is a good review article and I would like to invite readers who are interested in this topic to read it. I would like to note that in this article, Dr Wahl argues against discontinuation of anticoagulant therapy because he feels that the the risk of hemorrhage is minimal and is outweighed by the risk of thromboembolic events. To show the risk of withdrawl of anticoagulation, he cites that out of 542 documented cases of withdrawl of anticoagulation therapy for dental procedures, 5 patients had serious embolic complications including 4 deaths. Reviewing those 5 cases, however, show that the period of withdrawl of anticoagulation was either unknown or ranged from 5 days of discontinuation to 19 days’ discontinuation! This is quite an extended period of withdrawl and would in most patients normalize their coagulation status. One wonders if these complications would have occurred if the anticoagulation had been stopped for 2 to 3 days so that the international normalized ratio is not normalized, but below therapeutic range. It seems to me that these 5 cases of normalization of anticoagulation should not make the argument against reduction of anticoagulant therapy.

My experience is that even though bleeding is never life threatening, it can be difficult to control at therapeutic levels of anticoagulation and can be very worrisome and troublesome, especially for elderly patients. I want to make readers aware of other literature supporting reducing the level of anticoagulation2, 3 and some stopping anticoagulation therapy entirely4, 5. It is my hope in writing this letter that better communication can be carried out between the OMS and the primary care physican. Hopefully, when the medical community is consulted regarding anticoagulated patients, a consultation can be carried out regarding the patient’s risk of thromboembolism and balance this against the risk of persistent nuisance bleeding from the proposed procedure. The literature is not as definitive in terms of continuation of anticoagulant therapy as many in the medical community seem to believe.