Hemostasis in Oral Surgery

The control of hemorrhage is a key component for the clinician to understand before performing oral surgical procedures. Hemostasis may be obtained primarily by local hemostatic measures. If hemostasis is not achieved with this modality, various hemostatic agents exist, which may be used as adjuncts to obtain hemostasis. Preoperative, perioperative, and postoperative methodologies toward hemostasis in oral surgery have been presented.

Bleeding during oral surgical procedures can be bothersome to the operator and time-consuming to control. It may also compromise visibility and possibly the procedure itself. This article will cover the area of hemorrhage control in surgery. The topic can be divided into three main areas:

  • 1.

    Preoperative assessment and identification of risk factors of bleeding

  • 2.

    Intraoperative control of bleeding

  • 3.

    Management of postoperative bleeding.

Preoperative assessment

There are many confounding factors that can ultimately potentiate perioperative bleeding as well as create difficulty in controlling bleeding. Therefore, it is essential to obtain a comprehensive medical history that also entails all medications in the patient’s regimen. A thorough medical history is the best screening technique to identify potential bleeding issues.

When managing the anticoagulated patient, one must consider preoperative, intraoperative, and postoperative measures.

Preoperatively, if the patient is on anticoagulant therapy, one may need to break up exodontia into multiple visits to decrease the amount of bleeding encountered. Timing of the appointment has to be taken into consideration with patients who are at high risk for bleeding postoperatively; early morning appointments allow for patients to return to the clinic, if bleeding persists despite all measures. In medically compromised patients, laboratory values such as international normalized ratio (INR), prothrombin time (PT), and platelet count may be of critical value.

Many patients’ daily regimen consists of anticoagulant therapy such as aspirin, clopidogrel, warfarin, and heparin for underlying comorbidities. Therefore the clinician should be well versed in hemorrhage control after oral surgery. Although some practitioners advocate the discontinuation of anticoagulants before an oral surgical procedure, it is usually unnecessary. For the majority of these cases, local hemostatic measures are effective in managing postoperative bleeding. Stopping the anticoagulant can have deleterious effects and likely poses a greater risk to the patient. It has been assumed that stopping warfarin for short periods of time presents a negligible risk to the patient. However, it has been reported that discontinuing anticoagulation medication before a dental procedure gives a 1% incidence of serious thromboembolic complication. Local hemostatic measures generally suffice when managing patients on daily low doses of anticoagulants. More likely than not, the risk of discontinuing anticoagulants is higher than the risk of perioperative bleeding.

All antiplatelet medications affect clotting by inhibiting platelet aggregation, but they do so by a variety of different mechanisms. Aspirin irreversibly acetylates cyclo-oxygenase, inhibiting the production of thromboxane A 2, which results in decreased platelet aggregation. Clopidogrel selectively inhibits adenosine diphosphate (ADP)-induced platelet aggregation. Aspirin begins irreversibly inhibiting platelet aggregation within 1 hour of ingestion, and clopidogrel begins within 2 hours; this lasts for the life of the platelets (7–10 days). The formation of new platelets helps overcome this inhibitory effect; complete recovery of platelet aggregation may occur in 50% of cases by day 3 and in 80% of cases by day 4. Aspirin and clopidogrel work synergistically to inhibit platelet aggregation. Aspirin can double the baseline bleeding time, but this may still be within the normal range. Clopidogrel is considered a more potent antiplatelet agent and can prolong the bleeding time by 1.5 to 3 times normal. Combined use of aspirin and clopidogrel produces additive and possible synergistic effects as the two block complementary pathways in the platelet aggregation cascade. It is generally accepted that the cardioprotective benefits of low-dose aspirin outweigh the potential for untoward bleeding episodes in at-risk patients with cardiovascular disease. Nonsteroidal anti-inflammatory drugs (NSAIDs) other than aspirin have a reversible effect on platelet aggregation, and platelet function is restored once the drug is cleared from the circulation. Minor surgical procedures can be safely performed without altering the antiplatelet medication dose. When more than 2 or 3 teeth need to be extracted, it is generally advisable to do this in multiple visits rather than have the patient stop the anticoagulants.

Bleeding disorders can be broken up into disorders of intrinsic and extrinsic coagulation pathways. The intrinsic pathway involves factors VIII, IX, XI, XII, which all affect the activated partial thromboplastin time (aPTT). The extrinsic pathway involves factor VII, which will affect the PT. The intrinsic and extrinsic pathways both lead up to the common pathway, where factor X is activated to factor Xa. If there are any anomalies along factors in either the intrinsic or extrinsic paths, the formation of the fibrin clot can be compromised. Laboratory tests such as PTT and PT can help lead toward determining which pathway is affected, while bleeding time values will provide information concerning platelet functionality.

There are many congenital disorders that may have an impact on hemostasis-such as hemophilia, von Willebrand Disease, and others. Hemophilia is a rare bleeding disorder that can range from mild to severe, depending on how much clotting factor is present in the blood. Hemophilia is classified as type A or type B, based on which type of clotting factor is lacking,factor VIII in type A and factor IX in type B. Von Willebrand disease is a inherited condition that results when the blood lacks von Willebrand factor, a protein that helps the blood to clot and also carries another clotting protein, factor VIII. There are also many acquired bleeding disorders can be caused by certain factor deficiencies secondary to liver disease or vitamin K deficiency. These patients are typically closely monitored by their primary care physicians or hematologists; therefore more information can be obtained by contacting the appropriate provider.

Spolarichs’ study showed that many surgical patients fail to inform their surgeons of their use of herbal medications in preoperative interviews; therefore it is even more important to question patients specifically about herbal supplement usage. Herbal supplements such as ephedra, ginger, garlic, gingko biloba, ginseng, dong quai, St John’s wort, licorice, and kava kava can all have possible perioperative complications such as prolonged bleeding. Pribitkin and Boger documented garlic’s inhibitory effect on platelet aggregation in people, which occurs within 5 days of oral administration. Ginger is a potent inhibitor of thromboxane synthetase and can theoretically prolong bleeding times with long-term use. Ginkgo has been noted to have a potent inhibitory effect on platelet activating factor and consequently on platelet aggregation. Dong quai has been known to prolong PT and aPTT, and it may interact with the effects of warfarin. Licorice inhibits platelet aggregation and contains coumarin. Kava has been shown in vitro to cause platelet dysfunction through inhibition of thromboxane synthesis. It is recommended that herbal supplements be discontinued 2 weeks before patients undergo invasive surgical procedures.

Preoperatively, the surgeon should assess the bleeding risk of the patient as well as the bleeding risk of the surgery. For example, extracting multiple teeth in a single visit greatly increases the risk of perioperative bleeding. Patients with severe periodontal disease or gingival inflammation are also placed at a higher risk of perioperative bleeding. This surgical plan might involve scaling and root planing and chlorhexidine gluconate mouth rinse 2 weeks before an elective procedure. Once the bleeding risk is assessed, the surgeon can then formulate an intraoperative and postoperative plan.

Intraoperative control of bleeding

Management of bleeding has many key components that start with good surgical technique as well as anesthetic support. The less bleeding the surgeon encounters, the better visibility he or she will have. Typically, the control of bleeding starts before the incision is made with the injection of a vasoconstrictor. Intraoperatively, the surgeon may use various topical hemostatic agents to assist in the control of bleeding.

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Oct 29, 2016 | Posted by in General Dentistry | Comments Off on Hemostasis in Oral Surgery
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