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When anticoagulant therapy is required, the risk of extensive intraoperative or postoperative bleeding is relevant (Fig 2-6). Anticoagulant therapies are not an absolute contraindication; however, depending on the indication, the risk of a suspended medication or changeover should be weighed against the associated benefits of planned implant and augmentation therapy.⁸² When patients declare that they are taking one or more of the so-called blood thinners, it is crucial to find out the exact medication. In case of postoperative bleeding, it is important to know the exact mechanism and, if appropriate, to take into account the specific systemic treatment for the drug (Table 2-2). In some diseases such as atrial fibrillation and coronary artery stenting, double or even triple anticoagulant therapy is recommended.⁷⁸

Fig 2-6 Intensive hematoma after surgery in patient under regular aspirin medication.

A distinction should be made between antiplatelet agents such as ASS or P2Y12-antagonists or plasma disorders (coumarins, heparin). While platelet aggregation inhibitors are essentially prophylactically formulated to prevent arterial thrombi in the event of heart attack risk, the plasmatic drugs, in addition to the prophylactic indication, are primarily used therapeutically in cardiac arrhythmias, heart valve replacement, and deep venous thrombosis. The latest developments are direct oral anticoagulants (DOAC/NOAC), which are classified as thrombin or factor-Xa inhibitors. The extent of anticoagulant therapy can also be partially recognized during the patient examination. If old hematomas are already recognizable on the legs or hands, this indicates that the anticoagulant therapy is very heavily adjusted or uncontrolled.

The relatively rare congenital disorders of blood clotting are known mostly as hemophilia A and B and von Willebrand-Jürgens syndrome. When this disease is present, important factors in the coagulation cascade (mostly factors 8 and 9) are almost absent or ineffective and can have reduced activity that can reach a severe level until < 1%. Depending on the remaining activity of the factor, surgery can be performed by substituting the appropriate factors.^41,51

Consultation with the treating physician is recommended in all patients with hemorrhagic diathesis, as unauthorized conversion might present the risk of the complication of lethal thromboembolic. Therefore, it is important to decide with the responsible physician whether a change to subcutaneous heparin injections (‘bridging’) or intermittent paralysis of anticoagulant therapy is necessary. In the case of replacement medication, an uncontrolled change of the medication with the reduction of the dose of the previous therapy can already lead to serious complications. To reduce the risk of a lethal thrombosis, the general opinion today in cases of oral surgery is not to stop any kind of antithrombotic treatment and not to perform any bridging with heparin, even with platelet aggregation inhibitors such as clopidogrel, prasugrel, ticagrelor or ticlopidine. Heavy postoperative bleeding should be controlled with local surgical possibilities such as an atraumatic approach, avoiding cutting important blood vessels, the use of local hemostatic, and good wound closure with the use of compression plates (see Chapter 8 on complications).