Consultations for alterations of the coagulation system are frequent and originate in abnormalities manifested by bleeding or thrombosis and, less frequently, by alterations in coagulation tests detected, for example, in a preoperative analysis. In this article, Dr. Besses Raebel, a specialist in hematology, discusses the most frequent coagulation and thrombosis problems.
What is thrombosis?
Thrombosis means the formation of a clot within an artery or vein in any anatomical location that impedes blood flow to the affected area. Acute coronary artery disease and cerebral vascular accidents are a major cause of mortality in the Western world. Its origin is usually due to lesion or disease of the artery wall (arteriosclerosis) or also due to embolism, as in the case of cerebrovascular accidents.
It is important to distinguish between thromboses that occur in the arterial system and those that occur in the venous system. Most arterial thromboses occur in the coronary arteries of the heart and in the arteries supplying the brain.
What are the most frequent thromboses?
In general, the most frequent thrombosis consultations refer to venous thrombosis. The most frequent location is in the venous territory of the lower extremities (deep vein thrombosis) and in the lung (pulmonary thromboembolism). The causes are multiple and involve risk factors of the patient and/or diseases he/she suffers from. The former include age, obesity, immobility after surgery or prolonged air travel, hormonal treatments and hereditary or acquired genetic circumstances that produce the so-called prothrombotic state. Regarding the latter, the most frequent are trauma and abdominal surgery and the existence of cancer.
When the consultation is for hemorrhage, the clinical history, family history and blood count, as in the case of thrombosis, help to orient the problem. An acute decrease in the number of platelets, generally of immunological cause (primary autoimmune thrombopenia or ITP) causes punctate cutaneous hemorrhages (petechiae) or extensive (ecchymosis) and, on rare occasions, gastrointestinal bleeding (see Platelet disorders). The most common hereditary hemorrhagic disease is von Willebrand disease, with a prevalence of 100 cases per million population. It presents various types, with a predominance of clinically mild forms (cutaneous and mucosal) but sometimes severe, especially in the context of surgery or even after dental extractions.
How can it be treated by the specialty?
The role of the clinical hematologist is to find out the possible cause in order to advise on the means to prevent a new thrombotic episode from occurring (antithrombotic prophylaxis). He often requests a coagulation study aimed at discovering whether there is a prothrombotic condition or state (thrombophilia study). This analysis analyzes the existence of inherited genetic mutations and also of abnormalities or acquired deficits of the coagulation protein system.
What is the treatment?
The diagnosis of a hemorrhagic disease is based on the guided analysis of various coagulation tests that allow establishing the diagnosis and the orientation of substitutive or pharmacological treatment to prevent the occurrence of a new hemorrhagic episode.