RESUMO
The macrothrombocytopenias make up a heterogeneous group of disease involving thrombocytopenia and giant platelets; other clinical or laboratory findings, such as hereditary nephritis, sensorineural hearing loss, leukocyte inclusions, and cataracts, may also be present. The tendency to bleeding is highly variable and is due to decreased expression of the GP1b-V-IX complex on the surface of platelets, leading to altered platelet-vessel wall and platelet-platelet interactions. The 5 autosomal dominant giant-platelet disorders that are associated with macrothrombocytopenia are May-Hegglin anormaly, Epstein, Fechtner, and Sebastian syndromes, and Alport-like syndrome with macrothrombocytopenia. The mutation responsible is in gene 9 (MYH9) coding for the nonmuscle myosin heavy chain IIA that has been identified in the long arm of chromosome 22 (22q12.3-q13.2). The most recently described macrothrombocytopenia is Sebastian syndrome, consisting of thrombocytopenia with giant platelets and leukocyte inclusions. We report the case of a woman with Sebastian syndrome scheduled for abdominoperineal resection for rectal carcinoma. Preoperative studies revealed isolated thrombocytopenia (35,000 platelets/microL) and a mean platelet volumen of 13 fL. Preoperative prophylactic platelet transfusion was carried out with no adverse events. After a postoperative transfusion of packed red cells, needed because of abundant bleeding, clinical course continued to be satisfactory. The anesthetic implications of this syndrome are not well known because few cases have been reported in the literature, and none was found that describes anesthetic management. Nevertheless, thrombocytopenia and the tendency to bleeding present challenges to the anesthesiologist.
Assuntos
Adenocarcinoma/cirurgia , Anestesia Geral , Síndrome de Bernard-Soulier , Perda Sanguínea Cirúrgica/prevenção & controle , Neoplasias Retais/cirurgia , Trombocitopenia , Adenocarcinoma/complicações , Adulto , Amputação Cirúrgica , Anestesia Epidural , Anestesia Geral/métodos , Síndrome de Bernard-Soulier/classificação , Síndrome de Bernard-Soulier/genética , Colostomia , Contraindicações , Transfusão de Eritrócitos , Feminino , Transtornos Hemorrágicos/etiologia , Humanos , Transfusão de Plaquetas , Hemorragia Pós-Operatória/etiologia , Hemorragia Pós-Operatória/terapia , Cuidados Pré-Operatórios , Neoplasias Retais/complicações , Esquizofrenia/complicações , Trombocitopenia/genética , Trombocitopenia/terapiaRESUMO
Inherited giant platelet disorders are extremely rare. The aim of this article is to review the clinical and laboratory features of this heterogeneous group and to arrive at a working classification. We conducted our literature search using the National Library of Medicine database. A total of 12 clinical entities were described. We classified them into 4 groups depending on the clinical and structural abnormalities. The pathophysiology of these disorders is largely unknown, and more research is needed, particularly in the light of recent advances in laboratory medicine. This review may provide a valuable reference for clinicians and may form a basis for future classification and research.