Haema 2014; 5(1):54-67
by Styliani I. Kokori,1 Elias S. Kyriakou,1 Serena Valsami2
1Transfusion Service and Laboratory Haematology, “Attikon” University Hospital, Athens, Greece,
2Transfusion Service and Laboratory Haematology, Areteio University Hospital, Athens, Greece
Venous thrombosis at “unusual” sites constitutes a diagnostic issue with which various health care professionals confront with and it may even represent an incidental finding during the investigation of other clinical conditions of a patient. Splanchnic vein thrombosis is the commonest of these unusual sites and therefore is thoroughly investigated in this review. It may concern the hepatic veins (Budd Chiari Syndrome, BCS), the superior mesenteric and splenic veins which form the portal vein (Portal Vein Thrombosis, PVT) and the mesenteric veins (Mesenteric Vein Thrombosis, MVT), as different entities that may occasionally coexist. Other unusual locations of thrombosis regard the splenic vein, the azygous vein, the superior vena cava, the inferior vena cava, the renal vein, the iliac vein, the testicular vein, the umbilical vein, the ovarian vein and the dorsal penile vein. In addition, thrombosis at unusual sites involves the retinal vein, the cerebral veins, the internal jugular vein, the brachiocephalic (innominate) vein, and the upper-extremity deep veins. Considering the complicated venous web and the anatomic variations, potentially any site may be involved in a thrombotic process. The aetiology of these thromboses is often multifactorial and the diagnostic approach of the underlying thrombotic risk factor is a common procedure. However, differences related to the particularity of the venous web of each different organ should be taken under consideration. The underlying causes may be local or systemic and may be related to inherited or acquired thrombophilic conditions. Accordingly, all patients with unexplained venous thrombosis at unusual sites should be investigated, depending on the case, for all currently established thrombotic risk factors.