Acquired thrombophilic syndromes

Hypercoagulable Disorders in Orthopaedics: Etiology, Considerations, and Management

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Hypercoagulable disorders (HCDs) can be inherited or acquired. An HCD of either etiology increases the chance of venous thromboembolic events (VTEs).

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Patients with an HCD often have the condition discovered only after surgical complications.

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We recommend that patients with a concern for or a known HCD be referred to the appropriate hematological specialist for workup and treatment.

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Tourniquet use in the orthopaedic patient with an HCD is understudied and controversial. We recommend that tourniquets be avoided in the surgical management of patients with an HCD, if possible. When tourniquets are applied to patients with unknown HCD status, close follow-up and vigilant postoperative examinations should be undertaken.

Unusual Anemias

Many processes lead to anemia. This review covers anemias that are less commonly encountered in the United States. These anemias include hemoglobin defects like thalassemia, bone marrow failure syndromes like aplastic anemia and pure red cell aplasia, and hemolytic processes such as paroxysmal nocturnal hemoglobinuria. The pathogenesis, diagnostic workup, and treatment of these rare anemias are reviewed.

Splanchnic vein thrombosis in the mediterranean area in children

Abdominal venous thrombosis may present as splanchnic venous thrombosis (SVT) (occlusion of portal, splenic, superior or inferior mesenteric veins) or Budd- Chiari Syndrome (BCS) (thrombosis of inferior vena cava and/or hepatic veins). The aim of this review is to report the scanty data available for SVT in the South Mediterranean area. In one Egyptian study, the possible circumstantial risk factors for portal vein thrombosis (PVT) were found in 30% of cases: 19% neonatal sepsis, 8.7% umbilical catheterization, 6% severe gastroenteritis and dehydration. Another Egyptian study concluded that hereditary thrombophilia was common in children with PVT (62.5%), the commonest being factor V Leiden mutation (FVL) (30%). Concurrence of more than one hereditary thrombophilia was not uncommon (12.5%). The first international publication on hepatic veno-occlusive disease (VOD) in Egypt was in 1965 in children who rapidly develop abdominal distention with ascites and hepatomegaly. This disease was more frequent in malnourished children coming from rural areas; infusions given at home may contain noxious substances that were hepatotoxic and infections might play a role. VOD of childhood is rarely seen nowadays. Data from South Mediterranean area are deficient and this may be attributable to reporting in local medical journals that are difficult to access. Medical societies concerned with this topic could help distribute this information.

Risk factors of thrombosis in abdominal veins

AIM: To estimate the prevalence of inherited and acquired thrombophilic risk factors in patients with abdominal venous thrombosis and to compare the risk factor profiles between Budd-Chiari syndromes (BCS) and splanchnic vein thrombosis (SVT).

METHODS: In this retrospective study, 36 patients with abdominal venous thrombosis were studied. The patients were divided into Budd-Chiari group (hepatic vein, IVC thrombosis) and splanchnic venous thrombosis group (portal, splenic, superior mesenteric veins) based on the veins involved. Hereditary and acquired thrombophilic risk factors were evaluated in all patients.

RESULTS: Twenty patients had SVT, 14 had BCS, and 2 had mixed venous thrombosis. Ten patients (28%) had hereditary and 10 patients (28%) acquired thrombophilic risk factors. The acquired risk factors were significantly more common in the SVT group (SVT vs BCS: 45% vs 7%, χ² = 5.7, P = 0.02) while hereditary risk factors did not show significant differences between the two groups (SVT vs BCS: 25% vs 36%, χ² = 0.46, P = 0.7). Multiple risk factors were present in one (7%) patient with BCS and in 3 patients (15%) with SVT. No risk factors were identified in 57% of patients with BCS and in 45% of patients with SVT.

CONCLUSION: Hereditary and acquired risk factors play an important role in the etiopathogenesis of abdominal venous thrombosis. Acquired risk factors are significantly more common in SVT patients while hereditary factors are similar in both groups.

Etiology and consequences of thrombosis in abdominal vessels

The thrombophilia which can be either congenital or acquired in adult life has major implications in the abdominal vessels. The resulting portal vein thrombosis, Budd-Chiari syndrome and mesenteric vein thrombosis have a variety of consequences ranging from acute abdomen to chronic hepatomegaly and even totally asymptomatic patient in whom the only finding is pancytopenia. The complications like esophageal varices, portal gastropathy, ascites, severe hypersplenism, liver failure requiring liver transplantation are well known. Interesting features of collateral venous circulation showing itself as pseudocholangiocarcinoma sign and its possible clinical reflection as cholestasis are also known from a long time. The management strategies for these complications of intraabdominal vessel thrombosis are not different from their counterpart which is cirrhotic portal hypertension, but the prognosis is unquestionably better in former cases. In this review we presented and discussed the abdominal venous thrombosis, etiology and the resulting clinical pictures. There are controversial issues both in nomenclature, and management including anticoagulation problems and follow up strategies. In light of the current knowledge, we discussed some controversial issues in literature and presented our experience and our proposals about this group of patients.

Thrombophilia in mice expressing a tissue factor variant lacking its transmembrane and cytosolic domain

Mice with a targeted truncation in the gene encoding tissue factor of blood coagulation (TF) to eliminate the cytosolic domain and carrying a neo(R) cassette in intron 5 unexpectedly displayed severe spontaneous thrombosis in various vascular beds. Thrombosis was observed in heterozygous TF(+/neo) mice, causing death of over 50% of adults within 36 weeks of birth, and fulminantly exacerbating in pregnant females. Homozygous TF(neo/neo) mice were more severely affected and died within 7 weeks after birth. These TF(neo) mice primarily synthesized a mutant mRNA aberrantly spliced from exon 5 to neo(R), encoding an apparently non-vesicle-binding soluble TF lacking both the transmembrane and cytosolic domain, but still capable of blood coagulation induction. This severe thrombotic phenotype associated with the presence of a non-anchored soluble TF variant underscores the recently recognized significance of circulating TF for thrombus formation and development.

Endovascular management of venous thrombotic diseases of the upper torso and extremities

Central venous thrombosis in the upper torso can be either primary, occurring as a result of longstanding extrinsic compression, or secondary, resulting from an acquired intrinsic occlusive disease or foreign body. As in lower extremity deep vein thrombosis (DVT), anticoagulation therapy is the mainstay of therapy in upper torso and upper extremity DVT. However, in the presence of severely symptomatic acute thrombosis, pharmacologic and/or mechanical thrombolytic therapy represent the main invasive form of therapy for these conditions. After clearance of the acute thrombotic component, definitive management in patients with underlying anatomic abnormalities can be undertaken. Primary subclavian axillary vein thrombosis caused by extrinsic obstruction at the thoracic outlet is treated with thrombolytic therapy and anticoagulation followed by surgical decompression, whereas secondary causes of central venous obstruction and thrombosis are usually amenable to endovascular treatment with balloon angioplasty and stent placement. Postoperative interval anticoagulation is usually recommended. In addition to clinical follow-up, imaging follow-up with duplex sonography or conventional venography is usually recommended to assess the presence of restenosis and/or residual compression.

Thrombophilia and chronic venous ulceration

It is known that thrombophilia (TP) is a risk factor for deep venous thrombosis (DVT), and that DVT predisposes to chronic venous ulceration (CVU). However, the relationship between TP and CVU has not been well studied. Review of the literature reveals that the prevalence of TP in CVU patients is high--similar to the prevalence found in patients with a history of DVT. This is despite many patients with CVU having no clear history, or duplex evidence of previous DVT. TP may predispose to CVU by leading to macro- or micro-vascular thrombosis. This association raises several issues regarding the investigation, prevention and management of patients with venous disease.