|Year : 2016 | Volume
| Issue : 1 | Page : 87-88
Thrombophilic states and anticoagulants in portal vein thrombosis
Department of Pediatrics, NRS Medical College, Kolkata, West Bengal, India
|Date of Web Publication||22-Dec-2015|
Department of Pediatrics, NRS Medical College, Kolkata, West Bengal
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Nandi M. Thrombophilic states and anticoagulants in portal vein thrombosis
. Med J DY Patil Univ 2016;9:87-8
In the case report - Blocked mesocaval shunt with protein C deficiency in a child with extra hepatic portal hypertension, the authors describe an 8-year-old child with recurrent portal vein thrombosis (PVT). He was investigated for thrombopihilic conditions when there were recurrent symptoms and the mesocaval shunt also developed a block. The investigations revealed Protein C deficiency. So, two issues need to be considered here. Firstly, whether to screen all patients with PVT for thrombophilic states at the first instance itself. And secondly, whether to give anticoagulants in case of documented thrombophilic state. Also, if anticoagulants are considered, what should the modalities of such intervention?
Portal vein thrombosis is a common cause of portal hypertension that most commonly presents with life-threatening bleeding esophageal varices, especially in children. Various local and/or systemic factors have been implicated as causative agents of PVT. The contribution of both local and systemic factors seems to be more likely in the index case as all the episodes of block occurred in the portal vein drainage area only, without any thrombotic episode in any other site.
Hypercoagulable state due to presence of some thrombophilic condition like protein C, S and antithrombin III deficiency, factor V Leiden mutation, factor II mutation (G20210A) and methylenetetrahydrofolate reductase gene mutation have been reported as risk factors, although the exact contribution of each of these factors is not yet established. ,,, In a recent meta-analysis of nine studies by Qi et al.,  the pooled prevalence of inherited antithrombin III, protein C and protein S deficiencies in PVT were found to be 3.9%, 5.6% and 2.6%, respectively. The authors concluded that these inherited deficiencies may increase the risk of PVT by 9-18 fold.
The presence of local inflammatory, infective or traumatic factors do not exclude the presence of systemic thrombophilic disorders in PVT. , So, in view of the recent publications, a complete evaluation of all known etiological factors including thrombophilic states at the time of first clinical presentation of PVT seems to be prudent. Giving an etiological diagnosis is always better than stamping somebody as having "idiopathic" PVT. It becomes more important in the event of a potentially "treatable etiology."
It is also important to differentiate between inherited thrombophilic states and functional deficiencies of protein C, S and antithrombin III as a secondary phenomenon due to parenchymal liver disease or some other transient local infective or inflammatory conditions. An Indian study has found that the majority of children with PVT have functional protein C deficiency or abnormally elevated anticardiolipin antibodies.  Another study in patients with PVT with normal liver function tests found single or combined deficiencies of protein C, protein S and antithrombin in 62% of cases, but family studies suggested that majority of these were acquired, rather than hereditary.  Hence, in this particular report, even though the liver function tests were normal, one cannot be certain about the inherited genetic origin of these deficiencies in the absence of family screening. This differentiation between genetic or functional origin becomes even more important if anticoagulants are to be considered as a modality of treatment. Functional deficiencies need to be treated for a definite period whereas inherited deficiencies may need lifelong treatment. 
Considering the second issue, whether to treat with anticoagulants or not, again, the jury is yet out. Various issues need to be considered before any firm recommendation on anticoagulants can be given the selection of patients, type of drug, duration of therapy, modes of monitoring, and the possible side-effects.
Whereas the role of early anticoagulants in acute PVT seems to have a beneficial role, its use in chronic PVT/portal cavernoma is not yet clear. Long-term anticoagulation may be recommended in patients with identified prothrombotic disorders, recurrent episodes of thrombosis or family history of venous thrombosis.  In these patients, anticoagulation has been shown to prevent the progression and recurrence of thrombosis without any increased risk of gastrointestinal bleeding provided adequate prophylactic measures to prevent variceal bleeding or rebleeding have been adopted before starting anticoagulation. However, more evidence is needed before any firm, and strong recommendation is made regarding the use of anticoagulants in chronic/recurrent PVT.
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