In general, splanchnic vein thrombosis (SVT) is very rare. There are only a few cases per year. Nevertheless, there are concomitant diseases that increase the risk of a blood clot forming in a mesenteric vein. These include, for example, malignant diseases, but also liver cirrhosis or inflammatory and autoimmune diseases.
The diagnosis is often not clear-cut. The disease can have different presentations. In about a quarter of cases, there is gastrointestinal bleeding. An acute abdomen or suddenly developing or worsening ascites can also be a sign of thrombosis. About 20% of cases are asymptomatic and are an incidental finding.
Whether SVT is associated with an increased risk of bleeding is very patient-specific and clearly dependent on existing concomitant diseases. While people who are otherwise healthy do not have a significantly increased risk of bleeding compared to deep vein thrombosis or peripheral vein thrombosis, this is different for people with existing liver cirrhosis. Liver disease significantly increases the likelihood of bleeding. The same applies to malignant diseases.
The experts are unanimous here: if possible, yes in any case. Patients with an increased risk of bleeding should also be put on blood thinners. However, if there are complications in the context of liver cirrhosis, for example varicosis, this should be treated and included in the risk calculation.
Traditionally, heparin products have been the main treatment. But there are more and more studies that have also demonstrated the efficacy of oral anticoagulants (direct oral anti-coagulants - DOACs), which is why more and more sufferers are being treated with these drugs.
The current guidelines, for example, recommend DOACs for most patients with SVT. If there are contraindications, heparin can be used. Treatment should be given for about three to six months, but can be continued indefinitely if necessary. Caution: The use of DOACs for the treatment of SVT is still off-label.
If there is a malignant disease in addition to the thrombosis, people can be started on heparin or DOACs. Heparin is the first-line therapy for most people with cancers that are associated with a high risk of bleeding. These include, for example, endoluminal gastrointestinal tumours or ulcers in the urogenital region. Apixaban is an alternative therapy here. The drug has not shown an increased risk of bleeding in studies. Here, too, the target treatment duration is three to six months, with the option of extension.
SVTs are rare but require good anticoagulation. This also applies to people with concomitant diseases. Thus, affected patients should be adjusted to either heparin or oral anticoagulants.