Anticoagulation in splanchnic and cerebral vein thrombosis: An international vignette-based survey

Cancer-associated splanchnic vein thrombosis: Clinical implications and management considerations

Splanchnic vein thrombosis (SVT), a thrombosis which involves the portal, mesenteric, and splenic veins, and the Budd-Chiari syndrome, represents an uncommon type of venous thromboembolism (VTE). Like with deep vein thrombosis of the lower extremities and pulmonary embolism, ample evidence suggests a significant association between SVT and cancer, particularly intra-abdominal solid malignancies (e.g. hepatobiliary and pancreatic cancers) and myeloproliferative neoplasms (MPN). Clinical symptoms of SVT in cancer patients can be ambiguous, and frequently attributed to the primary cancer itself. Alternatively, SVT may be asymptomatic and detected incidentally during cancer staging or follow-up evaluations. SVT can also precede the diagnosis of cancer and has been associated with poorer outcomes in patients with liver or pancreatic cancers. Therefore, an unprovoked SVT warrants a thorough evaluation for an underlying malignancy or MPN. Cancer-associated SVT carries a high risk of VTE extension, recurrence and bleeding. Extended anticoagulant treatment is often required in the absence of a high bleeding risk. Guidelines suggest treatment with either low molecular weight heparin (LMWH) or direct oral anticoagulants (DOACs), although available data on the safety and effectiveness of DOACs in these patients is limited. This comprehensive review outlines the epidemiology, pathogenesis, risk factors, and diagnosis of cancer-associated SVT and underscores the importance of comprehensive patient evaluation and evidence-based management.

Anticoagulant therapy for splanchnic vein thrombosis: recent updates for patients with liver cirrhosis

INTRODUCTION

Liver cirrhosis is accompanied by several hemostatic alterations, which contribute to the current theory of "rebalanced hemostasis." Splanchnic vein thrombosis (SVT) is a frequent complication of liver cirrhosis (17-26% of the cirrhotic patients), and liver cirrhosis is a common risk factor for SVT (24-28% of SVT cases).

AREAS COVERED

This narrative review aims to describe the current state of the art on the anticoagulant treatment of cirrhotic SVT, with a particular focus on the possible role of the direct oral anticoagulants (DOACs) and recent guidelines on this topic.

EXPERT OPINION

Early anticoagulant therapy is recommended in cirrhotic patients with acute SVT, to obtain vessel recanalization and decrease the rates of portal hypertension-related complications. Gastroesophageal varices do not represent a contraindication to anticoagulation, if adequate prophylaxis of variceal bleeding is established, and varices band ligation can be safely performed without the need to stop the anticoagulant treatment. The conventional treatment of cirrhotic SVT consisted of low molecular weight heparin, as initial treatment of choice, eventually followed by vitamin K antagonists, but the DOACs can be considered as a reasonable alternative in patients with compensated liver cirrhosis.

Clots in unusual places: lots of stress, limited data, critical decisions

Although much less common than deep vein thrombosis of the lower extremities or lungs, clots in unusual locations, including the splanchnic, cerebral, retinal, upper-extremity, and renal locations, present with significant morbidity and mortality. In the last 2 decades, treatment of clots in these unusual locations is primarily managed medically, with interventional and surgical approaches reserved for more severe or refractory cases. The hematologist is well positioned to provide consultation to organ-specific specialties (ie, neurosurgery, hepatology, ophthalmology), especially because acquired and congenital hypercoagulability plays a major role, and anticoagulation is often the primary treatment. Historically, treatment has been based on expert opinion, but systematic reviews and meta-analyses have recently been published. Various societies have produced guidelines for the treatment of clots in unusual locations; however, randomized clinical trial data remain scarce. In the last few years, increasing data have emerged concerning the efficacy of the direct oral anticoagulants in treating clots in unusual locations. Cases have recently been described highlighting atypical thrombosis associated with COVID-19 infection as well as with the ChAdOx1 nCoV-19 (AstraZeneca) vaccine and Johnson and Johnson's Janssen Ad26.COV2.S vaccine. This article reviews clots in unusual locations with an emphasis on the splanchnic (mesenteric, portal, splenic, hepatic) and cerebral circulation. Through a case-based approach, key questions are posed, and data are presented to help guide diagnosis and treatment.

Evidence-Based Minireview: Should warfarin or a direct oral anticoagulant be used in patients presenting with thrombosis in the splanchnic or cerebral veins?

Case 1: A 23-year-old female third-year medical student who has no medical history seeks treatment for abdominal distention. She takes an estrogen-containing birth control pill and does not smoke or consume alcohol. Family history is unremarkable. Physical examination is significant for abdominal distention, and an abdominal fluid wave is detected. Complete blood count is normal. Imaging confirms occlusive thrombosis of the main portal vein. On endoscopy, grade 1 to 2 esophageal varices are noted and banded. Unfractionated heparin is begun. Subsequent workup reveals a homozygous factor V Leiden mutation. Long-term anticoagulation is planned, and she asks if warfarin can be avoided given her hectic ward rotations, erratic diet, and need for monitoring. Case 2: A 35-year-old woman who has no medical history seeks treatment for progressively worsening posterior headaches for 1 week. Magnetic resonance imaging of the brain shows dural sinus thrombosis with associated small areas of petechial cerebral hemorrhage. She is started on a continuous unfractionated heparin infusion and admitted to the hospital for further observation. Her grandmother is on warfarin for atrial fibrillation, and the patient would prefer to avoid warfarin because she does not think she can comply with the frequent monitoring that will be required. She inquires about other oral anticoagulant options for her condition.

[Diagnostic and treatment recommendations from the FACME ad-hoc expert working group on the management of cerebral venous sinus thrombosis associated with COVID-19 vaccination]

INTRODUCTION

Cases of cerebral venous sinus thrombosis have been reported in individuals vaccinated against COVID-19 with non-replicating adenoviral vector vaccines. We issue our recommendations on the diagnosis and management of patients presenting this complication.

METHOD

The multidisciplinary working group, led by the Spanish Federation of Medical and Scientific Associations and including representatives of several scientific societies, reviewed the available evidence from the literature and reports of the European Medicines Agency. We establish a definition for suspected cases and issue diagnostic and treatment recommendations regarding vaccine-induced immune thrombotic thrombocytopaenia.

RESULTS

We define suspected cases as those cases of cerebral venous sinus thrombosis occurring between 3 and 21 days after the administration of non-replicating adenoviral vector vaccines, in patients with a platelet count below 150,000/μL or presenting a decrease of 50% with respect to the previous value. Findings suggestive of vaccine-induced immune thrombotic thrombocytopaenia include the presence of antibodies to platelet factor 4, D-dimer levels 4 times greater than the upper limit of normal, and unexplained thrombosis. The recommended treatment includes intravenous administration of non-specific human immunoglobulin or alternatively plasmapheresis, avoiding the use of heparin, instead employing argatroban, bivalirudin, fondaparinux, rivaroxaban, or apixaban for anticoagulation, and avoiding platelet transfusion.

CONCLUSIONS

Non-replicating adenoviral vector vaccines may be associated with cerebral venous sinus thrombosis with thrombocytopaenia; it is important to treat the dysimmune phenomenon and the cerebral venous sinus thrombosis.

Diagnostic and treatment recommendations from the FACME ad-hoc expert working group on the management of cerebral venous sinus thrombosis associated with COVID-19 vaccination

INTRODUCTION

Cases of cerebral venous sinus thrombosis have been reported in individuals vaccinated against COVID-19 with non-replicating adenoviral vector vaccines. We issue our recommendations on the diagnosis and management of patients presenting this complication.

METHODS

The multidisciplinary working group, led by the Spanish Federation of Medical and Scientific Associations (FACME) and including representatives of several scientific societies, reviewed the available evidence from the literature and reports of the European Medicines Agency. We establish a definition for suspected cases and issue diagnostic and treatment recommendations regarding vaccine-induced immune thrombotic thrombocytopaenia.

RESULTS

We define suspected cases as those cases of cerebral venous sinus thrombosis occurring between 3 and 21 days after the administration of non-replicating adenoviral vector vaccines, in patients with a platelet count below 150 000/μL or presenting a decrease of 50% with respect to the previous value. Findings suggestive of vaccine-induced immune thrombotic thrombocytopaenia include the presence of antibodies to platelet factor 4, D-dimer levels 4 times greater than the upper limit of normal, and unexplained thrombosis. The recommended treatment includes intravenous administration of non-specific human immunoglobulin or alternatively plasmapheresis, avoiding the use of heparin, instead employing argatroban, bivalirudin, fondaparinux, rivaroxaban, or apixaban for anticoagulation, and avoiding platelet transfusion.

CONCLUSIONS

Non-replicating adenoviral vector vaccines may be associated with cerebral venous sinus thrombosis with thrombocytopaenia; it is important to treat the dysimmune phenomenon and the cerebral venous sinus thrombosis.

Treatment of portal vein thrombosis: an updated narrative review

Portal vein thrombosis (PVT) is the most frequent among the splanchnic vein thrombosis, accounting for 90% of cases. More than half of PVT are provoked by liver cirrhosis, solid cancer or myeloproliferative neoplasms. The remaining cases are non-malignant non-cirrhotic PVT and include either unprovoked events or thrombosis secondary to other less common risk factors (e.g. abdominal surgery, intrabdominal inflammations/infections, or hormonal stimuli). Anticoagulant therapy in patients with acute symptomatic PVT should be started early after diagnosis, if no active bleeding, to obtain greater vessel recanalization and reduce the occurrence of portal-hypertension related complications. Gastroesophageal varices do not represent a contraindication to anticoagulant treatment, as long as adequate measures have been undertaken for the prophylaxis of gastroesophageal bleeding. Different treatment options (unfractionated or low molecular weight heparin, vitamin K antagonists and direct oral anticoagulants [DOACs]) can be considered. In this narrative review we will discuss the treatment of PVT in the three most common scenarios (cirrhosis-associated, cancer-associated and non-malignant non-cirrhotic PVT). We will also discuss the role of the DOACs and summarise recent guidelines on this topic.

Pfortaderthrombosen – therapeutische Möglichkeiten

Die Pfortaderthrombose ist eine seltene Erkrankung, die eine Thrombose im Zustromgebiet der Pfortader in die Leber beschreibt bzw. in der Leber selbst in den entsprechenden Pfortaderästen lokalisiert ist. Oftmals liegt bereits eine chronische Lebererkrankung bzw. ein Malignom der Leber selbst oder unmittelbar benachbart liegender Organe vor; die Pfortaderthrombose kann aber auch bei Patienten auftreten, die keine entsprechende Vorerkrankung haben. Bei jeder neu diagnostizierten Pfortaderthrombose gilt es zu entscheiden, ob unmittelbar oder im Verlauf eine radiologisch-interventionelle Rekanalisation vorgenommen wird oder ein rein konservativer Therapieversuch mit Antikoagulanzien erfolgt. Aber auch chirurgische Verfahren, wie eine Shuntanlage oder die Notwendigkeit einer Lebertransplantation, müssen hierbei berücksichtigt werden. Für diesen Therapiealgorithmus ist die Kontaktaufnahme mit einem entsprechenden Zentrum sinnvoll. Die Therapieentscheidung muss die Ursache der Pfortaderthrombose und die Begleiterkrankungen adäquat berücksichtigen.

Direct oral anticoagulants for unusual-site venous thromboembolism

Direct oral anticoagulants (DOACs) are currently the preferred oral anticoagulant treatment for most of the patients with deep vein thrombosis of the lower extremities and/or pulmonary embolism. DOACs have several advantages over vitamin K antagonists, such as availability of fixed dosages, fewer drug interactions, faster onset of action, shorter half-life, and lower risk of major and intracranial bleeding. Although the evidence on the use of DOACs in patients with unusual-site venous thromboembolism (VTE) is limited to a few, small randomized controlled trials, these drugs are increasingly used in clinical practice, and several observational cohort studies have been published recently. This narrative review will describe the latest evidence for the use of the DOACs in patients with thrombosis in atypical locations (splanchnic, cerebral, upper extremity, ovarian, and renal vein thrombosis) and will provide some practical advice for their use in patients with unusual-site VTE.