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Abstract
Acute portal vein thrombosis (PVT) is a rare disorder defined by the sudden occlusion of the portal vein, which could be partial or complete. Prothrombotic states, inherited or acquired, are thought to be the cause in patients without cirrhosis or malignancy. However, the aetiology of some cases remains idiopathic despite a multidisciplinary diagnostic approach. The initial diagnostic modality to confirm PVT is either contrast-enhanced abdominal (CT) or MRI; as it can identify predisposing factors, and detect evidence of complications. Eliciting the underlying aetiology is critical to guide overall management and prevent future recurrence. The purpose of treatment is to stop thrombus extension and achieve portal vein patency by anticoagulation to optimise outcomes. Herein, we present an unusual case of spontaneous PVT in a young woman. We will also discuss the evaluation of patients without obvious aetiology.
- haematology (incl blood transfusion)
- venous thromboembolism
- cirrhosis
- portal vein
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Background
Acute portal vein thrombosis (PVT) is a rare disorder, often clinically silent and underdiagnosed. The prevalence and incidence of PVT can vary greatly according to the characteristics of the studied population.1 A large-scale population base study noted a prevalence of 1.0%,2 while another retrospective Swedish study, Rajani et al noted a prevalence of 0.7/100 000 per year.3 Despite this variation in prevalence both studies concluded the most common aetiology of PVT was related to chronic hepatic disease or underlying malignancy,1–3 while acute PVT related to non-cirrhotic and non-malignant PVT is much more uncommon.
In the absence of cirrhosis or malignancy, the aetiologies leading to the development of PVT suggest an underlying local or systemic hypercoagulable process, which may be inherited or acquired. Eliciting the underlying aetiology in PVT is critical for overall management and prevention of future recurrence. However, investigation may not reveal a cause despite a multidisciplinary diagnostic approach.4 5
The purpose of our report is to highlight the best initial diagnostic modalities, treatment and further discusses the importance of evaluation of the underlying aetiology of PVT.
Case presentation
Our 27-year-old woman with no significant medical history presented to the emergency department with sudden and progressively worsening epigastric abdominal pain for 2 days. She stated that she woke up in excruciating dull pain, 10/10 in severity, non-radiating. She had a similar episode 3–4 months previously; at the time she did not seek medical care and the pain resolved spontaneously. She denied any nausea, vomiting, aggravating or alleviating factors, use of aspirin or non-steroidal medications, recent antibiotic use or recent dietary changes, but did admit to having some loose stools. She did not use alcohol or illicit substances (eg, cocaine or heroin).
She had an ectopic pregnancy in 2 years prior to admission but denied any other miscarriages. She stated that she had a family history of deep venous thrombosis in her father at age 55, but it was unknown if it was provoked or associated with a genetic abnormality. She denied personal or family history of lupus or other autoimmune disorders. She did not use oral contraceptives (OCPs), herbal medications or supplemental oestrogen/progesterone. She had C-section 2 years and cholecystectomy 4 years ago without thrombotic complications. She had appropriate age screening the same year including pap smear which was negative. She has not been vaccinated for COVID-19.
Investigations
An ultrasound of the abdomen was performed and showed near total occlusive left portal vein thrombosis with no evidence of cirrhosis (figure 1). A CT scan was performed thereafter and confirmed the diagnosis. Liver function tests, international normalized ratio (INR) and activated partial thromboplastin time (aPTT) were normal.
Abdominal ultrasound with Doppler revealing nearly occlusive left portal vein thrombosis.
The patient was evaluated for genetic causes of hypercoagulability, including factor V Leiden, antiphospholipid antibody, beta-2 glycoprotein, protein C and S and Janus Kinase 2 (JAK2), which came back negative.
Treatment
She was started on heparin-warfarin bridge therapy and discharged 48 hours after INR/PTT were therapeutic
Outcome and follow-up
The patient’s condition improved on discharge. She was instructed to follow up in 1 month in the haematology clinic after being diagnosed with idiopathic portal vein thrombosis.
Discussion
Acute PVT is defined by the sudden occlusion of the portal vein, which could be partial or complete. Thrombosis may not be limited to the portal vein only; the extension of the thrombus to the mesenteric or splenic vein can be complicated by intestinal ischaemia and splenomegaly, respectively.
Prothrombotic states, inherited or acquired, are thought to be the cause of (PVT) in patients without cirrhosis with myeloproliferative disease being the most common.5 6 However, more than 25% of patients do not have a known cause (table 1).7 The most common inherited conditions associated with PVT include factor V Leiden, prothrombin gene mutations, protein C and S deficiency, and antithrombin deficiency.8–13 In our case, the patient was tested for all the inherited causes which came back negative.
Prevalence of PVT risk factor as reported one decade apart
Acquired conditions associated with PVT besides malignancy include antiphospholipid syndrome, paroxysmal nocturnal haemoglobinuria, Behçet’s syndrome, OCP use, abdominal infection, pancreatitis and inflammatory bowel disease, among others.9 14 Metabolic syndrome, particularly central obesity, has also been found to be associated with PVT.15 Abdominal surgery or surgical injury of the portal vein axis, transjugular intrahepatic portosystemic shunt and splenectomy are common procedures that predispose to PVT.14 16 17
Patients who develop acute PVT may be asymptomatic and are often diagnosed incidentally. However, the most common presentation is sudden or progressive abdominal pain over a few days.18 Septic PVT (acute pylephlebitis) is suspected in the presence of spiking fever, chills and right upper quadrant tenderness. The initial diagnostic modality to evaluate suspected PVT is either contrast-enhanced abdominal CT scan or MRI19; identification of predisposing factors (such as infection), assessment of the extent of thrombosis and detection of some complications (intestinal infarction) can be achieved in addition to confirming the diagnosis. If the suspicion for PVT is low (non-cirrhotic patient or no risk factors for thrombosis), it is reasonable to obtain a Doppler ultrasound, followed by abdominal CT scan if positive.20
The purpose of treatment in PVT is to stop thrombus extension and achieve portal vein patency. Management is composed of treating the underlying cause, hydration and anticoagulation, which is the mainstay of therapy as it reduces the risk of recurrence.14 Despite the heterogeneity in PVT population, low-molecular-weight heparin and warfarin are the most common anticoagulation regimen; however, direct-acting oral anticoagulant may become an alternative therapy as they have shown efficacy in non-cirrhotic PVT.21 22
Earlier anticoagulation has been associated with better outcomes23; Turnes et al24 found that patients who were anticoagulated in the first week had greater recanalisation rate (69%) compared with second week anticoagulation (25%).24 The recommended duration of anticoagulation is at least 3 months although there is no optimal period.25 Some studies have shown that complete recanalisation may not be achieved until 6 months of anticoagulation.26 27 Lifelong anticoagulation is required in hypercoagulable state or if the thrombus is extending to the mesenteric vein.25
There is little guidance on how to follow patients with idiopathic PVT; however, monitoring for recurrence of symptoms and repeating imaging in 3–6 months after anticoagulation using the same modality obtained at the time of diagnosis is a common practice.28 By extrapolating from the literature in unprovoked venous thromboembolism (VTE), testing for hypercoagulable state and screening for occult malignancy are recommended in patient with PVT.29 The highest incidence of occult malignancy diagnosis as demonstrated by most studies is within the first 6 months of VTE episode,30–32 which is the optimal time for cancer evaluation, although testing is preferred during the initial admission. This includes age-appropriate cancer screening and further radiographic imaging based on the clinical finding.29
This is a case of acute PVT that is notable for its idiopathic origin. Although it is associated with hypercoagulable state, it is important to remember that PVT may occur with no underlying cause and should be considered in patients of any age with abdominal pain and no identifiable aetiology. Anticoagulation for at least 3 months is the mainstay of therapy to avoid the extension of the thrombus and the subsequent complications which includes intestinal ischaemia and portal hypertension. The earlier the anticoagulation, the better the outcomes.
Learning points
Acute portal vein thrombosis (PVT) is a rare disorder, often clinically silent and underdiagnosed.
Investigation for an underlying aetiology may not reveal a cause despite a multidisciplinary diagnostic approach.
Anticoagulation for at least 3 months is the mainstay of therapy to avoid thrombus extension and subsequent complications.
In non-cirrhotic PVT, direct-acting oral anticoagulant may become an alternative therapy to low-molecular-weight heparin and warfarin.
Testing for hypercoagulable state and screening for occult malignancy are recommended in patient with unprovoked PVT.
Ethics statements
Patient consent for publication
References
Footnotes
Contributors DL, ZK, NZ and SA contributed to report preparation. SA took the lead in writing the case report. All authors provided critical feedback and helped shape the case.
Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
Competing interests None declared.
Provenance and peer review Not commissioned; externally peer reviewed.