Chronic portal vein thrombosis in adults: Clinical features, diagnosis, and management

INTRODUCTION — 

The portal vein is formed by the confluence of the splenic and superior mesenteric veins, which drain the spleen and small intestine, respectively (figure 1). Occlusion of the portal vein by thrombus (portal vein thrombosis [PVT]) typically occurs in patients with cirrhosis and/or prothrombotic disorders (table 1), although PVT may also develop in patients without an underlying condition.

PVT may be classified by disease duration [1]:

●Recent PVT – Recent (sometimes referred to as acute) PVT refers to PVT that developed less than six months ago. Patients with recent PVT usually have no or limited collateral circulation.

●Chronic PVT – Chronic PVT refers to PVT that persists for more than six months and may be referred to as cavernous transformation of the portal vein. Chronic PVT leads to the formation of collateral vessels that bring blood in a hepatopetal manner around the area of obstruction and may connect to the systemic circulation (ie, portosystemic collaterals) (image 1).

PVT may also be classified by thrombosis severity (eg, minimally occlusive, partially occlusive, or completely occlusive) or by response to therapy or interval change (eg, progressive, stable, regressive) (table 2) [1-3].

This topic will review the clinical features, diagnosis, and management of chronic PVT. Management of recent PVT is discussed separately. (See "Recent portal vein thrombosis in adults: Clinical features, diagnosis, and management".)

Management of mesenteric venous thrombosis is discussed separately. (See "Mesenteric venous thrombosis in adults".)

EPIDEMIOLOGY AND RISK FACTORS — 

The incidence of PVT among patients without cirrhosis is uncertain. PVT has been regarded as a causal factor in up to 10 percent of patients who develop portal hypertension in resource-abundant countries and in up to one-third of patients in resource-limited countries [4]. Infections associated with PVT have been more commonly reported in resource-limited areas. In a study of nearly 24,000 autopsies, the prevalence of PVT was 1 percent [5]. The most common predisposing conditions for PVT were cirrhosis (28 percent), primary or secondary hepatobiliary malignancy (23 and 44 percent, respectively), infectious or inflammatory abdominal disease (10 percent), or a myeloproliferative disorder (3 percent). Autopsy studies involving cirrhotic livers have reported prevalences of 6 to 64 percent, whereas studies that used ultrasonography to diagnose PVT reported prevalences of 5 to 24 percent [6]. These widely varying prevalence rates may reflect selection bias in the study populations.

Venous thrombosis predominantly results from reduced blood flow, vascular injury, and hypercoagulability (ie, Virchow's triad). The pathogenesis of PVT may differ in patients with cirrhosis compared with no cirrhosis:

●Patients with cirrhosis – Among patients with cirrhosis, the pathogenesis of PVT is not well understood. However, studies have suggested that severity of portal hypertension, severity of liver disease, velocity of portal blood flow, hepatocellular carcinoma, and possibly endothelial dysfunction at the portal venous bed may contribute to the risk of PVT [7-10]. In a study including 369 patients with cirrhosis, 29 patients (8 percent) developed PVT within five years [7]. Risk factors for PVT included low platelet count, history of variceal bleeding, worse Child-Pugh class, and a portal blood flow velocity <15 cm/second.

●Patients without cirrhosis – PVT in patients without cirrhosis has been associated with a predisposing condition such as an acute inflammatory abdominal process (eg, diverticulitis) or a thrombotic disorder (eg, Factor V Leiden, antiphospholipid syndrome) (table 1) [11-13]. In some patients with PVT, no specific cause is identified [14]. (See "Evaluating adult patients with established venous thromboembolism for acquired and inherited risk factors" and "Overview of the causes of venous thrombosis in adults".)

CLINICAL FEATURES

Patterns of clinical presentation — The clinical presentation of chronic PVT varies with the extent of venous occlusion and whether the patient has cirrhosis. The presentation ranges from asymptomatic patients to those with symptoms such as abdominal pain or gastrointestinal bleeding.

●Asymptomatic patients – Chronic PVT is usually discovered incidentally when abdominal imaging is obtained for other indications (eg, surveillance for hepatocellular carcinoma).

●Symptomatic patients – Symptoms related to chronic PVT include (see 'Managing complications' below):

•Gastrointestinal bleeding – Patients with chronic PVT may present with acute gastrointestinal bleeding related to esophageal or gastric varices [15,16]. As an example, in a study including 178 patients without cirrhosis who developed chronic PVT, variceal bleeding was the initial manifestation in 27 patients (15 percent) [17].

Patients with gastrointestinal bleeding typically report hematemesis, melena, or hematochezia [16]. (See "Overview of the management of patients with variceal bleeding".)

•Abdominal pain – If intestinal venous congestion, intestinal ischemia, or infarction develops, patients may report abdominal pain that radiates to the back, abdominal distension from ascites, or bloody diarrhea. Patients with chronic PVT may also develop intestinal ischemia and infarction if a thrombotic event occurs with extension of the clot into the superior mesenteric vein, although the risk of this complication is low [18].

•Symptoms related to portal cholangiopathy – Portal cholangiopathy (also referred to as portal biliopathy) is due to compression of the large bile ducts by venous collaterals. Thus, some patients develop symptoms of biliary complications such as obstructive jaundice, pruritus, biliary colic, or cholangitis [19,20]. Imaging studies have suggested that portal cholangiopathy was common in patients with longstanding non-cirrhotic chronic PVT, although most patients remain asymptomatic [19,21,22].

•Other symptoms – Patients with cirrhosis may present with signs of liver decompensation (eg, new onset ascites).

Laboratory features — Laboratory studies in patients with chronic PVT may include [23]:

●Normal or transiently elevated aminotransferases (alanine aminotransferase [ALT] and aspartate aminotransferase [AST]). Liver enzymes are usually normal because hepatic arterial blood flow compensates for reduced portal inflow (figure 1).

●For patients without cirrhosis, measures of liver synthetic function are typically preserved with the exception of hypoalbuminemia, which may be seen after fluid resuscitation for gastrointestinal bleeding. (See "Tests of the liver's biosynthetic capacity (eg, albumin, coagulation factors, prothrombin time)".)

●For patients with hypersplenism, laboratory testing may show anemia, thrombocytopenia, and leukopenia.

●For patients with portal cholangiopathy, laboratory findings may reveal a cholestatic pattern with elevated alkaline phosphatase and bilirubin. (See "Enzymatic measures of hepatic cholestasis (alkaline phosphatase, 5'-nucleotidase, gamma-glutamyl transpeptidase)".)

DIAGNOSTIC EVALUATION

When to suspect chronic PVT — Chronic PVT may be suspected incidentally in patients who undergo imaging for other conditions (eg, surveillance for hepatocellular carcinoma, tumor staging). Less commonly, patients may develop gastrointestinal bleeding or symptoms such as persistent, unexplained abdominal pain in addition to having risk factor(s) for thrombosis. (See 'Patterns of clinical presentation' above.)

Physical examination — Physical examination in patients with chronic PVT may be normal, although some patients have findings related to venous congestion, cirrhosis, or portal hypertension:

●Ascites – A small amount of ascites is seen in 10 to 20 percent of patients with chronic PVT who do not have cirrhosis [24], particularly after gastrointestinal bleeding with massive fluid resuscitation, which may lead to acute dilutional hypoalbuminemia. (See "Evaluation of adults with ascites".)

●Encephalopathy – Subclinical encephalopathy (may also be referred to as covert encephalopathy) may be seen in patients with cirrhosis or in some patients with PVT without cirrhosis. However, overt encephalopathy in patients without cirrhosis is uncommon and is typically seen in patients with PVT complicated by gastrointestinal bleeding, kidney failure, or sepsis [25,26]. (See "Hepatic encephalopathy in adults: Clinical manifestations and diagnosis", section on 'Clinical manifestations'.)

●Splenomegaly – Splenomegaly has been commonly reported in patients with chronic PVT [24]. The mechanism behind splenomegaly is not fully understood, but it may be related to increased venous congestion and splenic arterial flow. In patients without cirrhosis, the spleen size is often larger than that seen in those with cirrhosis.

●Other findings – Other findings may be related to underlying cirrhosis such as jaundice, spider angioma, or palmar erythema. (See "Cirrhosis in adults: Etiologies, clinical manifestations, and diagnosis", section on 'Physical examination'.)

Selecting an imaging method

Patients without abdominal pain — For patients without abdominal pain, we usually initiate testing with transabdominal ultrasound with Doppler study. If the ultrasound suggests PVT, we obtain a multiphase computed tomographic (CT) scan with intravenous contrast to confirm the diagnosis, assess the extent and severity of the thrombosis, assess for small vessels near the portal vein (also referred to as portosystemic collaterals) and evaluate for predisposing conditions (table 1). (See 'Patients with abdominal pain' below.)

We begin with transabdominal ultrasound because it is inexpensive, widely available, and can identify hepatobiliary pathology. However, ultrasound visualization of the mesenteric or splenic vein may be limited in some patients (those with obesity or abdominal distension). Thus, obtaining a contrast-enhanced CT scan for initial imaging is a reasonable alternative. (See 'Patients with abdominal pain' below.)

On abdominal ultrasound with Doppler, chronic PVT appears as isoechoic or hypoechoic material within the portal vein that may extend into the mesenteric or splenic veins, in addition to the absence of flow within the portal vein. Over time, the thrombus may become echogenic with fibrotic material [27]. Ultrasound may also show a mass of tortuous vessels at the porta hepatis or within the liver (also referred to as cavernous transformation of the portal vein, a phenomenon that has been reported as early as six days after acute thrombosis) [28]. The velocity of blood flow within those vessels is usually slower than blood flow in a normal portal vein [29-32].  

Patients with abdominal pain — For patients with suspected PVT and abdominal pain, we typically obtain multiphase abdominal computed tomography (CT) with intravenous contrast enhancement to establish the diagnosis, assess the extent and severity of the thrombosis (eg, partially occlusive, completely occlusive), assess for small vessels near the portal vein (also referred to as portosystemic collaterals) and evaluate for predisposing conditions (table 1).

On contrast-enhanced abdominal CT, the chronically thrombosed main portal vein may be obliterated or may be attenuated in appearance and have calcifications within the thrombus [27]. The thrombosed portal vein is often diminutive with low-density material in the lumen, or it is absent and replaced with small, tortuous collateral vessels [33]. In addition to portal collaterals, other features of portal hypertension (eg, splenomegaly, esophageal varices) may be seen.  

Magnetic resonance imaging (MRI) is an alternative to CT scan. On multiphase abdominal MRI with intravenous contrast enhancement, chronic PVT appears as diminutive portal veins without flow and collateral veins around the porta hepatis. In one study, MRI had a sensitivity of 100 percent and a specificity of 99 percent for detecting PVT [34].

Establishing the diagnosis — The diagnosis of chronic PVT is established with abdominal imaging (typically abdominal CT or MRI with intravenous contrast enhancement). Radiographic findings in chronic PVT include cavernous transformation of the portal vein, nonvisualization or occlusion of the main portal vein, and features of portal hypertension (splenomegaly, esophageal varices) [23]. (See 'Selecting an imaging method' above.)

POST-DIAGNOSIS EVALUATION

Assess for predisposing conditions — We evaluate patients without cirrhosis or other known risk factors for predisposing conditions such as thrombotic disorders (eg, myeloproliferative disorder, antiphospholipid syndrome) (table 1).

The evaluation of patients with PVT or other venous thromboses (eg, deep vein thrombosis of the lower extremity) for hypercoagulable conditions is discussed in detail separately. (See "Evaluating adult patients with established venous thromboembolism for acquired and inherited risk factors".)

Because PVT is common in patients with cirrhosis, we typically do not evaluate them for an underlying thrombotic disorder unless they have a history of thrombosis at another site, a family history of thrombotic disorder, or thrombocytosis [7]. Studies suggested that thrombotic disorders were not associated with PVT in patients with cirrhosis. In a study including 369 patients with cirrhosis, 29 patients (8 percent) developed PVT within five years. Hemostatic disorders were not associated with the risk of PVT in such patients.

Assess for malignancy — We assess all patients for malignancy-related PVT that may manifest as a tumor directly invading the portal vein (eg, hepatocellular carcinoma) or as a tumor externally constricting the portal vein (eg, pancreatic cancer, cholangiocarcinoma) [35]. In such patients, a thrombus within the portal vein may develop as a secondary event.  

We review cross-sectional imaging for any of the following characteristics that suggest a malignant PVT [36-38] (see "Recent portal vein thrombosis in adults: Clinical features, diagnosis, and management", section on 'Selecting an imaging method'):

●Abdominal or liver mass adjacent to the thrombus

●Disruption of the vessel walls or tumor encroaching on the portal vein

●Portal vein diameter >23 mm

●Enhancement of endoluminal material during the arterial phase of contrast injection

●On Doppler ultrasound, arterial-like pulsatile flow

In addition, an elevated alpha-fetoprotein (usually >400 ng/mL) suggests hepatocellular carcinoma.

The clinical features and diagnosis of abdominal malignancies that have been associated with PVT are discussed separately:

●Hepatocellular carcinoma – (See "Clinical features and diagnosis of hepatocellular carcinoma".)

●Pancreatic cancer – (See "Clinical manifestations, diagnosis, and staging of exocrine pancreatic cancer".)

●Cholangiocarcinoma – (See "Clinical manifestations and diagnosis of cholangiocarcinoma".)

Evaluate for complications — We assess all patients for complications of chronic PVT:

●Intestinal ischemia – We use multiphase, contrast-enhanced cross-sectional imaging with CT or MRI to assess for signs of intestinal ischemia (eg, bowel wall thickening, intestinal pneumatosis with portal vein gas, bowel dilation). However, intestinal ischemia is uncommon in patients with chronic PVT because collateral circulation has developed in most patients. The clinical manifestations and diagnosis of intestinal ischemia are discussed in detail separately. (See "Overview of intestinal ischemia in adults".)

●Complications related to portal hypertension – We review radiologic imaging for signs of portal hypertension including esophageal varices, splenomegaly, and ascites. (See 'Selecting an imaging method' above.)

We perform upper endoscopy to evaluate for esophageal or gastric varices as part of the pretreatment evaluation. (See 'Assess bleeding risk' below.)

●Portal cholangiopathy – We evaluate patients with unexplained severe cholestasis and/or symptoms of biliary obstruction for portal cholangiopathy. Portal collateral vessels around the common bile duct that accompany extrahepatic portal vein obstruction may lead to extrahepatic biliary obstruction. This secondary form of cholangiopathy may be referred to as portal cholangiopathy, portal hypertensive cholangiopathy, portal biliopathy, or portal cavernoma cholangiopathy [39-41]. Portal cholangiopathy is an uncommon complication of chronic PVT. Imaging findings include extrinsic compression on the bile ducts, bile duct strictures, and stone formation in the gallbladder, common bile duct, or intrahepatic ducts on contrast-enhanced CT or MRI and on magnetic resonance cholangiopancreatography (MRCP) [42].

MANAGEMENT

General measures — General measures for patients with chronic PVT include:

●Manage the underlying condition (if present) – If an underlying chronic inflammatory or thrombotic condition is identified (table 1), we initiate therapy for the underlying condition. Management of patients with a myeloproliferative disorder (eg, polycythemia vera, essential thrombocythemia) is discussed separately. (See "Polycythemia vera and secondary polycythemia: Treatment and prognosis" and "Essential thrombocythemia: Treatment and prognosis".)

●Specialist referral – We suggest that patients with PVT be referred to a center with specialty services, including hepatology, hematology, and interventional radiology.

Assess bleeding risk — We evaluate the patient’s bleeding risk following diagnosis of chronic PVT. This assessment is similar to evaluating patients who have venous thrombosis at other sites (eg, deep venous thrombosis), and these issues are discussed separately. (See "Overview of the treatment of lower extremity deep vein thrombosis (DVT)".)

Prior to initiating anticoagulation, we perform upper endoscopy in all patients with chronic PVT to evaluate for esophageal or gastric varices. For patients with high-risk esophageal varices, we use pharmacologic prophylaxis with a nonselective beta blocker or use endoscopic variceal ligation when beta blockers are contraindicated. Screening for varices and strategies for preventing bleeding are discussed separately. (See "Primary prevention of bleeding from esophageal varices in patients with cirrhosis".)

We screen for varices in patients without cirrhosis because studies have suggested that esophageal varices were common in noncirrhotic chronic PVT. In a study including 178 patients with chronic noncirrhotic PVT, variceal bleeding was the presenting feature in 27 patients (15 percent) [17]. In the remaining 151 patients, screening upper endoscopy showed large esophageal varices in 60 patients (40 percent), small esophageal varices in 28 patients (19 percent), gastric varices alone in 11 patients (7 percent), and no varices in 52 patients (34 percent).

For patients who presented with active variceal bleeding, we delay anticoagulation until hemostasis has been achieved and strategies to prevent rebleeding have been implemented (ie, endoscopic variceal ligation). (See "Prevention of recurrent bleeding from esophageal varices in patients with cirrhosis".)

For patients with chronic noncirrhotic PVT, anticoagulation has not been associated with a higher risk of variceal bleeding [17,43].

Selecting an approach — The decision to use anticoagulation in patients with chronic PVT is individualized and informed by several factors including severity of symptoms, severity and extent of portal venous obstruction, patient's bleeding risk, and whether the patient is a candidate for liver transplantation. In clinical practice, the benefits of anticoagulation are balanced with the risk of bleeding related to underlying portal hypertension. As an example, we typically anticoagulate patients with cirrhosis and chronic PVT who are awaiting liver transplantation because portal vein patency impacts the portal vein anastomosis between the donor liver and recipient [44-46]. (See 'Patients with cirrhosis' below.)

Patients without cirrhosis — Anticoagulation may benefit some patients with chronic PVT who do not have cirrhosis, particularly those with a chronic thrombotic condition who have not developed cavernous transformation [23]. Examples of high-risk thrombotic conditions include antiphospholipid syndrome, myeloproliferative disorders, and homozygous prothrombin gene mutation. (See "Antiphospholipid syndrome: Management" and "Overview of the myeloproliferative neoplasms".)

The decision to use anticoagulation involves shared decision-making and a discussion of the benefits balanced with the risks of adverse events (eg, gastrointestinal bleeding from varices). (See 'Assess bleeding risk' above.)

The primary goal of anticoagulation is to prevent all of the following:

●Recurrent episodes of thrombosis

●Extension of the clot into the mesenteric or splenic vein (see "Mesenteric venous thrombosis in adults").  

●Congestive intestinal ischemia (see "Overview of intestinal ischemia in adults")

Prevention of venous thrombosis in patients with specific thrombophilic disorders is discussed separately. (See individual topic reviews.)

Management of patients with tumor-related PVT is addressed separately. (See "Overview of treatment approaches for hepatocellular carcinoma" and "Supportive care for locally advanced or metastatic exocrine pancreatic cancer".)

Patients with cirrhosis — The decision to use anticoagulation in patients with cirrhosis and chronic PVT is individualized and informed by several factors including the presence of cavernous transformation, severity of symptoms, severity of thrombus, the patient's bleeding risk, patient preferences, and whether the patient is a candidate for liver transplantation or has coexisting inherited thrombophilia (ie, increased risk for recurrent thrombosis) (table 2) [23,41,47,48]. In clinical practice, the benefits of anticoagulation are balanced with the risk of bleeding related to underlying portal hypertension. As an example, we may anticoagulate patients with cirrhosis and chronic PVT who are awaiting liver transplantation because portal vein patency impacts the portal vein anastomosis between the donor liver and recipient. In contrast, we typically do not anticoagulate patients who are not candidates for liver transplantation and who have complete occlusion of the portal vein along with established collaterals because the benefit of anticoagulation in such patients has not been established [1].

The goals of anticoagulation in patients with cirrhosis include [3]:

●Preventing extension of the clot to mesenteric and splenic veins

●Promoting thrombosis regression and restoring vein patency

●Facilitating portal anastomosis at the time of liver transplantation

Clinical trials involving anticoagulation for patients with chronic PVT are lacking. Observational, indirect data have suggested that anticoagulation was beneficial and safe for selected patients with cirrhosis and PVT, although most studies included patients with recent PVT [49,50]. (See "Recent portal vein thrombosis in adults: Clinical features, diagnosis, and management", section on 'Management'.)

PVT complicates liver transplantation surgery [45,46,51]. In addition, data from a large cohort of liver transplant recipients (Scientific Registry of Transplant Recipients) suggested that PVT was associated with an increased risk of post-transplant mortality compared with no thrombosis (hazard ratio 1.32) [46]. Anticoagulation may promote portal vein recanalization, although use of anticoagulation in liver transplant candidates has not been studied in clinical trials [45,51].

The management of patients with cirrhosis and PVT related to hepatocellular carcinoma is discussed separately. (See "Overview of treatment approaches for hepatocellular carcinoma".)

Anticoagulation

Initial administration — We typically use low molecular weight heparin for initial anticoagulation therapy. After the patient’s symptoms have improved and no invasive procedures are planned, we transition to an oral anticoagulant (ie, vitamin K antagonist [VKA] such as warfarin or acenocoumarol). For patients treated with VKA, the target international normalized ratio (INR) is 2 to 3 [30]. Dosing and administration of anticoagulant therapy are generally similar to the approach for patients with venous thrombosis at other sites (eg, deep venous thrombosis), and these issues, including adverse effects, are discussed separately:

●(See "Overview of the treatment of lower extremity deep vein thrombosis (DVT)".)

●(See "Venous thromboembolism: Anticoagulation after initial management".)

●(See "Warfarin and other VKAs: Dosing and adverse effects".)

We use an oral anticoagulant (usually a VKA) because most anticoagulated patients require long-term therapy. An alternative is to use low molecular weight heparin chronically because it has a shorter duration of action, which may be beneficial for selected patients, such as those awaiting liver transplantation [52].

Direct oral anticoagulant (DOAC) therapy is an alternative to a VKA for long-term therapy. DOAC use is individualized and informed by the potential benefits (eg, oral administration, decreased need for laboratory monitoring), the risk of bleeding, and patient preferences. We generally avoid DOAC use in patients with decompensated cirrhosis and/or Child Pugh class B or C cirrhosis because of increased bleeding risk [53].

Data on efficacy and safety of DOACs for PVT have been mixed [54-58]. In a cohort study including 40 patients with chronic PVT and cirrhosis, DOAC therapy (rivaroxaban or dabigatran) for three months or for six months was associated with recanalization rates of 13 and 28 percent, respectively [54]. The risk of bleeding was not significantly higher for patients on DOACs compared with a historical control group. In another study including 50 patients with PVT and cirrhosis who were initially treated with danaparoid, subsequent therapy with edoxaban was associated with reduced volume of thrombus compared with warfarin, although the clinical implications of this outcome were uncertain [55]. Bleeding rates were numerically higher in the edoxaban group (15 versus 7 percent). In a report of three patients with PVT and cirrhosis, dabigatran was not associated with recanalization in any of the patients [57].

For patients with chronic PVT in the absence of cirrhosis, data comparing DOACs with other anticoagulants have been limited to observational studies. In a study including 63 patients without cirrhosis who had PVT, DOAC therapy was associated with higher rates of complete PVT resolution on imaging compared with warfarin (96 versus 55 percent) [56].

Duration of therapy — For patients with chronic PVT who have completed at least six months of anticoagulation therapy, we generally continue anticoagulation long-term if the patient has a chronic thrombotic condition [59].

For patients without an underlying thrombotic condition, the decision to continue long-term anticoagulation is individualized and informed by the risk of thrombosis recurrence or extension, the risk of adverse effects related to anticoagulation, patient preferences, and clinician preferences.  

Monitoring — We monitor patients for complications of portal hypertension (eg, ascites) and for symptoms (eg, abdominal pain). If symptoms or suspected complications develop, we reassess such patients with contrast-enhanced CT or MRI.

Patients with cirrhosis are monitored routinely with imaging for hepatocellular carcinoma, and this is discussed separately. (See "Surveillance for hepatocellular carcinoma in adults".)

Observation — For patients with chronic PVT who are not treated with anticoagulation, we monitor symptoms and repeat imaging with contrast-enhanced CT if new symptoms develop or symptoms worsen. If imaging shows clot progression (eg, >50 percent luminal venous obstruction, extension into mesenteric veins), we re-evaluate the patient for anticoagulation therapy. (See 'Anticoagulation' above.)

Patients with cirrhosis are monitored routinely with imaging for hepatocellular carcinoma, and this is discussed separately. (See "Surveillance for hepatocellular carcinoma in adults".)

Subsequent management

Transjugular intrahepatic portosystemic shunt (TIPS) — TIPS may be a treatment option for patients with complications related to chronic PVT (eg, portal cholangiopathy, uncontrolled variceal bleeding) or as a bridge to liver transplantation [60]. However, TIPS may be technically challenging, particularly in patients without a visible intrahepatic portal vein [61,62]. In a study including 61 patients with PVT who were awaiting liver transplantation and underwent portal vein recanalization followed by TIPS placement, 55 patients (92 percent) had a patent portal vein/TIPS after a median follow-up of 19 months [61]. Recurrent thrombosis occurred in five patients (8 percent). Twenty-four patients (39 percent) underwent liver transplantation, and there were no reports of recurrent PVT after transplantation during a median follow-up of 33 months.

Other interventions — Surgical shunting is rarely performed for managing complications related to chronic portal vein thrombosis. (See 'Managing complications' below.)

Managing complications

Portal cholangiopathy — Portal cholangiopathy refers to extrahepatic biliary obstruction from collateral vessels surrounding the common bile duct. (See 'Evaluate for complications' above.)

Data are limited regarding the treatment of complications related to portal cholangiopathy (eg, biliary obstruction, biliary stones). We usually manage biliary obstruction with endoscopic methods including biliary sphincterotomy, ductal clearance of biliary stones, and endoscopic stent placement for biliary stricture. (See "Endoscopic management of bile duct stones" and "Endoscopic management of postcholecystectomy biliary complications", section on 'Biliary stricture'.)

To manage the underlying cause of portal cholangiopathy, portal vein recanalization by interventional radiologic techniques and TIPS has shown promise and has replaced surgical interventions such as portosystemic shunt followed by hepaticojejunostomy [3,63]. (See 'Subsequent management' above and "Overview of transjugular intrahepatic portosystemic shunts (TIPS)".)

Intestinal ischemia — Patients with chronic PVT may develop intestinal ischemia and infarction if there is extension of the clot into the superior mesenteric vein, though the risk is low. In patients with impending bowel ischemia due to PVT, the decision regarding the best approach to decompress the portal vein and preserve the bowel (eg, interventional techniques, surgical shunting) should be individualized based on the patient's comorbidities, technical feasibility, and available expertise. (See "Mesenteric venous thrombosis in adults".)

Patients with intestinal ischemia require multidisciplinary care including clinicians with surgical, critical care, and radiology expertise.

Other complications — Other complications of chronic PVT are usually related to portal hypertension or cholestasis. In general, patients with these complications are managed similarly to those who have such complications in the absence of PVT.

●Variceal bleeding – We use endoscopic therapy plus pharmacologic therapy for patients with active variceal bleeding. (See "Methods to achieve hemostasis in patients with acute variceal hemorrhage", section on 'Management of esophageal varices'.)

After hemostasis is achieved, we typically use endoscopic variceal ligation plus a nonselective beta blocker to prevent recurrent bleeding. (See "Prevention of recurrent bleeding from esophageal varices in patients with cirrhosis".)

For patients with recurrent bleeding despite endoscopic and pharmacologic prophylaxis, a subsequent option is portal vein recanalization with TIPS (if a large collateral vessel is available) [61]. If interventional radiologic techniques are not successful and there is a patent vessel available, a surgical shunt may be another option. Management of refractory variceal bleeding is discussed separately. (See "Methods to achieve hemostasis in patients with acute variceal hemorrhage", section on 'Management if endoscopic therapy fails'.)

For patients with PVT and splenic vein thrombosis complicated by bleeding from isolated gastric varices, splenectomy is a treatment option [64]. (See "Elective (diagnostic or therapeutic) splenectomy".)

The severity of liver disease impacts surgical risk and informs decision-making. (See "Assessing surgical risk in patients with liver disease" and "Anesthesia for the patient with liver disease".)

●Hepatic encephalopathy – Management of hepatic encephalopathy is discussed separately. (See "Hepatic encephalopathy in adults: Treatment".)

●Ascites – Management of ascites related to portal hypertension is discussed separately. (See "Ascites in adults with cirrhosis: Initial therapy".)

●Pruritus – Management of pruritus associated with cholestasis is discussed separately. (See "Pruritus associated with cholestasis".)

PREVENTIVE STRATEGIES — 

Prevention of PVT in individuals with cirrhosis focuses on optimizing liver function, reducing portal venous pressure, and increasing portal flow, which diminishes stasis. These issues are presented separately. (See "Hemostatic abnormalities in patients with liver disease", section on 'Portal vein thrombosis (PVT)'.)

PROGNOSIS — 

Patients with chronic PVT who receive anticoagulation therapy have a good prognosis in the absence of cirrhosis or malignancy. In a study of 136 patients with chronic PVT who did not have cirrhosis or an underlying malignancy, 84 patients (62 percent) were treated with anticoagulation [25]. After five years, two patients (1 percent) who were not anticoagulated died from complications related to PVT. Other risk factors for mortality may include patient age, the cause of PVT (eg, myeloproliferative disorder or decompensated cirrhosis), or unrelated comorbidities [65].

SOCIETY GUIDELINE LINKS — 

Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Hepatic, portal, and splenic vein thrombosis".)

SUMMARY AND RECOMMENDATIONS

●Background – Portal vein thrombosis (PVT) is occlusion of the portal vein by thrombus that typically occurs in patients with cirrhosis or prothrombotic disorders (table 1). Chronic PVT is defined as thrombus that persists for more than six months. Chronic PVT leads to the formation of collateral vessels that bring blood in a hepatopetal manner around the area of obstruction and that may connect to the systemic circulation (ie, portosystemic collaterals) (image 1). The appearance of collateral vessels may be referred to as cavernous transformation. (See 'Introduction' above and 'Epidemiology and risk factors' above.)

In addition to disease duration, PVT may be classified by thrombosis severity (eg, minimally occlusive, partially occlusive, or completely occlusive) or by response to therapy or interval change (eg, progressive, stable, regressive) (table 2).

●Clinical presentation – The clinical presentation of chronic PVT varies with the extent of venous occlusion and whether the patient has cirrhosis. Chronic PVT is often discovered incidentally when abdominal imaging is obtained for other indications. When symptoms develop, they may be related to portal hypertension (eg, gastrointestinal bleeding) or portal cholangiopathy (eg, jaundice, pruritus). (See 'Clinical features' above.)

●Diagnostic evaluation – The diagnosis of chronic PVT is established with abdominal imaging that demonstrates nonvisualization or occlusion of the main portal vein, often with cavernous transformation. Radiographic findings may include features of portal hypertension (splenomegaly, esophageal varices). We also use imaging to determine the severity and extent of the thrombosis. (See 'Diagnostic evaluation' above.)

•For patients without abdominal pain, we initiate testing with transabdominal ultrasound with Doppler study. If the ultrasound suggests PVT, we obtain a multiphase computed tomographic (CT) scan with intravenous contrast to establish the diagnosis.

•For patients with abdominal pain, we typically obtain multiphase abdominal CT scan with intravenous contrast to establish the diagnosis.

●Post-diagnostic evaluation – The post-diagnostic evaluation includes (see 'Post-diagnosis evaluation' above):

•Assessing for predisposing conditions in patients without known risk factors.

•Assessing for underlying malignancy (eg, hepatocellular carcinoma).

•Assessing the patient’s risk of bleeding by performing upper endoscopy to screen for esophageal or gastric varices and by using a method similar to evaluating patients who have venous thrombosis at other sites. (See "Overview of the treatment of lower extremity deep vein thrombosis (DVT)".)

●General measures – General measures include (see 'General measures' above):

•Manage the underlying condition (if present) – If an underlying chronic inflammatory or thrombotic condition is identified (table 1), we initiate therapy for the underlying condition. (See "Polycythemia vera and secondary polycythemia: Treatment and prognosis" and "Essential thrombocythemia: Treatment and prognosis".)

•Specialist referral – We suggest that patients with chronic PVT be referred to a center with specialty services, including hepatology, hematology, and interventional radiology.

●Specific approaches – The decision to use anticoagulation is individualized and informed by severity of symptoms, severity and extent of thrombosis, patient's bleeding risk, and whether the patient is a candidate for liver transplantation. (See 'Selecting an approach' above.)

For patients with chronic PVT, the goals of anticoagulation are to prevent recurrent thromboses, clot extension, and congestive intestinal ischemia. (See 'Anticoagulation' above.)

•Patients without cirrhosis – Anticoagulation may benefit some patients who do not have cirrhosis, particularly those with a chronic thrombotic condition who have not developed cavernous transformation. Examples of high-risk thrombotic conditions include antiphospholipid syndrome and myeloproliferative disorders. (See "Antiphospholipid syndrome: Management" and "Overview of the myeloproliferative neoplasms".)

•Patients with cirrhosis – In clinical practice, the benefits of anticoagulation are balanced with the risk of bleeding related to portal hypertension. Patients with cirrhosis and chronic PVT often have cavernous transformation with portosystemic collaterals. However, we may anticoagulate patients who are awaiting liver transplantation because portal vein patency impacts the portal vein anastomosis between the donor liver and recipient.

For patients who are not treated with anticoagulation, we monitor symptoms and repeat imaging with contrast-enhanced CT if new symptoms develop or symptoms worsen. If imaging shows clot progression (eg, >50 percent luminal venous obstruction, extension into mesenteric veins), we re-evaluate the patient for anticoagulation therapy. (See 'Observation' above.)