Idiopathic noncirrhotic portal hypertension is associated with poor survival: results of a long-term cohort study

Vascular liver diseases on the clinical side: definitions and diagnosis, new concepts

The components of the hepatic vascular system (hepatic arteries, portal and hepatic veins, sinusoids, and lymphatics) can be damaged by various types of injury. Each of the resulting conditions is rare, which has limited knowledge and awareness. In the last two decades, international collaborations have allowed to reach critical masses of data, which has driven significant progresses in understanding and management of vascular disorders of the liver. The present paper discusses definitions, denominations, and diagnosis of such vascular disorders with the exception of those affecting hepatic arteries. Evolving pathogenic or pathophysiologic views relevant to the clinical aspects are also overviewed.

Idiopathic portal hypertension and extrahepatic portal venous obstruction

BACKGROUND

Idiopathic portal hypertension (IPH) and extrahepatic portal venous obstruction (EHPVO) are non-cirrhotic vascular causes of portal hypertension (PHT). Variceal bleed and splenomegaly are the commonest presentations.

AIM

The present review is intended to provide the existing literature on etiopathogenesis, clinical profile, diagnosis, natural history and management of IPH and EHPVO.

RESULTS

IPH and EHPVO are both characterized by normal hepatic venous pressure gradient, moderate to massive splenomegaly with preserved liver synthetic functions. While the level of block in IPH is presinusoidal, in EHPVO it is at prehepatic level. Infections, autoimmunity, drugs, immunodeficiency and prothrombotic states are possible etiological agents in IPH. Contrastingly in EHPVO, prothrombotic disorders and local factors around the portal vein are the incriminating factors. Diagnosis is often clinical, supported by simple radiological tools. Natural history is defined by episodes of variceal bleed and symptoms related to enlarged spleen. Growth failure, portal biliopathy and minimal hepatic encephalopathy are additional concerns in EHPVO. Long-term survival is reasonably good with endoscopic surveillance; however, parenchymal extinction leading to decompensation is seen in a minority of patients in both the disorders. Surgical shunts revert the complications secondary to PHT. Meso-Rex shunt has become the standard surgery in children with EHPVO.

CONCLUSION

This review gives a detailed summary of these two vascular conditions of liver-IPH and EHPVO. Further research is needed to understand the pathogenesis and natural history of these disorders.

Novel Rat Model of Repetitive Portal Venous Embolization Mimicking Human Non-Cirrhotic Idiopathic Portal Hypertension

BACKGROUND

Non-cirrhotic idiopathic portal hypertension (NCIPH) is characterized by splenomegaly, anemia and portal hypertension, while liver function is preserved. However, no animal models have been established yet. This study assessed a rat model of NCIPH and characterized the hemodynamics, and compared it to human NCIPH.

METHODS

Portal pressure (PP) was measured invasively and coloured microspheres were injected in the ileocecal vein in rats. This procedure was performed weekly for 3 weeks (weekly embolization). Rats without and with single embolization served as controls. After four weeks (one week after last embolization), hemodynamics were investigated, hepatic fibrosis and accumulation of myofibroblasts were analysed. General characteristics, laboratory analyses and liver histology were collected in patients with NCIPH.

RESULTS

Weekly embolization induced a hyperdynamic circulation, with increased PP. The mesenteric flow and hepatic hydroxyproline content was significantly higher in weekly embolized compared to single embolized rats (mesenteric flow +54.1%, hydroxyproline +41.7%). Mesenteric blood flow and shunt volumes increased, whereas splanchnic vascular resistance was decreased in the weekly embolization group. Fibrotic markers αSMA and Desmin were upregulated in weekly embolized rats.

DISCUSSION

This study establishes a model using repetitive embolization via portal veins, comparable with human NCIPH and may serve to test new therapies.

Idiopathic noncirrhotic portal hypertension: current perspectives

The term idiopathic noncirrhotic portal hypertension (INCPH) has been recently proposed to replace terms, such as hepatoportal sclerosis, idiopathic portal hypertension, incomplete septal cirrhosis, and nodular regenerative hyperplasia, used to describe patients with a hepatic presinusoidal cause of portal hypertension of unknown etiology, characterized by features of portal hypertension (esophageal varices, nonmalignant ascites, porto-venous collaterals), splenomegaly, patent portal, and hepatic veins and no clinical and histological signs of cirrhosis. Physicians should learn to look for this condition in a number of clinical settings, including cryptogenic cirrhosis, a disease known to be associated with INCPH, drug administration, and even chronic alterations in liver function tests. Once INCPH is clinically suspected, liver histology becomes mandatory for the correct diagnosis. However, pathologists should be familiar with the histological features of INCPH, especially in cases in which histology is not only requested to exclude liver cirrhosis.

Role of the transjugular intrahepatic portosystemic shunt in the management of severe complications of portal hypertension in idiopathic noncirrhotic portal hypertension

Idiopathic noncirrhotic portal hypertension is a heterogeneous group of diseases characterized by portal hypertension in the absence of cirrhosis. The efficacy and safety of transjugular intrahepatic portosystemic shunt (TIPS) in this population are unknown. The charts of patients with idiopathic noncirrhotic portal hypertension undergoing TIPS in seven centers between 2000 and 2014 were retrospectively reviewed. Forty-one patients were included. Indications for TIPS were recurrent variceal bleeding (n = 25) and refractory ascites (n = 16). Patients were categorized according to the presence (n = 27) or absence (n = 14) of significant extrahepatic comorbidities. Associated conditions were hematologic, prothrombotic, neoplastic, immune, and exposure to toxins. During follow-up (mean 27 ± 29 months), variceal rebleeding occurred in 7/25 (28%), including three with early thrombosis of the stent. Post-TIPS overt hepatic encephalopathy was present in 14 patients (34%). Eleven patients died, five due the liver disease or complications of the procedure and six because of the associated comorbidities. The procedure was complicated by hemoperitoneum in four patients (10%), which was fatal in one case. Serum creatinine (P = 0.005), ascites as indication for TIPS (P = 0.04), and the presence of significant comorbidities (P = 0.01) at the time of the procedure were associated with death. Mortality was higher in patients with significant comorbidities and creatinine ≥100 μmol/L (P < 0.001).

CONCLUSION

In patients with idiopathic noncirrhotic portal hypertension who have normal kidney function or do not have severe extrahepatic conditions, TIPS is an excellent option to treat severe complications of portal hypertension. (Hepatology 2016;64:224-231).

[Idiopathic non-cirrhotic portal hypertension: An update]

Idiopathic non-cirrhotic portal hypertension is an under-estimated cause of portal hypertension. The diagnosis requires the exclusion of cirrhosis, common causes of chronic liver disease and venous obstruction of the portal and hepatic veins. It has been associated with various extra-hepatic conditions that are most frequently immunologic, prothrombotic, hematologic and toxic. The most frequent clinical complications are variceal hemorrhage and portal vein thrombosis. Complications of portal hypertension should be managed as in patients with cirrhosis.

Differential Clinical Impact of Ascites in Cirrhosis and Idiopathic Portal Hypertension

Cirrhosis and idiopathic portal hypertension (IPH) are 2 major diseases showing portal hypertension. However, characteristics and outcomes of IPH with ascites have not yet been determined. The aim of the study was to examine the influence of ascites on the long-term clinical course of IPH.This observational study compared the long-term clinical findings including portal hemodynamics demonstrated by Doppler ultrasonography between 166 cirrhosis (87 males and 79 females; mean age ± standard deviation, 62.5 ± 11.8 years; age range, 20-89 years) and 14 IPH patients (3 males and 11 females; mean age ± standard deviation, 64.2 ± 6.6 years; age range, 51-78 years). Both groups comprised of consecutive patients from November 2007 through February 2013 and were studied retrospectively. The median observation period was 33.4 months for ascites and 34.5 months for survival.Ascites was detected in 60/166 (36.1%) and 116/166 (69.9%) cirrhosis patients and in 7/14 (50%) and 9/14 (64.3%) IPH patients, at baseline and at the end of the observation period, respectively. The cumulative incidence of ascites was 12.3% at 1 year, 35.9% at 3 years, and 59.9% at 5 years in cirrhosis, and 25% at 3 years, and 50% at 5 years in IPH (P = 0.36). Deterioration of ascites in patients showing mild ascites at baseline was found in 32.4% of cirrhosis patients and 42.9% of IPH patients (P = 0.41). Serum creatinine (mg/dl) at baseline was significantly higher in IPH patients who developed ascites (n = 2, 0.74 ± 0.14) than in those who did not (n = 5, 0.526 ± 0.06, P = 0.029). The overall survival rate appeared to favor IPH (100% at 1 year, 92.9% at 3 and 5 years; P = 0.2) more than cirrhosis (87.7% at 1 year, 75.2% at 3 years, and 63.6% at 5 years), but did not reach statistical significance. However, in patients with ascites at baseline, the survival rate was significantly better in IPH (100% at 1, 3, and 5 years, P = 0.04) than in cirrhosis (69.1% at 1 year, 43% at 3 years, 34.4% at 5 years).The presence of ascites at baseline correlated with worse survival rates in patients with cirrhosis as compared to those with IPH as the underlying etiology.

Idiopathic non-cirrhotic portal hypertension: a review

Idiopathic non-cirrhotic portal hypertension (INCPH) is a rare disease characterized of intrahepatic portal hypertension in the absence of cirrhosis or other causes of liver disease and splanchnic venous thrombosis. The etiology of INCPH can be classified in five categories: 1) immunological disorders (i.e. association with common variable immunodeficiency syndrome, connective tissue diseases, Crohn’s disease, etc.), 2) chronic infections, 3) exposure to medications or toxins (e.g. azathioprine, 6- thioguanine, arsenic), 4) genetic predisposition (i.e. familial aggregation and association with Adams-Oliver syndrome and Turner disease) and 5) prothrombotic conditions (e.g. inherited thrombophilias myeloproliferative neoplasm antiphospholipid syndrome). Roughly, INCPH diagnosis is based on clinical criteria and the formal exclusion of any other causes of portal hypertension. A formal diagnosis is based on the following criteria: 1) presence of unequivocal signs of portal hypertension, 2) absence of cirrhosis, advanced fibrosis or other causes of chronic liver diseases, and 3) absence of thrombosis of the hepatic veins or of the portal vein at imaging. Patients with INCPH usually present with signs or symptoms of portal hypertension such as gastro-esophageal varices, variceal bleeding or splenomegaly. Ascites and/or liver failure can occur in the context of precipitating factors. The development of portal vein thrombosis is common. Survival is manly limited by concomitant disorders. Currently, treatment of INCPH relies on the prevention of complications related to portal hypertension, following current guidelines of cirrhotic portal hypertension. No treatment has been studied aimed to modify the natural history of the disease. Anticoagulation therapy can be considered in patients who develop portal vein thrombosis.

Idiopathic Non-Cirrhotic Intrahepatic Portal Hypertension (NCIPH)-Newer Insights into Pathogenesis and Emerging Newer Treatment Options

Chronic microangiopathy of portal venules results in idiopathic non-cirrhotic intrahepatic portal hypertension (NCIPH). Recent data suggest a role for vasoactive factors of portal venous origin in the pathogenesis of this 'pure' vasculopathy of the liver. Enteropathies (often silent), are an important 'driver' of this disease. NCIPH is under-recognized and often mis-labeled as cryptogenic cirrhosis. Liver biopsy is needed to prove the diagnosis of NCIPH. In these patients, with advancing disease and increased porto-systemic shunting, the portal venous vasoactive factors bypass the liver filter and contribute to the development of pulmonary vascular endothelial disorders-porto-pulmonary hypertension and hepato-pulmonary syndrome as well as mesangiocapillary glomerulonephritis. Prognosis in NCIPH patients is determined by presence, recognition and management of associated disorders. With better understanding of the pathogenesis of NCIPH, newer treatment options are being explored. Imbalance in ADAMTS 13 (a disintegrin and metalloprotease with thrombospondin type 1 motif, member 13): vWF (von-Willebrand factor) ratio is documented in NCIPH patients and may have a pathogenic role. Therapeutic interventions to correct this imbalance may prove to be important in the management of NCIPH.

Idiopathic portal hypertension: natural history and long-term outcome

Idiopathic portal hypertension (IPH) is a rare cause of intrahepatic portal hypertension. Data on natural history and prognosis of IPH are limited. We sought to describe the complications and long-tem outcome of IPH by retrospectively studying 69 biopsy-proven cases of IPH. Mean duration of follow-up was 6.7 ± 4.6 years. All patients had evidence of portal hypertension (PH) at diagnosis, and 42% were symptomatic. Variceal bleeding (VB) was the most common manifestation. In those without bleeding at diagnosis, 74% had varices at first endoscopy. In those with large varices, the 1-year probability of first bleeding despite primary prophylaxis was 9%. The 1-year probability of rebleeding was 22%. Ascites and hepatic encephalopathy was documented in 26% and 7% of patients, respectively, at least once during the clinical course. The 1-year probability of developing portal vein thrombosis (PVT) was 9%, and 53% of patients receiving anticoagulation achieved recanalization. Human immunodeficiency virus (HIV) infection and VB at diagnosis were the independent predictors of PVT. Seven patients died (6 as a result of an IPH-related cause) and 2 were transplanted. Probability of liver transplantation-free survival was 82% at 10 years. Presence of a severe associated disorder and ascites as a presenting symptom were associated with poor survival.

CONCLUSION

Variceal bleeding is a major complication of IPH. Using, in IPH patients, the same management approach for PH as in cirrhosis is safe and maintains a low incidence of first bleeding and rebleeding in IPH patients. PVT is a frequent complication, particularly in those with HIV infection. Despite several complications, overall survival of patients with IPH is considerably good.

Non-cirrhotic portal hypertension

Non-cirrhotic portal hypertension (NCPH) encompasses a wide range of disorders, primarily vascular in origin, presenting with portal hypertension (PHT), but with preserved liver synthetic functions and near normal hepatic venous pressure gradient (HVPG). Non-cirrhotic portal fibrosis/Idiopathic PHT (NCPF/IPH) and extrahepatic portal venous obstruction (EHPVO) are two prototype disorders in the category. Etiopathogenesis in both of them centers on infections and prothrombotic states. Presentation and management strategies focus on repeated well tolerated episodes of variceal bleed and moderate to massive splenomegaly and other features of PHT. While the long-term prognosis is generally good in NCPF, portal biliopathy and parenchymal extinction after prolonged PHT makes outcome somewhat less favorable in EHPVO. While hepatic schistosomiasis, congenital hepatic fibrosis and nodular regenerative hyperplasia have their distinctive features, they often present with NCPH.

Non-cirrhotic portal hypertension - diagnosis and management

NCPH is a heterogeneous group of liver disorders of vascular origin, leading to PHT with near normal HVPG. NCPF/IPH is a disorder of young adults or middle aged women, whereas EHPVO is a disorder of childhood. Early age acute or recurrent infections in an individual with thrombotic predisposition constitute the likely pathogenesis. Both disorders present with clinically significant PHT with preserved liver functions. Diagnosis is easy and can often be made clinically with support from imaging modalities. Management centers on control and prophylaxis of variceal bleeding. In EHPVO, there are additional concerns of growth faltering, portal biliopathy, MHE and parenchymal dysfunction. Surgical shunts are indicated in patients with failure of endotherapy, bleeding from sites not amenable to endotherapy, symptomatic hypersplenism or symptomatic biliopathy. Persistent growth failure, symptomatic and recurrent hepatic encephalopathy, impaired quality of life or massive splenomegaly that interferes with daily activities are other surgical indications. Rex-shunt or MLPVB is the recommended shunt for EHPVO, but needs proper pre-operative radiological assessment and surgical expertise. Both disorders have otherwise a fairly good prognosis, but need regular and careful surveillance. Hepatic schistosomiasis, CHF and NRH have similar presentation and comparable prognosis.

The current clinical aspects of idiopathic portal hypertension

IDIOPATHIC PORTAL HYPERTENSION (IPH) COMPRISES DISORDERS DEVELOPING INCREASED PORTAL PRESSURE IN THE ABSENCE OF CIRRHOSIS: the clear mechanisms to explain this disease are still not well recognized. IPH usually suggests a benign prognosis, but sometimes is complicated with severe hemorrhage due to ruptured esophageal varices, or massive splenomegaly. Conventional treatments for those complications for patients with cirrhosis usually works when diverted to patients with IPH, although some of those patients might require liver transplantation if the treatment fails. However, there are few consistent treatment strategies for IPH itself, its complications or the indications for liver transplantation. In this mini review, we summarize the clinical manifestations and several potential theories to explain the etiology, as well as the current treatment options for IPH.

Histological features in western patients with idiopathic non-cirrhotic portal hypertension

AIMS

In the western world, idiopathic non-cirrhotic portal hypertension (INCPH) is a rare disease. This study aimed to investigate the histopathological features in western INCPH patients and to assess pathological differences between liver specimens of INCPH with and without HIV.

METHODS AND RESULTS

Biopsies of 70 INCPH patients (of which 15 were HIV-infected) were compared to 23 patients with non-cirrhotic portal vein thrombosis (PVT), which served as a control group for non-cirrhotic portal hypertension. Phlebosclerosis, nodular regeneration (NR), sinusoidal dilatation, paraportal shunting vessels, perisinusoidal fibrosis and portal tract remnants were the most prevalent morphological features of INCPH. There were significant (P < 0.01) morphological differences between INCPH and PVT liver specimens with regard to portal tract remnants (46% versus 0%), phlebosclerosis (95% versus 65%), portal vein dilatation (34% versus 78%) and NR (56% versus 22%). The degree of NR correlated with the severity of phlebosclerosis (P < 0.01). NR was seen more frequently in the HIV-INCPH group, compared to the non-HIV-infected patients (P < 0.001).

CONCLUSION

Portal tract remnants, phlebosclerosis and nodular regeneration are typical features of INCPH. Sinusoidal dilatation, paraportal shunting vessels and increased portal and parenchymal vessels might represent pressure-related morphological signs of portal hypertension. Finally, more nodular regeneration was observed in HIV-associated INCPH.

Role of anticoagulant therapy in liver disease

Anticoagulant therapy is a cornerstone in the treatment of different liver diseases. In Budd-Chiari syndrome (BCS), survival rates have increased considerably since the introduction of a treatment strategy in which anticoagulation is the treatment of first choice. In all patients diagnosed with acute portal vein thrombosis (PVT), anticoagulant therapy for at least 3 months is indicated. Anticoagulation should also be considered in patients with chronic PVT and a concurrent prothrombotic risk factor. Current evidence suggests that patients with PVT in cirrhosis will benefit from treatment with anticoagulation as well. In severe chronic liver disease the levels of both pro- and anticoagulant factors are decreased, resetting the coagulant balance in an individual patient and making it more prone to deviate to a hypo- or hypercoagulable state. An increased activity of the coagulation cascade is not solely a feature of chronic liver disease; it influences the development of liver fibrosis as well. Several studies in animals and humans have shown that anticoagulation could prevent or improve fibrogenesis and even disease progression in cirrhosis. Anticoagulation is therefore a promising antifibrotic treatment modality.

Risk factors and outcome of HIV-associated idiopathic noncirrhotic portal hypertension

BACKGROUND

Idiopathic noncirrhotic portal hypertension (INCPH) has been reported increasingly in patients with HIV infection.

AIM

To evaluate the number of nationwide diagnosed HIV-associated INCPH cases and to assess its clinical features, risk factors and outcome.

METHODS

All HIV centres in the Netherlands were contacted and requested to notify INCPH cases diagnosed in their population. A case–control study was performed to identify the risk factors of INCPH. The cases were group-matched for duration of follow-up after HIV diagnosis to controls. Controls were selected from a database of HIV patients with negative screening for signs of portal hypertension on abdominal ultrasound. Univariate and multivariate conditional logistic regression analyses were performed.

RESULTS

On 1st of July 2011, 18.085 individuals were infected with HIV in the Netherlands. Within this population, sixteen patients with clinically overt INCPH were identified. At the time of INCPH diagnosis, cases had a lower platelet count and a higher ALT level. In univariate and multivariate analyses, didanosine [OR: 1.9 (1.3–2.8)], concomitant didanosine and stavudine treatment [OR: 6.3 (2.1–19.1)] and concomitant didanosine and tenofovir treatment [OR: 5.1 (1.2–22.6)] were independently associated INCPH. During follow-up, 4 patients died [malignancy (n = 3), liver failure (n = 1)]. A significant decline in platelets was observed after didanosine discontinuation (P = 0.003).

CONCLUSIONS

HIV-associated clinically relevant idiopathic noncirrhotic portal hypertension appears to be a rarely diagnosed disease. Long-term exposure to didanosine and short-term combination of didanosine and stavudine or tenofovir exposure are associated with idiopathic noncirrhotic portal hypertension. Mortality in HIV-associated idiopathic noncirrhotic portal hypertension is mainly related to HIV-associated disorders. Portal hypertension continues despite didanosine discontinuation