Histopathological features of idiopathic portal hypertension: A systematic review and meta-analysis

BACKGROUND

Portal hypertension (PH) is a clinically significant entity that could present with life-threatening gastrointestinal bleeding. Cirrhosis is the most common cause of PH, with well-documented histopathology and etiology. However, in idiopathic portal hypertension (IPH), no single histopathologic finding is associated with PH. Our systematic review aims to identify and summarize the prevalence of the common histological findings of IPH.

METHODS

We systematically searched PubMed, Cochrane CENTRAL, Web of Science, and Scopus till 1ST March 2022 for studies describing the histopathological features of IPH. Data were extracted from eligible studies and pooled as events rate and 95% confidence interval (CI) using binary random-effects model by open meta-analyst software.

RESULTS

We included 23 retrospective studies with a total sample size of 813 patients. The overall incidence of nodular regenerative hyperplasia was 38.6%, 59.8% for portal fibrosis, 51.3% for periportal fibrosis, 39.3% for perisinusoidal fibrosis, 89.8% for portal vein sclerosis, 42.2% for portal inflammation, 53.3% for mega-sinusoids, 39.5% for thickening of portal vein branches, 93.8% for narrowing of portal veins, 53.3% for hepatic veins/venous outflow obstruction, 51.4% for aberrant portal/periportal vessels, 42.4% for shunt vessel, 50.9% for ductular proliferation, and 16.3% for steatosis.

CONCLUSION

Due to the relatively non-pathognomonic and non-specific nature of IPH, a combination of different histological features such as the portal and periportal fibrosis, portal vein sclerosis, mega-sinusoids, narrowing of portal veins, hepatic venous outflow obstruction, aberrant portal or periportal vessels, and ductular proliferation may be of value in diagnosing IPH as the incidence rate of these features was at approximately 50%.

Diagnostic performance of transient elastography in differentiation between porto-sinusoidal vascular liver disease and compensated cirrhosis

BACKGROUND AND AIMS

The efficacy of transient elastography (TE) in the differential diagnosis between porto-sinusoidal vascular disease (PSVD) and compensated cirrhosis has not been sufficiently studied. We aimed to investigate the diagnostic performance of TE and identify histological lesions associated with liver stiffness.

METHODS

We conducted a retrospective cohort study including patients with PSVD and cirrhosis (Child-Turcotte-Pugh class A) and healthy subjects. Both the PSVD and cirrhotic patients had at least one sign of PH. The area under the receiver operating characteristic curve (AUROC) was used for differentiation.

RESULTS

Ninety-two patients with PSVD (median age: 53 years, 33% male), 100 patients with compensated cirrhosis and 101 healthy subjects were included. The median TE-LSM in the PSVD patients (10.0 [7.0-13.0] kPa) was significantly lower than that in the cirrhotic patients (21.0 [15.0-28.0] kPa, p < .001) but was significantly higher than that in the healthy subjects (5.1 [4.6-6.0] kPa, p < .001). The AUROCs of TE-LSM for the discrimination of PSVD from the cirrhosis and healthy subjects were 0.886 (95% CI: 0.833-0.928) and 0.913 (95% CI: 0.864-0.949), respectively. The sensitivity and specificity to discriminate PSVD from compensated cirrhosis were 78.3% and 82.0%, respectively, at a cut-off of 13.6 kPa. Furthermore, portal fibrosis and aberrant cytokeratin 7 expression of centrilobular hepatocytes were significantly associated with higher TE-LSM (≥10.0 kPa).

CONCLUSION

TE-LSM can be used to differentiate PSVD from compensated cirrhosis. Pathological features in association with increased liver stiffness are identified.

Portal vein thrombosis, hepatic decompensation, and survival in patients with porto-sinusoidal vascular disease and portal hypertension

BACKGROUND

Porto-sinusoidal vascular disease (PSVD) is a novel nomenclature to describe non-cirrhotic portal hypertension and characteristic histology without portal vein thrombosis (PVT). It is a more inclusive definition than the previously well-recognized entity idiopathic non-cirrhotic portal hypertension. There is a paucity of data on PSVD patients.

METHODS

A total of 33 patients diagnosed with PSVD and portal hypertension (PH) between 2005 and 2021 were included. Data were retrieved from electronic medical record system and analyzed.

RESULTS

Of the 33 patients, 6 (18%) occurred in post-transplant allograft liver. After a median follow-up of 96 months (interquartile range, IQR [52, 139]), 14 deaths occurred (42%), 4 directly related to decompensated liver disease. The Kaplan-Meier survival estimates at 1, 5, and 10 years were 94%, 87% and 58%. PVT occurred in 10 patients (30%). The Nelson-Aalen cumulative risk estimate for PVT at 1, 5 and 10 years were 16%, 25% and 48%. The median model for end-stage liver disease and Child-Pugh score at initial presentation were 8 (IQR [7-12]) and 5 [5-6], and increased to 13 [8, 18] and 7 [5, 8], respectively, at the end of follow-up. Of the 11 patients who presented with splenomegaly and no specific sign of PH, 7 (64%) developed varices and 3 (27%) ascites at a median follow-up of 100 months.

CONCLUSIONS

PSVD with PH is not a benign entity. Mortality, PVT and hepatic decompensation are common. Patients with PSVD must be closely monitored, including those who only have non-specific clinical signs (e.g., splenomegaly) of PH.

Ultrasound Pressure Estimation for Diagnosing Portal Hypertension in Patients Undergoing Dialysis for Chronic Kidney Disease

OBJECTIVES

Hepatic venous pressure gradient (HVPG) is considered the standard in quantifying portal hypertension, but can be unreliable in dialysis patients. A noninvasive ultrasound technique, subharmonic-aided pressure estimation (SHAPE), may be a valuable surrogate of these pressure estimates. This study compared SHAPE and HVPG with pathology findings for fibrosis in dialysis patients.

METHODS

This was a subgroup study from an IRB-approved trial that included 20 patients on dialysis undergoing SHAPE examinations of portal and hepatic veins using a modified Logiq 9 scanner (GE, Waukesha, WI), during infusion of Sonazoid (GE Healthcare, Oslo, Norway). SHAPE was compared to HVPG and pathology findings using the Ludwig-Batts scoring system for fibrosis. Logistic regression, ROC analysis, and t-tests were used to compare HVPG and SHAPE with pathological findings of fibrosis.

RESULTS

Of 20 cases, 5 had HVPG values corresponding to subclinical and clinical portal hypertension (≥6 and ≥10 mmHg, respectively) while 15 had normal HVPG values (≤5 mmHg). SHAPE and HVPG correlated moderately (r = 0.45; P = .047). SHAPE showed a trend toward correlating with fibrosis (r = 0.42; P = .068), while HVPG did not (r = 0.18; P = .45). SHAPE could differentiate between mild (stage 0-1) and moderate to severe (stage 2-4) fibrosis (-10.4 ± 4.9 dB versus -5.4 ± 3.2 dB; P = .035), HVPG could not (3.0 ± 0.6 mmHg versus 4.8 ± 0.7 mmHg; P = .30). ROC curves showed a diagnostic accuracy for SHAPE of 80%, while HVPG reached 76%.

CONCLUSION

Liver fibrosis staging in dialysis patients evaluated for portal hypertension appears to be more accurately predicted by SHAPE than by HVPG; albeit in a small sample size.

Idiopathic Non-Cirrhotic Portal Hypertension and Porto-Sinusoidal Vascular Disease: Review of Current Data

Idiopathic non-cirrhotic portal hypertension (INCPH) is a clinicopathologic disease entity characterized by the presence of clinical signs and symptoms of portal hypertension (PH) in the absence of liver cirrhosis or known risk factors accountable for PH. Multiple hematologic, immune-related, infectious, hereditary and metabolic risk factors have been associated with this disorder. Still, the exact etiopathogenesis is largely unknown. The recently proposed porto-sinusoidal vascular disease (PSVD) scheme broadens the spectrum of the disease by also including patients without clinical PH who are found to have similar histopathologic findings on core liver biopsies. Three histomorphologic lesions have been identified as specific for PSVD to include obliterative portal venopathy, nodular regenerative hyperplasia and incomplete septal cirrhosis/fibrosis. However, these findings are often subtle, under-recognized and subjective with low interobserver agreement among pathologists. Additionally, the natural history of the subclinical forms of the disease remains unexplored. The clinical course is more favorable compared to cirrhosis patients, especially in the absence of clinical PH or liver dysfunction. There are no universally accepted guidelines in regard to diagnosis and treatment of INCPH/PSVD. Hence, this review emphasizes the need to raise awareness of this entity by highlighting its complex pathophysiology and clinicopathologic associations. Lastly, formulation of standardized diagnostic criteria with clinical validation is necessary to avoid misclassifying vascular diseases of the liver and to develop and implement targeted therapeutic strategies.

Interobserver study on histologic features of idiopathic non-cirrhotic portal hypertension

Background

Histologic features of idiopathic non-cirrhotic portal hypertension (INCPH) may overlap with those without INCPH. Recently, these features have been recognized as part of the larger spectrum of porto-sinusoidal vascular disease (PSVD). We assessed interobserver agreement on histologic features that are commonly associated with INCPH and studied whether a provision of relevant clinical history improves interobserver agreement.

Methods

The examined histologic features include lobular (such as anisocytosis, nodular regeneration, sinusoidal dilatation, increased parenchymal draining veins, and incomplete fibrous septa) and portal tract changes (such as paraportal shunting vessel(s), portal tract remnant, increased number of portal vessels, and obliterative portal venopathy). Thirty-four archived liver samples from patients with (group A) and without (group B) INCPH were retrieved. A total of 90 representative images of lobules (L) and portal tracts (P) were distributed among 9 liver pathologists blinded to true clinical history. Each pathologist answered multiple choice questions based on the absence (Q1) or presence (Q2) of clinical history of portal hypertension. Fleiss’ kappa coefficient analysis (unweighted) was performed to assess interobserver agreement on normal versus abnormal diagnosis, in L and P, based on Q1 and Q2.

Results

The kappa values regarding normal versus abnormal diagnosis were 0.24, 0.24, 0.18 and 0.18 for L-Q1, L-Q2, P-Q1, and P-Q2, respectively. With true clinical history provided, the kappa values were L- 0.32, P-0.17 for group A and L-0.12, P-0.14 for group B. Four pathologists changed their assessments based on the provided history. Interobserver agreement on the interpretation of L and P as normal versus abnormal was slight to fair regardless of provision of clinical history.

Conclusions

Our findings indicate that the histologic features of INCPH/PSVD are not limited to patients with portal hypertension and are subject to significant interobserver variation.

Supplementary information

The online version contains supplementary material available at 10.1186/s13000-020-01049-0.

Histologic Lesions of Porto-Sinusoidal Vascular Disease Following Phlebotomy in Hemochromatosis

Background

Phlebotomy induces regression of liver fibrosis in genetic hemochromatosis. We assessed the histologic changes in pre-phlebotomy and post-phlebotomy liver biopsies from patients with HFE mutation as a model to study regression of fibrosis. We aimed to show that phlebotomy-induced histologic lesions overlap with porto-sinusoidal vascular disease (PSVD, also known as idiopathic non-cirrhotic portal hypertension), histologically.

Methods

A total of 51 biopsies (22 pre-phlebotomy and 29 post-phlebotomy) were reviewed, and three variables were studied: iron index indicative of the amount of accumulated iron (range 0 to 18), the combined score of vascular changes reflecting the presence of histological lesions that are described in PSVD (range 0 to 9) and the high-grade shunt vessel by calculating the proportion of portal tracts with shunt vessels, with a cutoff of 50%. Two-tailed Student's t-test and Fisher's exact test were performed to compare the means of two variables and frequencies of the histologic lesions in two groups, respectively. A P-value < 0.05 was considered statistically significant.

Results

The iron index was higher in the pre-phlebotomy compared to post-phlebotomy group (P = 0.01). Compared to the pre-phlebotomy group, the combined score was higher in the post-phlebotomy group when the cases of advanced fibrosis were excluded (P = 0.023) and remained higher when patients with risk factors for PSVD were further excluded (P = 0.034). The high-grade shunt vessel tended to be more common in the post-phlebotomy group when advanced fibrosis was excluded; however, the statistical significance was marginal (P = 0.056).

Conclusions

Phlebotomy reduces hepatic iron load and induces histologic lesions of PSVD in patients with HFE mutation. Our data support a postulation that some of the histologic lesions of PSVD represent vascular remodeling following a regression of fibrosis and may not be reflective of risk factors or etiopathogenesis of PSVD. Regressed fibrosis and PSVD may not be reliably distinguished in a limited sample, therefore warranting cautious interpretation in the right clinical context.

Impact of hemodialysis on liver stiffness measured with real-time two-dimensional shear wave elastography

BACKGROUND AND AIMS

The impact of hemodialysis on liver stiffness is still unclear. The aim of the study was to assess liver fibrosis by real-time two-dimensional shear wave elastography (RT 2D-SWE) and to quantify the influence of net fluid withdrawal on liver stiffness during one hemodialysis session. The second aim was to investigate the influence of systolic blood pressure and time spent on dialysis (in years) on liver stiffness measurements.

METHODS

This before/after hemodialysis (HD) study in a group of end stage renal disease (ESRD) patients was carried out with patients on regular HD. Measurements of liver stiffness were done using RT 2D-SWE directly before and after a hemodialysis session.

RESULTS

In this study 27 patients with mean age 69.4 ± 14.75 years were included. Mean net fluid withdrawal volume per session was 2874.07 ± 778.35 ml. Mean pre-HD and post-HD liver stiffness measurements were 8.15 kPa (95% confidence interval, CI 7.61-8.68) and 6.70 kPa (95% CI 6.10-7.30 kPa), respectively. Mean liver stiffness reduction was 1.448 ± 1.14 kPa. The amount of fluid removed correlated with the decline in liver stiffness values after HD (ρ = 0.523, P = 0.003). There was a positive but statistically not significant correlation between time spent in HD and liver stiffness (ρ = 0.151, P = 0.623) CONCLUSION: Liver stiffness significantly declined after one session of HD. The change in liver stiffness was strongly correlated with the amount of net fluid withdrawal. Random liver stiffness measurements (LSM) by RT 2D-SWE does not precisely show the degree of fibrosis, Furthermore, it is presumed that postdialysis liver stiffness values likely reflect the real degree of liver fibrosis.

Clinical features of idiopathic portal hypertension in China: A retrospective study of 338 patients and literature review

BACKGROUND AND AIM

Idiopathic portal hypertension (IPH) refers to a relatively rare condition characterized by intrahepatic portal hypertension in the absence of underlying disease such as liver cirrhosis.

METHODS

We retrospectively reviewed 338 patients with IPH that were diagnosed at the pathological consultation center of our hospital.

RESULTS

The ratio of male to female patients was 1:1. Mean age at onset was 35.1 ± 16.5 years; male patients on average were 12 years younger than female patients at onset. The median duration from onset to IPH diagnosis was 12 months. In 50 patients, medication use may have been an etiological factor. The most common clinical manifestations were splenomegaly (91.3%) and hypersplenism (68.9%); 57.0% patients presented varicosis, while 25.1% patients had a history of variceal bleeding. Nodular regenerative hyperplasia was found in 22.2% liver biopsies. Among patients for whom laboratory data were available, 65.0%, 50.3%, and 71.4% patients presented leukopenia, anemia, and thrombocytopenia due to hypersplenism. Liver function was mostly in the compensated stage. Female patients showed worse leukopenia and anemia, while male patients were more likely to have abnormal serum transaminase and bilirubin levels. Sixty-seven patients received surgical or interventional treatment.

CONCLUSIONS

High-quality liver biopsy, detailed clinical information, and expert pathologist are necessary for diagnosis of IPH. IPH can occur concurrently with other liver disease such as hepatitis and drug-induced liver injury. Medication appears to be an important etiological factor for IPH in China. Management approach was largely focused on treatment of portal hypertension and its complications.

Prevalence of histological features of idiopathic noncirrhotic portal hypertension in general population: a retrospective study of incidental liver biopsies

BACKGROUND

Idiopathic noncirrhotic portal hypertension (INCPH) is associated with histologic changes secondary to obliterative portal venopathy without cirrhosis. We studied the prevalence of individual histological features of INCPH in liver biopsies obtained incidentally during unrelated elective procedures and in elective liver biopsies with the diagnosis of fatty liver disease.

METHODS

A total of 53 incidental liver biopsies obtained intraoperatively during unrelated elective procedures and an additional 28 elective biopsies with the diagnosis of fatty liver disease without portal hypertension and cirrhosis were studied. Various histologic features of INCPH were evaluated.

RESULTS

Shunt vessel (30%), phlebosclerosis (27%), increased number of portal vessels (19%) and incomplete septa (17%) were common in these liver biopsies after confounding factors such as co-existing fatty liver disease or fibrosis were excluded. At least one feature of INCPH was noted in 90% of the biopsies. Eight (10%) biopsies showed 5-6 features of INCPH. In total, 11 (14%) of 81 patients had risk factors associated with INCPH, including hypercoagulability, autoimmune disease, exposure to drugs, and infections. No patient had portal hypertension at the end of the follow-up.

CONCLUSION

The histologic features of INCPH are seen in incidental liver biopsies and fatty liver disease without portal hypertension. Ten percent of the biopsies show 5-6 features of INCPH without portal hypertension. Interpreting histologic features in the right clinical context is important for proper patient care.

Idiopathic Noncirrhotic Portal Hypertension: An Appraisal

Idiopathic noncirrhotic portal hypertension is a poorly defined clinical condition of unknown etiology. Patients present with signs and symptoms of portal hypertension without evidence of cirrhosis. The disease course appears to be indolent and benign with an overall better outcome than cirrhosis, as long as the complications of portal hypertension are properly managed. This condition has been recognized in different parts of the world in diverse ethnic groups with variable risk factors, resulting in numerous terminologies and lack of standardized diagnostic criteria. Therefore, although the diagnosis of idiopathic noncirrhotic portal hypertension requires clinical exclusion of other conditions that can cause portal hypertension and histopathologic confirmation, this entity is under-recognized clinically as well as pathologically. Recent studies have demonstrated that variable histopathologic entities with different terms likely represent a histologic spectrum of a single entity of which obliterative portal venopathy might be an underlying pathogenesis. This perception calls for standardization of the nomenclature and formulation of widely accepted diagnostic criteria, which will facilitate easier recognition of this disorder and will highlight awareness of this entity.